What do you think of my Chevy 383 GenI Build?

[UltRoadWarrior9]

Hello, this is a bucket list item for me. Being a mechanic of 30yrs I've always wanted to build an engine from scratch. The Chevy 383 stroker has always appealed to me from the John Lingenfelter days and the 3rd Gen Camaro and Firebirds/Trans Ams.

This is a project that's taken almost 2 years and is nearing completion. I still need a distributor/spark box, ECM and custom torque converter. I'll be getting these before the end of year and begin tuning it myself.

Initial goal was a screamer 7000+RPM, 500HP, fuel injected Chevy small block for my 1986 IROC. So far the car has had primarily brake mods to fit 2015 Corvette 4 piston calipers and rotors all around and subframe connectors welded in but still has the stock 305 TPI 190HP engine. Rear end is from 2002 Camaro SS. TH700R4 has B&M shift kit.

But I post here about the engine setup I chose because I know alot of extremely knowledgeable people also post in here. So please don't hesitate to comment on my setup, positive or negative!

Here's most of the spec's.

Chevy Performace Cast Iron Block: 88962516, 4 bolt mains. Single piece RMS.
Forged Crank/6" Rods/Pistons: Scat Engine Rotating Assembly
Moroso Oil Pan: Deepsump with windage tray/crank scraper
AFR210 65cc Aluminum Heads: Competition porting, 10deg titanium retainers
Fel-Pro Head Gaskets: PermaTorque MLS
PAC-1934 Valve springs for AFR210: 400lbs hydraulic roller springs
Competition Products Shaft Mounted Roller Rockers for AFR210: 1.6Int/1.6Exh Ratio
Comp Cams XFI292 Hydraulic Roller Camshaft: Duration 292int/300exh Lift@1.6ratio .584/.579
Comp Cams Lifters: Short travel lifters
Manley pushrods: 7.1" .080 thickwall.
RHS Single Plane EFI Intake Manifold: Aluminum
Edelbrock 90mm Elbow: Aluminum
'7730 ECM: Modified EBL_P4 Flash ECM
Modified TPI wiring harness: MAP based, EGR, Canister delete
92mm LSx Throttle Body, with IAC & TPS from eBay.
44 lb/hr fuel injectors.
ECM Programmer: Moates APU1
OBX Racers SS 1 3/4" Longtube Headers.
Stewart Stage 2 Water pump.
March Pulleys.
AFR Short Valve Covers.
Autolite 3922 Iridium Plugs.

Block work and cylinder head work was done by Boyette's of Raleigh,NC.

There's more cool stuff, but what it boils down to is 11:1 static compression and about 9:1 dynamic. Hope to run on 93 or 94 octane gas. Possible 150 shot of nitrous is a dream, but possible with the solid bottom end and the ECM.

[RevTheory]

I'm sure everyone would do something a little differently here or there like titanium retainers but it sounds like a well thought-out build. I bet it's a blast on the street.

[UltRoadWarrior9]

Digging up pics to start this thread. This one is from April, 2019. Shows the general idea + a 1/2" phenolic spacer to 'try' to keep the heat off of the elbow.

Elbow.1plane.Injectors.Shaft_Rockers.jpg

[UltRoadWarrior9]

This is a more up to date pic, like today. Harness and headers + Y-pipe installed. Not as easy as it sounds. Never is...
This is going to be a stand where I can run and tune the engine for at least idle. Poor neighbors, I really mean no harm.

[GARY C]

Are you going to dyno it? Just curious how the 210 head works vs the more favorable 195 head in this application.

[Orr89rocz]

Having done a similar thing, i will recommend the 210 head over the 195. I used the 195 and it did well but peaked at 6300. The 210 isnt too big for a 7000 rpm 383 and that combo will want to go there

Only thing i do not like is the valvespring choice. Afr has a pac spring thats 1.27-1.29” diameter that is 150 seat 420-ish open. Shim it to 180 seat and i think it would work much better. Thatswhat i used on mine.

Cam i would order on a tighter lsa 110-111.

[SpeierRacingHeads]

Cool! Maybe I can post what I'm doing for my '86 IROC as far as engine build and we can make this the official 3rd GEN Engine thread!!

I'm keeping the factory 7165 ECM, and using a TPiS Mini Ram. Going to use a solid roller.

Big bore, short stroke 354.

[UltRoadWarrior9]

Having done a similar thing, i will recommend the 210 head over the 195. I used the 195 and it did well but peaked at 6300. The 210 isnt too big for a 7000 rpm 383 and that combo will want to go there

Only thing i do not like is the valvespring choice. Afr has a pac spring thats 1.27-1.29” diameter that is 150 seat 420-ish open. Shim it to 180 seat and i think it would work much better. Thatswhat i used on mine.

Cam i would order on a tighter lsa 110-111.

Justin, surprised to see you over here! (Not really) How's that killer twin turbo of yours?

The engine shop measured 395lb open and 165lb seat which seems real close to the advertised spec. Do you think there's danger of valve float? The PAC1934 springs are the largest diameter advertised, @1.550", to work under the shaft rockers and visually looking it is super close.

@Gary C: Definitely plan on dyno to see if I hit my goal of 500HP.
@SpeierRacingHeads: Sure man! Doesn't have to be just 'MY' build. Feel free to post here too.

[GARY C]

Having done a similar thing, i will recommend the 210 head over the 195. I used the 195 and it did well but peaked at 6300. The 210 isnt too big for a 7000 rpm 383 and that combo will want to go there

Only thing i do not like is the valvespring choice. Afr has a pac spring thats 1.27-1.29” diameter that is 150 seat 420-ish open. Shim it to 180 seat and i think it would work much better. Thatswhat i used on mine.

