Hi,
My L48 just died, I got the car in 2018 with engine in fair condition.
Plan was to use it in vintage car racing cup in Poland, so most of my attention was to the suspension, brakes, steering, safety related mods.
It terms of performance I have changed rear end to 3,73 and adopted, 6sp overdrive tranny from 350z to make it more fun to drive on few miles long race tracks.
Cam, intake, side pipes, double hump heads provided some improvement but that definitely was not enough.

I was pushing this engine to its limits for 4 years and must admit it was very reliable but was lacking performance to be competitive with other European cars with much smaller engines. I was able to improve handling to the point it is very predictable and fun to drive,
Have not looked into engine yet but failure was catastrophic as I see some dents on the oil pan. I am out of the competition this season and started educating myself on which way to go.

Now, I need Corvette Community to help me out in building strong but budget oriented 383 stroker and kick some a.. during next season.
If there is anyone experienced in this topic willing to spend some of his/her time to help me out I would be grateful for help and suggestions in selection of the kit/parts etc...

It is going to be my 1st engine build however I am quite experienced with the car making all the mods so far on my own.
Thanks
Greg

 

Well Greg, there are so many ways to build a SBC engine I'm hesitant to express anything.
Perhaps we can start with the basics.
What do YOU have in mind?
Rebuild the block you have?
New or good used 4 bolt main block?
What is the starting point here?
What actually is the budget here?
The expected results?

 

right, some starting point items:what I think I need:
- plan to rebuild my 2 bolt block
- priority would be low end torque over high rpm due to the profile of most of the tracks I visit
- budget sensitive but open to invest in robustness considering what the car is used for
- plan to replace rotating assembly, rods, pistons, all bearing, oil pump
- change flat tappet to hydraulic roller cam
- install aluminum heads for better heat dissipation

I do not have any specific torque/power numbers in my head as sometimes too much power is not good on curvy track...and fixing fiberglass body takes me a lot of time

 

On a budget, I would probably go with

scat 9k crank
summit forged 4340 pistons
scat I beam rods, 7/16
Arp main studs
AFR enforcer heads, or Brodix IK200 heads

flat deck the block, use flat top pistons, 64 cc chamber heads, ~230 duration cam with a.550 lift. That will get you 425+ hp

 

Are you required to run a Gen 1 SBC due to class restrictions?

If not, can you source an LS engine where you are? (Gen III or IV)

 

Not sure what the machine shop costs. But with a 2-block main, you may not have a forged crank, pistons and connecting rods. If you do all that, plus a new black and cam shaft, a crate motor may be similar cost to a total rebuilt. A short block will be MUCH easier to install.

I have a mild motor with around 450 HP. I tracked the car last year and a ZR1 Camaro and performance Porsche just blew me away on how fast they were. Of course, their cars have help (Traction control, anti lock brakes) that your car will not.

BTW: I agree. I ran the car on a tight track at Pocono. It wasn’t nearly as much fun as a track with longer straights. Bridgehampton (long closed) was a dream track.

 

2 bolt main block. Nothing at all wrong with them. But, I'd probably keep it down around 400ish HP or do the splayed 4 bolt conversion.
Just about any Alloy head is going to flow better than the stock junk.
Still kinda got to wonder if a crate long block wouldn't be cheaper and stronger. But in your location I can only guess on costs. I know in my location, much cheaper to build what I have. The guys in the states sometimes don't have that perspective.

 

I'm thinking before anyone can really give you truly sound advice. You need to get your existing engine stripped down. Checked thoroughly for any and all issues. Then make the decision if the original block is indeed the way to go.

 

You might also want to mention availability of parts and resources. Being in Poland you might have limited availability.

 

Thanks all,
I am in Poland, cost of shipping/customs/tax of entire crate engine is over my budget. I visit US on business 2-3times/yr, my suitcases are always full of parts on a way back
I plan to use my block it it ends up being piece of junk will source other one locally and machine it here, there are already reputable shops who know what they do.
My car is the national registry of classic automobiles, I cannot drop LS or any other parts that will be very visually different from the original small block.
400-450hp will be enough, I keep it being a hobby not a widow maker.
Also lowest octane fuel here is 95, we also have 98 and 100 (all are expensive )


C3 racing in Poland by Greg_Gd | (corvetteforum.com)

 

Skip White performance puts together some really nice aluminum inexpensive heads that make great power. Here is my 383 with his heads and cam. This thing pulls like a freight train out of a slow turn maybe to hard


I know the date is wrong

 

these are the same heads as AFR sells as the enforcers... if fact I think they have transitioned to just carrying the AFR enfocers under afrs branding and machine work now..

