Motorgen - Automotive Events, Meets, Cruises and Forums

Page 2 of 8

Last »

Show 40 post(s) from this thread on one page

Motorgen - Automotive Events, Meets, Cruises and Forums (http://www.motorgen.com/forum/index.php)

- Engines, Transimissions, Suspension, etc. (http://www.motorgen.com/forum/forumdisplay.php?f=98)

- - Another misfire in the Cobra! (http://www.motorgen.com/forum/showthread.php?t=25160)

Throttle Crazy

02-15-2011 09:22 AM

That's actually 16% leakage, but still good.

Vettezuki

02-15-2011 10:58 AM

Quote:

Originally Posted by 94cobra69ss396 (Post 68481)

I can't get down there to look into the spark plug hole and I don't have borescope. However, I did compress the valve springs down to make sure they moved freely. The 10% leakage tells me that there isn't a broken piston ring, blown head gasket, or even a hole in the piston. I'm not sure where the piston is at relative to the stroke but I probably should make sure it is at bottom dead center and do the leak down test again. That way I can make sure that there isn't a crack in the cylinder wall.

I think he's on the road, but big2bird has a bore scope if you want to take a look.

94cobra69ss396

02-15-2011 12:03 PM

I ordered the new rocker arm and pushrods. I'm just going to bolt it back together when they come in and see how it runs.

enkeivette

02-15-2011 04:56 PM

If there was a crack in the cyl wall or the piston it would puff air out of the rocker cover like a steam engine.

Can you see the lifters?

enkeivette

02-15-2011 04:56 PM

When I first assembled my motor I had pushrod guide plate clearance issues. Check yours to make sure they haven't shifted, causing binding.

94cobra69ss396

02-15-2011 06:54 PM

Quote:

Originally Posted by enkeivette (Post 68653)

If there was a crack in the cyl wall or the piston it would puff air out of the rocker cover like a steam engine.

Can you see the lifters?

I thought about that later. I don't have guide plates because I have shaft mount rockers. Take another look at the first picture.

Shaolin Crane

02-16-2011 01:14 PM

did you inspect the lifters and that portion of the cam to see what could have caused the bind? One lifter might have extended out of the block and thats what bent the pushrod or snapped the rocker, i would investigate further while you have everything apart.

94cobra69ss396

02-16-2011 01:19 PM

The lifters are fine. I can't see the cam and I don't want to take the front end apart to pull it. I'll put it together and then hand cycle the engine over a couple times to make sure it all looks good. If it does then I'll put the intake back on and do a compression test as well as another leakage test. If they both come out good I'll start it up and see how it runs.

enkeivette

02-16-2011 02:02 PM

This is so strange. I can't visualize what might have happened.

94cobra69ss396

02-16-2011 02:08 PM

Phil and I are at the same point. It broke the exhaust rocker and bent the intake pushrod but everything seems fine. The valves move freely and are sealing so they're not bent. The leak down shows that the rings and piston should be fine. I'm just hoping what happened is that the rocker was fatigued and broke and some how caused the intake to bind momentarily which bent the pushrod.

All times are GMT -7. The time now is 03:12 PM.

Page 2 of 8

Last »

Show 40 post(s) from this thread on one page