383 Combo newly bulit up



383 Combo newly bulit up

Postby greenmile » December 2nd, 2010, 8:08 am

Hello, i am deeply impressed with the level of in depth information in this forum, tried to get some hard facts information in other forums, but "Opinions" is mostly what i am getting.

Here is my questions:

1.) What HP/Torque output would you expect from the following Combo
2.) What changes would you suggest if i am aiming at acceptable street manner and 2000-5000RPM optimum range

-383 with Probe forged pistons (Flat Top), 1973 350 block 4mains
- Scat nodular 9000 series crank, Rods 5.7''
- AFR 195 Heads with 64cc's
- Projected static CR 10.6:1 (Will run in Germany, we have 98Octane, no problem for detonation issues)
- Roller Rocker arms 1.6 Ratio
- Edelbrock AVS Thunder 650cfm carburator
- Edelbrock RPM Air gap Manifold(Will be port matched to AFR head)
- Standard HEI Distributor
- Headman-Headers 1 5/8, original Car Mufflers(Corvette 1973 original)
- camshaft hyrd. flat tapped Mike Jones 110 LSA, duration @ 050 224/232, lift at valve 0.528“ / 0.534“
-Manual transmission M20 with diff ratio 3.55

Would be very interested in your qualified thoughts,

Thanks :P
greenmile

 
Posts: 16
Joined: December 2nd, 2010, 7:50 am

Re: 383 Combo newly bulit up

Postby grumpyvette » December 2nd, 2010, 8:49 am

Image

this dyno should give you some idea, (417hp/434 tq) its usually reasonably close as a guide,but it shows flywheel not rear wheel hp/tq, and keep in mind that software dyno results show trends the horsepower numbers , are usually reasonably close but its not unusual for there to be a 5%-8% variation with the true flywheel hp
you can expect the rear wheel hp/tq to be reduced about 19%
that combo looks like it should meet your goals, for a decent street combo
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

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: 383 Combo newly bulit up

Postby greenmile » December 2nd, 2010, 9:08 am

grumpyvette wrote:Image

this dyno should give you some idea, (417hp/434 tq) its usually reasonably close as a guide,but it shows flywheel not rear wheel hp/tq
you can expect the rear wheel hp/tq to be reduced about 19%


Thank you very much !!, does match pretty much what i have calculated myself.

Howe´ver, would you be so kind to comment what i shall improve in your opinion if i make the following assumptions:

A.) Power Range 2000-5000RPM
B.) Main forcus is on increasing torque , M20 Muncie with 3.55 rear axle ratio present setup(Will not change that, may go for 5gear change later)

I want this combo to fire off from low RPM, will not drive it on race tracks......any suggestions for improvements(Even if they are small) ??

Thx
greenmile

 
Posts: 16
Joined: December 2nd, 2010, 7:50 am

Re: 383 Combo newly bulit up

Postby grumpyvette » December 2nd, 2010, 9:32 am

my dyno program suggests that swapping to a moderate hydraulic roller cam like a crane 119661 would help the power curve

http://www.cranecams.com/product/cart.p ... il&p=24188

but that adds about $800 to the cost

Image

yeah I know most people won,t read all the sub links that contain a great deal of info, but youll be very surprised at all the info those sub links contain


viewtopic.php?f=44&t=38&p=46#p46

viewtopic.php?f=50&t=428

viewtopic.php?f=50&t=1249
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

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: 383 Combo newly bulit up

Postby greenmile » December 2nd, 2010, 9:50 am

Yes, i assumed that much, i did not want to spend that money, that is the reason for not going to hydraulic roller, i am aware of the potential power gain.Money rules.....i had to stop somewhere :-))))
However, what you are showing me here is a bigger gain potential than i thought i would really see in reality......

My original exhaust pipes allready have 2.5'' don't want to go to 3'' also for noise reasons, will for now also stay with original mufflers and not change to Magnaflow, will first take a look at backpressure when combo is finished, if i see from my real dynocurves that i need to do something on the exhaust side, i still can go for the magnaflows.....correct strategy ???

PS: Original casted ex.manifolds will allready be exchanged with hedman headers, i thought 1 5/8 is ok for my combo.

I still am a bit worried about my 650cfm carburetor, according to the calculations (Vizard for example) i should be fine with what the engine needs, however i see a lot of 750holleys or even bigger combos all the time....do you think my 650 is a bottleneck ???