I would but a cast rotating assy with hyper flat top pistons and 64cc chambered heads if I were the OP based upon what his wants and needs are. much better than whats been in the car for the last 50 years.

 

383 ci is attained with a 3.750 stroker crank and a 4.030 inch bore. I built one for my racing. I figured out right away that I had wasted my money because for the same cost you could buy a forged 3.875 stroke crank, 6 inch rod, forged piston rotating assembly. Making about 396 ci. With everything the same like the cam, intake, and heads the HP is the same, but at a lower rpm and TQ is a function of cubic inches. They just kick 383's butt!

With enough cam your motor with 11.2 C/R using flat top pistons and 64 cc aluminum heads it would run fine on your local 95 octane.

I originally had a TH350 and went to a racing 700R4 OD auto tranny. It had no kick down function and I could manually shift it up and down. My Vette as power went up had a traction problem and I had to install a 5 speed.

The higher flowing in CFM of the head intake ports the higher the potential HP and the ability to use less duration and still get big HP. I ended up using AFR 210 heads on both my 383 and 396. I went to solid roller engines a long time ago so I didn't have the RPM limitations of H-rollers and the destructive problems of valve float.

Performance is all about power to weight ratio. So if you can put your car on a diet and get down to 1500 Kg with you in the car and have 500 hp You will just beat up on any smaller lighter car with say sub 400 hp. If you gave a traction problem you are not using big enough tires!

 

I like the idea of 396ci. Any kit number you would help me to determine? I assume I would need internally balanced kit that would work with my tweaked flywheel for 6sp Nissan transmission.

 

You should look up 3.875 x 4.030 bore forged stroker kits. With flat top pistons you end up with 11:1 compression with 64 cc heads. I have a solid roller, but h roller cam would work with a 236/242 cam like the comp Cams extreme series using pump gas. Yes I only do internally balanced engines


396 kit. Just ensure that you get the balanced assembly.

https://www.usaperform.com/rotating-...op-11-1-1.html

 

There are other things about stroker. you have to grind clearances for the rod bolts on the front 4 cylinders. You also need main cap studs. I bought a stroker clearanced road racing oil pan

 

I threw in an extra crank on the right for grinding the lower part of the block because metal flakes go everywhere. Then I installed the studs on the left picture for final assembly.

Two bolt blocks with main studs and maybe better caps or even stock caps have been able to run up to the 500+ HP range.

 

396 looks to be over my budget. I will likely stay with 383.
Here are some parts I am considering to purchase based on what I learned, PNs and vendors will likely change once I collect feedback from more experienced peers:

Heads:
IN STOCK Pair of AFR 1001 SBC 195cc Aluminum Cylinder Heads Chevy Straight 64cc | eBay
Small Block Chevy Aluminum Cylinder Head Assembly - 200cc, 355-T6, .600 lift hyd roller | USA Performance Parts
SBC CHEVY 350 383 406 NKB-200cc ALUMINUM HEADS 64cc STRAIGHT PLUG NKB-274 | eBay

Rotating assembly:
SCAT Engine Components 1-40605BI Scat Engine Rotating Assemblies | Summit Racing

Oil pump:
More Information for MELLING 10551ST (rockauto.com)

No idea for now about:
- cam
- hydraulic lifters
- rockers
- pushrods
- head gaskets

I am going to reuse, HEI distributor, Edelbrock Performer intake and QJet carb.

Appreciate if you point me into right set up or vendors being able to offer a kit at reasonable price.

 

You still have to do block clearancing with 3.750 and studded main caps.

You can't use an edelbrock performer intake on 195cc intake heads. The port size are different sizes. That is why I had to go to a different carburetor and single plane intake manifolds.

Going to roller timing chain, roller lifters, cam, and roller rockers is another $2000