Cam i would order on a tighter lsa 110-111.

Justin, surprised to see you over here! (Not really) How's that killer twin turbo of yours?

The engine shop measured 395lb open and 165lb seat which seems real close to the advertised spec. Do you think there's danger of valve float? The PAC1934 springs are the largest diameter advertised, @1.550", to work under the shaft rockers and visually looking it is super close.

@Gary C: Definitely plan on dyno to see if I hit my goal of 500HP.
@SpeierRacingHeads: Sure man! Doesn't have to be just 'MY' build. Feel free to post here too.

I don't think 500 will be a problem, the guy that does my machine wrk does a 10.5:1 383 with the 195 head, a cam close to yours on a 108 lsa and a little more lift with an airgap intake that makes 530.

[hereinmissoula]

Cool engine and combo you got there!!!

I'll give my opinion


To get rpm i would not go with the comp lifters. I would use morel's . 4602's would work.

I think a dedicated cam person or even bullet could give your a better cam choice. I would proabably not favor the exhaust to try and carry rpm, i would run it straight and with more duration. Lobe seperation with fuel injection is tricky because I would want it down 108 ish.. I don't have enough experience to give sound advise here. I really think there is a better lobe choice to help you rpm.

My Whack

Comp QXI 13456 299 adv. 247@.050 .638 w 1.6 on 108 lsa straight up ?

don't neck down the exhaust. dual 3"

[Orr89rocz]

Having done a similar thing, i will recommend the 210 head over the 195. I used the 195 and it did well but peaked at 6300. The 210 isnt too big for a 7000 rpm 383 and that combo will want to go there

Only thing i do not like is the valvespring choice. Afr has a pac spring thats 1.27-1.29” diameter that is 150 seat 420-ish open. Shim it to 180 seat and i think it would work much better. Thatswhat i used on mine.

Cam i would order on a tighter lsa 110-111.

Justin, surprised to see you over here! (Not really) How's that killer twin turbo of yours?

The engine shop measured 395lb open and 165lb seat which seems real close to the advertised spec. Do you think there's danger of valve float? The PAC1934 springs are the largest diameter advertised, @1.550", to work under the shaft rockers and visually looking it is super close.

@Gary C: Definitely plan on dyno to see if I hit my goal of 500HP.
@SpeierRacingHeads: Sure man! Doesn't have to be just 'MY' build. Feel free to post here too.

165/395 might be fine. I just dont see why you’d want a heavier large diameter spring to accomplish the same thing as modern small diameter ls style springs are doing. Good thing is afr uses 8mm stems so valves are bit lighter. But xfi lobes are pretty aggressive
You have more than enough cam for 500 hp imo. Depending on vacuum requirements you could go tighter lsa. Ecm can handle it, you can tune around it

My new motor is running. All motor for now. Just to break in. Dyno tomorrow maybe. Then start rest ofthe fab

[UltRoadWarrior9]

Cool engine and combo you got there!!!

I'll give my opinion


To get rpm i would not go with the comp lifters. I would use morel's . 4602's would work.

I think a dedicated cam person or even bullet could give your a better cam choice. I would proabably not favor the exhaust to try and carry rpm, i would run it straight and with more duration. Lobe seperation with fuel injection is tricky because I would want it down 108 ish.. I don't have enough experience to give sound advise here. I really think there is a better lobe choice to help you rpm.

My Whack

Comp QXI 13456 299 adv. 247@.050 .638 w 1.6 on 108 lsa straight up ?

don't neck down the exhaust. dual 3"

Those Comp lifters no good? Morel almost double the price @$800 for a set...
I hear you on the neck down from 3" to 2.5" on the collector. :thumbs up: Not settling for 2.5".

[UltRoadWarrior9]

Having done a similar thing, i will recommend the 210 head over the 195. I used the 195 and it did well but peaked at 6300. The 210 isnt too big for a 7000 rpm 383 and that combo will want to go there

Only thing i do not like is the valvespring choice. Afr has a pac spring thats 1.27-1.29” diameter that is 150 seat 420-ish open. Shim it to 180 seat and i think it would work much better. Thatswhat i used on mine.

Cam i would order on a tighter lsa 110-111.

Justin, surprised to see you over here! (Not really) How's that killer twin turbo of yours?

The engine shop measured 395lb open and 165lb seat which seems real close to the advertised spec. Do you think there's danger of valve float? The PAC1934 springs are the largest diameter advertised, @1.550", to work under the shaft rockers and visually looking it is super close.

@Gary C: Definitely plan on dyno to see if I hit my goal of 500HP.
@SpeierRacingHeads: Sure man! Doesn't have to be just 'MY' build. Feel free to post here too.

165/395 might be fine. I just dont see why you’d want a heavier large diameter spring to accomplish the same thing as modern small diameter ls style springs are doing. Good thing is afr uses 8mm stems so valves are bit lighter. But xfi lobes are pretty aggressive
You have more than enough cam for 500 hp imo. Depending on vacuum requirements you could go tighter lsa. Ecm can handle it, you can tune around it

My new motor is running. All motor for now. Just to break in. Dyno tomorrow maybe. Then start rest ofthe fab

Fin sweet dude. Been Subscribed to your channel on YTube. Ain't easy to do what you do...
Thanks for your input! Staying with the springs.

[UltRoadWarrior9]

BTW, my logic in the larger diameter spring was longer life for the steel spring metal compared to the same rate spring with a smaller outer diameter.