assembling and installing connecting rods/pistons



assembling and installing connecting rods/pistons

Postby grumpyvette » September 24th, 2008, 10:40 pm

look closely at the connecting rods one edge of the main bearing are is beveled noticeably more than the other that beveled side faces away from the rod its paired with because it matches the slight radiased bevel of the crank journal
many builder class pistons are designed to go in, in either orientation ,and have both the valve notches and piston pin offset that are identical but most performance pistons have a dot or an F stamped on the crown indicating the side facing the front of the engine, naturally the rod big end bevels face the crank counter weights on each pair and the non-beveled big end faces the matched rod

http://www.hotrod.com/techarticles/hrdp ... ting_rods/

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cleaning threads before assembly is always a good idea
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check manufactures tech guide info
http://arp-bolts.mobi/p/tech.php?page=3

http://arp-bolts.mobi/p/tech.php?page=2

http://arp-bolts.com/
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it should be rather obvious that youll need to know the exact distance the piston deck sits at TDC ,above or below the block deck surface and the valve notch recess or pop-up dome volume of the piston to do accurate quench or compression calculations
http://www.harborfreight.com/1-inch-tra ... r-623.html
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http://www.summitracing.com/parts/arp-1 ... /overview/ $248
http://www.summitracing.com/parts/arp-1 ... /overview/ $186
yes you can find non-name brand rod bolt stretch gauges from about $50-$80
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ARP rod bolts are set up to use a stretch gauge with both ends of the bolt pre-machined for the gauge the bolt packaging from ARP,comes with the correct length the bolts are supposed to reach under the correct pre-load tension, in the instructions OR its available on their web site
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most guys are familiar with use of a torque wrench to tighten rod bolts to the correct preload, but while this gets you very close its not as precise as a rod bolt stretch gauge,
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viewtopic.php?f=50&t=11029&p=48839#p48839
having consistent clamp loads are mandatory for proper assembly
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if you wonder why I suggest using SCAT (H) beam style cap screw connecting rods vs stock or most (I) beam designs this picture should show the increased cam to connecting rod clearance
one factor to keep in mind is that rods typically have a side that rides against its matched companion and a side thats BEVELED for clearance on the crank journals radias EXAMPLE
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notice the top rods non-beveled side that faces the matching rod is up, but on the lower rod the the beveled side that faces the crank counter weight is up on the lower rod
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FOR YOUR OWN GOOD< READ THE SUB LINKED INFO

http://www.kb-silvolite.com/assets/kb_installation.pdf

viewtopic.php?f=53&t=2795&p=8966#p8966

viewtopic.php?f=53&t=5064&p=14370#p14370

viewtopic.php?f=69&t=3814&start=240

http://www.connectingrods.net/connectin ... tretch.php

viewtopic.php?f=53&t=3759

viewtopic.php?f=50&t=11029&p=48839#p48839

http://www.enginebuildermag.com/Item/38 ... rings.aspx

viewtopic.php?f=53&t=852

viewtopic.php?f=53&t=2795

https://www.uempistons.com/installation ... lation.pdf

viewtopic.php?f=53&t=3540
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when in doubt call the PISTON manufacturer and ASK!

