porting can help



porting can help

Postby grumpyvette » October 10th, 2008, 3:27 pm

I get lots of requests that basically ask, how do I port or improve the heads I have so they flow better, because I just don,t have the extra money to dump into better heads, well theres no doubt that most heads can have the flow improved with a port and bowl clean-up and contouring the short side radias and smoothing the bowl area, but theres a cost to benefit ratio,its fairly easy to increase stock head flow rates in the 5%-10% range but if your looking at spending several hundred dollars in port work and if your looking for major improvements your generally better off selecting aftermarket heads with larger and far better designed ports than sinking a ton of time and money in stock heads, that in many cases your eventually replace.
port throats generally run 80%-85% of total valve diameter because you need to maintain sufficient valve seat contact area to allow sealing and cooling and some wear during operation.

THERES ABOUT 90% of the INFO YOULL NEED IS IN THE SUB LINKS ..READ THOSE ALSO

theres also lots of guys who find that the intake manifolds available for the application they have, are rather restrictive, especially for some of the less popular engines like Cadillac, or Pontiac engines Ive worked with in the past, or if the intake designs available are mostly for non-racing applications. runners can be too small in cross sectional area, and aftermarket parts can be non-existent and theres not always enough material in all intake runner designs to allow porting them to a significantly larger port size without having made the gasket sealing area to thin to seal properly.
this does not necessarily mean you have zero options, in many cases a quality machine shop can tig weld extra aluminum on the intake in critical areas to allow you to port the runners larger and then they can reface the gasket sealing area thus allowing you to significantly increase the intake runners cross sectional area.

READ THIS
http://www.maliburacing.com/patrick_budd_article.htm

yes its worth the time required to read thru the sub linked info

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viewtopic.php?f=27&t=1831&p=4763#p4763
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notice how the valve seat supporting casting in the cylinder head, throat extends out into the port and restricts the valve flow, a critical area that port and bowl clean -up can usually gain significant flow improvements
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http://www.mondellotwister.com/ArtPtngAtHme.htm

http://www.powerblocktv.com/episodes/HP ... wer-how-to

http://victorylibrary.com/mopar/alternate-c.htm

viewtopic.php?f=52&t=3293&p=8709#p8709 (got twisted wedge heads? read this)

http://www.carbideselect.com/burshpescuts.php

https://www.youtube.com/watch?v=rXzRwi2C2xM

https://www.youtube.com/watch?v=T_BXeXoGzD8

viewtopic.php?f=55&t=5378&p=20984&hilit=port+matching#p20984

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

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

viewtopic.php?f=52&t=10145

https://www.youtube.com/watch?v=1_5TnlX-Ams

http://www.hotrod.com/techarticles/engi ... z28MLMTEYU

http://www.camarohomepage.com/project/part2.htm
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http://racingsecrets.com/speedtalk_head_porting.shtml

http://www.mondellotwister.com/ArtHeadPort.htm

http://www.ronsportingservice.com/#edelbrock15

http://www.j-performance.com/forum/phpB ... um.php?f=5

http://theamcpages.com/documents/engine ... -ports.doc

viewtopic.php?f=55&t=2773&p=7200#p7200

http://www.j-performance.com/index.php? ... view&id=28

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

viewtopic.php?f=50&t=3422&p=9066#p9066

http://www.ehow.com/how_4928270_port-po ... heads.html

http://portingtools.com/

READ THRU THIS LINK
http://www.circletrack.com/enginetech/1 ... ch_engine/

http://www.maximumraceengines.com/intak ... rting.html

http://www.allpar.com/fix/holler/porting.html

http://www.project33.com/Categoryarticl ... ory=Engine

http://www.project33.com/Categoryarticl ... ory=Engine

http://www.project33.com/Categoryarticl ... ory=Engine

http://www.hotrod.com/howto/3398_alumin ... ld_repair/

http://www.j-performance.com/index.php? ... view&id=27

http://www.allpar.com/fix/holler/porting.html

http://racingsecrets.com/speedtalk_head_porting.shtml

viewtopic.php?f=55&t=4362&p=11826&hilit=porting+plenums#p11826

below are a few ideas
as a guide
read the links carefully

(1) open throat to 85%-90% of valve size
(2)cut a 4 angle seat with 45 degree angle .065-.075 wide where the valve seats and about .100 at 60 degrees below and a .030 wide 30 degree cut above and a 20 degree cut above that rolled and blended into the combustion chamber
(3)blend the spark plug boss slightly and lay back the combustion chamber walls near the valves
(4)narrow but dont shorten the valve guide
(5) open and straiten and blend the upper two port corner edges along the port roof
(6) gasket match to/with intake and raise the port roof slightly
(7) back cut valves at 30 degrees
(8) polish valve face and round outer edges slightly
(9)polish combustion chamber surface and blend edges slightly
(10) remove and smooth away all casting flash , keep the floor of the port slightly rough but the roof and walls smoothed but not polished.
(11) use a head gasket to see the max you can open the combustion chamber walls
(12) blend but don,t grind away the short side radius
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http://www.mondellotwister.com/school.html

