Flem

How much stroke is gained in the offset ground stock cranks? What are the ramifications to the overall strength. Who sells them?

fast2001

I would like to know this also. I am wanting to get my crank ground to a 3.71 inch stroke or TSP 3.82 inch stroke. But I am worried about how it would hold up with nitrous.

Flem

Anybody out there know anything?

Crazyquik

You pick up what, ~12 cubic inches I think?

You will lose some strength in the crank, although no one really knows how much. Of course, we really dont know how strong the stock crank is because I dont think anyone has broke one yet.

J.

L-EATER

iTrader: (2)

Sorta unrelated but I have done this on my bigbock Buick, offset it from like 2.3 inches to 2 inches. Gained like 30 cubes and so far no probs with 2 years of racing on it, most of it on a 250 shot.

quickWS6

Didn't TSP just unload a good bit of nitrous into their offset-ground motor and the stock crank did fine? I think the thread was a few months back.

SStrokerAce

iTrader: (2)

With a offset ground crank you loose rod journal to main journal overlap. That makes a weaker crank, but if they put good radii in the corners of the journals then you are going to o.k.

The stock cranks hold up a ton. I'm thinking of doing smaller rod journals on my crank but don't know if the stroke is going to increase or not. The so far have looked like a super strong piece.

If you want to do it right and start off with a new GM crank I can get you whatever you want.

Bret

fast2001

Has anyone else have any experence with TSP offset ground cranks. Is taking the crank up to a 3.82 stroke going to weaken it too much to run nitrous. any comments good or bad please.

Smoke_Ford

Your best best is a balanced and blueprinted crank.

Nasty N8

iTrader: (33)

Strength should be fine you are not loosing a lot of material nascar uses that size jurnals. The big issue is you have to have custom rods made and are quite pricy. For the 19 cubes you gain from stock or the 9 you would gain just offseting it to 3.72 stroke and use standard rods?
Nate

Jason 98 TA

iTrader: (4)

We have great pricing on the nascar rods, my c5 put down 729 rwhp on spray with that crank We have a couple of offset rods & cranks in stock, and I have a complete 396 rotating assembly in stock & ready to roll

Jason
Texas Speed

robertbartsch

Jason:
Can you tell us more about the complete rotating assembly that yields 396?

Can this be installed in a stock bored block?

ROGERSPERF.

I would like to say somthing about cranks being ground.For years the mith was a crank ground more then .010 .010 it was junk and weak. Ihave built busch grand national engines and we use honda rod size,s on them and they hold up fine. The IRL use even small size. As long as the crank has good radius it will be strong.By the way besides the Busch engines,s using honda rod size,s the cranks al so can weight any where from 30 lbs to 37 lbs.



mike

-Joseph-

iTrader: (12)

4.060" Custom Pistons
6.125" Carrillo Connecting Rods 7/16 rod bolts (Honda 1.88" rod journal)
Stock offset ground crank (3.822" stroke)
Crank is Magnafluxed, and entire reciprocating assembly is professionally balanced by our engine shop, who by the way builds about 400 racing engines per year.

The 396ci rotating assembly is for a 6.0L cast iron block bored .060" oversized, assuming it sonic checks thick enough to bore that far. .060" oversize = 396ci while a .030" oversize = 390ci.

If you wanted to use the stock 5.7L block with the offset crank you'd be at 366ci, while a resleeved 4.125" bore would be a 409ci engine.

ls1290

iTrader: (20)

You can safely offset grind a crank 0.2" That seems like a lot. How will the stability of crank hold?

fast2001

I would like to know how reliable the crank would be also.

malibu350

what's the cost on those rotating assemblies?

ls1290

iTrader: (20)

ttt

fast2001

waiting to see if TSP can answer ls1290 question!

LEO

iTrader: (3)

I would assume it is safe since TSP's car is making 700+ rwhp without breaking. Most LS1 owners won't ever see those kind of power levels, but not sure how much over that mark the stock crank can handle.