viewtopic.php?f=53&t=3897&p=26602#p26602

viewtopic.php?f=53&t=509&p=28226&hilit=hone+plate#p28226

viewtopic.php?f=53&t=10213

http://www.circletrack.com/enginetech/c ... ce_basics/

viewtopic.php?f=53&t=852&p=1812&hilit=resistance+rotation#p1812

viewtopic.php?f=53&t=2726&hilit=plastigauge

viewtopic.php?f=52&t=5078

http://www.stockcarracing.com/techartic ... index.html

http://www.circletrack.com/howto/1815_c ... to_04.html

http://www.youtube.com/watch?v=H2YrL3k__dA

http://arrc.epnet.com/autoapp/9102/9102 ... SEMBL1.htm

http://www.corvette-restoration.com/res ... lation.htm

http://www.popularhotrodding.com/engine ... index.html

viewtopic.php?f=50&t=8745&p=30913#p30913

viewtopic.php?f=53&t=3540
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http://www.pawengineparts.com/shoppingc ... ?catid=206
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naturally youll measure the bearing journals
one factor to keep in mind is that rods typically have a side that rides against its matched companion and a side thats BEVELED for clearance on the crank journals radias EXAMPLE
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notice the top rods non-beveled side that faces the matching rod is up, but on the lower rod the the beveled side that faces the crank counter weight is up on the lower rod
rod-grinding
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on some stroker applications SOME rods need to have the bolts ground for cam lobe clearance
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bearings AND connecting rods have an inner facing side and outer side the inner side facing the matching rod has far less edge clearance because they don,t need the radias that is required for the edge of the crank journals
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notice the top rods non-beveled side that faces the matching rod is up, but on the lower rod the the beveled side that faces the crank counter weight is up on the lower rod
notice how one side of the bearing holding section has a radias (left)(GOES TOWARD CRANK COUNTER WEIGHT) but the opposite sides flush (right) (FACES MATCHED ROD)
ok lets look at a few things, first , if you look closely at your connecting rods you'll see that one side has considerably more bevel ground on the inner edge of the connecting rod around the bearing than the other side does, to side with that bevel ground on it is to provide clearance for the radius ground onto the crankshaft where the crank throw meets the counterweights like you mentioned, that side of course goes out away from the other rod, to side with far less pronounced bevel is the side where the two connecting rods meet, and ride against each other during normal engine operation normal clearance there is in the area of six to 15 thousands of an inch. When the two connecting rods are correctly torque in place and a feeler gauge is fitted between them to check the maximum clearance.
Now a small block Chevrolet the valve placement or valve layout is in this order on a normal head, E I I E E I I E , the letter (E) of course representing exhaust and the letter (I) of course representing intake your Pistons will have to be inserted into the cylinders matching that layout, this will mean there will be two left and two right Pistons on each cylinder bank, if there is a dome on the Pistons it will go towards the outside of the block, when the machine shop installed the Pistons on the connecting rods, they should have been set up with four of the Pistons set up with the exhaust valve notch on the Pistons facing towards the bevel on the connecting rods and four of the Pistons set out live the intake valve side of the Pistons facing that bevel, lets look at the first two cylinders, cylinder number one is the front left forward facing forward look at the diagram per cylinder layout any
on that Piston both the bevel for the Crank Journal that provides bearing clearance and the exhaust valve notch would be towards the front of the engine, but on the next cylinder number two, on the opposite side of the engine. That Piston would have the bevel on the connecting rod facing the rear of the engine, but the exhaust valve notch would be facing the front of the engine, now let's look at cylinders three and four, cylinder number three, would have the bevel on the rod of course facing forward but the exhaust valve notch facing the rear of the engine, on cylinder number four you would have the bevel on the connecting rod facing towards the rear of the engine, and the exhaust valve notch facing towards the rear of the engine, now let's look at cylinders 5 and 6 cylinder number five, bevel forward exhaust forward, cylinder number six exhaust forward but bevel towards the rear for cylinders number 7 & 8 on cylinder number seven, exhaust out notch towards the rear, bearing bevel towards the front of the engine on cylinder number eight bearing bevel towards the rear of the engine and exhaust out towards the rear of the engine
keep in mind that some non- standard head / port layouts can potentially change the piston notch layout
you¢ll also need to make sure youe piston ring end gap is correct, that the piston rings have the correct side facing upwards that the bearings are installed with the correct clearance, and coated with assembly lubricant, that the piston to cylinder block deck clearance is correct ,that your quench distances are correct, and that after you degree in the cam that the piston to valve Clearance is correct. Youll also need to be careful that you don,t hit the connecting rod or rod bolts to the crank journals potentially causing any damage during the installation, and its normal to oil the rings and piston with a lite machine oil during the installation.
Ive personally found that the piston ring compressors that work best are this type,

this type is far easier to line up to the block surface at a slight angle that allows the rings to partly pop out from under its lower edge just as the rings leave the lower edge of the compressor and enter the cylinders bore, now Im not saying you can,t do it, just that its far easier to do it correctly with this type of ring compressor.IVE dunked my piston/ring assembly's in a can of MARVEL MYSTERY OIL just before installation with a ring compressor and have never seen the slightest indication of problems either on ring sealing getting the rings broken in, or on tearing the engines down later for inspections

http://www.tpub.com/content/constructio ... 24_423.htm

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[b]always protect the connecting rod journals from getting scratched during the rod assembly process, a 18" long section of 3/8" or 7/16" inside diam. rubber fuel line can be pushed over rod bolts , after being looped 180 degrees around the rod journal on the crank, if the rod bolts extend down from the rod or a 18" section of 7/16" fuel line with a u shaped section of 5/16" thread rod that's 24" long, bent in the center over a 2.5" section of pipe so the ends remain parallel and even in length can be used as a handy tool so that 3" of the thread rod extends from each end, you then cover all but the last 1" on each end with plastic electrical tape and place the ends thru the rod bolt holes, and thread on a nylon washer and a nut finger tight, can be used as a tool to draw into place a rod on the rod journal if you use cap-screw rod designs

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basic rod bearing assembly
1. Clean the bearing surface of all the connecting rods and connecting rod caps and closely inspect them, in an ideal world they have both the upper and lower should be engraved or stamped so, they can,t get mixed.

2. Clean upper connecting rod bearing and lubricate the bearing face with clean engine oil and moly assembly lube.

3. Clean lower connecting rod bearing and lubricate the bearing face with clean engine oil and moly assembly lube..

NOTE: Align the tabs on the connecting rod bearings with the tab grooves in the connecting rod.

