The Ford Barn

BILL WILLIAMSON · 04-17-2017, 07:50 AM

Model A valve train is NOT a good design, for HIGH RPMs.
Bill Slowly

DJ S · 04-17-2017, 07:58 AM

The car isn't undrivable, it does very well at a moderate RPM range. Perhaps it will get better in time? I'll put some MMO in the gas to keep the valves lubricated and hopefully it will gradually get better. A very experienced club member keeps stressing to try a dofferent distributor just to see if that helps at all, which I will just to eliminate that also. But I do really feel it's that valve or valve springs. If it persists, I'll change the springs.

DJ S · 04-17-2017, 07:06 PM

Can you change valve springs with the head on?

updraught · 04-17-2017, 07:54 PM

Quote:

Originally Posted by DJ S

... Perhaps it will get better in time? I'll put some MMO in the gas to keep the valves lubricated and hopefully it will gradually get better.

Squirt some of that gunge thru the plug hole at the open valve to lube the stem. It'll be a bit smokey for a bit.

redmodelt · 04-17-2017, 08:25 PM

Without knowing the condition of your distributor and maybe the replacement, sounds like someone playing a guessing game and shooting off ideas. Unless the other distributor is brought back to factory, including where the upper plate rotates on the center with new cam/shaft/bushings and body to rotor air gap is set, why bother.

Benson · 04-17-2017, 11:23 PM

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From what I read the valves, lifters, guides and springs were removed ...

Were all of the valves and lifters returned (in matched pairs) to their original positions?

If not that would explain the clearances being "All over the place".

DJ S · 04-18-2017, 12:17 AM

Quote:

Originally Posted by Benson

From what I read the valves, lifters, guides and springs where removed ...

Were all of the valves and lifters returned (in matched pairs) to their original positions?

If not that would explain the clearances being "All over the place".

Everything was labeled and placed back exactly where they came out.

Benson · 04-18-2017, 05:27 AM

Quote:

Originally Posted by DJ S

Everything was labeled and placed back exactly where they came out.

Good that eliminates that possible problem.

Tom Wesenberg · 04-18-2017, 07:28 AM

Quote:

Originally Posted by Benson

Good that eliminates that possible problem.

Hopefully that will work.

Back in the 70's I changed distributor caps on a Chevy V8 and labeled the plug wires, but still managed to get them plugged in one hole off.

DJ S · 04-21-2017, 02:15 PM

Nobody suggested a condenser. Tried a new condenser, solved the problem entirely.

Big hammer · 04-21-2017, 03:00 PM

Glade you figured it out, way to go young man! I would have thought good or bad not intermittent.
Soon you will be an expert, and we will ask for your help :-)

Richard Lorenz · 04-21-2017, 03:06 PM

The spring assembly that is attached to the movable points in the distributor can get weak and not able to close the points at high speed. It can also be in a position that it can short out temporarily at high speed.

04-17-2017, 07:50 AM	#21
BILL WILLIAMSON Senior Member Join Date: Dec 2010 Location: FRESNO, CA Posts: 12,560	Re: Sputter at high RPMs Model A valve train is NOT a good design, for HIGH RPMs. Bill Slowly __________________ "THE ASSISTANT GURU OF STUFF"

04-17-2017, 07:58 AM	#22
DJ S Senior Member Join Date: Aug 2014 Location: Southwick, MA Posts: 590	Re: Sputter at high RPMs The car isn't undrivable, it does very well at a moderate RPM range. Perhaps it will get better in time? I'll put some MMO in the gas to keep the valves lubricated and hopefully it will gradually get better. A very experienced club member keeps stressing to try a dofferent distributor just to see if that helps at all, which I will just to eliminate that also. But I do really feel it's that valve or valve springs. If it persists, I'll change the springs.

04-17-2017, 07:06 PM	#23
DJ S Senior Member Join Date: Aug 2014 Location: Southwick, MA Posts: 590	Re: Sputter at high RPMs Can you change valve springs with the head on?

04-17-2017, 08:25 PM	#25
redmodelt Senior Member Join Date: May 2010 Location: Portland OR Posts: 6,340	Re: Sputter at high RPMs Without knowing the condition of your distributor and maybe the replacement, sounds like someone playing a guessing game and shooting off ideas. Unless the other distributor is brought back to factory, including where the upper plate rotates on the center with new cam/shaft/bushings and body to rotor air gap is set, why bother. __________________ I know the voices aren't real but damn they have some good ideas!

04-17-2017, 11:23 PM	#26
Benson Senior Member Join Date: May 2010 Posts: 2,597	Re: Sputter at high RPMs Sponsored Links (Register now to hide all advertisements) From what I read the valves, lifters, guides and springs were removed ... Were all of the valves and lifters returned (in matched pairs) to their original positions? If not that would explain the clearances being "All over the place". Last edited by Benson; 04-21-2017 at 04:52 PM.

04-21-2017, 02:15 PM	#30
DJ S Senior Member Join Date: Aug 2014 Location: Southwick, MA Posts: 590	Re: Sputter at high RPMs Nobody suggested a condenser. Tried a new condenser, solved the problem entirely.

04-21-2017, 03:00 PM	#31
Big hammer Senior Member Join Date: Jun 2014 Location: Land of Lincoln Posts: 3,131	Re: Sputter at high RPMs Glade you figured it out, way to go young man! I would have thought good or bad not intermittent. Soon you will be an expert, and we will ask for your help :-) Last edited by Big hammer; 04-21-2017 at 03:03 PM. Reason: Addition

04-21-2017, 03:06 PM	#32
Richard Lorenz Senior Member Join Date: May 2010 Posts: 447	Re: Sputter at high RPMs The spring assembly that is attached to the movable points in the distributor can get weak and not able to close the points at high speed. It can also be in a position that it can short out temporarily at high speed.