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Old 03-23-2011, 11:14 AM
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Quote:
Originally Posted by anglia427
i would start with a leak down test first before tearing that thing apart.check one cyl. at a time,make shure valves are closed and conect air pressure into spark plug hole and see if you can hear for air leak at exhaust or intake and crankcase this will rule out valve and ring leaks.
leak down won't work as rings have not been seated yet. tried presurizing the cylinders and valves are definitely closing. some blow by the rings is obvious, but I expect that.

ya, did the compression test after all else failed and wouldn't strart. question, would it fire up with such low compression? and if not where does it need to be?

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Old 03-23-2011, 11:58 AM
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Missing piston rings, missing/incorrect head gasket, reverse rotation ( marine) cam. Bent valves.
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Old 03-23-2011, 12:53 PM
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low compression

Quote:
Originally Posted by theccrider
leak down won't work as rings have not been seated yet. tried presurizing the cylinders and valves are definitely closing. some blow by the rings is obvious, but I expect that.

ya, did the compression test after all else failed and wouldn't strart. question, would it fire up with such low compression? and if not where does it need to be?
depends on your compression ratio but 140 or so would be a reasonible starting point,how much air is getting past rings even new rings should seal with out break in,also do you remember what the ring gaps were when checked?
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Old 03-23-2011, 01:11 PM
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If all you got on a compression test is 40psi, its not going to start.

Usually around 70 to 80psi it gets real hard to start up.
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Old 03-23-2011, 02:06 PM
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Quote:
Originally Posted by Irelands child
- 180* off on "timing" the chain (crank turns 2x for ever 1x of camshaft)
or
- valves not seating - adjustment, camshaft, lifters, pushrods
You cant be 180 off on the timing chain. Once you turned the crank 1 revolution it would be back to correct.
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Old 03-23-2011, 02:13 PM
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Quote:
Originally Posted by theccrider
leak down won't work as rings have not been seated yet. tried presurizing the cylinders and valves are definitely closing. some blow by the rings is obvious, but I expect that.

ya, did the compression test after all else failed and wouldn't strart. question, would it fire up with such low compression? and if not where does it need to be?
It wont start with 40lbs. Does the crank sprocket have more than 1 key way.
You need to rule out cam timing first as it is the most obvious cause as long as everything (gaskets, rings etc) are all installed properly.
A leak down test could still be beneficial, you will still have some leakage but it should still be fairly slow. If you back off the valves and put 150LBS of air in the cylinder, if there is something major wrong it should show up.

If you have the cam card you can check cam timing with a degree wheel or a taped balancer. By looking at the opening degree spec of the intake you should be able to see if you are ok.
This beats tearing the engine apart.
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Old 03-23-2011, 02:15 PM
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Where in MA are you located. If you are close, maybe I can help you
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Old 03-23-2011, 03:00 PM
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Did you put the pistons/rings in the cylinders dry? They need oil on them to seal. If all else is correct, put a couple squirts of 10W30 in each spark plug hole. Might up the compression enough to start??
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Old 03-24-2011, 07:19 AM
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shart

I'm in foxboro

AARRGGHH, nothing i can think of left to check on the outside, looks like i'm goin in captain.

Pistons went in wet (two months ago), I can't think of anything I could have missed, so into the rabbit hole I go. Any suggestion of what to look for would be great. obviously ring offset and position, degree the cam ( just for the f of it), check that the cam hasn't washed with all the cranking, but anything else?

This is what it looks like this morning.... but lot for long
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Old 03-24-2011, 07:24 AM
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Just curious, have you tried the compression tester on another vehicle. It bugs me that you say it goes back down to 0 from 40. Most have a check valve that holds the highest reading. You say you used several gauges, did you use the same hose with all of them.
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Old 03-24-2011, 07:29 AM
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Tried three guages and two different hoses. I think when I pull it back down I'm going to mic the bores, initially I just checked the ring end gap.
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Old 03-24-2011, 07:30 AM
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I guess sometimes the shortest distance between two points can still be the wrong way
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Old 03-24-2011, 07:43 AM
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Chet looks like it's time for a road trip. I'm in Bellingham and Chet is near Worcester.

You know you're in for it when 2 moderators come knocking. lol
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Old 03-24-2011, 06:16 PM
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my 2 cents

It has been my experience that even the poorest of rings still seal enough to create a good initial pressure. Especially if you have squirted oil in the bore. I would completely remove all of the rockers thus totally eliminating the valve train. My bet would be head gasket issues. Either improperly seated or improper gasket. Did the intake manifold bolt right up easily and uniformly? If not that would indicate that the heads were not totally seated to the block.
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Old 03-25-2011, 12:39 PM
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I'm figuring something in the bottom end isn't right. Did the rocker thing and it was breathing heavy in the pan. Its out now so i can tear it down and hopefully it was a brain fart when I assembled it.

I'll let you guys know what I found, Thanks
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