http://www.ws6transam.org/ported.html

http://victorylibrary.com/mopar/chamber-tech-c.htm

http://victorylibrary.com/mopar/chamber-tech-c.htm

http://www.eecis.udel.edu/~davis/z28/buildup/plenum/

http://www.babcox.com/editorial/us/us110128.htm

http://www.hotrod.com/howto/51058_cylin ... index.html

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

http://www.diyporting.com/Shrouding.html

http://www.gmtips.com/3rd-degree/dox/ti ... t/port.htm

http://www.babcox.com/editorial/ar/eb120121.htm

http://www.babcox.com/editorial/us/us110128.htm

http://www.hotrod.com/techarticles/engine/hrdp_0802_chevy_intake_manifold_porting/index.html

http://www.sa-motorsports.com/diyport.aspx

http://www.circletrack.com/techarticles/general/139_0305_port_matching_engine_porting/index.html

http://speedtalk.com/shows/027_jim_mcfarland.html

http://www.chevyhiperformance.com/techarticles/95518_small_block_cylinder_head_porting/index.html

http://www.gmtips.com/3rd-degree/dox/tips/plen-port/port.htm

http://www.bfranker.badz28.com/96ss/58porting.htm

http://www.eecis.udel.edu/~davis/z28/buildup/plenum/

http://www.diyporting.com/molds.html

http://www.fordmuscle.com/archives/2006/12/MakingMolds/index.php
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http://www.harborfreight.com/air-die-gr ... 99698.html
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I usually buy these three at a time, they last a long time but think of them as disposable like the BURRS because they do wear out and at roughly $20 each are a bargain even if you need to occasionally pitch one in the dumpster
you can order this set of these long carbide burrs for about $36-$40

http://www.mcsdepot.com/browseproducts/ ... REACH.HTML
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http://www.browntool.com/Default.aspx?t ... ductNumber

http://www.grainger.com/category/carbid ... alog/N-9o0

http://www.eastwood.com/8pc-dual-cut-ca ... shank.html

http://www.victornet.com/subdepartments ... /2150.html

http://www.carbideprocessors.com/sgs/long-shank/

http://www.pferdusa.com/products/202a/index.html

http://dewitt-tool.com/b_dc_oval.aspx

http://boroburrs.com/14-shank-burs/

http://www.falcontool.com/Falcon_Carbide_burs.pdf

most of the time you'll find a few seconds time to put on safety equipment and the minimal cost spent is far FAR less than it costs in time and money to deal with the medical cost resulting from rushing into a job without their use!Ive generally used and strongly suggest you consider using, one or both of these when using angle grinders or while porting heads due to learning from past experiences
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http://www.homedepot.com/p/DEWALT-Safet ... 220499-_-N

http://www.harborfreight.com/adjustable ... 46526.html
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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!!
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Re: porting can help

Postby grumpyvette » October 27th, 2008, 3:56 am

http://www.ws6transam.org/ported.html

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

http://chevymusclecars-tom.blogspot.com ... shing.html

http://www.autobodytoolmart.com/pc-1476 ... 14tin.aspx

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

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

http://www.hotrod.com/techarticles/engi ... index.html

http://www.circletrack.com/techarticles ... ching.html
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http://www.summitracing.com/parts/sum-900013/overview/

http://www.summitracing.com/parts/sum-900012/overview/

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read these

some excellent info well worth reading thru

http://www.gofastnews.com/board/technic ... uding.html

http://www.rbracing-rsr.com/runnertorquecalc.html

http://racingsecrets.com/speedtalk_head_porting.shtml

http://www.diyporting.com/Shrouding.html

http://victorylibrary.com/mopar/chamber-tech.htm

Tips For Porting a cylinder head and

Tools needed for porting a cylinder head

#1 we use carbide burrs for starting the roughing trying to do this with a stone based burr will cost you much more in the the long run in wasted time and the stones cost less but you will end up using them up so fast it will cost you more

#2 Use 1/4 inch air grinder air power rules ! a 1/8 inch dremel just won't cut it you will burn it up before you finish and again time is money

#3 air again do not wimp out on size you will need at least a 60 gallon tank with a 5 hp air compressor

