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Thread: Some thoughts upon Built motor dissasembly

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Posts: 21-30 of 58
2010-03-08 06:00:43
the pistons should rock forward and aft to the engine layout. That is normal. The skirts on the pistons resist side-to-side movement from the crank pull/push. Even a fresh new Nissan motor will have some play in there.

If you don't see any scoring or chatter marks on the cylinder walls, then perhaps there is just a bit of bad sealing on the head?

It is worth using another gauge as well because I know some (like mine) read pretty low. I was getting just barely over 100psi on this motor, and only 170psi on my stock VE. I changed the compression tester and the 100psi turned into 145-150 across the board.

Checked a fresh DET and it had 155psi across the board with the factory pistons/ring gap. So I am in the clear now. Cylinder 2 was reading lower than the rest, but it has swallowed some plugs in the past lol. Minor piston pitting can be seen on the top of the piston when you take the plugs out. 5psi is negligible though. The motor runs like a raped ape.
2010-03-09 02:33:12
dont put the ve head on with the det pistons especially the way you drive and rev that motor
2010-03-09 02:43:37
VE head with stock cams, and Supertech S&R's, ive done my research on the clearance and have ran a de+ve head before without issues with stock cams. I plan to rev to 9500 and it should not be a clearance issue with it. I would never rev that high on N1's thats for sure.

Ive decided to keep the bottom end block and just build a sleeved block motor on the side. Its final. My compression numbers are not that bad and the bore is still in great shape. Plus with the ve head the compression will be 9.2:1 and should boost the numbers quite a bit. Will be a fun motor with the 72mm T4 open .82 housing turbo im going with. Turbo is good to a little over 800whp. Ill be shooting for 750whp give or take. Ive seen eagle rods take the abuse before and i have no doubt that mine should as well. Ive got everything else in line as far as bearing oil clearances, good ve oil pump, and CP pistons, cant go wrong there. The pistons are in great shape too. Not bad at all.

And dont forget the GE studs. Dang those things hold. I can see why miller uses them in his 1200whp civic.
2010-03-09 02:45:04
okay good luck when it breaks I would like a piston for my wall of shame
2010-03-09 02:49:54
lol, hahaha, not gonna happen (getting a piston) but hey if it breaks it breaks. My original plan for the build was to just buy a new ve motor anyways and tear it apart, send the block out, and yada yada yada. since i can get one for 875 anyways. But i want to see how much abuse my motor can really take and how much the stock sleeves can really take. Should be interesting enough. Ive seen a couple stock sleeve blocks go 700+ for a long while.

But hey its all learning. I want to be able to safely rev higher, not worry about throwing rockers if i pounded off the limiter. Hell the only reason i dont just pound the rev limiter on my burnouts now is because of that, fear of throwing the rocker.

Not to mention the added flow from the VE head. That and the minor port work ill be doing to it as well.
2010-03-09 02:53:40
I know its going to break with the ve head on the det pistons
2010-03-09 02:57:49
And how would you know this, ?? last i looked mazworx has done ve heads on det blocks all the time with stock sr20ve cams without an issue at all of clearance. Last i checked as well the det pistons have more of a dish than the stock 9.5:1 pistons do and thats been done how many time???? its not the revs thats gonna kill it, again S&R's, and good ones will take care of that issue. No floating= happy valves and pistons.
2010-03-09 03:08:39
Try a different compression tester. One time I had a compression tester and it tested 80 accross the board. I definetly did the test correctly, I knew it was ok because it was consistent across the board, no one cylinder was low, and no two cylinders next to eachother were low.

I tried a different tester a month later and it was 140-150 across.
2010-03-09 03:12:21
Thing is it was a brand new tester right out of the package. And there were variations from cylinder to cylinder. but again not rediculous. My vac with the s4 cams was still pulling 12-13 hg at 750rpm idle. Same as what it is on code3smiths car with the s4's in there now, so i know its not related to a piston problem.

Again test was done cold as well. So it again probably wasnt very accurate to do it that way anyways. But figured id give it a try.
2010-03-09 04:11:24
What pistons you running again? What brand? I wouldn't trust the wiseco with a VE head. JE pistons have huge valve reliefs for oversized valves and are 2mm deeper as well. Even the reg DE pistons from JE work really well for the VE.

On another note, off topic. I started my lil beast today for the first time in months. I love the smell of unspent fuel vapors from a catless exhaust. Thursday I am taking it down to the shop to fix a few leaks and fit the new A/W intercooler.

750whp on your car will be insane. I don't know how you will keep it planted. You will need a shute, that's certain. Trapping 160mph lol.
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