4. Install upper connecting rod bearing in connecting rod, so the bevel on the bearing matches the bevel on the rod and tabs align.

5. Pull the connecting rod and piston assembly into position against the crankshaft. using both a ring compressor, and a rod guide after verifying the ring gap and ring side clearance, ring indexing and the rings are installed with the proper side facing upwards

6. Install lower connecting rod bearing in connecting rod cap.

7. Install bearing cap in position on connecting rod. Ensure that the identification numbers you previously are stamped on the same side, of the rod and rod caps.

8. If you have Type A connecting rods, install two bolts and two nuts. If you have Type B connecting rods, install two bolts. The torque is very important. verify the correct torque, in this section of the site,and with the connecting rod manufacturer

9. Repeat Steps 1 through 8 for the remaining connecting rod bearings.

http://www.youtube.com/watch?v=oG9xF5EjEz0
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » November 25th, 2008, 9:22 am

read thru these related threads, posted below, youll find a good deal of info, on installing pistons and rings.

viewtopic.php?f=53&t=509&p=12277&hilit=gapping+rings#p12277

viewtopic.php?f=53&t=5454

viewtopic.php?f=53&t=4630

viewtopic.php?f=53&t=2795

viewtopic.php?f=53&t=2837

viewtopic.php?f=53&t=852

viewtopic.php?f=50&t=8744&p=30912&hilit=cleaning+piston+grooves#p30912

viewtopic.php?f=53&t=3897

viewtopic.php?f=51&t=588&p=869&hilit=hone+plate#p869

viewtopic.php?f=53&t=509

viewtopic.php?f=53&t=1168

viewtopic.php?f=53&t=1797&p=7233#p7233

http://www.kb-silvolite.com/news.php?ac ... ad&N_id=27

http://www.circletrack.com/enginetech/c ... index.html

http://www.circletrack.com/techarticles ... index.html

http://www.popularhotrodding.com/tech/0 ... index.html

http://www.circletrack.com/enginetech/c ... index.html

http://www.kb-silvolite.com/assets/auto ... ctions.pdf

http://www.circletrack.com/enginetech/c ... index.html

http://www.circletrack.com/enginetech/c ... index.html

http://www.kb-silvolite.com/article.php ... ad&A_id=56

http://www.circletrack.com/enginetech/c ... index.html

http://www.circletrack.com/enginetech/c ... index.html

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if you have oil ring expanders with the plastic bits,they are there to prevent you from over lapping the ends of the oil ring expander, theres some oil ring expander s that are vertical ,some horizontal, but all have the ends butt , none over-lap
ideally the pressure above the piston gets behind the top compression ring and increases the force holding the ring face to the bore surface, noticabl;y more than the ring tension alone can do.
BTW GAPLESS PISTON RINGS HAVE TWO PIECES THAT EACH MUST BE GAPPED< THE IDEA IS THAT THE TWO GAPS IN THE SET ARE ON OPOSIRE SIDES OF THE PISTON GROOVE
your going to need decent feeler gauges
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here is where you, or your machine shop can screw things up on ring to bore seal, you need to have the cylinders bored and honed to the correct size specified by the manufacturer of the pistons,after MEASURING THE PISTONS to verify their size per the piston manufacturers instructions, then gap the rings per the ring manufacturers instructions, when you hone the bores,get and use block deck hone plates, during the hone process , keep in kind you want to use the same (STUDS OR BOLTS) the machine shop used and the same torque settings they used when the cylinders were honed with deck plates or the distortion of the bore and ring seal won,t be identical (exactly round)or ideal, keep in mind the piston side clearance must match what the piston manufacturer states.

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Ive used several sets of total seal gapless rings in several engine builds over the years, they usually have a slightly better leak down test result , but I can,t really see and measurable power or durability increase
youll need the info in this link, ABOVE and its sub links ALSO
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MEASURING RING END GAP
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The stock ring filer just had too much end play in the shaft that holds the abrasive disk. So I stopped
by the local bearing supply and picked up a couple of bushings. If I wanted to wait it might have been
easier to buy a metric size bushing, but they weren't in stock so I bought the fractional size. The only
thing wrong is both the OD and ID were not correct. So I reamed the hole in the aluminum frame to accept
the larger OD of the bushing and turned the shaft on a lathe to fit the ID of the bushing.

I used JB weld to make the bushings permanent so I left it sticking out far enough to keep the shaft from moving to
the left and the locating pin would keep it from moving to the right. Since I turned the OD of the shaft down, I
had to drill and tap the 5mm x .8 metric threads, moving it closer to the centerline so it would intersect the
groove again.

There is NO end play now, much nicer !!!


