The Ford Barn

glenn in camino · 04-14-2013, 04:43 PM

I've driven my A 50 miles since I installed new rings and a Snyder 5.5 head. This morning it wasn't running right so I checked the compression and found that #1 had 0. There was also oil coming out the breather pipe. I suspect a broken ring so I'm pulling the head and pan to pull out #1 piston. I'll let you know what I find.

Patrick L. · 04-14-2013, 05:16 PM

Could hear anything strange or different ? Did you try and check the valve lash or retightening the head gasket?

Larry Seemann · 04-14-2013, 06:17 PM

Check for a stuck valve. Lots easier than pulling the head!

Tom Wesenberg · 04-14-2013, 06:31 PM

Turn the engine to number 1 firing, then remove the spark plug and blow air down the plug hole. If it comes blowing right out the breather then it sounds like a busted piston. Out the intake or exhaust could be a stuck valve.

Mitch//pa · 04-14-2013, 06:35 PM

Agree do a leak down test first but with your description of blowby sounds like piston

QGolden · 04-14-2013, 06:37 PM

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Quote:

Originally Posted by Tom Wesenberg

Turn the engine to number 1 firing, then remove the spark plug and blow air down the plug hole. If it comes blowing right out the breather then it sounds like a busted piston. Out the intake or exhaust could be a stuck valve.

I've never thought of that!. Brilliant.

Tom Wesenberg · 04-14-2013, 07:15 PM

Quote:

Originally Posted by Mitch//pa

Agree do a leak down test first but with your description of blowby sounds like piston

I agree that it's almost got to be a busted piston. I'm anxious to see the picture and wonder what was the cause. I know the high compression head needs LESS spark advance, so I hope it wasn't from driving too advanced.

P.S. · 04-14-2013, 07:22 PM

Quote:

Originally Posted by Tom Wesenberg

Turn the engine to number 1 firing, then remove the spark plug and blow air down the plug hole. If it comes blowing right out the breather then it sounds like a busted piston. Out the intake or exhaust could be a stuck valve.

That's BRILLIANT!!!

Richard in Anaheim CA · 04-14-2013, 10:31 PM

Glenn,

I think it is a stuck valve. You would get some blowby out the breather with only 50 miles on it anyhow. Look down the sparkplug hole with the engine at TDC. You may see a valve open.

Dump some Marvel Mystery Oil in the gas and squirt some in #1while you are at it.

Richard
Anaheim CA

MikeK · 04-14-2013, 10:34 PM

With your oil puking out the filler pipe it's not likely a valve. A piston doesn't have to break or have a hole to show zero. This engine was 52-58-55-0. This piston design did not have a reduced diameter at the ring lands. Running about 58mph it was at full throttle and the piston heat expansion exceeded the bore. It was not overheated, the water was about 180. The scraping froze the rings fully compressed into the lands and when it cooled off and the piston contracted there was no ring contact. This was not a build that I did !

Surprisingly the cylinder was not very scuffed and would have cleaned up with just a light touch of the hone and the piston could have been saved with a ring groove reamer and a little clean up. Not being a babbitt fan, I just threw the pistons and rods in the trash and rebuilt everything.

04-14-2013, 05:16 PM	#2
Patrick L. Senior Member Join Date: May 2010 Location: Largo Florida Posts: 7,225	Re: 0 compression in # 1 Could hear anything strange or different ? Did you try and check the valve lash or retightening the head gasket?

04-14-2013, 06:17 PM	#3
Larry Seemann Senior Member Join Date: May 2010 Location: Spokane, WA. Posts: 496	Re: 0 compression in # 1 Check for a stuck valve. Lots easier than pulling the head! __________________ Larry Seemann

04-14-2013, 06:31 PM	#4
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: 0 compression in # 1 Turn the engine to number 1 firing, then remove the spark plug and blow air down the plug hole. If it comes blowing right out the breather then it sounds like a busted piston. Out the intake or exhaust could be a stuck valve.

04-14-2013, 06:35 PM	#5
Mitch//pa BANNED Join Date: May 2010 Location: Bucks County, PA Posts: 11,454	Re: 0 compression in # 1 Agree do a leak down test first but with your description of blowby sounds like piston

04-14-2013, 10:31 PM	#9
Richard in Anaheim CA Senior Member Join Date: May 2010 Location: Anaheim California Posts: 562	Re: 0 compression in # 1 Glenn, I think it is a stuck valve. You would get some blowby out the breather with only 50 miles on it anyhow. Look down the sparkplug hole with the engine at TDC. You may see a valve open. Dump some Marvel Mystery Oil in the gas and squirt some in #1while you are at it. Richard Anaheim CA

04-14-2013, 04:43 PM	#1
glenn in camino Senior Member Join Date: May 2010 Location: Camino, CA. Posts: 3,086	0 compression in # 1 I've driven my A 50 miles since I installed new rings and a Snyder 5.5 head. This morning it wasn't running right so I checked the compression and found that #1 had 0. There was also oil coming out the breather pipe. I suspect a broken ring so I'm pulling the head and pan to pull out #1 piston. I'll let you know what I find.

04-14-2013, 10:34 PM	#10
MikeK Senior Member Join Date: May 2010 Location: Windy City Posts: 2,919	Re: 0 compression in # 1 With your oil puking out the filler pipe it's not likely a valve. A piston doesn't have to break or have a hole to show zero. This engine was 52-58-55-0. This piston design did not have a reduced diameter at the ring lands. Running about 58mph it was at full throttle and the piston heat expansion exceeded the bore. It was not overheated, the water was about 180. The scraping froze the rings fully compressed into the lands and when it cooled off and the piston contracted there was no ring contact. This was not a build that I did ! Surprisingly the cylinder was not very scuffed and would have cleaned up with just a light touch of the hone and the piston could have been saved with a ring groove reamer and a little clean up. Not being a babbitt fan, I just threw the pistons and rods in the trash and rebuilt everything.