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Head gaskets again?? Maybe not.

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That's one horrible looking piston. What brand and type is it?

and do you know the bore size? I'm curious on the piston to wall clearance.

Yea , I'm pretty good at breaking stuff. I believe a stock piston, TRW Stamped in the bottom and numbered on rod and cap. Did the factory do that?


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Yea , I'm pretty good at breaking stuff. I believe a stock piston, TRW Stamped in the bottom and numbered on rod and cap. Did the factory do that?


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Nope. Those TRWs are nowhere near as robust as the stock pistons.

http://www.gnttype.org/techarea/pictureguides/pistonguide/38turbopiston.html


The trick is to figure out if you have a cast piston or a forged unit (and what size it is. Clean the crown real well and you should see a part number and oversize. If the part number starts with H, you have a cast piston and I wouldn't run those in my lawn mower.
 
Taking that stand with these cars you're going to learn to live poor too.


...and with a broken car.

I will clean it up and check. So those are not stock pistons you are saying?

Don't worry i will do it the right way.


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Nope. Those TRWs are nowhere near as robust as the stock pistons.

http://www.gnttype.org/techarea/pictureguides/pistonguide/38turbopiston.html


The trick is to figure out if you have a cast piston or a forged unit (and what size it is. Clean the crown real well and you should see a part number and oversize. If the part number starts with H, you have a cast piston and I wouldn't run those in my lawn mower.

It appears I can see a 030 on the piston, I think I cleaned the rest of it away.. and I don't think it has a H.. but I also can't see it that well.




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There won't be an L or an H on the 030. Thats the size, the part number will start with one of those letters.
 
There won't be an L or an H on the 030. Thats the size, the part number will start with one of those letters.

I got the piston and rings, what is the gap on the rings, got a wiseco forged piston 3.820 I put the top ring in the bore and the gap is larger than .040 since my feeler gauges only go up that high.


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When I was reading your symptoms I was thinking cracked piston. I bought a GN that acted exactly the same way and the piston that came out looked exactly the same. Hope you get it all sorted out. Good luck
 
I got the piston and rings, what is the gap on the rings, got a wiseco forged piston 3.820 I put the top ring in the bore and the gap is larger than .040 since my feeler gauges only go up that high



What is your bore size? It looked like you had .030 over pistons earlier in the post. 3.820 are .020 over. Over .040 ring gap is not going to work. Piston to wall would be .015 if that is the case. No way it will work. Measure the bore size and get the right pistons and rings. Use the piston to bore clearance and ring gap recommended by the manufacturer of the pistons and rings.
 
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I got the piston and rings, what is the gap on the rings, got a wiseco forged piston 3.820 I put the top ring in the bore and the gap is larger than .040 since my feeler gauges only go up that high.


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You can't run a 20 over piston in a 30 over hole.
 
I got the piston and rings, what is the gap on the rings, got a wiseco forged piston 3.820 I put the top ring in the bore and the gap is larger than .040 since my feeler gauges only go up that high.


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Wait what? You put in another brand piston that is not the right size?


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I don't believe it is 30 over, something isn't right. From the look of the bearings ( main & rod) I don't see why it would be 30 over and no bearings put into the engine, 160k on the stock bottom end. I put that piston in and it's holding 140 psi and running decent. All the other pistons are 155-160. I put a patch on it now until I can get the money together to build it. Put new main and rod bearings and tightened everything up and seems fine. Stopped a lot of oil leaks and some other new parts.


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Trying to figure out why it's overboosting/spiking, which I'm trying to figure out now. It's running better than before but not quite perfect.


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Run a brand new hose with zip ties from the turbo straight to the wastegate and see what that does.

I would also HIGHLY recommend a magnetic drain plug.
 
Trying to figure out why it's overboosting/spiking, which I'm trying to figure out now. It's running better than before but not quite perfect.


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Internal or external waste gate ? Might have to port the exhaust hole on the turbo housing to get the pushing pressure out of the housing faster/easier.
 
Run a brand new hose with zip ties from the turbo straight to the wastegate and see what that does.

I would also HIGHLY recommend a magnetic drain plug.

Ok, take out the rjc controller out and just run a hose to it right?

I have a magnetic drain plug already.


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Internal or external waste gate ? Might have to port the exhaust hole on the turbo housing to get the pushing pressure out of the housing faster/easier.

I've been hearing that also, it is a external wastegate, anyone tell me what brand it is?

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I've eliminated the y fitting going to the factory solenoid and running it from the compressor to the controller then to the wastegate.


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