Cam selections is what you would recommend ???
greenmile

 
Posts: 16
Joined: December 2nd, 2010, 7:50 am

Re: 383 Combo newly bulit up

Postby grumpyvette » December 2nd, 2010, 10:03 am

greenmile wrote:Yes, i assumed that much, i did not want to spend that money, that is the reason for not going to hydraulic roller, i am aware of the potential power gain.Money rules.....i had to stop somewhere :-))))
However, what you are showing me here is a bigger gain potential than i thought i would really see in reality......


we almost ALL work on limited budgets

THE DYNO GAINS THE SOFTWARE SHOWS are based on the assumption that all other factors being close to ideal, they seldom are, so gains tend to be lower ,but the trends are obvious


My original exhaust pipes allready have 2.5'' don't want to go to 3'' also for noise reasons, will for now also stay with original mufflers and not change to Magnaflow, will first take a look at backpressure when combo is finished, if i see from my real dynocurves that i need to do something on the exhaust side, i still can go for the magnaflows.....correct strategy ???

for what your doing thats a good idea,test but Id doubt 2.5" pipes will be a significant restriction in the low and mid rpms (especially if theres an (X) pipe mounted as close as clearances under the car permit to the header collectors

PS: Original casted ex.manifolds will allready be exchanged with hedman headers, i thought 1 5/8 is ok for my combo.

its probable that the AVERAGE tq will be better with the 1 5/8" headers than with larger 1 3/4" headers but the PEAK power may be a bit restricted

I still am a bit worried about my 650cfm carburetor, according to the calculations (Vizard for example) i should be fine with what the engine needs, however i see a lot of 750holleys or even bigger combos all the time....do you think my 650 is a bottleneck ???

its VERY unlikely to be!, and its easy to test with a vacuum gauge

Cam selections is what you would recommend ???


given the application and goal and budget the cam is reasonably good, I doubt youll see any significant advantage to minor changes

these links and sub links may help

viewtopic.php?f=55&t=1038

http://www.idavette.net/hib/camcon.htm

viewtopic.php?f=52&t=3802

viewtopic.php?f=55&t=2994&p=7857&hilit=+restrictive+carb#p7857

viewtopic.php?f=69&t=2378&p=6279&hilit=hemi#p6279

viewtopic.php?f=55&t=109&p=8207&hilit=+restrictive+carb#p8207

viewtopic.php?f=56&t=495&p=8333&hilit=+back+pressure#p8333
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

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: 383 Combo newly bulit up

Postby greenmile » December 2nd, 2010, 10:53 am

Yes and Yes to all your statements.....

So in the end if i summarize you would see the most bang for the buck i can do IF i still want to improve with going to hydr. roller camshaft.......

I was wondering if a injection would be a nice thing to have, but again the money.....was looking into FASTor PowerjectionIII but was told the latter is no good.......

Anyways. thanks a lot for your input, if you are interested as soon as my engine is complete and dyno tested i will post the results if there is interest.

Regards,
greenmile

 
Posts: 16
Joined: December 2nd, 2010, 7:50 am

Re: 383 Combo newly bulit up

Postby grumpyvette » December 2nd, 2010, 11:01 am

as soon as you get dyno results or just pictures of the engine assembly process and components or your car,please post them,
we are ALWAYS wanting to see the dyno results of any engine as it adds to our understanding of how things work in the real world vs theory
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

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: 383 Combo newly bulit up

Postby greenmile » December 2nd, 2010, 11:03 am

OK, will do , will be after years end.

Thx again.
greenmile

 
Posts: 16
Joined: December 2nd, 2010, 7:50 am

Re: 383 Combo newly bulit up

Postby greenmile » March 21st, 2011, 7:49 am

Hello, i have promised to show results when engine is finished and car has been dynoed.
Now i have first results, will show graph in a few days.

However, i have reached 345 HP(measured after DIN spec) at 5.500 and max torque pretty much beetween 2.000-4.500 of about 500 NM.
Dynoed NOT on Engine Dyno but on rear wheel driven Dyno(Don't now the tech name in english for this kind of set up, sorry.)
Engine is now really a different animal compared to the status before the change
Hope i recall correctly from memory, will have the sheet soon and will upload.

Basically pretty identical built motors have reached 375HP, only difference is my carb (Edelbrock 650 AVS).
That identified the potential problem....below 3.800 it is running too rich, between 4.000-5.000 it is ok, above 5.000 it is going too lean.
All potential tested jet changes etc did not help solving the issue.
The 375 HP example was reached with a quickfuel 680 SS vacuum secondary carb, i am wondering if i should use this carb, or would you have other recommendations ?? (AES or other ??).
Will not use double pumper, not enough fuel economy there....

