Where do oil squirters fit in this discussion at all? Like any self respecting self tuning Evo owner, I'm gonna cook that sucker someday! Curiosity beckons!

( no need to infer that everyone blows motors )

 

Some think the extra insurance is worth it. Some think it doesn't help anything.

Arguments to support both.

 

I don't run them no problem with mine.

 

Lol

Point taken.

 

Just curious, do you track the car at road courses? How often?

 

I have no problem agreeing with anything you have to say if you're correct, but your statement was not accurate. The 4G64 cylinder walls are thinner- fact. We sonic test the cylinder walls of every single engine that we build and the '64's are consistently thinner. If you want to call that boredom then so be it but that is a step which should be part of the process of building any performance engine.

 

Tom "TSCOMP" we built the motor in my basement. Tony @ JAM did all the machine work too it. Reading post above im glad you do that Tony customers like me apperate that, that is why my motor is still ticking and working perfect! Thanks man!


Ive prob tracked it like 1/4 mile 30-45 times down the track. Fooling around on the street pretty much whenever I take it out being that its a weekend car so its a hard 10k miles it has on it. Ive driven it to the BR shootout 1,000 mile round trip. Pretty much I cant complain about anything with it.


I do not road course the car tho. Don't have to much interest, im sure if I turned my boost down a little it would be fun to do tho.

 

I went into my shop to look at both blocks. Past the deck in the coolant passages you can see the cylinder wall taper in on both blocks (which appears to be thinner than the distance between bores). The distance between the bores is one area of measurement of cylinder wall thickness. I would think the most important measurment is the thinnest area of the cylinder wall. Is the thinnest area thinner on one of the blocks?

Regardless, I'm looking forward to building both the 4G63 and 4G64.

 

Since the blocks are the same besides deck height and using Tony's comment that a 4G64 is .030-.040 thinner makes perfect sense since the block is bored .060 bigger than a 4G63. If you wouldbore both to the same bore they should be similar. I decided if I ever split a cylinder wall in my 2.4 I was going to sleeve it down to an 85mm bore to get the thickest walls possible while having all the benefits of the taller deck.

Tony were your measurements on stock bores or the same diameter bore? I had previously bored a 63 block to 87mm bore to make a stock block 2.1L. The deshrouding of the valves really helps with cylinder head flow past the valves.

 

The Wiseco HD Pistons me and Steve run don't really need them imo.

Here's what a 2.4LR that JAM machined for me did with one of my customers that wanted them though. Its a pretty neat design. The oil squirters are built into the engine block where the main bearings sit.

 

The measurements were taken from standard bore cores right after they came out of the hot tank. We test them all before we bore them. We have come across a handful which had spots so thin that they couldn't be used.

In general, the blocks are plenty strong for use and I like the larger bore. The incorect comment was made that the '64 block is no thinner than a '63 which is why I chose to reply.

 

I must say I would not want oil squirters fed from the main bearings. The 1G motor and the EVO motor both have them on the main oil galley. There is no issue with volume there and the large valves prevent them from robbing oil pressure in low pressure situations such as idle. The 2G 7bolt has them off of the main bearings and we all know what happens when the center main doesn't get adequate oil pressure and volume. ��

I do not think squirters are necessary on a forged piston. The cast pistons are much weaker and could fail without the added cooling but I feel the benefit is far outweighed by any possible negative associated with oil squirters fed from the main bearings.

 

You are correct that it isn't the amplitude of torsional whip, but the frequency. As rpm rises, so does the resonance of parasitic harmonics that make it vibrate like a tuning fork. Also, crank length is a factor. It's a big reason why inline 6 cranks aren't as durable at high rpm as a V6 crank.


And there you have it. Good info.



The squirter isn't there for the piston itself, but to reduce piston temperature. The difference in temp between the piston crown and the oil is several hundred degrees F at WOT. To put that into perspective, it's like a jet of liquid nitrogen hitting the backside of your hand. That 'cold' oil takes heat away from the piston, reduces the potential for preignition, and increases power potential with octane limited fuels. It is effective, which is why it has trickled down from manufacturers' race engines to their passenger car engines.

 

Ted... you're a genius...

 

How do you get an additional lower oil ring? Do you use a thicker lower oil rail, or what?

Just by googling for pictures, it does look like the most you can move the wrist pin up without getting into the oil ring groove is 3mm (1.252" compression height).