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Another 383 build

4K views 24 replies 9 participants last post by  my87Z 
#1 ·
I just joined the site after searching through all the 383 builds and info

I am building my first 383 here is a list of parts. What do you guys think, and what kind of torque and horsepower can I expect?

350 block 2 bolt main 010 casting bored 30 over
ARP main studs
Scat cast crank
Moroso 23020 windage tray
Melling M55HV oil pump ARP pump stud
7 qt deep pan with pickup
Pro Comp 5.7 bushed 383 rods (clearanced)
Probe flat top forged pistons
Moroso 25050 Lifter Valley Baffle
Edelbrock performer RPM heads 64cc straight plug
1.5 ratio aluminum roller rockers
Stud girdle
.100 chromoly push rods
gear drive (noisy)
Comp Cams hydraulic roller XR288HR-10 Lift 0.520 int./0.540 exh. Duration at 050 inch Lift 236 int./242 exh.
Edelbrock performer RPM intake
APP bolts for heads and intake

The reciprocating assembly has been balanced

As for a carb I have a Holley 0-4779c 750 double pumper, but when I talked to the Holley tech they said that it's to big and to go with a 0-4778c a 700 double pumper.
 
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#4 ·
I think those numbers are real generous. I'm not sure the Edelbrock Performer RPM heads are capable of that HP out of the box. Without knowing deck heights, valve relief volume, head gasket thickness, etc., I'm thinking you may be pushing the edge for pump gas with the 64cc chamber. JMO

I agree with Holley on the carb. Maybe even a 650 DP.
 
#6 ·
It can still be used, according to the instructions, it says to in large the holes so that the lifter will fit. Obviously it will no longer hold the lifter in if there is a push rod failure, but it still shields the bottom of the intake from hot oil.

So those numbers look off to you, what do you think I can expect out of this motor?
 
#7 ·
MUD CHILD said:
It can still be used, according to the instructions, it says to in large the holes so that the lifter will fit. Obviously it will no longer hold the lifter in if there is a push rod failure, but it still shields the bottom of the intake from hot oil.

So those numbers look off to you, what do you think I can expect out of this motor?
Purely a guess on my part..........I think 440hp would be the upper limits. You might think about a little less duration cam for that head/intake combo. JMO
 
#8 ·
I agree, the program is pretty wildly optimistic. You might get 500 hp with all your ducks in a row tuning-wise. I feel Holley is out to lunch telling you you need a smaller carb, they just want to sell you one. 50 cfm will be unnoticable, the 750 is a good choice and I personally wouldn't go smaller, especially on a dual plane intake. IMO the gear drive is a bad choice, use a good timing chain set, my opinion is the only place for a dual idler gear drive is on someone else's motor, they are too sloppy and transfer harmonics from the crank up to the valvetrain.
 
#9 ·
I appreciate all info, I will be assembling the engine in a couple of weeks so I'm looking for any input. Has anyone here ran a similar combo? Or has anyone used any of the parts I am using, if so how did the work for you?

Anyone else feel that I should stay away from the gear drive?
 
#10 ·
I think you'll find that most, if not all, the regular contributors on this board will tell you the same thing about gear drives.

If it sounds cool to you and your buddies, go for it. But you should know that the old guys will tag you as a poser who places making noise and impressing geeks as being more important than mechanical efficiency in your motor.
 
#12 ·
I will say this on the gear drives. I "thought" I would like the gear drive whine in an engine I built a couple of years ago. Well I thought wrong, I hated it so much that a month after I rebuilt the engine I pulled that POS out and put in a good chain set-up. I ended up going with a Cloyles Double roller set up......
 
#13 ·
MUD CHILD said:
Thanks for the input, I will ditch the gear drive in favor of a good timing chain. Any suggestions as to which one to use?
Here's an example of a timing set I might use on a budget rebuild for a street motor. The crank sprocket is hardened, but the cam sprocket is not....
http://www.summitracing.com/parts/CLO-9-1100/

I might use this set if I were building a more performance-oriented motor. Both sprockets are hardened and the set is hand-matched at the factory....
http://www.summitracing.com/parts/CLO-9-3100/

If I were interested in changing the cam phasing to find the sweet spot cam-crank I might use a Hex-A-Just set like this...
http://www.summitracing.com/parts/CLO-9-3100A/
and a timing cover like this to allow easy access to the adjustment....
http://www.summitracing.com/parts/CLO-9-221/
 
#14 ·
techinspector1 said:
Here's an example of a timing set I might use on a budget rebuild for a street motor. The crank sprocket is hardened, but the cam sprocket is not....
http://www.summitracing.com/parts/CLO-9-1100/

