offset the crank in the block?

[englertracing]

Has anyone ever put a large journal crank in a small journal block but offset it to the left?
If you don't know what I'm talking about it would act like a long rod on the way down and a short rod on the way up.
An old man known as pinto jim told me to try it.
Him and his dad built all kinds of boat hydroplane and even top fuel motors.

[Jk21]

Might be alot easier to angle bore...

[Old Rob]

Doing the bearings would be simple enough. How ever the rear main seal could be a problemWould need to weld up right side. Unless you could find a seal with the right ID and a larger OD

[Dan32]

Has anyone ever put a large journal crank in a small journal block but offset it to the left?
If you don't know what I'm talking about it would act like a long rod on the way down and a short rod on the way up.
An old man known as pinto jim told me to try it.
Him and his dad built all kinds of boat hydroplane and even top fuel motors.

clutch problems will insue been there!

[Old Rob]

Use offset bellhousing alignment dowls holes. Drill and slot the bolt holes in the Bellhousing. You will need to use bolt and nut for the lower four bolts. You can use the stock bolts for the top two. This will also align the starter to flywheel. However you're not goint to move it much.
This was an old trick that Smokey Yunick used in his Hudsons, I believe.

[Dan32]

cool never thought of that ! thanks!!

[englertracing]

I'd like to try it. I'm sure it will help. I'm not sure how much it will help. I was hoping to hear from someone who has done it and can say it runs better. I sure didn't even think of the trans alignment or main seal!!! A lot of work for not knowing what its worth.

[englertracing]

Might be alot easier to angle bore...

I didn't think of this I wonder if its possible to get nearly the same offset this way.. although I'm already hard pressed to get my rod and crank to fit in the block this will cause one side of the piston to protruded farther out of the deck then the other. But probably only a tiny amount.

[steveshawjr]

sounds like alot of work and extra cash why not just go long rod or just offset grind the rod journals. the whole idea of moving the crank itself seems like a lot of work but im sure it dose work we can test it on mine if you want to pay the machinist bill lol.

[dannyracer6]

What are you trying to accomplish here? I can't see the positives here being worth the cost to try it.

[Dan32]

I didn't think of this I wonder if its possible to get nearly the same offset this way.. although I'm already hard pressed to get my rod and crank to fit in the block this will cause one side of the piston to protruded farther out of the deck then the other. But probably only a tiny amount.

order pistons with offset pins in them!!

[englertracing]

sounds like alot of work and extra cash why not just go long rod or just offset grind the rod journals. the whole idea of moving the crank itself seems like a lot of work but im sure it dose work we can test it on mine if you want to pay the machinist bill lol.

Just what will I offset grind on a 3.5 stroke crank? And 5.75 rods. The point is to increace rod angle btdc and decreace rod angle atdc at the bottom it does the opposite. Basically the benefits of a long and short rod.

Also having a different piston tdc vs crank tdc. This can reduce crankshaft stress.
Sport bike engines are offset. Prius engines are offset. Efficiency is power.

[englertracing]

order pistons with offset pins in them!!

No.

Think about the extreme of this. Move the con rod to one side of the piston. Now the piston trys to rotate around the pin causing more friction. Race pistons aren't offset. Stock ones are and there made that way to always maintain more pressure on one side of the piston so it doesn't rock and slap and make noise.

Apples and oranges.

A yz450 yamaha dirt bike has the crankshaft offset 12mm!

[englertracing]

I know it works or a Prius wouldn't use it.

I just wonder how much and if anyone around here has done it to a pinto.
Would be really sneaky to do to at a track that has real tear down tech.

[return to dirt]

instead of offsetting the crank offset the bore. should be able to go 0.010-0.020 offset without cyl. wall or head gasket problems. should be able to go even more on the new big e block. then you would have to figure out how to do your cam and ign timing to take advantage of it.

olin