1952 compression

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dterhaar2000
Posts: 35
Joined: Wed Jan 02, 2019 7:56 pm
Zip Code: 47330
Tractors Owned: 1952 Farmall Cub

1952 compression

Postby dterhaar2000 » Sun May 02, 2021 1:55 pm

First off I know there are several threads talking compression, but I couldn't find one like my situation.

Awhile back I did a clutch and rear main. Got it all back together and wouldn't start. I replaced coil, condenser, points, plugs, wires, rotor, and distributor cap. Still nothing. So I got it back in time and she started for a minute or so. But wouldn't restart.

I was guided to do compression tests on one of my earlier posts. I had reading 30-50 on all cylinders dry and wet. So I decided to dive in and do a complete valve and pistons and rings. Figured head was off, perfect time to do it. Valves are set to .013 gap like the manual said. My compression wont go over 60 now. They all are free and move well. When cranking I feel a small poofs of air by the fan.
What am I missing? I feel I have checked everything I know of.
Thanks

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raystractors
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Re: 1952 compression

Postby raystractors » Sun May 02, 2021 3:43 pm

Did you dress the valves and seats? Did you hone the cylinders? Did you check the ring end gap when they were installed?

dterhaar2000
Posts: 35
Joined: Wed Jan 02, 2019 7:56 pm
Zip Code: 47330
Tractors Owned: 1952 Farmall Cub

Re: 1952 compression

Postby dterhaar2000 » Sun May 02, 2021 4:05 pm

I honed the cylinders and had the ring gaps offset. I also lapped the valve seats and valves. The valves are working as they should, not 1 is stuck. I blew air into the cylinders. Cylinder 1 is tight. 4 goes thru exhaust 2 is tight and 3 goes through carb on manifold. I have the carb off right now.

Eugene
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Re: 1952 compression

Postby Eugene » Sun May 02, 2021 4:11 pm

Wet compression test results were?
I have an excuse. CRS.

dterhaar2000
Posts: 35
Joined: Wed Jan 02, 2019 7:56 pm
Zip Code: 47330
Tractors Owned: 1952 Farmall Cub

Re: 1952 compression

Postby dterhaar2000 » Sun May 02, 2021 4:47 pm

60-65 psi for all 4 cylinders

tst
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Re: 1952 compression

Postby tst » Sun May 02, 2021 4:59 pm

you have problems with compression, that is why it does not run,need at least 90 lbs to run and have sum power
put air in the cylinder, if it comes out carb its a bad intake, comes out exhaust, bad exhaust valve
blows back through oil filler bad rings/piston

dterhaar2000
Posts: 35
Joined: Wed Jan 02, 2019 7:56 pm
Zip Code: 47330
Tractors Owned: 1952 Farmall Cub

Re: 1952 compression

Postby dterhaar2000 » Sun May 02, 2021 6:08 pm

I have air coming out of the back 2 manifold holes. Hole 5 and 6. How do I go about fixing it? Do I need to remove the head and relap the valves?

Jim Becker
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Re: 1952 compression

Postby Jim Becker » Sun May 02, 2021 7:04 pm

dterhaar2000 wrote:I have air coming out of the back 2 manifold holes. Hole 5 and 6. . . .

Did you bring each individual cylinder to TDC on the compression stroke to apply pressure to each cylinder?

dterhaar2000
Posts: 35
Joined: Wed Jan 02, 2019 7:56 pm
Zip Code: 47330
Tractors Owned: 1952 Farmall Cub

Re: 1952 compression

Postby dterhaar2000 » Sun May 02, 2021 7:41 pm

I didn't but just did it. I'm getting air from the last manifold hole with cylinder 3 and 4 at TDC. I have the valve cover off and can watch all the valves do their thing.

Eugene
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Re: 1952 compression

Postby Eugene » Sun May 02, 2021 7:46 pm

Double check your valve/tappet clearance.
I have an excuse. CRS.

dterhaar2000
Posts: 35
Joined: Wed Jan 02, 2019 7:56 pm
Zip Code: 47330
Tractors Owned: 1952 Farmall Cub

Re: 1952 compression

Postby dterhaar2000 » Sun May 02, 2021 7:52 pm

It's at .013.

Eugene
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Re: 1952 compression

Postby Eugene » Sun May 02, 2021 8:02 pm

dterhaar2000 wrote:It's at .013.
OK. Then don't double check. But I would.
I have an excuse. CRS.

dterhaar2000
Posts: 35
Joined: Wed Jan 02, 2019 7:56 pm
Zip Code: 47330
Tractors Owned: 1952 Farmall Cub

Re: 1952 compression

Postby dterhaar2000 » Sun May 02, 2021 8:09 pm

I did double check. It is at .013. That is the correct clearance? Or is it .015?

Eugene
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Re: 1952 compression

Postby Eugene » Sun May 02, 2021 8:18 pm

Head and head gasket not seated.
I have an excuse. CRS.

dterhaar2000
Posts: 35
Joined: Wed Jan 02, 2019 7:56 pm
Zip Code: 47330
Tractors Owned: 1952 Farmall Cub

Re: 1952 compression

Postby dterhaar2000 » Sun May 02, 2021 9:01 pm

I just bought a new head from steiner about 2 weeks ago. I'll look at that again and make sure the bolts are torqued to 45 ft lbs. What would cause it not to seat properly? I cleaned the top of the block very well before putting it on.


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