#4 a regulator you will find if you use a in line regulator you will be able to control you air grinder much better if you think you can regulate it with the handle on the grinder forget it turn it down if you get a lot of of bouncing or chatter from you burr otherwise you will just dull it

one other very frequent use for my shop vac is to collect metallic debris, when I port cylinder heads, I usually tape some 3/4"-1" plastic conduit to the shop vac suction hose, then tape the tip of the conduit to the opposite end of the port Im working on with duct tape, (obviously youll remove the valves before porting or port matching heads)
you can place the suction hose extension, in the far end of a port and duct tape it in place temporarily, and then use a die grinder to clean up the port and the shop vac will collect the vast majority of the metallic chips , having the shop vacuum constantly sucking the metallic debris out of the port also tends to cool the cutting burr, and slow the flutes on the burr from clogging with crud, but youll still want to dip the cutting burr in a mix of marvel mystery oil and WD40 every few seconds to prevent aluminum chips from clogging the burrs cutting flutes or the burr heating up

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http://www.summitracing.com/parts/PRO-66483/
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a decent cylinder head stand helps

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read these threads
viewtopic.php?f=52&t=462&st=0&sk=t&sd=a&hilit=porting+help

viewtopic.php?f=52&t=3143&p=8387&hilit=porting+help#p8387

viewtopic.php?f=55&t=2773&p=7802&hilit=+porting+help#p7802

viewtopic.php?f=52&t=2630&p=6788&hilit=+porting+help#p6788

viewtopic.php?f=27&t=1831&p=4763&hilit=+porting+help#p4763
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: porting can help

Postby grumpyvette » November 17th, 2008, 12:17 pm

posted by Z51L9889

I have been working (very slowly) on porting a set of AFR 195 street heads for use on my 383 build. I debated whether or not to even touch the heads for a long time before I decided to give it a try. I talked to many experienced porters, including Tony Mamo of AFR, to get an idea of where I might find some improvements. Tony didn't exactly encourage me to get wild and crazy with the grinder, but at the same time he was very helpful and did tell me about areas I should try to avoid.

The heads in stock form are works of art, but I noticed that there are a few places where the CNC cutter paths intersect inside the port where I felt that some blending might yield an improvement. I also did some reshaping in other areas but the changes were pretty minor. Here are some before and after pictures, and the flow results vs. the advertised numbers are below the pictures.

Before:

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Areas to avoid: Do NOT remove any material from the bulge in the intake ports around the head bolt hole. Here are a picture that shows the area and what happens if you try and grind on it. I had to have a sleeve installed.

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After:

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Flow Results:

My flow numbers were obtained using a radiused inlet, a 4.03 bore adapter, and no adapter (no pipe) on the exhaust. I show my results and the difference to the AFR advertised numbers. I do not know all the particulars of the flow test setup for the AFR results as posted on their website, so this may not be a true apples-to-apples comparison. Also, please note that I did not obtain "before" numbers. This would make the data more meaningful and technically accurate but it was not practical for me to obtain the data at the time I started work on the heads.

Intake

Lift ------ CFM ----- Diff. to AFR
.200 ----- 147 ----- +10
.300 ----- 206 ----- +10
.400 ----- 253 ----- +10
.500 ----- 278 ----- +4
.600 ----- 280 ----- (AFR is 280 @ .550)

Exhaust

Lift ------ CFM ----- Diff. to AFR
.200 ----- 106 ----- -4
.300 ----- 149 ----- -9
.400 ----- 192 ----- +2
.500 ----- 206 ----- -1
.600 ----- 213 ----- (AFR is 211 @ .550)

All in all, I'm quite pleased with the way this turned out, particularly the intake. I do show a small deficit on the exhaust but the AFR results were obtained using an adapter pipe (which increases the numbers) so I'm probably right in the ballpark.

If I had to do this all over again knowing what the results would be, I'm not sure that I would choose to do so. I have a TON of time in these heads and I can't honestly say at this point that the gains are worth all the time spent. I'm sure that someone with a lot more porting experience than me could probably find some additional gains, but I think that for most people considering these heads they would probably be better off just bolting them on.

I will be using a heavily ported FIRST intake with these heads, and I plan to re-flow with the intake and runner. At that time, I may reflow the heads by themselves with a pipe on the exhaust.