Stock Ring Filer
RingFilerUnmodied01.jpg

The pin was moved closer to the centerline of the abrasive wheel shaft.
SetPinLocation0577.jpg

Pin0573.jpg

Finished Ring Filer
FinishedRingFiler0565.jpg



Edit on 11/09/2011


I wanted to see if theory and reality were close when it comes to the gap needed on the left stop pin of the ring filer to correct the angle filed on the ring end such that they would be parallel. I knew I couldn't do the math, but I could use Microsoft Visio and let it do the math for me.

I did the drawing to scale so that I could move the ring over until it's CENTER-LINE lined up with the right side of the grinding wheel while also touching the RIGHT stop pin, then measure the gap. I did this for two bore sizes so I could see how much difference the bore made. I used a 4" bore and a 4.5" bore for this test. The difference was only 0.005", hardly worth taking into consideration.

The LEFT STOP PIN needs to be 0.35" to 0.36" in diameter or you could replace it with a pin of 11/32"(0.35437") or 23/64"(.3593"). Dowel pins don't seem to come in those sizes, the only thing I've found so far is "Drill Rod" which would be hard to cut. Or you could do as Grumpy has suggested above and slip some copper tubing over the 1/4" stop pin that is already there.

You can purchase the drill rod for $5-7$ for a 3 foot length from Fastenall.
http://www.fastenal.com/web/search/prod ... evyx&Nty=0
http://www.fastenal.com/web/search/prod ... evyw&Nty=0

RingEndGappingTool01.jpg


BTW
if your un-aware, most rings have a DOT on the upper surface to indicate which side goes up , if they don,t the inner edge is sometimes beveled, or stepped and the wider gap or stepped recess faces up to allow high pressure gasses , from the combustion chamber to push it outwards

http://www.amazon.com/KD-Tools-850-Diam ... 0002STSMG/
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this type (ABOVE) handles many applications but the cheap versions are a P.I.T.A. to work with

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BTW when you go to buy a ring compressor....this type(ABOVE & BELOW) works far better than the others, but its specific to a very limited range in bore size applications

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http://store.summitracing.com/partdetail.asp?autofilter=1&part=PRO%2D66766&N=700+115&autoview=sku

Proform 66766 $31
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » November 25th, 2008, 2:32 pm

general rule for N/A engines is ring gaps should be between, .0040--.0045 per inch of bore dia.

example

a 4" bore like a 350 x .004--.0045 = .016-.018 ring gap


heres a chart and links to tools for referance

viewtopic.php?f=53&t=5454

http://kb-silvolite.com/article.php?action=read&A_id=32

http://www.hanzenginehouse.com/HANZENGI ... nggap.html

http://www.muller.net/sonny/crx/rings/index.html

http://www.tavia.com/cat16.html#2

http://www.jegs.com/webapp/wcs/stores/s ... 2_74772_-1

http://www.jegs.com/webapp/wcs/stores/s ... 9_-1_10693

http://www.jegs.com/webapp/wcs/stores/s ... 2_55122_-1

http://www.jegs.com/webapp/wcs/stores/s ... 1_-1_10693

http://www.jegs.com/webapp/wcs/stores/s ... _841806_-1

you naturally take the time and effort to use clean components and tools during assembly and try to work in a reasonably dry and well lighted location with the engine up on an engine stand,and frequent use of lint free wipes, soaked in marvel mystery oil helps, as it keeps the metal surfaces from rusting or collecting crud, Ive generally found that if your cover the engine with a large plastic bag and duct tape, when your not actually working on it, its not been a factor worth worrying much about, in a reasonably clean shop with no open doors to let in wind carried debris.
heres some pictures I found on the web that may help
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http://www.summitracing.com/parts/DRT-BAG-ENGINE/

http://www.summitracing.com/parts/SUM-G1009/

CHECKING TRUST BEARING CLEARANCE

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when building a 383 stroker ,you need to check rod to cam and rod to block clearances, you should have not problem grinding .080 or so clearance on the lower bore wall edge with zero chance of getting into the water jacket passages or water jacket at the area of the yellow paint indicated in that picture, most people forget to check that area
obviously youll want to check all 8 cylinders and remove the cam and clean carefully before re-installing the cam.
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Posts: 14105
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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » December 20th, 2008, 8:07 am

keep in mind youll need to check the cam lobe to connecting rod clearances as they pass very close to each other on some cylinders at some points in thier rotation,finding out if youll need to grind clearances on the upper edge of some rod bolts needs to be verified, durring assembly,
the answer depends BOTH on the max lift, durration and LCA of the cam and the design of the connecting rods outer profile, IE wher it sticks out and how far it sticks out away from the crank journal. its the upper rod bolt area near the crank journal that tends to hit the cam lobes on sone cylinders, and you should verify about a .060 clearance between lobes and connecting rods durring the assembly process, AFTER degreeing in the cam, I usually use a large paper clip as a gauge, if it easily passes between the lobe and the rod bolt at thier closest point thier tangent rotational arcs youll be ok.
once EITHER the duration exceeds about 225 @ .050 or the lift exceeds about .520 in a 383 SBC youll probably have clearance issues with stock connecting rods,and the cam lobes, aftermarket (H) or SOME (I) style stroker rods with 7/16" capscrew bolts are stronger and profiled to clear and use of both a small base billet roller cam and stroker profile rods will usually prevent that .


