pawcio

Hello everyone

My plan is to build a streetable 383 stroker engine from my L98. The goal is 500+hp at the crank. Is it possible with 6500rpm and high compression? Below are specs which I choose. Please post opinion ;-) Thanks for any help from you.

1989 L98 block bored 0.030
forged crank 3.750 stroke
6 inch forged I beam rods
forged domed pistons (+7cc)
AFR 195cc competition heads (65cc)
fel pro 1010 head gasket (0.039inch)

after my math these elements gets me about 11.8:1 compression ratio.



and the valvetrain...I don't know what to do. stay with hydraulic? or go solid..remember 6500rpm ;-)
the same situation with induction...MiniRam or single plane carburetor?


regards

VincentZ28

iTrader: (2)

I have 515 at the crank without dome Pistons. 2 valve flat top and 11:1 compression.

86LG4Bird

iTrader: (1)

Stay away from domed pistons for pump gas use. 11.8:1 CR is way too high for a Gen 1 SBC (conventional cooling) anyway. I run 12.0:1 in my LT1 but that's Gen 2 (reverse cooling).
AFR heads generally want a little more timing also; more reason to stay away from domes and high CR.
I'd shoot for 11.0:1 max. with a fairly big cam, that should five you a generous tuning window for ignition timing.
6500 rpm is not solid roller territory IMO. 7/16" studs, NSA rockers & guideplates, and stiff wall 5/16" pushrods is all you need. 500 crank hp will be a piece of cake with the Competition heads. I'm around 540 crank in my 350 CID HR motor.
I'd go Miniram rather than giving up EFI tuneability.

pawcio

OK, I decided to go with another pistons and compression 10.5:1.

what about cam? comp cams XR294 or 300? (or another cam?)

Orr89RocZ

iTrader: (20)

195's can do it. 210's is what i'd run. Having done the 195 383 thing

Cam high .500's lift. 236 deg at .050, 240-ish exhaust. 108-110 lsa. That be what i'd do.

Afr 8019 springs, possibly slightly shimmed to 165 lbs seat pressure. Let it eat

Miniram for efi can work, rather see single plane efi or can do carbed single plane

86LG4Bird

iTrader: (1)

IMO, either of those is too much for 10.5 SCR. Disregard Comp's "rpm ranges" for any single plane or miniram manifold. You'll make power much higher than what they state.
I agree with Orr on the 236-ish recommendation, which would be the XR288. It'll work better with your CR. I'd be calling up Lloyd Elliott for a custom grind. No more money than Comp's shelf grinds, and you'll pick up some extra performance.

heat seeker

iTrader: (5)

This is my second build with dome tops on pump gas, and haven't had any problems. I run 34 degrees at WOT.....no problems here.


BLOCK………………………..…..sbc 383ci
COMPRESSION……………....11.5:1
HEADS…………………….….……Jegs 210 64cc (custom ported by LE Performance)
CAMSHAFT………………….….COMP CAMS XR-294hr
PUSHRODS……………….…….COMP cams (stock length)
ROCKER ARMS………………..TPIS stainless 1.6 FULL ROLLER ROCKERS
VALVE SPRINGS.............Comp CAMS
PISTONS…………………….…..SPEED PRO - DOME TOPS
CRANKSHAFT…………….….…400 STEEL
RODS……………………….………5.7” Forged, Pro-Comp
THROTTLE BODY……….…….AS&M 1300CFM MONO-BLADE
INDUCTION……………………..3” CUSTOM maf & RAM AIR
INTAKE…………………………….HOLLEY STEALTH RAM (CUSTOM ported)
FUEL INJECTORS…….…….….42# FMS (green tops)
FUEL REGULATOR…………….BILLET, KIRBAN PERFORMACE
FUEL PUMP………………………walbro 67 gpm
IGNITION……………………..….CRANE HI-6 cd, lx-91 COIL
WATER PUMP………………….PRO-FORM ELECTRIC (55gpm)
ENGINE MANAGEMENT…..oem 165 ecm, CUSTOM TUNED
EXHAUST SYSTEM………….…1-3/4” HOOKER LT & 3” DUAL, MOROSO BULLETS
TRANSMISSION………….…….BOWTIE OVERDRIVE 700R4 LEVEL 2
TORQUE CONVERTER……....3800 Edge Racing
REAR END………..………………3:73 BORG WARNER (FULL SPOOL), TA PERFORMANCE

86LG4Bird

iTrader: (1)

Not too shabby
What happened to your first build?

heat seeker

iTrader: (5)

It was a 355....I sold the complete short block for my 383 setup. I needed more grunt.

The cylinders looked new.....guy who bought it, inspected it and paid me top dollar.

pawcio

ok guys. next modification...210CC competition AFR's than 195...

cam..Lloyd Elliot? please contact ;-)
heat seeker, are you running custom cooling? what is your highway/traffic temp?

Orr89RocZ

iTrader: (20)

I dont feel you even need the competition series. It only gives you a few more hp in a maxed all effort deal

Street series is fine imo and cheaper.

My old 11:1 383 ran great on 93 oct gas, afr eliminator 195 non competition, ported hsr intake and a 230 .600" hyd roller. Shifted 6800 rpm. Ran 11.4's at 119 in summer hot air. 3450 lbs race weight. 400 whp, which is getting close to 475-500 crank

heat seeker

iTrader: (5)

Yes, I run a custom cooling system 55gpm electric water pump, a dual core radiator, and OEM dual electric fans that I control manually. In the middle of summer heat......when I'm moving it's about 170, and sitting in traffic about 185.

I still drive it to work....runs like a champ. I couldn't be more pleased with the build.

pawcio

and the next Q

what about rockers and valvetrain geometry..I mean length of pushrods? stock pushrods from L98 are 7.200" long? Am I correct? Can I use thicker with stock length with AFR heads?

heat seeker

iTrader: (5)

Yep, you're right on the length. You should be able to use stock push rods on the AFR heads, unless they specify otherwise.