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Old 04-22-2007, 05:31 PM   #1
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Default My engine has Interference ... why?

Ok so a week after I spun a rod bearing, i have begun to poke around and try to figure out once and for all where all that oil was leaking from on the front. My first step was to remove the cover behind the timing gears and warm the motor up to have a look ... hopefully then I would be able to see the leak. It was at this point that I discovered that I was able to make both intake and exhaust valves interfere with the piston at TDC. Since they both hit, I dont think I installed the pistons with the relief cuts on the wrong side. The only thing that has been altered that could affect this is a resurfaced head and carillo rods from FM. So either I got the wrong set of rods, which I find unlikely ... or the head was shaved too much which is more likely.

I guess it explains why I got 210 on my compression test eh? Anyway I guess Ill still use the motor, but keep the boost at around 10psi until it blows or something and keep a watchful eye on the timing belt as well. It also explains why the car felt soooo freaking fast at only 8psi. I suppose I could pull the head and get an oversized gasket to lower it a bit, but Ive got a nice cometic one on there right now and that **** is $$. If I blow this motor after fixing it, I am going with a stock and unmolested one next.

Any thoughts??
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Old 04-22-2007, 05:45 PM   #2
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i know someone who tore down an engine FM built when they got into that business early on (a couple of years ago). his pistons were making contact with the head. (wtf!) i don't think FM's engine/head quality is as good as they think it is. i think your guess of too much of a shave is correct.

for central cal, i woud have considered tri-point engineering in LA.
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Old 04-23-2007, 12:27 AM   #3
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when did you have the head worked on by FM??? They had problems with their engine builder (Replika).
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Old 04-23-2007, 12:45 AM   #4
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FM didn't do my head, I did an extremely mild port and polish and combustion chamber polsh/deshroud myself, then took it to a local shop to be resurfaced and I specified that I wanted as little taken off as possible. Only thing FM did was send me some parts. Oh well, actually sort of like the idea of a highish compression turbo engine.

In other news, i get to work on pulling the motor tonight and got to the point where all that is keeping the motor from being pulled is the transmission (having a bit of trouble separating it) It will be the 6th time i have pulled a motor out of this car in the year I have owned it lol. It has not gotten much quicker, but less stressful and clean for sure
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Old 04-23-2007, 12:48 AM   #5
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Damn i thought my 3 times this year was bad you make me feel better about doing it atleast it gets quicker and easier everytime why not pull both together? That is the way i do it. Anywho GL man, are you going to go with some billet oil pump gears, i have been thinking about it myself.
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