1993Fast_Z

hello, i am currently building a 383 setup, need help on selecting pistons & rods...my build is going to consist of:

383 bottom end
LE2 Heads w/LE2.2 cam
LS7 Lifters
1.6 Comp Pro Mags(NSA)

if any more info is needed, just let me know..i need help making some selection on pistons and conn. rods though...

i had talked to some people and they recommended Probe Ind. Forged Pistons. I personally havent heard much about them, maybe you guys have..money is kinda tight so trying to build a budget engine..i also want this engine to be a streetable engine..you know like where i can go on a 250 mile road trip and depend on the engine..

now, should i go 5.7 in rod or 6.0 in rod?
H-beam or I-beam Rods?
Studs on the Mains?
Floating Pin or Pressed Pin pistons?
What Comp. Ratio should i run?
is it true i can run 11.5-12:1 compression and still run pump gas?..thats what im being told..

i was originally going to build a 355 but was talked into the 383...
just need some advice...thanks

'94 Bad A Z28

My car is 11.8:1 and runs great on pump, 93 octane, gas. I have I-Beams in my 383. My motor has JE Forged -5cc relief pistons, I have never personally heard of Probe Inc.

I just recently took my car on a 240+ mile trip, just to get to where we were going and race, not a single problem, car ran at ~170* the whole way, and got about 16mpg, not great but I didn't build the car for gas mileage, lol.

1993Fast_Z

thats good to hear...are those 5.7 or 6 inch rods? you wouldnt happen to know of any pistons similar to those(-5cc) that arent $750?

ENRKyle20

I did a budget build using prety much the same specs you have there. You can run 11 or 12:1 compression with these motors on pump gas. I have 11.9:1 and I do just fine.

I use SPEEDPRO forged pistons. $20 each
http://www.northernautoparts.com/Pro...tModelId=15101

EAGLE 5.7" forged I-beams. $260 set
http://www.jegs.com/i/Eagle/356/SIR5700BBLW/10002/-1


you can find better prices tho, google it

1993Fast_Z

those are hypereutetic ENKRkyle...but i appreciate the help...arent you the one that built ur engine in your trailer? on youtube that is?

I guess the main question is, whats better 5.7in or 6 in rods? i realize that the 5.7 rod will have more angle from piston to crank, would this put more bind on the rod? would that increase chances of bending a rod?

ENRKyle20

yep they are hyper pistons. and yes I am the owner of the video on youtube. and yes I did build the engine in the kitchen of my trailer.

sorry I can not help you figure out if u want to use 5.7 or 6inch. It work work great either way as long as your pistons are made for the rod your using.

1993Fast_Z

Well, I guess I am going to go 5.7 inch since my buddy sold me a set for cheap..now, as far as crankshaft..internal or external balance..someone please explain the plus side to which ever one is better

94zgreenmachine

Compstar seems to be a decent brand, for the same money as the "all CHINA" eagle stuff.
Try this site for stuff: http://flatlanderracing.com/ They seem to have somewhat reasonable prices.

Internal balance for all hi performance engines. Just make sure they have your balancer, rotating assembly and flywheel.

Mahle ,Wiseco and Ross make a good forged piston at a reasonable price.

Check my sig. Thats on 93 octane with no spark retard.

What headgaskets are you going to use? Are you going to have the block decked? Keeping your quench tight will help with the counter detenation with higher compression ratios. I'd deck the block so the piston is in the hole .010 and then use the Impala Gaskets giving you a quench in the .038-.039 range.

Kevin Blown 95 TA

Second the Flatlander Racing source for parts. Decent prices and fast shipping.

1993Fast_Z

Wasn't going to deck the block..talked with some people and they said I wouldn't have too??? Don't know if this is true or not..I'm not very familiar with building bottom ends. They said with the pistons I'm running my deck height will be .022 in the hole. I'm running the mr gasket 5716 gasket with .029? Thickness..so far I've decided Probe Ind. 12336-030 piston with Eagle SIR 5.7 rods..just wondering whether to go Internal or External balance..I will have to get my pistons, rods, crank, etc balanced either way correct?

rskrause

i had talked to some people and they recommended Probe Ind. Forged Pistons.
Probe makes good pistons

now, should i go 5.7 in rod or 6.0 in rod?
Trivial difference, but go with the 6.0" rod

H-beam or I-beam Rods?
Makes no difference

Studs on the Mains?
Yes

Floating Pin or Pressed Pin pistons?
Floating

What Comp. Ratio should i run?
is it true i can run 11.5-12:1 compression and still run pump gas?..thats what im being told.
Depends on the cam


Rich

slomarao

do you plan on using n2o? what kind of rpm?

I would go 6 inch rod. Run a cam that will allow for more compression.

97WS6SCharged

A stock LT1 has the front half of the motor using an internal balance and the back half using an external balance with a weight on the flywheel/flex plate.

When I built my 383 I went with an internal balance and had the weight machined off of the flywheel (later upgraded to a billet flywheel without a weight). I would say do that if you don't mind the cost of Mallory metal. Make sure you match the rods to the crank though. If the counter weights on the crankshaft are too large they will contact the pistons which is usually a bad thing.

And yes, Probe does make a good product. No complaints from me anyways.

1993Fast_Z

im not going to hurt anything running a 5.7 rod am i? the reason i ask is because my buddy sold me a new set of SIR rods(5.7) for $120..if they wont work or cause problems, ill have to make a change i guess...so if i go with internal balance, all i will have to do is remove my counterweight on the flywheel? i already have an SLP lightweight Flywheel..what crank would match Eagle SIR rods? common sense would say an Eagle crank, but what are the opinions of the Eagle crank? Would i have to get my rotating assembly balanced with Internal Balance or is that an External Balance thing? you guys are helping me along very nicely..I appreciate all the info you guys have given me so far..

bw_hunter

No, you won't hurt anything with stock length rods. The basic purpose of going with longer rods is to reduce the side load on the piston and thrust surface of the cylinder and the friction associated with it. Most people go with 5.7" rods with a 383 but some go with 5.85 or 6.0" rods. It really doesn't matter except for the angularity thing I just mentioned. A negative to a long rod is that it puts the wrist pin close to the ring pack...sometimes into it, requiring a support rail. Whatever you decide, just make sure the individual manufacturers know which other components you are using. Anyway, when it's all said and done, I haven't seen any solid evidence than longer rods yield higher horsepower than shorter rods. Of course, I don't read everything out there so don't be surprised if others disagree.

The suggestion that your pistons might hit the crank using 5.7" rods isn't true unless you use pistons designed for a different length rod. Remember, the total height of the assembly (centerline of the crankshafts main journal to the top of the piston) of the is approximately equal to the blocks deck height (centerline of the crankshaft main journal to the head gasket surface). This has to be true regardless of the rod length used. If you use a longer rod, you need a piston with the wrist pin moved up. A shorter rod and you have ot move the wrist pin down.

I hope this helps...