I hope you find this info useful. :thumbs:

heres a vortec head thats been ported
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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!!
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Re: porting can help

Postby grumpyvette » February 28th, 2009, 2:46 pm

if you decide to do some home cylinder head porting , step back and think it thru, if your looking for a major improvement in many cases youll be far better off buying a differant performance cylinder head thats designed to flow sigificantly more air, because theres NOTHING your going to do to most heads that will allow them to flow nearly as well as the better performance head designs
, but if your goal is more in the lets make these heads flow up to thier potential, and a few treaks that add a few hp are your goal,the first thing youll want to get is a decent carbide burr and a die grinder,

http://www.pirate4x4.com/tech/billavist ... asives.pdf

http://store.summitracing.com/partdetai ... toview=sku

http://www.autobodytoolmart.com/pc-1476 ... 14tin.aspx

http://store.summitracing.com/egnsearch ... &D=-112815

http://store.summitracing.com/partdetai ... toview=sku

something that runs on compressed air will be best but electric can be used, a 2" long shank and a 1/2" egg shaped burr will do most work.
youll also need a valve spring compressor.

http://store.summitracing.com/partdetai ... toview=sku

viewtopic.php?f=55&t=858&p=2669&hilit=grinder#p2669

viewtopic.php?f=27&t=408&p=502#p502

ok the object is NOT to remove a great deal of metal or enlarge the port size.
you'll want to smooth the area in the port throat under the head of the valve and narrow the cast boss surrounding the valve guide without significantly shortening it, open the intake port to match the intake gaskets, the object IS more TO REDUCE RESTRICTION TO FLOW, smooth the port surface, blend the edges, remove obvious ridges and casting flash, but polishing it can be counter productive.
you'll have better results if you try to smooth out the port flow rather than change it radically

viewtopic.php?f=50&t=1266

http://www.hotrod.com/techarticles/engine/hrdp_0802_chevy_intake_manifold_porting/index.html

http://www.gofastnews.com/board/technical-articles/1181-porting-school-6-secrets-reduce-valve-shrouding.html#post5343

http://www.sa-motorsports.com/diyport.aspx

http://www.circletrack.com/techarticles/general/139_0305_port_matching_engine_porting/index.html

http://speedtalk.com/shows/027_jim_mcfarland.html

http://www.chevyhiperformance.com/techarticles/95518_small_block_cylinder_head_porting/index.html

http://www.gmtips.com/3rd-degree/dox/tips/plen-port/port.htm

http://www.bfranker.badz28.com/96ss/58porting.htm

http://www.eecis.udel.edu/~davis/z28/buildup/plenum/

http://www.diyporting.com/molds.html

http://www.fordmuscle.com/archives/2006/12/MakingMolds/index.php
some excellent info well worth reading thru

READ THRU THIS LINK
you might have somehow gotten the IN-CORRECT idea that the valve center-line and CYLINDER center-line are exactly matched in a sbc, they are NOT!
plus the valves are angled at a 23 degree angle so the outer valve edges close to the cylinder walls do not drop strait down into the bore as the valves open at the point of the cylinders largest diam. moving the head center-line to move the valve center- line to maximize flow at max valve lift potentially helps performance.
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http://www.circletrack.com/enginetech/1 ... ch_engine/

http://www.gofastnews.com/board/technic ... uding.html

http://www.hotrod.com/how-to/engine/061 ... d-porting/

http://www.motortecmagazine.net/article.asp?AID=30&AP=1

http://www.eurospares.com/graphics/engi ... 0Time!.pdf

http://www.gofastnews.com/showthread.ph ... rt-Volumes

http://www.rbracing-rsr.com/runnertorquecalc.html

viewtopic.php?f=52&t=8460&p=29682&hilit=curtain+flow+angle#p29682

http://users.erols.com/srweiss/tablehdc ... _Big_Block

http://www.j-performance.com/index.php? ... view&id=48

http://www.cfmperformance.com/cfmproducts/flowbenches

http://racingsecrets.com/speedtalk_head_porting.shtml

http://www.diyporting.com/Shrouding.html

viewtopic.php?f=27&t=3379&p=8922&hilit=+shop+filter#p8922

viewtopic.php?f=50&t=3422

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

http://victorylibrary.com/mopar/chamber-tech.htm
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valve seat and back face angles ,valve diameter and valve lift and duration effect the flow thru the curtain area
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restrictive, as cast
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less restrictive after unshrouding the valve

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heres some old fuelie heads with the chamber slightly un-shrouding the intake valve pocket walls
polishing the combustion chambers and smoothing contours tends to reduce detonation and improve power, combine that with port and bowl area clean-up and careful blending of the port walls. and a back cut on valves with a multi angle valve job, etc. and its not unusually to gain 25-40 hp or more, from port work and combustion chamber mods that improve air flow rates
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BTW HERES SOME REWORKED BIG BLOCK HEAD COMBUSTION CHAMBERS, TO UN-SHROUD THE VALVES, SMOOTH THE COMBUSTION CHAMBERS

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STOCK
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SIGNIFICANTLY IMPROVED FLOW
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: porting can help

Postby joegagan » February 28th, 2009, 7:08 pm

great pics, really nice work there!

makes me really excited to get back to porting.

your info is really helpful too.
Send a message to Washington, join SEMAsan ( http://www.semasan.com/main/main.aspx?I ... m/HomePage ), free membership. There is power in numbers, act now before any more more crap laws are passed. Vote the bums out in 2010!!!
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Re: porting can help

