Hey folks...

Block is at the machine shop, now I just need to finalize on the parts with my builder so he can get to work.

Does anyone know where I can get a configurator to test this combo out? I want to make sure expectations are being meet. I am looking for at least 475/500 HP/TQ


Eagle forged 4340 crank
Stroke - 3.75

Eagle forged H beam rods
Rod - 6.0”

SRP forged Flat Top pistons
10.3 Compression Ratio (w/70cc heads)
(-5cc)
419 grams each
JE Pro Seal rings
Clevite 77 bearing set

Extreme Energy Hydraulic Roller Cam #XR294HR
Duration @.050 - IN. 242 EX. 248
Valve lift W/ 1.5 rockers - IN. .540 EX. .562
Lobe sep. angle 110 deg

Edelbrock Performer RPM heads #350-607119
Angle plug,
Chamber size - 70c
Intake Port Size -170cc
Valve Sizes (in/ex) - 2.02"/1.60"
.575” max lift

Comp Pro Magnum Rockers #1301-16
Ratio – 1.52
Rocker stud – 3/8”

 

I like everything but your cylinder heads. The intake at only 170 is very small for a 383. You want at least 190 or better. I have a set of AFR 190 heads on mine and I am just at 480 to 500 HP/TQ. My limiting factor on my setup is the cylinder heads and the 190s flow pretty good numbers. I would like to go to the new 195 Eliminaters from AFR or even bigger. The 170 cc head is going to run out of air at about 5000 rpm if that. A set of Victor heads if you want to stay with Edelbrock should work good. The rest of the combo I like.

 

Send a PM to billla... he has a thread going with dynosim results in this forum...
http://forums.corvetteforum.com/show...highlight=dyno

Looking at your build specs... you should get close to your target.
You will definitely need the rpm to achieve that elusive 500hp mark though, and you have the bottom end to do that.

I do think you will need a single plane manifold to get the air in at higher rpm. But that will mean a slight drop off in torque at lower rpm.

My buildup came out at 460hp at 5500, and 490 lb-ft at 4000 using Desktop Dyno.
On the first dyno runs I managed 310 rear wheel horses at 5500 and ~ 370 lb-ft at 3750. That's in full street trim: belt driven fan, A/C, Alt and water pump and full exhaust with reverse flow mufflers and with tuning issues with Edelbrock carb.

I've ditched the Edelbrock and fitted a Holley Street HP (double pumper) and it is running harder. I'm still chasing a few more horses at top end with further tuning, and need to get it back on dyno to get actual numbers. I expect to get around 350 at the wheels.

500 hp in a 383 is achievable with the right parts.
See if Billla can run the numbers for you.


cheers
tom

 

and wanted to make sure that I was not the only one thinking that.

How else can I get to 10.3 compression, but below 11.0 as I want to run on 93 pump gas?

 

Hey Tom!!

I do not have the flow numbers for the heads so It will not be accurate. I prefer to get a consensus going on the 170cc being to small if posssible.

As you can see I am running into compression ratio issues

 

My AFR heads are a 68cc head so your compression would be slightly higher. You have a longer duration cam so it will bleed off some of the compression. You should not have any problems with 93 octane gas. I run no additive to mine and the closest I figure I am at 10.6 to 1 compression. My setup is in my signature along with my chassis dyno numbers.

A 170cc head will only feed a mild cammed 350.

 

500HP with correct heads, 400HP if you are lucky with the 350ci low compression ratio heads you have. You have a mismatch here, little heads big cam, you will see the results. I ran 200cc heads on a 350ci and it ran good, real good

 

So those are not the right head then!

Any idea what top get?

Under 11.0.0 compression a must (Pump gas friendly)


gordonm,
Do they not make the 190cc head anymore? At 68cc's it should be 10.8 or something close right?

Thanks in advance.

 

Definitly not the right head.

No they do not make the 190 anymore. It was replaced by the 195 now replaced by the Eliminator 195. The Eliminator 195 flows real well and would be a good head for you. I would like to run the Eliminator 195 on mine but the budget just is not allowing this at the moment. I'd have to sell the 190s and then get the 195s.

 

I do like those, but can't use them becasue at 64cc the compression ratio is 11.1.....to high for me to be comfortable running on pump gas.

 

Use a little thicker head gasket to increase the cc's a little?

Dave

 

OK.. I have heard of that, but 3 questions arise.
1) Is this 100% safe to do assuming the best head gaskets are being used?
2) Also, I want to run a 200 NOS shot later down the road, NP with this?
3) is there some type of equation to know how thick of a gasket to get asumming I want 10.2 to 10.5?

 

Have you bought the piston yet ? These are the heads you want if you want to make 500HP

They come in 64cc or 75cc

http://www.airflowresearch.com/195sbc_sh.php

Personally I would stay with those pistons and get the 64cc heads, you will be alright, don't run a vacuum advance, now everything will match including the cam. Lose the engine builder if he says different

If you do this, you will go from a lame duck motor to a tire shreading beast, who picked those parts anyway ?

 

You should not have any problems with this setup on pump gas.

 

No, I have not bought them yet. We have to come to an agreement about all the parts as a system before they are purchased.
I do really like those heads, but I am worried about the commpresssion and pump gas.

The guy building my engine along with me is a pretty serious racer and builds them for the guys at the local track all the time. His current setup gets him at 5.38 in the 1/8 on motor alone. He is also a friend and doesn't realy charge me, but I will throw him $400 for his time and effort.

I am pretty sure he will say forget the heads once he hears of the 170cc, but he will also be concerned with the compression as I prefer to be closer to 10.5.

Will a gasket get me there?

 

TQ is a direct result of ci. I don't waste money building 383's when for the same money you can build 3.875 stroker and get 396 ci

This forum probably has 5-6 396 builders and even a few 4 inch stroker 408's

The smallest heads I used on my 383 were AFR 210. The biggest is Dart 227cc Both in 64 cc with JE flat tops and thin head gaskets to make @ .040 quench

Your cam is too big for only 383

 

Thanks I will have to discuss this thought (396) with my guy

I am surprised that you really think that cam is to big for a 383

Actually I wanted to go slightly larger, but my builder is trying to talk me out of it.

It is not big cam...good size I think.

 

The reason that it is to big is:

You are rpm limited by going with a H-roller. So just when that cam gets going you are at valve float. Even going with a solid roller like I use the little 383 would be too high of rpm biased. I use less duration and spin 7500 rpm most ever day i drove it.

 

Yes the 180cc intake runner is to small. AFR 195's or Brodix 200's are more like what you need for reliable 450HP build. I doubt 500Hp The ulta skinny Felpro 1094 Head gasket should get the compression up a little more and May improve the quench Number.

 

My 383 build I went with AFR 195 and milled them to 70 CC with flat top pistons, zero deck and Felpro .039 gaskets. Comp cams XE 288 HR. 10.4 comp 8.3 DCR. over 500 HP and 495 Torque on desktop dyno.