GOSFAST posted this great photo to illustrate the differance between rod designs

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it should be obvious that the connecting rod on the right has some extra clearance to the cams lobe rotation arc.

http://www.scatcrankshafts.com/index.htm

rods designed like the 3 SERIES generally won,t work with stroker cranks while the 2 series usually will

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these threads have good related info

viewtopic.php?f=51&t=125

viewtopic.php?f=53&t=3897

viewtopic.php?f=53&t=2795

viewtopic.php?f=53&t=852


viewtopic.php?f=51&t=588


viewtopic.php?f=53&t=509


viewtopic.php?f=51&t=1458



viewtopic.php?f=51&t=976
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: assembling and installing connecting rods/pistons

Postby grumpyvette » December 30th, 2008, 4:52 pm

http://store.summitracing.com/partdetai ... =pro-66766 (4.0-4.090)

http://store.summitracing.com/egnsearch ... toview=sku (4.125-4.205)

http://store.summitracing.com/partdetai ... toview=sku (4.250-4.310)

http://www.jegs.com/i/JEGS/555/80516/10002/-1

http://www.jegs.com/webapp/wcs/stores/s ... ompressors

don,t forget to carefully check the piston skirt to crank counter weight clearance, it should be a MINIMUM of .080 thousands
heres some pictures taken of an engine assembly that use a crank designed for a MINIMUM of a 6.25" connecting rod that was used with a 6.135" connecting rod


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you can clearly see where the piston pin boss was being hit bye the counter weights, even though the builder checked one piston and found it had .025 clearance during assembly
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the result was a trashed engine with lots of damage

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IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Posts: 14105
Joined: September 14th, 2008, 1:40 pm
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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » December 31st, 2008, 5:48 pm

heres a stretch chart
http://www.arp-bolts.com/Tech/TechTorque.html
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Do not assume all the rod bolts will all take the same torque to get to the specified listed stretch

SUMMIT SELLS ROD BOLT STRETCH GAUGES
http://www.summitracing.com/parts/ARP-100-9942/
http://store.summitracing.com/partdetai ... toview=sku
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http://store.summitracing.com/partdetai ... toview=sku

heres a stretch chart
http://www.arp-bolts.com/Tech/TechTorque.html

heres the short version,AFTER each rods installed with its bearing on the crank, during the short block assembly process,set the stretch gauge to zero on the bolts un-stretched length, you use a torque wrench on rod bolts lubed with assembly lube too tighten each of them in several stages, tighten the rod bolts to the recommended torque then loosen them and re-tighten them a minimum of three times each, after the final torque value is reached for the third time, you check each bolt against the chart values, most will be a bit short,of the full permitted stretch value, while the bolts being measured , you can slip the stretch gauge off for a second and use the correct long wrench to further tighten them slowly and carefully too just under or up too the stretch chart limits in length, if they are not at that length due to the torque wrench stretching the bolt,this insures max clamping loads, without exceeding the bolts elastic limits so its at max holding strength for the application. cycling the bolt thru several cycles tends to make sure its firmly seated and fully stretched and tends to find problems like defective bolts, and bolt that doesn,t shrink back below the chart value when the tensions released is defective and needs replacement


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FROM ARP

"We highly recommend using a stretch gauge when installing rod bolts and other fasteners where it is possible to measure the length of the fastener. It is the most accurate way to determine the correct pre-load in the rod bolt.

Simply follow manufacturer’s instructions, or use the chart on page 25 of the ARP catalog for ARP fasteners.

Measure the fastener prior to starting, and monitor overall length during installation. When the bolt has stretched the specified amount, the correct preload, or clamping load, has been applied.

We recommend you maintain a chart of all rod bolts, and copy down the length of the fastener prior to and after installation. If there is a permanent increase of .001˝ in length, or if there is deformation, the bolt should be replaced. "

http://www.carcraft.com/techarticles/11 ... index.html


a few more less expensive tools

http://www.chevyhiperformance.com/techa ... rices.html


IF your installing a longer stroke crank in a SBC, the first step is test fitting and carefully marking the connecting rods and block after carefully checking which rods need clearance, in most cases only two or four cylinders will require cam/rod clearance work, and the amount that is normally required too be removed is small enough that the difference in weight is so minimal it won,t have any significance in the engine balance, so grind the rod only in the potential area of cam to rod interference, only on one side, just at that one location, try hard to allow a .060 rod/cam clearance and no more, and do it in a shallow rounded depression so you don,t create stress risers, with any and all the grind mark lines only parallel to the rods long axis and then polish, the grind marks until the areas smooth with 500 grit sand paper, then clean carefully to remove metallic dust
on many blocks all the block rails will need minor clearance work for the rods to clear the oil pan rails, and don,t forget to verify the counter weight to lower cylinder clearance,
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keep in mind the problem is easy to totally avoid simply by selecting rods designed for stroker engines,EXAMPLE
SCAT and LUNATI both make 7/16" rod bolt rods with far stronger than stock forgings, that have cap screw rods designed for much greater clearance


