The Ford Barn

GITCHIGUMI · 06-25-2014, 12:57 PM

Having problems getting a flathead in a 41 fordor to run right. Did a compression test this AM. All but #2 come in at 90 lbs or better. #2 comes in at a paltry 30 lbs. Added some motor oil, but no change. The test was done cold as we cannot get the thing started right now.

Car sat overwinter each of the last couple of years after purring and running like a kitten 2 years ago. Had similar rough running last two years although this year its particularly bad.

We have poured in some MMO and are going to let it sit till tomorrow. I'm thinking a valve problem, hopefully only stuck open, and not rings. Any words of wisdom?

Would one cylinder with low compression cause the thing to basically run like a piece of.... you know what I mean.?

Any comments would be appreciated.

41panelmark · 06-25-2014, 01:09 PM

I just got one running that had even compression in all but one cylinder. It ran pretty well other than a miss. I ended up having to do some work on an exhaust valve seat. You may have carb issues along with the low cylinder. Might also want to check over the distributor/points and related. It should start even if one cylinder is bad so I would guess you have some other problems.

Bruce Lancaster · 06-25-2014, 01:15 PM

Commonest problem with long storage on a flathead is a valve sticking open...peer into plug hole of bad cylinder while someone slowly rotates engine with the crank.
If it is stuck, squirt some oil down that hole and push down with a screwdriver or something, keep rotating and pushing if the thing moves until it loosens up enough for spring to handle it. Put some MMO into oil to promote healing.
Be careful on the pushing...valves are easier to bend than you might think!

FRANK PKNY · 06-25-2014, 01:29 PM

Almost always a stuck valve, if it's been sitting. the MMO should do the trick without putting foreign objects into the plug hole. JMHO

GITCHIGUMI · 06-25-2014, 04:47 PM

Thanks very much for the replies. Time and applying your suggestions will tell the end of the tale.

regards

Gitchi.

B-O-B · 06-25-2014, 04:55 PM

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You did not state if you ran any MMO & marine grade sta-bil,seafoam or other gas stabilizer thru the engine before storing for the winter.
Your carb & or fuel pump may have issues also along with the stuck valve.

flatjack9 · 06-25-2014, 05:21 PM

When you take the plug out, the exhaust valve will be easily visible. You will just be able to see the edge of the intake valve.

06-25-2014, 12:57 PM	#1
GITCHIGUMI Junior Member Join Date: May 2010 Location: Thunder Bay, Ontario Canada Posts: 14	Need and educated guess Having problems getting a flathead in a 41 fordor to run right. Did a compression test this AM. All but #2 come in at 90 lbs or better. #2 comes in at a paltry 30 lbs. Added some motor oil, but no change. The test was done cold as we cannot get the thing started right now. Car sat overwinter each of the last couple of years after purring and running like a kitten 2 years ago. Had similar rough running last two years although this year its particularly bad. We have poured in some MMO and are going to let it sit till tomorrow. I'm thinking a valve problem, hopefully only stuck open, and not rings. Any words of wisdom? Would one cylinder with low compression cause the thing to basically run like a piece of.... you know what I mean.? Any comments would be appreciated.

06-25-2014, 01:15 PM	#3
Bruce Lancaster Member Emeritus Join Date: May 2010 Location: Madison, NJ Posts: 5,230	Re: Need and educated guess Commonest problem with long storage on a flathead is a valve sticking open...peer into plug hole of bad cylinder while someone slowly rotates engine with the crank. If it is stuck, squirt some oil down that hole and push down with a screwdriver or something, keep rotating and pushing if the thing moves until it loosens up enough for spring to handle it. Put some MMO into oil to promote healing. Be careful on the pushing...valves are easier to bend than you might think!

06-25-2014, 01:29 PM	#4
FRANK PKNY Senior Member Join Date: May 2010 Location: POUGHKEEPSIE NY 12601 Posts: 1,020	Re: Need and educated guess Almost always a stuck valve, if it's been sitting. the MMO should do the trick without putting foreign objects into the plug hole. JMHO __________________ [email protected]

06-25-2014, 04:47 PM	#5
GITCHIGUMI Junior Member Join Date: May 2010 Location: Thunder Bay, Ontario Canada Posts: 14	Re: Need and educated guess Thanks very much for the replies. Time and applying your suggestions will tell the end of the tale. regards Gitchi.

06-25-2014, 04:55 PM	#6
B-O-B Senior Member Join Date: May 2010 Location: Ft Mohave,Az Posts: 2,013	Re: Need and educated guess Sponsored Links (Register now to hide all advertisements) You did not state if you ran any MMO & marine grade sta-bil,seafoam or other gas stabilizer thru the engine before storing for the winter. Your carb & or fuel pump may have issues also along with the stuck valve.

06-25-2014, 01:09 PM	#2
41panelmark Senior Member Join Date: May 2010 Location: Colorado Posts: 1,264	Re: Need and educated guess I just got one running that had even compression in all but one cylinder. It ran pretty well other than a miss. I ended up having to do some work on an exhaust valve seat. You may have carb issues along with the low cylinder. Might also want to check over the distributor/points and related. It should start even if one cylinder is bad so I would guess you have some other problems.

06-25-2014, 05:21 PM	#7
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,600	Re: Need and educated guess When you take the plug out, the exhaust valve will be easily visible. You will just be able to see the edge of the intake valve.