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Thread: Some thoughts upon Built motor dissasembly

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2010-03-07 20:28:42
Some thoughts upon Built motor dissasembly
Well i now know why the compression on my motor was soo low and always has been. After getting the head off it was apparent now that everything wasnt soo shiny. The piston has soo much play in the bore all the way around, not just front and back that i can probably almost fit an 87mm piston in there and it would be probably be fine.

My pistons are the CP 86.5mm. Its rediculous that the machine shop screwed it up that bad. They have done overbores before without issues. But they even had the pistons on hand while doing the bore. Oh well. Live and learn i guess. I can guarantee this is why the rings were not sealing properly.

Another thing is the Golden Eagle head studs are absolutely amazing. 10k miles, one year of use and no retorquing necessary and they were tight as hell. This was following the installation instructions provided by Golden Eagle to a T. I love it. The pistons, block and gasket have no signs of any detonation at all, ever.

Ill post some pics up.
2010-03-07 20:32:50
how low was your compression? sometimes the machine shops leave them loose for very high boost motor...
2010-03-07 20:32:53
One thing we have learned was to get our blocks and pistons matched per cylinder. We have never just sent a block out to get bored without providing the pistons for cylinder matching. I have seen this happen many times when cylinders are bored out to big or the off the shelf pistons were not exactly the size they were sold for.

Did your motor piston slap at all?
2010-03-07 21:19:17
No, no slap at all. Thats the weird part. The cylinder walls are pretty darn good as well. I understand high boost turbo motors are left looser on the piston to wall clearance but this amount is rediculous.

According to the CP sheet if i remember right for boost aps the wall clearance should be between 8 and 11 thousandths Its tighter with n/a motors.

But i can tell you right now that the piston to wall clearance is way more than that. I can litterally move the piston both side to side and back and forth. I can push it up agains one side of the wall and look down and see probably half the ring width or more.

I did send the pistons with the motor to get matched. I wouldnt have done it any other way.

Well time to send the block to mazworx for sleeving. Im gonna stick with the 86mm standard bore as well. CP ve pistons. What rods would you guys recommend for 700-800whp. I know the eagles have been proven to handle that much but i dont want to risk it. Im thinking of going with maybe the manley turbo tuff rods. I know honda guys using them to 900-1000 whp.
2010-03-07 21:20:17
my compression was 110, 120, 130, 130. This was done cold and with the S4 cams.

Last time i did it hot was back in May of last year and it was 145, 150, 130, 145.
2010-03-07 21:27:03
I have manley h beams for my build but do not intend to make that much power.
2010-03-07 21:28:36
yeah that's pretty low which backs up your post. there's a place in CT that does the darton or aebs sleeves for $1100.00 parts and labor.
2010-03-07 23:23:18
shhhhhhhh giving out all the secrets haha.
2010-03-08 00:04:58
Mazworx is doing sleeved blocks for 675 right now includes parts and labor lol that's where my block is going. Overall I'm very happy with how well my motor took the abuse I threw at it and I'm sure it would have taken another year of the same abuse without a hitch. Other than the blowby which was plenty tollerable its been a dream. It had no troubles during up or running. Usually fired with one crank revolution. So I couldn't have been happier. This next motor will be even bigger and better. Go big or go home.
2010-03-08 00:08:44
Highly doubt they are doing it for 675
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