Will the stock crank handle Powerdyne at ~6 PSI w/355, small custom cam (215 intake duration), Lloyd Elliot heads, 75 shot?? Without the 75 shot I feel confident the stock crank (44K miles) will be ok at the 450 ~ 500 RWHP level from the PD and mild cam/heads. However, with the 75 shot we could be talking over 600 hp at the flywheel .....is that too much for the stock crank or am I overestimating? My PD is overpullied and makes nearly 8 PSI now on stock motor. It appears I have spun a bearing and need a rebuild so I will likely go all out with the best cam I can match to the heads once I have flow numbers on them. Then 58MM TB, Meziere, light flywheel, etc to get the most out of it. I would like to switch to Vortech but feel as long as I can make ~475 RWHP with the Powerdyne and a really good heads/cam combo ....that would suffice especially if I could add a 75 shot later. Also, if I would add the 75 shot ....would it be ok on 9.9:1 forged slugs or would I need to go a little lower on the CR?

 

i have heard that 500 to the fly is about all the stock crank would handle, and thats pushing its limits some imho. if you want to do it right, do it right.

 

Get a forged eagle crank and H-beam rods, and JE forged -31cc extreme duty pistons and be done with it. All can be had for around $1600 from Combination Motorsports.

That will handle anything your PD can throw at it and then some. Don't dick around with this like you did when trying to find the optimal injector for your combo Get something that can handle what you have and be able to grow. You will save time and money

 

Well stated SMOKNZ

 

When I tore down my last Blown 355 with about 500FWHP I had a cracked stock crank, Crank and stock rods were twisting enough to tear up the Main and rod bearings. If it was me I would get a forged crank with a blown motor, Do it right so you don't have to go back in. I built a 385 and got a Callies Dragonslayer Crank, Eagle H-Beam rods and JE Blower pistons for $1675

 

If you're building the engine with good components (i.e. forged internals), then, why would you not spend the extra $$$ on a nice steel crank? Not slamming you, however, why risk it and take a chance? You're already spending a bit of $$$ on the forged stuff so why not go all the way with it?

Just my $.02

 

Gee this is not the response I expected at all. So many times I've read people talking about rebuilding and they say you're wasting money to not re-use the stock crank and rods if you're sticking with low boost and a mild motor. Thanks for the advice though, it sure would suck to have to do it again but damn ....this is going to be some money if I go all forged. Saving stock crank and reconditioning rods would have saved quite a bit of money, but I guess we are talking about some pretty good insurance with all forged and it would be nice to know I can throw a good bit of spray or extra boost to it later. Should I convert to 4-bolt mains or stick with 2-bolt? If 4-bolt what kind?

I'm also considering 5.75 or 6.0 inch rods for a little extra dwell in the power stroke and less side loading. Is piston thickness and pin placement safe for a 6 inch rod?

Oh yeah, one big concern is the CR. Like I said before ....would 9.9:1 be ok with the Powerdyne and a 75 shot, or do I go lower? I just hate to go lower since the Powerdyne doesn't make much boost at the low end (or at all really). SMOKNZ, not sure what you mean about injectors. When I first got the Powerdyne I went with 24# SVO's because I was going to use the FMU. Later on I discovered my FMU wasn't pumping up the pressure as much as I'd like so I switched to 42# SVO's and no FMU.....no dicking around. Thanks for the tip on Combination Motorsports.

 

I know a few people who have used the GM 14088532 crank with great success. It's a forged steel crank you can get in the mid $200 range. It's a great crank for a budget boost build-up.

Definitely upgrade to 4-bolt (whether you get a 4 bolt block or splay a 2-bolt one). The power levels you're putting out are putting quite a bit of stress on the bearings and mains.

 

Not flaming you but when you were looking to replace your 24# injectors I can't remember how many posts you made about going with smaller (30 range) and all the calculations if it would be enough injector with and without an FMU. I simply recommended just going with the 42# injectors, buying tunercat and tune it yourself. After what seemed like a few months of calculating and hypothetical posts about if "these type would be enough for my combo" you bought the 42# injectors anyway. Then you spent ALOT on your tuning horror story, now without Tunercat your looking at another custom tune when the motor is back in the car. Thats what I was commenting on.

I helped tune a buddies ATI 8 pound car, and the program wasn't really far from stock, hell mine isn't far from stock, just timing changes, Upper MAF table changes, injector constant/offset changes, and PE changes. His car ran everything stock, just speed pro pistons, and an FMU. His car ran low 12's and was an animal for what it was. That was the first car that I ever played with tuning, and it really wasn't to hard, and we had Zero KR from it!

If you were just sticking with the PD blower and no N20, then Reusing the stock crank/rods would probably be ok. I am using mine still, up to 18 psi and 542 Hp. I'm planning an upgrade and plan on keeping the boost on my new twin kit limited to 7 psi until the new motor is done.

Bill

 

I kept a factory crank (turned 0.010) in my 4 Bolt 355 with forged Eagle H-Beams and Wiseco pistons and my race day HP is close to 600 rwhp. I have run this combo for 2 1/2 years now with no problems <shrug>.

I hope I didn't just put the jink on myself

 

hey guys,

I have not been a member here very long, but I have been around hot cars for quite a while. Stock cranks can handle quite a bit of power as long as you keep the motor out of detonation. As an example, I am just refreshing a 355 that I have sprayed hard for 3 seasons. This motor put out 620 HP and was in 2 different cars. The crank that's in there is a stock '94 CAST crank. I also used '95 powdered metal rods and trw forged pistons in a 4 bolt block. This crank is still good and I could reuse the bearings if I wanted. One of the keys to a cranks longevity is to have the reciprocating assembly balanced and use a good harmonic balancer like a Fluidamper or Ati. I know a few guys that are running deep in the 10's with stock bottom end parts and the motors stay alive. Now, as others have recommended, if you have the cash, definitely step up to a 4340 crank as that will buy you insurance for being off on your tune up, but, if you're on a budget a stock crank will work at these horsepower levels as long as you don't rattle the motor.

 

What is this crank used in? Because I have searched thru the GM parts catalog and the number isn't any good. Just curious...

 

from what i can tell that crank number is from a 86-88 Pontiac something...an MPV (multi purpose vehicle) but it wasnt clear what the vehicle was.

 

Honestly, I haven't the slightest idea...

Here's all the info I can find on it:

14088532 -- forged steel
1986-1988 truck
350 block, 3.48" stroke
main/rod journal size: 2.45"/2.10" (medium)

$245 from Northeast Machine:
http://www.northeastmachine.com/2003...tockcranks.pdf

 

So long as your using the small cam, and you keep the revs low.. I'd say a stronger cast piece such as the Scat Cast would hold the 500rwhp you'd throw at it. However, if you've got the cash.. go for the callies

Good Luck,