Crazy Talk

[DaGr8Tim]

I know what I'm asking does not apply to an I6, but the theory still should be the same. I figure if it's possible or been done, somebody here will know about it.

Would it be possible to say have a 1 inch thick plate made (machined) that matched the bores and all of the oil & coolant passages. This plate would be put between the head and the block.

Then run a really radical crank, that you would be running a standard connection rods. In this "theoritical model" the the piston at BDC would be at or near the stock BDC location, and the piston at TDC would be relative to the top of the space plate what the stock TDC is to the top of the block. So I guess I'm basically adding 1 inch to the stock stroke.

The idea is create a sitution where you would have some insane displacement.

I know this is not as easy as it sounds, it would requires basically gasket matching the plate for all of the passages and bores. Then you would need longer head bolts. Not to mention you'd be basically doing a double head gasket deal. Then you'd need longer push rods.

Mainly, I'm just curious if #1 it's possible, #2 if anyone has ever done it.

My next question is with a 4 cylinder with a bore of 3.680, a standard stroke of 3.300, connection rod length (mean) 5.4570, Deck Height 8.700, pin to top of piston 1.520, and a standard displacement of 141CID/2.3L. What would be the new displacement.

Isn't it amazing what you ponder when you are highly sleep deprived?

 

[addo]

So, why are you highly depraved?

You'd likely need to use thickwall liners for such endeavours. I have heard of some "out there" Y-block engine builds that overbored and overstroked, relying on the liners to stay put.

Whether you could add 1" or only ½" to the stroke would depend on what the crank/rods might hit. Typical interference points are bottom of cylinders, oil pan gasket rails, and camshaft.

I think for the same investment dollars, you could probably get much further with a really good forced induction package.

Cheers, Adam.

 

[DaGr8Tim]

So, why are you highly depraved?

You'd likely need to use thickwall liners for such endeavours. I have heard of some "out there" Y-block engine builds that overbored and overstroked, relying on the liners to stay put.

Whether you could add 1" or only ½" to the stroke would depend on what the crank/rods might hit. Typical interference points are bottom of cylinders, oil pan gasket rails, and camshaft.

I think for the same investment dollars, you could probably get much further with a really good forced induction package.

Cheers, Adam.

I have no designs on actually doing this. I was just curious.

If I had the scratch to throw around for something like this, I'd be dropping a 3.2 SHO motor with an MTX IV 5 speed behind it into my car. It'd probably be cheaper and provide better gains.

 

[xctasy]

DaGr8Tim said:-

Mainly, I'm just curious if #1 it's possible, #2 if anyone has ever done it.

My next question is with a 4 cylinder with a bore of 3.680, a standard stroke of 3.300, connection rod length (mean) 5.4570, Deck Height 8.700, pin to top of piston 1.520, and a standard displacement of 141CID/2.3L. What would be the new displacement.

Isn't it amazing what you ponder when you are highly sleep deprived?

Answer is you can stroke until you hit the camshaft! I'd never do anything to a 2.3HSC, since the 2.5HSC is already 9% bigger with a taller deck.

I'm not sure of the sump width on the 2.3 or 2.5, but the 2.3 could become a 2.5 just by adding a 680 thou plate on the block, and sleaving it. Then drop in the 2.5 crank, with its 3.585" stroke. The 2.5 is already 9.38" tall, and the idea would be to use a 250 throw crank, for 2.726 liters. No block height increase required. I'm guessing the width of the block is the issue. I'd expect the 2.5 to have the same width as the 250 block, so perhaps a Chrylser 2.5 style 106 mm crank could go in, with the shallow piston, for a 2.91 liter engine based on the 2.5HSC.

Been done by Aussie Merv Waggot in the Twin Cam Holden 2950 cc six back in 1958. One of these hit fame in the offshore power boats, another in the Waggot Centuar. Merv was a self taught pattern maker with lots of plucky ideas.

He just added sleaves, a seven bearing crank using a special girdle(aka the modern RB Nissan girdle), then dowled in a 500 thou plate on the Holden block. The engine was now much bigger than the 2262 cc it was when it started, a 31% boost in capacity. It, the costom steel crank, and the twin cam head bosted power from 75 hp to 229. Three times the power, and still using stock rods!

It was expensive. He lost money on each one!

 

[Anonymous]

the 141 would stroke out to be 183CID if you could pull that off but I'd just get a good cam,roller rockers,forced induction ect. ect...

 

[rbohm]

8) jon kaase has also done it when building mountain motors. he actually extended a 460 ford block 2" and built a crank with something like a 5.5" arm on it and got something close to 900ci . he started with a motorsport 460 block to allow him a large enough bore. he used cylinder sleeves with a lip at the top to hold the sleeves in place as he made the sleeves fairly easy to remove, and they were installed dry. the combo does work as he gets nearly 2000hp from a normaly aspirated engine.

 

[MustangSix]

The real trick is to get the crank and rods to clear the block and cam.

This is also done to create some whopping huge Jaguar V12 engines. The standard Jag v!2 is either a 5.3 or 6.0 liter engine, but by adding block plates and longer liners they have done bore and stroke combinations that go over 8 liters ( close to 490 cubes).

Now, since this is a theoretical discussion, consider that a longer stroke also carries a big penalty in friction. Scraping those rings up and down costs some energy. So just building displacement may not get you the gains you want.

Also, you have to consider that a long stroke engine usually is a slower engine. Piston speeds will be greater and redline may be lower. A really BIG block with a 5" stoke is probalby doing extemely well to run to 5000rpm.

 

[DaGr8Tim]

Also, you have to consider that a long stroke engine usually is a slower engine. Piston speeds will be greater and redline may be lower. A really BIG block with a 5" stoke is probalby doing extemely well to run to 5000rpm.

Being as this is all therotical, could an idea like that be used to make a torque monster?

 

[MustangSix]

Yes, but it would sure be easier to start with a big engine.

Actually, I think if I were building a stump-puller, I would start with a BIG turbo diesel.

 

[DaGr8Tim]

Yes, but it would sure be easier to start with a big engine.

Actually, I think if I were building a stump-puller, I would start with a BIG turbo diesel.

I agree. This original thought came out of a mental state that is somewhere between consiousness and unconsiousness.

 

[addo]

I agree. This original thought came out of a mental state that is somewhere between consiousness and unconsiousness.

You work in customer service?

 

[DaGr8Tim]

You work in customer service?

Yes and no. I do internet technical support on graveyard. Why do you think most of my posts are in the middle of the night for the eastern part of the US?