theres a great deal of useful info in the links so read and take advantage of it

http://www.carcraft.com/techarticles/cc ... roker.html

http://www.chevymania.com/tech/383.htm

http://www.hotrod.com/howto/69883_strok ... index.html

viewtopic.php?f=69&t=2145

viewtopic.php?f=69&t=1598

viewtopic.php?f=50&t=1249&p=3752&hilit=burr#p3752

viewtopic.php?f=50&t=804&p=1168&hilit=+burr#p1168

both these pictures show a rod that was probably over or excessively ground & clearanced for most engines, careful rechecking as you rough grind,the rod, helps, take off as little material as you can to get the required clearance.
Image
Image

don,t forget to verify these areas also

Image
Image
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » January 19th, 2010, 9:36 pm

http://www.carcraft.com/techarticles/11 ... index.html
ARP SUGGESTED TORQUE/STRETCH
http://www.arp-bolts.com/Tech/TechTorque.html

http://www.arp-bolts.com/Tech/TechTorque.html
FROM ARP
Image

We highly recommend using a stretch gauge when installing rod bolts and other fasteners where it is possible to measure the length of the fastener. It is the most accurate way to determine the correct pre-load in the rod bolt.

Simply follow manufacturer’s instructions, or use the chart on page 25 of the ARP catalog for ARP fasteners.

Measure the fastener prior to starting, and monitor overall length during installation. When the bolt has stretched the specified amount, the correct preload, or clamping load, has been applied.

We recommend you maintain a chart of all rod bolts, and copy down the length of the fastener prior to and after installation. If there is a permanent increase of .001˝ in length, or if there is deformation, the bolt should be replaced.

Key Tool: Stretch Gauge

You can easily monitor the condition of the rod bolts through use of a stretch gauge, or a micrometer for that matter. Prior to installing the rod, measure the length of the bolt in a “relaxed” (untorqued) state. Write this down. You can make up a chart similar to the one shown on this page to properly keep track of the data. When you tear the engine down for maintenance, again measure the length of each rod bolt – being careful to keep everything in the proper order. If any of the rod bolts have taken a permanent set and have stretched by .001˝ or longer you should replace the fastener IMMEDIATELY! The stretching is a sure indicator that the bolt has been compromised and taken past its yield point.

if the stretch method cannot be used in a particular installation, and the fasteners must be installed by torque alone, there are certain factors that should be taken into account. ARP research has verified the following “rules” pertaining to use of a torque wrench:
Image

1. The friction factor changes from one application to the next. That is, the friction is at its highest value when the fastener is first tightened. Each additional time the fastener is torqued and loosened, this value gets smaller. Eventually the friction levels out and becomes constant for all following repetitions. Therefore, new fasteners should be tightened and loosened through several cycles before applying final torque. The number of times depends on the lubricant. For all situations where ARP lubricants are used, five cycles are required before final torquing.

2. The lubricant used is the main factor in determining friction, and therefore, the torque for a particular installation. Motor oil is a commonly used lubricant because of it’s ready availability. If less friction is desired in order to install the fasteners with less torque, special low friction lubricants are available. With special lubes, the required torque can be reduced as much as 20 to 30 percent. It is important to keep in mind that the reverse is also true. If the torque value has been specified for a particular fastener on the basis of low friction lube, installing the fastener with motor oil will result in insufficient preload; the torque has to be increased to compensate for the extra friction caused by the motor oil.

3. Surface finish is also important. For example, black oxide behaves differently than a polished fastener. It is therefore important to observe the torque recommendations supplied with each fastener.

NOTE: It is possible for even the most expensive of torque wrenches to lose accuracy. We have seen fluctuations of as much as ten (10) foot pounds of torque from wrench to wrench. Please have your torque wrench checked periodically for accuracy.

