I am in the process of planning a LT1 engine rebuild. I am on a budget of course (aren't we all) but want to do this as correct as I can afford. My big sticking point right now the bottom end. This will be mostly a street car with a few trips to the strip a year. At the very least I want to go with forged pistons as there could be small boost or nitrous in the distant future. I would prefer to get a complete BALANCED rotating assembly as I figure by the time i buy forged pistons, get the crank balanced and polished/ground I can literally buy a complete assembly for a couple hundred dollars more. I was looking at the Callies Speedpak assemblies and I know they cost around $2K but was wondering what else is available as far as a balanced assemblies. For now I want to stick with a 355. I know a 383 is the same price but I seem to hear far more horror stories about 383 builds than I care to remember. My end goal is no more than 450RWHP NA and will be happy with anything over 400. It would be great if you all could give me some suggestions along with some part numbers/prices.

Thanks a bunch,
TOM B

 

Tom,

I build race bottom ends that are less than 2K!

If you want new parts for the whole thing that will hold up to 450rwhp NA the cheapie route is

Eagle/Scat Cast stock replacement crank
Eagle/Scat I beam Forged Rods with Bushed Pins
Mahle Pro Pack Pistons

Probably around $1200 at the most for that balanced.

You can upgrade the rods to a forged H beam if you want but it's not needed, the N2O would warrant that and the boost would want less CR unless you put a head with a larger chamber on there later like a TFS head. I would not advise going to lower compression to start just so you can put a blower on it later, two different animals.

Bret

 

We are sponsors of this site and carry a variety of stroker kit from Compstar, Lunati, and Eagle. We can also build a package to fit most budgets. Please feel free to contact us with any questions.

 

IF AT ALL POSSIBLE YOU SHOULD DEAL WITH THESE GUYS, DAMN NEAR LEGENDARY CUSTOMER SERVICE.

 

Call Probe industries. They can fix ya up also.
Cast crank
Forged rods
Forged pistons or????
Bearings
Rings
Balance
They have some pretty good prices but don't know what ya are exactly looking for.

 

There in lies my delima. It seems no matter how I approach this, it comes out to between $1500 to 2K for a balanced assembly. By the time I have the stock crank worked over and the whole assembly balanced with new forged pistons I am up to $1200 after tax. Granted I know the stock crank is plenty strong as are the rods, I am still left with 160K mile rotating parts. Because there could be nitrous or boost in the future I am really thinking about what other people are spouting...... don't skimp.

What kind of power or advantages would a Eagle/Scat cast crank have over a reworked stock piece? Is there any? Lets say I am hoping for 400HP NA and adding a 150 shot or 6-8PSI boost in the future. Would a stock crank/rods be up to the task or even a cast crank forged rods setup? How is the Callies Speed Pack components. Would that setup support 550-600 HP without me worrying about it?

Bret, you state you can build full on race setups for less than 2K. Is that balanced? I just have this fear of buying some cheaper crank/rod/piston setup and end up spending a bunch of money at the machine shop getting it balanced when I could have bought some nicer pieces for the same amount of money in the end.

Thanks for the input thus far,
TOM B

 

With the right parts you should have a standard balance fee. I always netural balance everything which can add to the cost since you either need a neutral small flexplate or need to neutrally balance the flywheel.

You adding in boost or a small shot is ok, I would look at either a H beam rod or a Scat I beam rod with 7/16ths bolts. About any flat top piston will do, but you have to gap the rings to what will happen to it later which leaves some on the table.

A cast aftermarket crank is a better place to start than a stock crank. Better fillet radius in the corners of the journals, doesn't need to be reground, usually lighter as well and made of a better base material. Usually around $180-$250 also which is cheap compared to doing a bunch of work to the stocker.

Bret

 

Depending on the type of balance I decide on, would I have to provide the flywheel out of my current car (which would defeat the purpose of building a separate engine)? The "standard" LT1 is neutralally internally balanced correct?? And the stock replacement Street Twin clutch is also neutral balanced?

Thanks for your help,
TOM B

 

The Lt1 is half/half. It is internal in the front and external in the rear and the flywheel has a weight.
If ya have it internal balanced then a "0" balance flywheel will be needed. The balancer is already "0".

 

Just pick up another flywheel and keep that attached to the motor.

Bret

 

Great information thanks Bret.

-Dustin-