383 combo in Enginepro

[racear2865]

Have built 10 of these in last 3 months. Each one ,we methodically learned how to raise the far slightly each time. We spent time on the dyno , especially the last 4. Have use carburetors and fuel injection. And Im not sure I would be satisfied with 450/475 at that RPM.
reed

[427dart]

IMO a bit big on duration for strong torque down low. Think 230's and an RPM Air Gap intake manifold !

Thought I mentioned this....but then I know nothing.

[Raybo]

IMO a bit big on duration for strong torque down low. Think 230's and an RPM Air Gap intake manifold !

Thought I mentioned this....but then I know nothing.

You did and I saw it. I appreciate the input.

[Raybo]

Have built 10 of these in last 3 months. Each one ,we methodically learned how to raise the far slightly each time. We spent time on the dyno , especially the last 4. Have use carburetors and fuel injection. And Im not sure I would be satisfied with 450/475 at that RPM.
reed

Are those combos streetable

[travis]

I had a very similar combo in a 3400 pound Nova...388, 10.3-1, ported 200cc pro-topline heads, 250@.050 solid flat tappet, 3.73’s, etc. With a weiand 7530 and a 4400 flash stall converter it was a riot to drive on street tires, but miserable for anything other than ripping around town. With a 3400 converter and a 300-36 dual plane, it had much better street manners but was still nothing I would want in a heavy truck with a tight converter and relatively tall gears. It was pretty soggy under 2500 rpms, but revved like a chainsaw above that...especially with the single plane and looser converter

[Frankshaft]

Build up an LS series engine and call it done!

Why don't you build one?

[427dart]

Build up an LS series engine and call it done!

Why don't you build one?

Really no need as I have no GM vehicle to put one in....Ford guy. BUT the LS is a very good platform to build on when starting from scratch.

[Orr89rocz]

fairly large cam and small head runner is likely where your program is coming up with lowish torque numbers. 195-200cc head and ballpark 235degr cam will likely show you better numbers, and be a bit more pleasant to drive.

I was just about to comment pull 10-12 degrees out of the cam and that 200 cc head will make what you are looking for

X2 no need to go over 230 deg at .050 with agood lobe. A 195-200 head and decent intake will make power to 6300-6500 rpm with a proper 230 deg lobe. Let the induction do the work. 248 deg would be very wild and sluggish down low imo.

[Frankshaft]

Build up an LS series engine and call it done!

Why don't you build one?

Really no need as I have no GM vehicle to put one in....Ford guy. BUT the LS is a very good platform to build on when starting from scratch.

What do you mean? More fox body mustangs have ls engines than Ford engines. Heck, sbc and bbc's too. Lol. Seriously, in my area, I know of about 15-20 of them, and MAYBE 5 have Ford engines.

[racear2865]

Have built 10 of these in last 3 months. Each one ,we methodically learned how to raise the far slightly each time. We spent time on the dyno , especially the last 4. Have use carburetors and fuel injection. And Im not sure I would be satisfied with 450/475 at that RPM.
reed

Are those combos streetable

All are on the street
reed

[Orr89rocz]

https://youtu.be/bnon8fMoji8

11:1 383 AFR 195 eliminators
Custom 230/245 hydraulic roller .603/.613 109 lsa
Weiand Holley stealth ram efi intake lightly ported
1 3/4 long tubes. 700r4 trans 3600 stall
Heat soaked 10th pull, 392@6250 hp, 371@4100 tq
I drove this almost daily for the summer/fall
Efi helps tho

[randy331]

I’m building a 383 for Chevy truck. I put everything in enginepro and it doesn’t spit out the numbers I expected. I’ve seen several combos discussed here that show better numbers and a lower rpm peak torque number.

.040” 3.75 with 6” rods, intake flow of 260 cfm
248 duration @ .050 HR. cam specs it ask for are limited.
Single plane intake
10.8 CR
770 CFM carb
Shows 421 ft-lbs @ 4700

I need this thing to be streetable and make torque at low rpm with a good torque curve

Any help or advise will be greatly appreciated.

I have Engine Pro and Engine pro probably isn't real accurate on an engine like your building. I don't think Patrick Hale had much data on engines like yours. I have the Engine Pro book too and reading it you can see how it could be off on an engine like your building.
Engine Pro has missed it on several I've done similar to your build.
If you add CFM in EP it always shows more power and that isn't always the case.


I agree with those saying a little bigger head and smaller cam.

Randy

[F-BIRD'88]

To maximize street torque change the single plane manifold to a dual plane hirise with a full split plenum.
(You can optimize that later with carb spacer.
Advance the 248 cam (wich is too big) by 7 to 10 deg from straight up (degree it don't guess) 100-103 installed in c/l.
The dual plane manifold can be a dual quad, to good effect.
It will have vastly better low end and street manors.
A different cam will taje it even further.

[cjperformance]

How many of the parts and what do you already have ?
What tyre size?

[67RS502]

I believe my 383 is very similar to what youre wanting.
stock roller block
10.8:1
Scat cast rotating assm.
Trickflow 215R heads - home ported.
224/224 hr on 114lsa cam
RPM intake
950 carb
1 3/4" headers.
490hp@6200
495tq@4500

This was more of a sleeper setup (no cam), but its been in a few cars running low 11s to high 10s.
Idle is almost smooth, sounds like a work truck, very drivable, used it as a daily driver/cruise for a while.

Now the heads are on the large side, a 200cc would be a better choice for a heavy truck, but otherwise this would be a good combo for you.
I'd keep the cam around 230s max.
Hope that helps.