Postby grumpyvette » June 20th, 2009, 9:34 am

combustion chamber surface finish should be smooth to promote heat retention in the combustion chamber and help prevent detonation hot spots that sharp edges and rough surfaces can provide, intake ports are a different deal! the roof of the intake port in most cases sees far higher air speeds than the walls and floor areas, polishing, smoothing and blending the roof of the port rarely hurts and frequently helps, the lower air flow rates on the port floors and walls can frequently benefit from a slight texture as it promotes surface turbulence that tends to keep fuel in suspension in the air flow rather than forming a liquid coating of fuel that drops out of suspension.
you don,t need a mirror smooth port surface and you don,t want the floor extra rough, as that can restrict flow.

read these threads also

viewtopic.php?f=52&t=1563

viewtopic.php?f=52&t=1740

viewtopic.php?f=52&t=333

viewtopic.php?f=52&t=322


BTW, while were discussing intake manifold modifications lets spend 2 seconds on what may be the most over-looked and one potentially important area, the runner entrances.
I can,t tell you how many times I see guys take intakes out of the box and just bolt them on, and then expect the thing to perform up to its full potential....which its NEVER going to do with out some basic clean-up. de-burr, and contour work being done because the as cast surfaces are rarely smooth or correctly contoured, its not going to give you an extra 50 hp , but it can result in 5-10-even on occasion 20hp over a significant part of your engines primary power band


heres a couple professionally re-worked single plane intake plenums, notice they don,t look a lot like the out of the box plenumsthe port entrance is raised and smoother the dividers are contoured, etc.
Image

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Image

this is what you currently have :shock:
Image

This is what you want to have (you can almost see the HP) :twisted:
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porting helps flow significantly

READ THE LINKED INFO
http://www.maximumraceengines.com/intak ... rting.html

viewtopic.php?f=52&t=333&p=8319&hilit=porting+help#p8319

viewtopic.php?f=52&t=462&st=0&sk=t&sd=a&hilit=porting+help

http://www.hotrod.com/techarticles/engi ... index.html

viewtopic.php?f=55&t=2773&p=7200&hilit=+port+match#p7200
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: porting can help

Postby stroker87 » June 22nd, 2009, 8:48 am

I read that last night after I PM'd you "good reading"

do you have any advice for the valve seats? is there a simple way to protect them so I dont nick them?
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Re: porting can help

Postby grumpyvette » June 22nd, 2009, 9:36 am

stroker87 wrote:I read that last night after I PM'd you "good reading"

do you have any advice for the valve seats? is there a simple way to protect them so I don't nick them?


http://www.j-performance.com/index.php? ... view&id=27

most guys use a couple layers of duct tape, as a protective shield when doing a pocket port work with an air die grinder,and carbide burr,but just try not to get carried away and be careful and remember to mark and replace the valves in their original locations

http://www.harborfreight.com/cpi/ctaf/d ... mber=99698

Image

this model die grinder is surprisingly good quality for a disposable throw away die grinder,and usually last for more than two cylinder heads, its a true bargain, if it lasts only for two! don,t even think about use of the hard stone grinding bits they shatter and are cheap crap, get real carbide burrs

BUY & WEAR THE MANDATORY SAFETY GOGGLES, and face shield as tiny bits of crap get to flying around at times

http://www.harborfreight.com/cpi/ctaf/d ... mber=66538

http://www.harborfreight.com/cpi/ctaf/d ... mber=46526


BTW on INTAKE PORTS,Its been my experience that a 120-150 grit sand paper provides all the rough surface you need, anything smoother tends to allow fuel droplets to sheet,like a film over the port wall surface, anything much rougher tends to increase the boundary layer, and restrict flow, on exhaust ports, and combustion chamber surfaces the 400-500 grit works better
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: porting can help

Postby grumpyvette » January 24th, 2010, 7:31 am

"Headwork entails enlarging the intake and exhaust passages in a head to allow for more flow. Good headwork entails subtle reshaping, not just hogging the whole port out bigger. Generally, good headwork leaves the floors of the port alone since most of the flow activity in a port is near the roof of the port. The roof is the outside radius of the bend going to and from the combustion chamber and by inertia, most of the air wants to flow up there. Good headwork usually rounds the floor hump which is the transition from the valve seat to the floor of the port. Stock, this is usually a sharp edge which causes non-laminar (turbulent) flow separation.

