hey guys i have been posting up and down about building this motor. it seems i cant get replies about it though so i am posting here to see if i am doing this right....

i have a 350/4bolt/1 piece/ bored .030
i have speed pro flat top forged pistons with 4 valve reliefs (-6.1cc)

i was thinking about builing a 383 with a carb. What do you think of this combo?

Trick Flow 23 degree heads 195cc 72cc 2.02/1.6 angle plug
Trick Flow Cam:
246°/254° duration at .050, .558/.558 in. lift, with 1.5 ratio rockers and a 112° lobe separation
Edlebrock RPM Air Gap Intake Manifold
Holley 670 Street Avenger Carb
Mallory 3 port Regulator
Eagle Cast Crank 3.750 stroke 5.7 rod length
2800 Stall 10 Inch Torque Convertor
3.42 Posi Rear

will a 383 crank with the pistons i have and those heads create too much compression?

Is that combo going to be enough to make the power im after (mid 12s)?

if you see something i pick thats wrong point it out and help me pick something. thanks

 

That's not too much compression; actually, with that much cam, it's probably too little. Alot, too little. You'd end up down around 9.5 or 9.6:1 with a stock .025" deck clearance.

You'd come out better with the 64cc version of those heads, and that cam; and zero-deck the block to the pistons, and use a standard .039" head gasket. That combo will bring you to 11:1, which is more where it ought to be.

That's not enough carb. A 750 in that series of carb will be alot more appropriate for that engine size.

 

I can't imagine any good reason for putting a vacuum secondary carb on a performance engine.

 

Uhhh, you don't want to reuse your 350 pistons with a 3.75" stroke crank, either. That type of piston top, perhaps, but a little low on the CR, as RB said.

 

I think that cam is too big. Wont have enough vacuum to run power brakes. Although the 112 LSA will help a little with
idle vacuum, its still pretty big for a sreet driven motor, and
probably need around a 3200 stall with it too...

 

whats wrong with the pistons?

what about this cam:

230/234 .528/.539 112

And this Carb:

Street Avenger 770

Whats the difference in Mechanical and Vaccum Secondaries?

 

If they're 350 pistons, they won't fit in the block with a 3.75" stroke crank and 5.7" rods. They'll come out the top of the block about 1/8".

I made the assumption (wrongly perhaps?) that these were going to be new, 383-specific pistons. That's the only way it will work.

If they're 350 pistons, they would only work if you use the short 400 rods; but if you do that, you'll have to go with external balance. But there's no external balance parts (flywheels specifically) for 1-piece cranks, because there's no such thing as a 1-piece RMS 400. So, if you want to build a 1-piece RMS 383, you're going to pretty much have to get the right pistons for it.

The cam size looks fine to me. I've run bigger FWIW. Power brakes will definitely be a problem with it though.

 

Go to the Holley website, click on carburetors, tech data, and compare the links on vacuum and mechanical secondaries.

 

i run 246/246 .525 .525 110 and power brakes work fine.I also run alot of compression too.

 

ok so i guess i will stick with a 350. i dont want to go to the extra trouble for stroking it.

which cam should i get the first specs or the second?

which carb would be cheap but also a good performer? im not too cheap i just dont want to overpay for things i dont need.

 

I say stay with your first camshaft selection and just up the compression to match that camshaft.Also with that cam installed in a 350 i would go at least 4000 stall converter.What type of cam is the 246/254 (solid,hydraulic,roller,tappet)?????
Solid ,Solid rollers cams are the way to go.

 

im gonna go with the second cam. this is a street driven car and i cant stall at 4000.

the cams are hyd. rollers

what compression is a 350 with the pistons i have, 64cc version of those heads, the second cam, and stock 350 crank.

also i looked on holley and it is saying 650 cfm is what i need to flow and all i found out about the secondaries is springs control one and vaccum somehow controlls the other.

so here is how the setup looks after switching a few things.

350/4bolt/1 piece/ bored .030
speed pro flat top forged pistons with 4 valve reliefs (-6.1cc)

Trick Flow 23 degree heads 195cc 64cc 2.02/1.6 angle plug
Trick Flow Cam:
230/234 duration at .050, .528/.539 in. lift, with 1.5 ratio rockers and a 112° lobe separation
Edlebrock RPM Air Gap Intake Manifold
Holley Street Avenger 670
Mallory 3 port Regulator
Eagle Cast Crank
2800 Stall 10 Inch Torque Convertor
3.42 Posi Rear
SubFrame Connectors
Headers (rest of the exhaust is done already)

I want to hit mid 12s so keep that in mind when helping me select parts. also remember this car is driven on the street almost daily. also there is no emissions here anymore.

 

also i hope you guys arent being offended here. i am using the info you are giving me to reform the setup in hopes of getting a better engine out of it. i hope i dont seem stubborn or stuck up or anything. i appreciate all the help and i hope none of you are getting mad

 

anyone?

 

Well, I would say, if You really want to run deep into the 12's, do what daverr and the others suggested...if You want a nice streetable 350, the above combo will be good, and probably run high 12/13flat... IMO...

 

hey thanks for the help guys. i will take what i can get high 12s isnt bad. when i get a beater i will take your suggestion and put a bigger cam and stall in there. thanks again

 

you want this to run all motor ? or can you use the bottle? building a stout motor, that would be built to handle quite a bit of juice would probably be perfect for you since it's daily driven. Then you can just run 12's when you feel the urge to hit the giggly juice... and still keep your streetability the rest of the time.

 

i dont have anything against the juice. im afraid of it though.

that and wouldnt i need forged crank and rods? the pistons are on the rods already i got them with the block.

i would be pleased to run that set up and maybe run a small shot of nos if i need it. if i can do it safely that is.

 

im building a similar engine. mine is in fact a 383 though and the cam i picked is 230/236 .544/.555 and i will be spraying it with a 150 shot that combo you have is very nice and powerful though......if you want some power from that 350 maybe try putting a blower on it man there is one that would be perfect for you in the classifieds