no compression
- ritchiegilby
- 40C crawler
- Posts: 20
- Joined: Mon May 05, 2008 5:25 pm
- Location: Enfield NS CANADA
- Contact:
no compression
hi all just re ringed a running 1010 gas, ran it for about 2 hours, now NO compression in 2and 3 cylinders. less than 30 psi in 1 and 4 it ran fine while it was running, distributor is still turning, cam and crank are lined up with the DC on flywheel and still makes 50 psi oil pressure while cranking engine,all pistons are moving full stroke, valves closing etc. .....I am dumbfounded. don't want to pull head yet, though i know it is next...my wifes uncle, who plays with old iron says maybe the rings did not seat, why did it make enough compression to run fine for a couple of hours then lose compression in all cylinders at the same time....
any ideas would be great
Ritchie
any ideas would be great
Ritchie
- joeturner1977
- 430 crawler
- Posts: 53
- Joined: Tue Feb 17, 2009 11:59 am
- Location: central WI
If you want to know for certain, put an air fitting used for holding the valves shut while changing individual valve seals in place of the spark plugs & see where the air is going. I'll bet that 2 & 3 are leaking across to each other & 1 & 4 are leaking into 2 & 3 respectively. That pattern would account for the pressures. What would cause that pattern? Head bolts insufficiently torqued, or torqued to spec in threads not chased of corrosion/old sealer. Regardless, the process of finding where the air is going will tell the story. Here's hoping that you can remedy the situation without snatching the head off again! I like the Permatex Teflon paste product for sealer/lube on head bolts.
- Willyr
- 2010 crawler
- Posts: 695
- Joined: Sat Jul 17, 2010 3:03 am
- Location: Downeast Maine (North of Ellsworth)
I trust also that you did not re use the old headgasket. Yet I too would suspect your valves.
former owner of a 1956 420c
All help is greatly appreciated.
Proud owner of a project 1952 JD 60
http://www.youtube.com/watch?v=nFehqXVd9z4
All help is greatly appreciated.
Proud owner of a project 1952 JD 60
http://www.youtube.com/watch?v=nFehqXVd9z4
- ritchiegilby
- 40C crawler
- Posts: 20
- Joined: Mon May 05, 2008 5:25 pm
- Location: Enfield NS CANADA
- Contact:
HD was i supposed to use sealer on the head bolts ???
the manual i have did not specify to so i did not. I have done several other engines. sb chevs, jeeps etc, did not do anything that i have not done on others.
the valves are set to spec .12 and .18 if valves were the case would i not hear air leaking through the valves ?
willyr
i did not reuse any old gaskets.....bought complete gaskets set upper and lower
the manual i have did not specify to so i did not. I have done several other engines. sb chevs, jeeps etc, did not do anything that i have not done on others.
the valves are set to spec .12 and .18 if valves were the case would i not hear air leaking through the valves ?
willyr
i did not reuse any old gaskets.....bought complete gaskets set upper and lower
- Willyr
- 2010 crawler
- Posts: 695
- Joined: Sat Jul 17, 2010 3:03 am
- Location: Downeast Maine (North of Ellsworth)
The fact that after it warmed up, was when you lost compression. Leads me to ask did you do a compression check before you started?
If you do have a adapter for the spark plugs, hook it up to compressed air and start looking. No idea about being able to hear the air leak. With my hearing, I constantly am hearing an air leak 24/7.
If you do have a adapter for the spark plugs, hook it up to compressed air and start looking. No idea about being able to hear the air leak. With my hearing, I constantly am hearing an air leak 24/7.
former owner of a 1956 420c
All help is greatly appreciated.
Proud owner of a project 1952 JD 60
http://www.youtube.com/watch?v=nFehqXVd9z4
All help is greatly appreciated.
Proud owner of a project 1952 JD 60
http://www.youtube.com/watch?v=nFehqXVd9z4
I'd figure the biggest factor is chasing the threads in the block & on the bolts themselves. It might be possible to drain the coolant & R&R the bolts one at a time After running a tap brazed to a tap extension through the holes, IDK. As far as ear enhancement, a piece of heater hose makes a good isolator/ear trumpet. I've just got a thing about using the Teflon paste on head bolts that run into water jackets & light oil (3in1 or Liquid wrench) on bolts that go in blind tapped holes. I also believe in running the torque sequence multiple times, taking the bolts down 15 ft/lbs a trip. I could well be wrong, but the air doesn't lie. Oh, did you think to check the 'flatness' of the head & block while it was apart? I've been bitten by that as well.
- ritchiegilby
- 40C crawler
- Posts: 20
- Joined: Mon May 05, 2008 5:25 pm
- Location: Enfield NS CANADA
- Contact:
i did not check the flatness of block or haed as the engine ahd been running prior to the re ring, the book did not specify any"open"unselaed bolt holes so i did not use a thread sealant. the head bolts were all torqued as per the directions in the book. one thing i will check tonight is the air leak with a pressure test, is it possible that my local engine rebuilder supplied me with the wrong head gasket ??? after the air test the head is my next step, or the cam gear moved on the cam possibly shearing the key though i did not take the cam or the crank out of the engine ......
- Eric.MacLeod
- 440 crawler
- Posts: 120
- Joined: Sun Feb 10, 2008 9:15 pm
- Location: wells,maine
- ritchiegilby
- 40C crawler
- Posts: 20
- Joined: Mon May 05, 2008 5:25 pm
- Location: Enfield NS CANADA
- Contact:
- ritchiegilby
- 40C crawler
- Posts: 20
- Joined: Mon May 05, 2008 5:25 pm
- Location: Enfield NS CANADA
- Contact:
- ritchiegilby
- 40C crawler
- Posts: 20
- Joined: Mon May 05, 2008 5:25 pm
- Location: Enfield NS CANADA
- Contact:
If you have a good piston out, we will need to compare dimensions. The kit I have is aftermarket, and no application, so we will have to do some measuring to be sure they will fit.
As to another engine, I guess I would not. An original engine overhauled ads value. Cobbling in something else pretty well ruins it. Plus, if you go any bigger in HP, you will be buying drivetrain components.
Lavoy
As to another engine, I guess I would not. An original engine overhauled ads value. Cobbling in something else pretty well ruins it. Plus, if you go any bigger in HP, you will be buying drivetrain components.
Lavoy
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