Id point out that a bit of thought as to the direction of forces when your torquing your main caps or trying to rotate your engine location will help a great deal, ESPECIALLY WITH THE SMALLER BASE ENGINE STAND DESIGNS
more than one guy has failed to pay attention to that and placed a good deal of force on the end of a torque wrench or breaker bar and flipped the engine, off balance.....trust me when I say your first instinct is to try and catch or push the engine back as it falls and you are not going to win that contest....if 600-800lb of engines headed to the floor you better NOT get in the way, so its best to use a very stable wide base engine stand and pay attention to keeping forces along the engine block center-line.
Image

this picture tends to make me think this guys NOT thinking that factor thru, moving the handle, on the wrench 90 degrees could lower the engines tendency to tip.
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » February 12th, 2010, 1:14 pm

http://www.harborfreight.com/cpi/ctaf/d ... mber=90124

Image

its usually standard practice to lightly stamp the outward facing rods and rod caps with the cylinder number they will be or are located in and a matched stamped number on the oil pan rail of the block, its also useful to stamp the main caps on one edge and a matched stamped number on the oil pan rail of the block, indicating which direction each main cap faces and its location during the original DIS-assembly process or first engine assembly to prevent potential screw-ups during later builds or refresh builds.
just make the stamped number clearly readable but not deeply stamped as you don,t want to induce potential stress risers that might weaken the connecting rods

Image
Image

READ THRU THESE THREADS AS EACH CONTAINS USEFUL INFO AND LINKS

viewtopic.php?f=53&t=509

viewtopic.php?f=50&t=267

viewtopic.php?f=51&t=2851

viewtopic.php?f=50&t=79

viewtopic.php?f=50&t=1027

viewtopic.php?f=50&t=55

viewtopic.php?f=50&t=1086

viewtopic.php?f=51&t=2851&p=7377#p7377

http://www.themotorbookstore.com/resmchstvi.html

how to assemble an engine basics on video

covering the rod bolts to protect the crank journals during assembly or dis-assembly, by slipping opposite ends of a 24" section of rubber fuel line of the correct size to snugly fit the bolts over the exposed bolts , helps prevent crank journal, nicks/damage

IF you use the type of rods that use cap screws , you obviously won,t have bolts exposed, but a cheap connecting rod guide tool can be fabricated from a 2 foot long section of 5/16" thread rod by slipping a section of 3/8" rubber fuel line about 20" long over the rod so that 2" of the thread on each end remain exposed, and bending the rod at the center over a 2" pipe to form a deep (U) the tips are passed over the journal and out thru the cylinder bore and out thru the ring compressor , then the rod bolt holes in the rod are slipped over the tips of exposed thread rod and two 5/16" nuts are threaded on finger tight, this will allow you to guide the rod onto the crank journal once the rings on the piston pass thru the ring compressor, while protecting the rod journal
Image

http://www.compperformancegroupstores.c ... Connecting
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » May 25th, 2010, 10:37 am

I get asked all the time,
"should you re-use those stock rods, when I rebuild my 350 or when I build my 383 stroker"
most sbc gen I stock rods are designed to be cheap, and dependable in engines spinning under 6000rpm that make under 400hp,
this is one area where I'm simply amused at the lack of thought shown in selecting components, by some guys.
most Chevy small block rods are VASTLY inferior in strength to many of the mid range and better aftermarket rods available.
a 7/16" cap screw type ARP rod bolt is EASILY 200%-300% stronger than a stock 3/8" factory rod bolt and frankly, the cost & TIME to correctly modify and prep stock rods is a total waste, its almost always cheaper to buy decent aftermarket rods.

example

http://sdparts.com/details/gm-performan ... s/12495071

$265 for a set of stock rods and then you should still have ARP bolts installed, polish, balance and sized your looking at easily $500-$600 or more for a set ready to run

compared to something like this below its a joke

http://store.summitracing.com/partdetail.asp?part=...

http://store.summitracing.com/partdetail.asp?part=...


keep in mind theres far stronger rods available if you have some extra cash,but even these are a big improvement over stock, and that connecting rods and their rod bolts are under a huge amount of stress at high rpms....one rod bolt stretching at high rpm will usually result in engine failure and its common for only the intake, valve covers, distributor, and water pump and a few other parts to be salvageable if that were to happen at high rpms...stretch a rod bolt and the piston contacts the head, or bends a valve, the rod bends, the heads destroyed, the block can be history and it can go down hill rapidly from there as fragments work their way around thru other of the moving parts as the engine locks up

ITS not generally HP but RPMS or lack of lubrication to the bearings that kills rods, I know guys with turbo cars that have carefully reworked stock rods pushing over 700 hp but they don,t generally exceed 6300rpm, rods generally fail in TENSION when the rod or rod bolts stretch /stretches not in compression due to cylinder pressure.
that's why the 7/16" rod bolts are so much better, as the bolts are the weakest component in most designs
on the compression stroke the whole rod structure resists deformation on the exhaust stroke the rod bolts are playing crack the whip and the rods trying to keep the piston from pulling/distorting it maybe 25-40 thousands it takes to prevent head to piston contact, and the bearing shells from distorting ,under the load so they don,t loose the oil pressure support, if the rod elongates and hits the head or valves in valve float bad things cascade into worse things fast.
the rod bolt cross sectional area is generally far smaller than the rod itself and if the piston compresses the rod a few thousands on the power stroke there not much effected, but let the rod stretch and bad things happen real fast.
a 7/16" rod bolt is about 20% larger in cross section than a 3/8" rod bolt and the L19 ARP steel in the better rod bolts is easily 50%-100% stronger than the stock rod bolt steel in many cases, giving a decent aftermarket cap screw rod design a significant strength advantage