The object of good porting is to increase flow as much as possible while keeping the port volume as low as possible to maintain as high of a flow velocity as possible. Big ports have low velocity at low rpm. This results in a loss of bottom end power due to the lack of energy available in the moving gas column behind the valve. The gas column has inertia which helps fill the cylinder, especially at low RPM. Generally porting your head will cause some loss of bottom end power. Good head porters might be able to increase flow in the head up to 40 percent with no loss in bottom end but that is usually for American Iron heads which are terrible to start with. Modern Japanese engines donft usually see as big gains as their design is much better to begin with. Gains of 10-20 percent are typical with a modern Japanese motor.

The other major area of headwork flow gain is in the valve job. A large percentage of gain can be in the valve job alone. The best valve jobs are called multi angle valve jobs with three or more distinct angles. The main angles are the throat cut, which is a 60-70 degree cut that blends the port wall to the seating cut. The seating cut is a 45 degree cut which is the sealing surface for the valve. This critical cut should be 0.040-0.060 wide for a multi valve engine like an SR20. Finally there is the top cut which is a 30 degree cut which blends the seating cut to the combustion chamber. The purpose of these cuts is to help the air flow smoothly around the valve, especially when the valve is starting to open or close.

Another valve job trick is to place a 30 degree back cut above the 45 degree seating cut on the valve itself. This helps the air get around the valve better especially at low lifts. A five angle valve job uses two extra cuts to make the transition even smoother. The best valve jobs are radius valve jobs which are a 3 or 5 angle valve job which is hand blended after cutting for a perfectly smooth transition. The quality of a valve job is very important because it can contribute up to 50% of the flow gains that headwork will get you.

The best valve jobs are done on a Serdi machine. The Serdi is very high precision which insures that all the valve angles and depths come out equal. Most low price shops use stones. Stones can give a good valve job but the stones must be dressed frequently and dial indicators must be used to insure that the seating surface remains concentric. Stones require a highly skilled person who is conscientious of doing a good job. A butcher can make a big mess with stones.

Unshrouding the valves is an operation where the edge of the combustion chamber is cut back by about 25% of the valve diameter so that the wall of the combustion chamber does not block the air going past the valve into the cylinder.

Polishing the combustion chamber removes sharp edges that can glow red hot and trigger detonation. It also makes it harder for carbon to stick. Polishing should be limited to the combustion chamber and exhaust port. The intake port should be no smoother than 220 grit as maintaining some boundary layer turbulence is good for good bottom end. This turbulence makes the port virtually a little smaller at low flow velocities."(by Shaddoh international tuner)
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: porting can help

Postby grumpyvette » January 24th, 2010, 1:11 pm

HEAD TERMINOLOGY

Cylinder Head Design and Terms

By Joe Alaniz (Air Flow Technician)
ALANIZ has taken the time to hopefully educate the sports car enthusiast about certain words and procedures. So lets get started.



BACK CUT VALVE
This describes an additional angle added to the valve head to improve flow. Be aware different angles give different flow results at certain valve lifts.




BOTTOM CUT (throat cut)
The bottom cut is just as it sounds, the cut furthest into the valve-throat area. This cut opens the throat diameter to mate up with the main seating angle. On Honda B16/GSR heads, this angle has the greatest affect on mid to high valve lifts.

BOWL PORT/BOWL BLEND/POCKET PORT (They all mean the same thing.)
This is the most important part of porting a head. This place if done correctly will result in good CFM gains. At the same time one wrong move here will result in a head that flows less than a stock. You cant make any mistakes here. Our flowbench testing has shown us what to touch and what not too. Most porters blend the short sides as common practice not realizing some of those edges are what makes the head flow well as we discovered on an Honda S2000 head. Bumps and sharp edges are not bad all the time. Once again flowbench testing helped us determin this.


CUT SEATS/GRIND SEATS
ALANIZ uses special carbide cutting tools/machines to cut the valve seats. Grinding procedures are also performed because we have found carbide tooling doesnt always cut perfectly round on hardened seats. Carbide cutters have a tendency to jump when it comes in contact with hard spots. A simple way of checking a carbide cut is place the valve in the seat with no spring and look through the port while holding it with one finger. Look through the port. If you see light you know its not perfectly round. Thats were the stone comes in. We here at ALANIZ always come back and KISS the seats with a finishing stone. The stone grinds away the hard spot leaving you with a perfect seal. On extreme applications such as supercharged, turbo, NOS engines there is no room for errors. Any gaps in the VALVE to SEAT contact area will result in a burned valve. ALANIZ pays special attention to these areas resulting in leak proof valve jobs. Knowing what angles to use is very important here. Honda heads are very sensitive to valve jobs. One wrong angle will reduce flow dramatically. When valve seatwork is performed, it's important to measure the installed height with an indicator. Setting all valves to the same height ensures consistency of combustion-chamber volume and helps equalize spring pressure.



