High Compresion EA82T is now in my car

[GeneralDisorder]

FWIW, I just did HG's on an EA82 carb, and it blew on the disty side - #4 cylinder. Same situation - combustion chamber to adjacent water passage. But the HG's had 226k on them - clearly original by the looks of things.

 

The datsun engines are cast iron block are they not? That's got to make some difference in the design of things. I'm not sure that's a totally fair comparison. Metal expansion rates, and other factors I imagine. I'm no engineer tho.

 

GD

[daeron]

yah cast iron.. certainly alot more of a solid seat for the headbolts, and its not a common issue at all. we even heli-coil them when they get buggered, without thinking twice about it.

[mdjdc]

Well: I began this project after I read a thread about high compression engines and it looked fairly positive. I figured that, since this engine is factory new I would have a better engine to build off of. I also figured that if I kept things stock other than the pistons I'd be in good shape.

 

I guess only time will tell. Maybe I didn't see other threads or I haven't been around long enough to know the problems that others have had.

 

I guess only time will tell if some of my assumptions are correct about a newer engine being stronger. Perhaps the HG's will hold.

 

For those who have had these engines go out, what were the circumstances?

 

I'm still in possession of the original motor so if I do blow this one it'll take a day to replace this one. Not the best scenario, but at least I've tested some of my theories. I hope I'm not disappointed, but nothing ventured nothing gained and besides, it too late to go back as the engine is already in. Oops.

[Phizinza]

Just keep us updated. And I hope not to hear from you!

 

Good luck.

[mikeshoup]

For those who have had these engines go out, what were the circumstances?

I blew the passengar side head gasket (cyl #3) on mine a few thousand miles after the motor was built (I didn't build it, so I'm not sure exactly when it was). I suspect the short block had a lot of miles on it, and the heads probably came with the car (185K on the car). Its got turbo heads with an SPFI shortblock.

 

Why did it blow? Most likely neglegence on my part with the cooling system. First thing I did after replacing the head gaskets was a new two row radiator.

 

Keep the thing from overheating. You will regret it if you don't.

[kingbobdole]

I can talk for mikes car. My GF owned it AFTER the guy who originally built it (steve X35). We both were rather hard on it, not bad, but kinda. The bigger issue was that the motor had a cooling problem sometimes which Mike has since fixed... it also had an issue where the timing was just too much for it when we got it, and it had a bit of ping for a while as well. It was a fast car and I know I put it through its paces a few times... I'm sure Roni was nicer to it tho, not that I tried to blow it up, it was just fun and encouraged "spirited" driving:banana:

Also, Mikes headgasket blew by warping the cylinder "ring" in the gasket, just pushed part of it out into the water jacket, and egged the gasket.... very odd... it may not have been retorqued....

[mdjdc]

Well I've got almost a thousand on the new engine and it is running like a top. I think that I may have a leg up on the other engines, since it was brand new and I redid everything from the crank on out. just a guess, but I'll keep you all informed as to the progress of the car. I love the lower end torque and not having to hit the turbo as much. Gas mileage has gone up by three MPG around town too.

 

Thanks for everyones help and opinions

[BoostedBalls]

The higher compression should be ok with stock boost and stock timing, just don't get into boost at low rpm. That will kill it for sure.

 

I would actually prefer to have the compression ratio of my turbo engine lowered beyond the stock 7.7:1. The bottom end torque would be nonexistant but it could handle a lot more air and fuel per stroke at the same timing.

 

Also, you are pretty much stuck with the stock 7-8psi boost unless you put a spring on the wastegate lever or modify the wastegate actuator. The spring would be positioned in a fashion that would add a little bit of force to the arm in the opening position. The oposite can be done to increas the boost reliably. Not as good as a pneumatic solenoid, but it's nearly fail safe.

-Chuck