Rocksiroc

Im planning on building a 383 and I want to know if the parts i have selected work well together. The car is going to be a weekend warrior so im looking for around 500 hp, I also want a nice lopey idle. This is the list of parts i was leaning towards.

Gm performance parts 383 block, 4bolt mains, 1 piece rear main seal
Enginekits.com powerhouse 383ci forged stroker kit compression for flat head pistons with 64 cc comb chamber is supposed to be 10.7:1
Dart pro 1 top end kit consisting of dart pro1 aluminum heads 215 cc and 64 cc combustion chamber and a dart single plane intake manifold.
mighty demon 750 carb
crane gold race rockers 1.5:1

The cam is where i need some advice i was thinking of running a solid roller cam i was thinking of a 12-771-8 comp cam kit, or a 12-772-8 comp cam kit. One question i have is would i have to change the springs in the dart pro 1 heads to run a solid roller or are the springs in these aftermarket heads strong enough. Also Does anyone know the part number for the right pushrods for this combo. One last question could i run this engine on pump gas or is the compression too high. Any suggestions and advice are greatly appreciated, this is also going to be my first engine build so any advice will be a great help.

86camaro383

iTrader: (3)

Just get a pushrod lengh checker. Your probally going to need .100 longer then stock. I just build a 500 HP 383, so if you have any ? just ask.

88Convertible

iTrader: (8)

Your building my motor.

Just got done with mine also, u have a nice set up there.

I had a 350 block 1 piece rear main seal, went with the Eagle 383 forged kit with flat top pistons also.
Dart pro 200 cc with 64cc combustion made 10.5.1(race ported)
Also have the gold race 1.5 rollor rockers.
Comp cam kit 12-423-8 (nice lope to it, but not over done)

I went with the super ram,(unported for now).

I made mid 400hp and upper 400 torque.
So you should be right around your goal with that set up.

Rocksiroc

Thanks for the replys

Did u guys get ur cam ground on a small base circle, do u need to to have adequate clearence. Also are the valve springs in the pro1 heads strong enough to use the solid roller cams i mentioned. I heard that in order to run solid roller lifters on the street u need to buy the endurex lifters that have an oil groove cut into them, is this true. If it is im gonna have to give comp cams a call and see if i can substitute them into a cam package for extra money. As i said before this car is a weekend warrior so im thinking of pretty much the same set up as u guys a th350 with a 3000 stall convertor with either 3.73 or 4.11 gears.

Rocksiroc

Can anyone answer these questions

Rocksiroc

Im gonna use the Gm performance parts 383 block and my question is, is this a roller block. Im pretty sure it is but the only reason im questioning it is because in the description it says lifter valley desgined for hydraulic and flat tappet camshafts. it doesn't say roller if anyone can answer my question it would be appreciated.

85C4

iTrader: (1)

Running a smaller base circle cam will give you more room between you cam lobes and your connecting rod ends. Depnds on how small of a base circle you run will determine what lifters you need.

Solid roller lifters come in the same specs as flat hydrolics. If its a standard GM block, you can use an off the shelf set of roller lifters, no problem.

B Rhodes

from your description of what GM calls it it sounds like a 2 piece rear seal non roller cam block. I looked in my GMPP catalog and didnt see a 383 short block (but its old) You could always use retrofit roller lifters but they are more expensive. But the price of a non roller 383 short block vs 383 newer roller block (more expensive)with 1 piece seal may make up the difference

fireturd350

iTrader: (8)

I'm running the 12-771-8 XR280R camshaft in my 383. It's 10.1:1 with AFR 210cc Race Ready heads. Very noticeable lope in it. I don't have the carb tuned properly right now since I've only done break-in and still putting a few heat cycles on it.

I've spoke to CompCams much about what you're asking. They highly recommended the 977 springs listed in the catalog. Mine were 220 lbs closed and close to 400 lbs open. They told me that way to much pressure and I would grind most of the lobes on start-up, but it's still running fine. ;-)

I also asked them about the oiling. They said solid rollers on the street don't get as much oil on the camshaft and to the topend, since the lifter don't pump up like a hydra. So make sure you use a good set of roller rockers. The solution we came up with was if I was going to be idling for several minutes I would need to rev the motor up to 2500 to 3000 rpms a few times to splash oil around again.

The endure-x lifters do have extra groove for oil, but if I remember right they're .300 taller bodies.

Another possible option would be to pay the $160 or whatever for the CompCams lifter bore scoring tool. It allows you to cut oil lines into the actual block instead of on the lifters like the endure-x. Summit carries it.

I used a pre 80s truck 4-bolt and retrofitted the rollers into it. Only thing you really need to look out for is a nice camshaft button and timing cover to prevent camshaft walking.

As for the base circles. I used speedomotive imported rods that had ARP cap screws for stroker clearance. That allowed me to only have to clearance the throw on the oil rails of the block. There was plenty of room for the camshaft.

I can't remember which pushrods I bought but I remember the OEM length rolled right off the tips with 1.6 rockers. I'm sure if I dug around I could find the box somewhere.
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Also I did end up buying a vacuum canister I didn't even feel like trying it with just the booster.

I'm also using a stock volume but high pressure oil pump.

CompCams said lash can be ran much less if I used stud girdles. So I bought them too. I also purchased the rev-kit just for peace of mind if something breaks or comes loose the lifter won't come out of the bore and starve everything else of oil.

five7kid

iTrader: (14)

From GM Performance Parts - Engine Parts :

12498332 Engine Parital 383ci
What a great starting point to build your own hot rod 383 engine. The only major items you will need to complete your engine are cam, lifters, cylinder heads, and manifold.

This 383 ci partial engine is used on all 383 crate engines.

So, same shortblock as - http://www.gmgoodwrench.com/perfpart...f/12497317.pdf Roller cam, 1-piece rear main seal, 4.000" bore by 3.80" stroke.

85SILVERBULLET

this sounds a lot like my combo and i would highly recomend a solid roller. dont make the mystake that i did by buying a solid mechanical cam.i bought the solid and i had issues with it going flat(4 lbes to be exact) and that is where i am at now. I spoke with comp and they recomended the cl 12-771-8 solid roller 242-248@50 610-616 lift (w/1.6 rockers) 110 lobe sep 106 center. they say it good from 2500-6700. i really think that is a hell of a power band. I also have the dart pro 1 215 heads and they sure are nice. Everybody that i have spoken with says that this should easy be a 500 hp combo.

five7kid

iTrader: (14)

By that I assume you mean solid flat-tappet (or mechanical flat-tappet - same thing).

Rocksiroc

Thanks for answering my questions
I think im gonna go with the 12-771-8 cam and use the lifters that come in the kit. I don't think im gonna change the springs, I think they are strong enough. Just to make sure i can use a solid roller cam in this block right.

Rocksiroc

Five7kid I also think that the 383 gm performance parts block is the same block they use in their 383ht crate motor. I know its a 1 piece seal, 4inch bore, clearenced to fit up to an 3.8in stroke crank, i think its a roller block. If its a 1 piece rear seal it has to be a roller block correct.
They have it on summit take a look and tell me what u think.

five7kid

iTrader: (14)

Well, that's what I was trying to confirm in my post above. Roller, 1-piece, clearanced, ready to be topped off.

Rocksiroc

I was just making sure thanks alot five7kid for clarifying that for me.
This motor is gonna be a beast when im done