Any thoughts would be appreciated
greenmile

 
Posts: 16
Joined: December 2nd, 2010, 7:50 am

Re: 383 Combo newly bulit up

Postby grumpyvette » March 21st, 2011, 8:21 am

rear wheel hp generally runs about 17%-20% under flywheel hp, so your 345hp is close to the range predicted, of about 420 flywheel hp
your carb may need different metering rods and jets, a 650cfm carb thats properly tuned will support the additional flow and power, and you might want to play with carb spacers, and verify the exhaust back pressure, fuel pressure and ignition timing curve, youll generally want to get the fuel air ratio, on an engine running at below 3000rpm into the 13.7-14.7:1 ratio range, than slowly and evenly transition to a slightly richer 12.7-13.3 fuel air ratio range by the time you reach 6000rpm to maximize torque, and have less than 2 psi of exhaust back pressure
take the time to read thru these links and sub linked info

viewtopic.php?f=55&t=1820&p=10167&hilit=metering+rods#p10167

viewtopic.php?f=55&t=3052&p=10979&hilit=edelbrock+carb#p10979

viewtopic.php?f=55&t=109

viewtopic.php?f=55&t=4362&p=11450&hilit=carb+spacer#p11450

viewtopic.php?f=56&t=495

viewtopic.php?f=55&t=635

viewtopic.php?f=55&t=211
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

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: 383 Combo newly bulit up

Postby greenmile » August 2nd, 2013, 7:51 am

For whatever reason, i never came around to post the dyno-graphs.
I apologize, here they are.
Maybe you can interpret anything further out of it.
The main things i still think to improve is carburetor change and magnaflow or flowmaster mufflers.
Regards,
You do not have the required permissions to view the files attached to this post.
greenmile

 
Posts: 16
Joined: December 2nd, 2010, 7:50 am

Re: 383 Combo newly bulit up

Postby grumpyvette » August 2nd, 2013, 9:52 am

Image

I wish I could see the intake manifold vacuum reading and fuel/air ratio at each 500rpm level, on that graph, plus the ignition advance curve used

" youll generally want to get the fuel air ratio, on an engine running at below 3000rpm into the 13.7-14.7:1 ratio range, than slowly and evenly transition to a slightly richer 12.7-13.3 fuel air ratio range by the time you reach 6000rpm to maximize torque, and have less than 2 psi of exhaust back pressure"
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

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: 383 Combo newly bulit up

Postby greenmile » August 5th, 2013, 4:44 am

Hy , thanks for your patience.....

All three items you are asking are not available and i forgot to ask these during the dyno(I was not present myself)
However, Car is right now again at repair shop, we currently discuss carburetor change.

I will ask for the items you are looking for if possible:

1.) Vacuum Intake
2.) Fuel ratio
3.) Iginition advance curve

Hope it will not take again 2years :-)))
greenmile

 
Posts: 16
Joined: December 2nd, 2010, 7:50 am

Re: 383 Combo newly bulit up

Postby grumpyvette » August 5th, 2013, 9:58 am

greenmile wrote:Hy , thanks for your patience.....

All three items you are asking are not available and i forgot to ask these during the dyno(I was not present myself)
However, Car is right now again at repair shop, we currently discuss carburetor change.

I will ask for the items you are looking for if possible:

1.) Vacuum Intake IDEALLY LESS THAN 2PSI vacuum READING IN PLENUM AT WIDE OPEN THROTTLE AT PEAK RPM
2.) Fuel ratio 13.7:1-14.7:1 below 3000rpm, slowly and predictably shifting to 12.7:1-13:1 AT WIDE OPEN THROTTLE
3.) Iginition advance curve , VARIES WITH COMBO BUT 6-8 DEGREES ADVANCE AT IDLE AND 34-38 DEGREES AT 3200RPM IS WHERE I TRY TO START tuning

Hope it will not take again 2years :-)))
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

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: 383 Combo newly bulit up

Postby grumpyvette » August 27th, 2013, 11:48 am

PUMP GAS 383 build with v2.50BI heads. Built by Einstein Enginebuilder, and dyno'd on his Stuska.

4.030 x 3.750
HERES A RECENT COMBO THAT WAS POSTED ELSE WARE THAT PRODUCED DECENT RESULTS
certainly not a racing engine but one that would work well in some muscle cars
010 Block
Scat cast crank- Internal Balanced
Scat I beam Rods
236/240 110LC 106CL .600/.600 HYD Roller
10.9-1 93 Octane
1.6 Scorpion Rockers
98445 Howard Springs w/TI Retainers
5/16 .080 wall pushrods
Edelbrock 2892 w/1" epoxy in the plenum
1 3/4 3.50" collector headers
Kevco Oil Pan
QFT 850 carb.

Image
Einstein Enginebuilder, "Those heads are awesome, not just fluff numbers they work, My combo just is not wild enough to see the full potential but this is something I think alot of people would like to build."
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

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Next

Return to Engine Combos and Dynometer Database

Who is online

Users browsing this forum: No registered users and 5 guests

cron