FLOW BENCH
A flowbench is machine, which tells you how much air can flow through a port, manifold or throttle body. This machine is the most important tool when it comes to porting. Without one you will never be able to achieve the highest possible CFM gains. All of our porting and valve job experience comes from utilizing a Superflow flowbench. It guides us in the rite direction by telling us if flow is gained or lost while keeping good port velocity. All Competition heads are flowed to make sure they perform flawlessly. ALANIZ heads are flowed @ 28" of water.


GASKET MATCH/PORT MATCH
All this means is equalizing diameters of adjoining runners. E.g. manifold to head. Most modern multi valve head from the factory come almost perfect in respects to the intake side. A light massage is all it needs.


LAP VALVES AND SEATS
A very light abrasive compound is use to lightly sand the valves into place. When ALANIZ performs its valve jobs it uses this procedure to check margin thickness and quality. We do not use it to cure an out of round, off center or just plain bad valve job as others shops may do. We vacuum check our work rights after the Valve job is performed then lap the valves in.


MILLING
This is a machining process that removes metal from the head-gasket-surface area. It purpose is to remove imperfections from the head surface. It is also used for increasing the compression ratio of an engine. ALANIZ checks both valve cover surface as well as the head gasket surface to make sure the head is straight before milling. Milling should never done if the head is bent. STRAIGHTEN IT FIRST then mill it otherwise uneven cam journal wear will occur. In a worst-case scenario the cam journal and cam will simply destroy it self.


MULTI-ANGLE VALVE JOB
A multi angle valve job is the cutting or grinding of 2 or more angles on the seat and valve. The purpose of a multi angle valve job is to improve airflow. By now you have probably heard of 5 angle and radius valve jobs. The truth, this is more applicable in the American iron heads. There just isnt enough material in the small diameter seats or valves to see any real noticeable differences on a flow bench. A .5% gain maybe seen on a flowbench but the flowbench has a plus or minus error factor that has to be eliminated before a true flow figure can be attained. Older American iron heads may benefit from a five angle or radius valve job but only because the head is so bad to begin with. The Honda head is diffrent. Our flowbench testing has proven time after time that the correct angles and angle widths is what is important. More CFM gains have been made through this procedure than applying 5 angles or radiuses.


POLISHING
Polishing a port or combustion chamber does not alter the shape or size, but instead smoothes the surface to increase flow and reduce the build up of combustion deposits. On the intake side of an ALANIZ port job we give it a rough polish. Why? Your fuel injectors work in milliseconds. Ever wonder in 8 milliseconds how many degrees your crankshaft has turned if it is operating at 9000rpm? Your crankshaft has turned approx. 450deg. That means your injector has to start firing fuel way before the intake valve has even opened. Most of the fuel does vaporize as it hits the back of the valve but the rest of the fuel that doesnt vaporize ends up on the walls, short sides and around the valve area until the valve finally opens and draws in the air fuel mixture. Keeping the walls rough in theory helps break up the fuel particles before it enters the combustion chamber. Atomized fuel burn better resulting in more horsepower and better fuel economy.


PORTING
Porting reshapes or enlarges by cutting, grinding, machining or in some cases adding material.


SHORT SIDE OR TURN
This refers to the shorter, tighter side of a turn in a port.


TOP CUT
The valve seat angle nearest the combustion chamber.



UNSHROUD THE VALVES
Removal of chamber material closest to the valve from the valve seat to the head surface. This is one
area that if you get correct, you will see major horsepower increases.


VALVE GUIDES
A thick sleeve usually cast iron or bronze which helps guide the up and down motion of the valve. Guides are very important because if worn out they can cause valve instability and consume oil by letting it seep in to the combustion chamber. Running some hot cams? Loose guides will also cause problems during the overlap period when the intake and exhaust valves are closest to each other causing the probability of valve to valve contact.


VALVE SEALS
A valve seal is a seal, which helps oil not seep into the combustion chamber. It is positioned on top of the valve guide.



ALANIZ CYL HEAD TECH 2007
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: porting can help

Postby grumpyvette » February 10th, 2010, 8:50 am

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: porting can help

Postby ChevyInf » February 12th, 2010, 9:39 am

in the picture of your die grinder and porting bits, it looks like you're using a single cut bur. supposedly a double cut bur makes a nicer cut... from the pictures i don't see how much cleaner the cut could be.. but single cut and double cut burs are about the same price. anyways, is the double cut bur really better than a single cut? and what are the drawbacks of using a double cut? if there are any.
btw the heads look awesome
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Re: porting can help

Postby grumpyvette » February 12th, 2010, 11:09 am

ChevyInf wrote:in the picture of your die grinder and porting bits, it looks like you're using a single cut bur. supposedly a double cut bur makes a nicer cut... from the pictures i don't see how much cleaner the cut could be.. but single cut and double cut burs are about the same price. anyways, is the double cut bur really better than a single cut? and what are the drawbacks of using a double cut? if there are any.
btw the heads look awesome



IVE used BOTH designs and your correct that some burrs cut better than others,all burrs will have a rotational speed they work best at and all burrs work best if cooled during use with cutting fluid or at least occasional & rather frequent stops for dipping in cutting oil, the problem IVE found is that you can,t always find or buy the quality or design of burr you want to.

