Skip to main content

I have a .030 overbored standard stroke short block that's in great shape. I'd like to put a stroker kit in it. What's the largest easily obtainable engine size that I can get from this bore size? I'd like to avoid the whole machine shop ordeal if I can. The bores are in excellent shape, the hash marks are still crisp and visible in the bores. The engine only has about 2000 miles on it since the last total rebuild. I was thinking about disassembling the short block, run a hand held cylinder hone through the bores just to clean them up, and toss a stroker kit in it. I don't mind some minor clearancing that I can easily do at home with a hand held die grinder, but I don't want to start with a machine shop. That snowballs into a whole big ordeal that I don't want to get involved in. Who's stroker kit should I use, and how large an engine can I easily obtain given the limitation of the .030 over bore?
Original Post

Replies sorted oldest to newest

Originally posted by NYCleveland:
...I'd like to avoid the whole machine shop ordeal ...

the alternative may be an ordeal too
...toss a stroker kit in it...

It may toss something back at you
quote: large an engine can I easily obtain given the limitation of the .030 over bore...

408 cubic inches

the guy below avoided the machine shop too


Images (1)
  • exploding_car_3
The Reaper is right, 408 cubic inches is the max (that's a 4.00 inch stroke). He's also right, with the attitude you have, the motor may just toss something back at you. A good machinist is not an option, he's a necessity. So is a dyno operator.

If finding a good machine shop is the problem, several of us here could recommend something for you in the NY area. If budget is the hold back, then perhaps its best to wait until the budget situation improves. I'm not one to go into a motor project with the philosophy "spend as little as possible". I'm from the "spend what it takes to do it right" school.

To answer your crank question, Scat has the best reputation amongst the companies that sell the inexpensive Chinese made crankshafts. By a long shot. It seems Scat is almost always out of stock, waiting for another shipment, but people are willing to wait on Scat's shipment rather than do business with one of the other crank vendors.

To go any further in helping you the folks here need to know what car the motor is going in, what the budget is, what are the intended uses of the car, what is the power goals, what are most important considerations for you in the performance of this motor, i.e. drive-ability, reliability, endurance, rev to a certain rpm, a certain type of torque curve, what kind of idle do you want, fuel economy, etc.

cowboy from hell
NY CLEVELAND ... basically If youd like to ....

" I'd like to avoid the whole machine shop ordeal if I can " & "some minor clearancing that I can easily do at home with a hand held die grinder "

First of all I dont recommend not using a good machine shop ... need to go with something in the area of a 377 like I did .. the big inch cranks require alot more then grinding the pan rails .. the oil ring ends up in or very close to the piston pin and ends up comsuming oil.

The big inches maybe good on the street due to the fact you gain Cubes with pump gas and that = more hp.

But as George summarized .. whats the intent .. is it all out or a sunday drive.

Heres some info from another topic on this forum .. our friend DAN JONES posted :

QUOTE - Power band best between 2500-6500 -- with that goal in mind, is a stroker the right thing to do? I think a stroker loses the ability to revhigh and quickly?
1. 377 (3.7" stroke, 0.030" over): 3.7" offset ground Cleveland crank with 6" rod (Olds or 2.1" journal Chevy), custom pistons. Offset grind 351C crank to SBC journal, widen crank
journal or narrow rods (easiest), 6" rods, custom pistons. Assuming your crank
grinder works reasonably, the least expensive. If not, the 3.75, 3.85", or 4" stroke SCAT or Eagle cranks may be as cheap. Room to go to longer rods (6.125" or 6.2", if desired. Conservative compression height and rod
ratio with room for a standard ring pack. Done right, pretty bullet-proof. The Pantera Performance Center in Colorado stocks pistons for this combo.

Have some info for you,
this is the results of endless search's on the net, there is more but I filterd it down to these, also with every person you talk to there are another opinion. Figure what you want, find out if someone has gone down that road, tried and true and use that as an example.
I to like to do all the work I can without handing over everything to someone else, including my checkbook! I believe that is what distinguishes a Hot Rodder from a collector.
If you find your parts the one thing you will need without a doubt is the balancing,

Good Luck and injoy the adventure,
I stayed with Eagle for both the rods and the crank.
I don't think that Scat is better. It just has a better web page.
Scat is a porn term isn't it?

The choice really should be nodular iron or steel.
Both have advantages. Neither are foolproof.

I believe that when we say iron here, it is nodular iron.

As I recall the tensile strength differences on the cranks are iron 90-92,000 psi, nodular iron 95,000+ and steel was 100,000psi.

The longer the stoke the more signifigant these numbers are because of more twisting on the crank.

Any stroker is going to make the odds of a crankfailure increase to a power of an unknown number.

Steel was used by the racers more for the hardness of the bearing journals = less rebuilds.

The steel also adds a little worry comfort but that's about it.

A little bending of the crank never hurt until superchargers and nitrous enter the equation.

I do remember Chevy having BB rod failures in the late '60s with overhardening of the steel.

I have personally had failures of ultra hardened push rods. I kind of lean towards the nodular iron cranks.

If a steel crank failed, it failed for one reason only. It was overstressed. The load exceeded the strength of the material.

I have rarely heard of anyone calculating the loads on the stroker cranks. The couple that I can recall put rpm limits on then in the low 5000 rpm range. I can't remember the source though. I don't remember whether or not the rods and cranks were iron or steel.
It could possibly not even matter now because or the change in materials used.

In the past strokers did not have any kind of a posative reputation for longevity. I'm not surprised when I hear of a failure.

This is just my 2cents.
Last edited by panteradoug
A good source for you would be Joe Devilio of Perfect Bodies ..hes in LI. As for machine shops .. once you round up all your parts, like I did you can bring it to anyone .. I use Olsen Engines in Nyack NY, there Cerralli in Paterson NJ, and I;m sure there is a bunch in Long Island...take a ride over and see Joe.

I;m in Suffern NY probably an hour from you ..if I can be of any help me at ...theres bunch of us up here and I;m sure we can help you with some parts, pieces and sources.

Link copied to your clipboard.