I might use this set if I were building a more performance-oriented motor. Both sprockets are hardened and the set is hand-matched at the factory....
http://www.summitracing.com/parts/CLO-9-3100/

If I were interested in changing the cam phasing to find the sweet spot cam-crank I might use a Hex-A-Just set like this...
http://www.summitracing.com/parts/CLO-9-3100A/
and a timing cover like this to allow easy access to the adjustment....
http://www.summitracing.com/parts/CLO-9-221/
Thanks for the links. I've noticed quite a few of your post while reading different threads on engine builds. You seem quite knowledgeable about engines, mind if I pick your brain for some info. What do you think of the parts that I have purchase to build my 383? bear in mind I am doing this on a budget. The engine is going into a 77 Chevy short box 4 linked on 46" tires. It will be mated to a 4 speed, and running 5:13 gears. The Engine will be running 1 5/8" long tube headers and 3" exhaust. What do you think this engine is capable of making in torque and horsepower? My goal was 500 for both.
 
#15 · (Edited)
First, let me say that I've had enough feedback from several different sources including professional engine builders who flow these heads in the real world to convince me that flow figures published by head manufacturers are pretty much bogus and are inflated in order to sell heads. Since I don't have the facilities to flow each head before I enter it into the DynoSim software, I've decided to factor published head flow by .90 in an attempt to approach reality. I'll post that caveat on each DynoSim pull that I do from now on, including this one for you.

Now, with that said, it looks like you'll need more head to reach 500/500. On a brighter note, I don't know if you chose the cam for this combo, but if you did, kudos to you. You nailed it. I couldn't find any more power with less or more cam on this DynoSim pull.

It's a shame that Edelbrock hasn't stepped up to the plate with the RPM-XT head for the small Chevy. They have it available for the 351 Ford, but not for the SBC yet. That's the head that a 383 needs.

Using 64cc heads, 6cc's in the piston crown, an 8cc gasket and zero deck, I calculated a 11.05:1 static compression ratio for your build.

THE PUBLISHED FLOW FOR THESE 60899 EDELBROCK RPM HEADS HAS BEEN FACTORED BY .90 FOR THIS DYNOSIM PULL.

RPM HP TQ
2000 145 380
2500 184 386
3000 235 411
3500 296 445
4000 355 466
4500 404 471
5000 442 464
5500 460 438
6000 448 392
Peak volumetric efficiency 99.5% @5000
Peak BMEP 185.7 @4500
1.6 rockers on both valves will only add 6 hp, so I wouldn't think it would be worth the extra stress on the valvetrain.

Just because I like doing this, I ran the numbers on the RPM-XT Ford heads and factored them by .90 as well, figuring that when Edelbrock releases the Chevy head, it will be close to the same flow as the Ford...I used the same cam as above...

RPM HP TQ
2000 144 381
2500 183 384
3000 236 414
3500 303 454
4000 369 484
4500 427 499
5000 473 497
5500 499 476
6000 506 443
6500 477 385
Peak volumetric efficiency 104.7% @5000
Peak BMEP 196.5 @4500
It's clear that your combo needs more head.
 
#18 ·
Another option would be sending them out to be ported and finished, that (depending on the guy that does it) can get you to your 500/500 goal. Or selling them and using the money to buy a 210cc-ish iron head for about the same money.

When it comes to power I have yet to see any advantage in aluminum heads- however they do machine easier and repair easier and there is a lot to be said for that.
 
#19 ·
techinspector1 said:
First, let me say that I've had enough feedback from several different sources including professional engine builders who flow these heads in the real world to convince me that flow figures published by head manufacturers are pretty much bogus and are inflated in order to sell heads. Since I don't have the facilities to flow each head before I enter it into the DynoSim software, I've decided to factor published head flow by .90 in an attempt to approach reality. I'll post that caveat on each DynoSim pull that I do from now on, including this one for you.

Now, with that said, it looks like you'll need more head to reach 500/500. On a brighter note, I don't know if you chose the cam for this combo, but if you did, kudos to you. You nailed it. I couldn't find any more power with less or more cam on this DynoSim pull.

It's a shame that Edelbrock hasn't stepped up to the plate with the RPM-XT head for the small Chevy. They have it available for the 351 Ford, but not for the SBC yet. That's the head that a 383 needs.

Using 64cc heads, 6cc's in the piston crown, an 8cc gasket and zero deck, I calculated a 11.05:1 static compression ratio for your build.