BTW I use the HF die grinder and pitch them in the dumpster when they eventually fail as they are expendable and dirt cheap but work surprisingly well for a couple jobs before wearing out, more that paying for their cost with the work performed, surprisingly a really good deal actually from HF, just be sure to get the EXTENDED design not the standard design

http://www.harborfreight.com/cpi/ctaf/d ... mber=99698
Image

this model die grinder is surprisingly good quality for a disposable throw away die grinder,and usually last for more than two-sometimes up to 8-9 cylinder heads, its a true bargain, if it lasts only for two! don,t even think about use of the hard stone grinding bits they shatter and are cheap crap, get real carbide burrs, not the cheap crap hf sells for burrs


http://www.summitracing.com/parts/SUM-900640/
Image
BTW the port finish is the result of flapper wheels (sandpaper strips on bits) not burrs
USE A DECENT AIR POWERED DIE GRINDER , and a compressor thats up to the job, electric die grinders or dremel tools are heavy, easily over heated, hot and generally don,t work well, compared to a decent compressor and air die grinder

http://www.summitracing.com/parts/SUM-G1060/

Image

having a decent source of 100 psi ,dry compressed air feeding your air tools is a wonderful thing in a shop, fighting a air tool matched to a compressor that can,t supply enough air is a P.i.t.a.

viewtopic.php?f=27&t=24&p=5002&hilit=+compressor#p5002
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: porting can help

Postby ChevyInf » February 12th, 2010, 8:05 pm

i can't really afford an air compressor setup that will support the use of a die grinder for porting.
i mean air die grinders use like 3-5 cfm they say, but if im running it for minutes straight.. it will be using 12 - 20 cfm or something like that... an air compressor that can handle that is usually pretty expensive. or.. what would be the minimum requirements of a compressor to run a die grinder continuously? i've been looking at a rotary tool from eastwood that comes with a 1/4" collet and has a 1/3 hp motor.. i have a bench grinder with a 1/3hp motor that is about 10 years old and runs like a champ. right now i'm just using a drill, but it's been around 20 degrees outside here so it keeps the drill from overheating. once spring hits though, it won't be cold enough for the drill so i'll have to get the rotary tool or save some money up to go the air route. not to mention, the drill really doesn't spin fast enough.
here is the rotary tool:
http://www.amazon.com/Hanging-Flex-Shaf ... 038&sr=1-1
let me know what you think

also, i've thought about getting that summit 3 bur kit but i've also been looking at these burs:
http://store.b2bprofessionaltools.com/3 ... 6-jpg.html
http://store.b2bprofessionaltools.com/3 ... 6-jpg.html

i think this one would be good for blending the narrow part between the valveguide and port wall
http://store.b2bprofessionaltools.com/3 ... 2-jpg.html
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Re: porting can help

Postby grumpyvette » February 12th, 2010, 8:17 pm

I used an electric porting set-up very similar to that, with the flex feed for my first few set of heads, and while its slow, it will do the job, if your persistent and don,t bear down on the cutter to hard. remember the objects to reduce the restriction to flow and smooth out the port some, smooth ridges left by the valve seat machine work,and transition, in direction of flow points, such as the areas under the valve heads and seats but not to remove significant metal in the port walls roof,floor or alter the port significantly in shape or volume.

http://www.gofastnews.com/board/technic ... tions.html

http://www.gofastnews.com/board/technic ... rting.html

http://www.gofastnews.com/board/technic ... l#post5343

IT looked very similar to this eastwood tool below

but I picked it up from northern tool, 20 plus years ago, it was barely useable but it did allow me to get a couple heads ported before its motor quite working

http://www.eastwood.com/kit-with-2-hand ... llets.html

BTW thanks for posting these links

http://store.b2bprofessionaltools.com/3 ... 6-jpg.html

http://store.b2bprofessionaltools.com/3 ... 6-jpg.html

be careful when buying BURRS many are rated for NON-FERROUS METALS ONLY, and ALL burrs require frequent cooling and coolant flow to prevent clogging the cutting flutes, or quickly dulling

btw
http://www.harborfreight.com/cpi/ctaf/d ... mber=44141
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: porting can help

Postby ChevyInf » February 12th, 2010, 8:21 pm

no problem, heh i was posting them to see if you approved of them and i guess you do
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