viewtopic.php?f=53&t=1168

viewtopic.php?f=53&t=343

viewtopic.php?f=53&t=1110

viewtopic.php?f=53&t=510

viewtopic.php?f=53&t=942
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » July 31st, 2010, 8:20 pm

when your setting the ring gap theres been a few changes in whats been found to work best, over the years
for most of my 40 years of engine build experience most builders gaped the top rings for a
Normally aspirated
.0045 per inch of bore top
.004-.0045 per inch of bore second (slightly tighter end gap on the second ring)
because the second ring was not exposed to the same intense heat so it needed less gap to prevent the ring ends from touching as the heat expanded the rings and lowered the resulting end gap, remember that .0045 per inch of bore results in about a .019-.020 " end gap on the rings of a 427-454 bbc with its 4.25" bore

READ THE LINKS THERES A TON OF GOOD INFO

viewtopic.php?f=53&t=2837

http://www.kb-silvolite.com/assets/kb_installation.pdf

lately thats changed to

.0045 per inch of bore top
.005-.0055 per inch of bore for the second ring second

this is the typical approach nowadays that most builders use.
the reason for the change is that its been found that the compression, and combustion tends to build pressure between the rings and that pressure build up,tends to significantly reduce the effective seal of the top ring
A fairly recent development with the second ring has been to open up the ring end gaps more to allow more trapped gases to escape from between the top ring and second ring, The larger second ring end gap flow area, allows any potential pres sure build up keeps the top ring from fluttering, it also allows trapped oil to escape back to the crankcase.
greg_moreira posted this info
"[Inter-ring pressure] is somewhat minor but all of the little things add up," says Sealed Power's Gabrielson. "The flow gap on the second ring should be twice the flow gap on the top ring. That doesn't necessarily mean the ring gap is twice as large. The flow area is that little bit of area that includes the ring gap and part of the end that hangs over the land underneath the ring. Everything else is closed off because the ring is sitting on the piston ring land. So you actually have only that little spot that is hanging over the edge."
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: assembling and installing connecting rods/pistons

Postby Indycars » October 28th, 2010, 3:45 pm

Your links to ARP Fasteners website are broken, they have updated their website.
The new link is:
http://www.arp-bolts.com/pages/technica ... e_us.shtml

This is the table you are linking to:

ARP_TorqueValues02.jpg
You do not have the required permissions to view the files attached to this post.
Last edited by Indycars on October 29th, 2010, 12:00 pm, edited 1 time in total.
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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » October 28th, 2010, 4:26 pm

thanks for the help, your a true valuable asset to the site!
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: assembling and installing connecting rods/pistons

Postby Indycars » October 28th, 2010, 5:03 pm

Thanks Grumpy, I try to help when I can!

Do you have an easy way to replace all the links throughout your forum for a specific website??? Like when a link is broken, can you replace all the bad links with the new link???
Rick
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- Check Out My Dart SHP Engine Project: viewtopic.php?f=69&t=3814
- Need a Dynamic Compression Ratio Calculator: viewtopic.php?f=99&t=4458
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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » October 28th, 2010, 5:10 pm

no, unfortunately its a one at a time swap process
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » December 18th, 2011, 8:53 am

Somebody please school me on why pistons with 4 valve reliefs were originally installed in these motors at the factory. Was it simply to allow for assembly line errors, where a given piston might be installed incorrectly? Or maybe to cut manufacturing costs, so that the same piston part # could be installed in cylinders on either side of the block?

And why are they still available? Since pistons with two reliefs give slightly more compression, why would someone still choose to buy pistons with four reliefs?

I have an issue with this, because I'm shopping for pistons for my 327 and see that the 2-relief pistons are generally more costly. It makes no sense, unless the 4-relief pistons are more popular and therefore benefit from greater economies of production. :willynilly:
Image
Image
Image
[color=#00BF00] BTW, most piston compression rings have a dot on the upper surface to indicate the side designed to face the top of the piston

Examples:[/color]
4 Relief: http://www.summitracing.com/parts/SLP-L2165F30/

2 Relief: http://www.summitracing.com/parts/SLP-WL-2326F30/



thats simple Image

chevy has both a right and left piston due to the exhaust not always being on the same side of the cylinder, for the same piston to be used on either location in the block and on either side the valve notches needed to be mirror or duplicated for ease of assembly,btw
Image
notice the top rods non-beveled side that faces the matching rod is up, but on the lower rod the the beveled side that faces the crank counter weight is up on the lower rod
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: assembling and installing connecting rods/pistons

Postby grumpyvette » December 18th, 2011, 11:16 am

Image
Image
Image
Image
Image
Image

if you have free float piston pins your most likely familiar with these
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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