THE PUBLISHED FLOW FOR THESE 60899 EDELBROCK RPM HEADS HAS BEEN FACTORED BY .90 FOR THIS DYNOSIM PULL.

RPM HP TQ
2000 145 380
2500 184 386
3000 235 411
3500 296 445
4000 355 466
4500 404 471
5000 442 464
5500 460 438
6000 448 392
Peak volumetric efficiency 99.5% @5000
Peak BMEP 185.7 @4500
1.6 rockers on both valves will only add 6 hp, so I wouldn't think it would be worth the extra stress on the valvetrain.

Just because I like doing this, I ran the numbers on the RPM-XT Ford heads and factored them by .90 as well, figuring that when Edelbrock releases the Chevy head, it will be close to the same flow as the Ford...I used the same cam as above...

RPM HP TQ
2000 144 381
2500 183 384
3000 236 414
3500 303 454
4000 369 484
4500 427 499
5000 473 497
5500 499 476
6000 506 443
6500 477 385
Peak volumetric efficiency 104.7% @5000
Peak BMEP 196.5 @4500
It's clear that your combo needs more head.

Thank you for taking the time to run my set up on your DynoSim. I did pick all the parts for this build, I by no means claim to be an engine guru, but I have built several 355 for my stock car. So more head you say. Is it worth while getting these heads ported or is it better to go Worth a different set of heads? possibly a set of AFR 195cc Eliminator Street Cylinder Head? or?
 
#20 ·
Tell you what, I'll just post the flow figures I used in that second pull and you make up your own mind what you want to do. I would never suggest that you spend another nickel if you don't have to. It's just too shaky taking the word of a software program when $1500 is at stake.

.100 70 57
.200 131 107
.300 192 156
.400 231 177
.500 253 184
.600 263 188
.700 256 189

If you go to AFR's site and look at the dyno results they have posted, you'll see 500/500 from their 195 Street heads in a 9.5:1 383. Call them up and talk to them. Ask them under what conditions the dyno pulls were made and if you could expect to duplicate the numbers. Maybe they'll tell you the truth, maybe not.
http://www.airflowresearch.com/chevy_dyno.php
 
#21 ·
While you're at it get timing and fuel tuning for taht engine, the headers used, what kind of water pump etc. In those "little things" alone you can make up close to 100hp on a dyno... and then you put it in yoru car, tune it down just a hari in case of a tank of bad gas, use headers that fit your chasis and your "500hp" engine only has 300 at the wheels...
 
#22 ·
techinspector1 said:
Tell you what, I'll just post the flow figures I used in that second pull and you make up your own mind what you want to do. I would never suggest that you spend another nickel if you don't have to. It's just too shaky taking the word of a software program when $1500 is at stake.

.100 70 57
.200 131 107
.300 192 156
.400 231 177
.500 253 184
.600 263 188
.700 256 189

If you go to AFR's site and look at the dyno results they have posted, you'll see 500/500 from their 195 Street heads in a 9.5:1 383. Call them up and talk to them. Ask them under what conditions the dyno pulls were made and if you could expect to duplicate the numbers. Maybe they'll tell you the truth, maybe not.
http://www.airflowresearch.com/chevy_dyno.php

Once again thank you for the info. I plan on taking my heads in and getting them ported. I have talked with a couple local machine shops and with people that have dealt with them. I found a good place to deal with so I will take them in and see what they can do with them. I would really like to see those 500's
 
#24 ·
Just figured I'd update this thread with what the engine actually made on the dyno. I ended up using the edelbrock rpm heads with mild port work and a 750 ultra double pumper carb, and a timing chain instead of the gear drive. The rest of the parts are the same as the the original post.

428 HP
458 ft-lb
 
#25 ·
MUD CHILD said:
Just figured I'd update this thread with what the engine actually made on the dyno. I ended up using the edelbrock rpm heads with mild port work and a 750 ultra double pumper carb, and a timing chain instead of the gear drive. The rest of the parts are the same as the the original post.

428 HP
458 ft-lb

those are respectable numbers. i was reading your earlier post about the comp cams dyno sim and the 500+ numbers it gave you too and i too thought it was a good bit inflated. with everyone i have talked to the edelbrock heads are really not that impressive, the victor heads i have been told aren't too bad though. if you ever feel the need to up the power in the motor i would suggest taking the heads to your closed performance shop, and get them unshrouded, valves back-cut, and some minor port work. this will probably run you about 400.00-600.00 depending on how much time they spend on the heads, and make sure that what ever shop you have them done at has a flow bench this way you will acutally be able to see the improvments. but i think just his could be an increase in 25-30hp
 
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