| parrish | -- 12-21-2009 @ 11:24 AM |
|
the flathead is now starting and idling on its own, but the compression is low. When I first started trying to get it started (last ran in 1960), the readings were from 15 to 50 lbs. As I've idled the motor (maybe 4 times so far for 20 minutes or so), the readings have crept upward a little...cyl/lbs: 1/35,2/50,3/55,4/28,5/55,6/60,7/70,8/50 I would guess that the increase in due to unsticking of valves, not rings related? Anyway, my question for you guys is: would these readings warrant removing the heads for inspection or would you let it go for now? I have a poly tank coming and a tube shock solution is brewing, so it won't be too long before I'd like to take it out for the maiden voyage...
|
|
| alanwoodieman | -- 12-21-2009 @ 1:05 PM |
|
did you put marvel mystery oil in the tank? or down the carb? This oil will unstick valves and rings. These engines are tough and I would continue to try to ungum it awhile more. Did you change the oil? what did it look like?
|
|
| TomO | -- 12-22-2009 @ 7:20 AM |
|
Parrish, I would add some MMO to the oil as well as the gas to help free up the rings. Add 1 quart of MMO to 4 quarts of oil. Tom
|
|
| supereal | -- 12-22-2009 @ 9:10 AM |
|
It is time to do a "wet/dry" compression test. First, remove all plugs, prop the throtte open,and then test the cylinders dry, and redo the test after squirting some oil into the cylinder. If the compression improves, worn or stuck rings are at fault. If the compression stays mostly the same, valves are leaking. There is nothing wrong with trying the MMO cure, but usually sticky valves are due to carbon and varnish buildup on the valve stems, or weak springs, and MMO won't fix that. If you overdo it, spark plug fouling will result. A sure sign of leaky rings is excessive blowby that is visible when you remove the oil filler cap while the warm engine is running.
|
|
| parrish | -- 12-22-2009 @ 2:03 PM |
|
I initially used MMO in the heads when hand turning the motor while preparing for first starting cycle since 1960. I then dumped the oil which had been changed by the former owner (just because...), so it didn't reveal much of anything. After that I squirted oil in the heads and maintained the hand turning until the necessary ignition parts arrived. Since then, maybe 2 - 2 1/2 hours of mostly idling. I'll try the dry/wet readings sometime soon. Are there drawbacks to removing the heads? I fear broken head studs or stripped nuts...anything else? Thanks everybody!
|
|
| supereal | -- 12-22-2009 @ 6:00 PM |
|
Removing heads after many years is always "interesting", but take time to work the heads loose by inserting a putty knife or other such instrument until they loosen enough to lift off. Most head nuts will come off easily. If any head studs come out with the nuts, note where they came from, as there are 3 different sizes of studs. Frankly, I wouldn't pull the heads unless you plan to do a valve job after determining it is required. Just looking at the engine won't do much if you haven't diagnosed the problem to see where the problem lies.
|
|
| parrish | -- 12-22-2009 @ 7:49 PM |
|
I ran it for about 30 minutes tonight and pulled the filler cap to check for blowby and saw nothing...so maybe sticky valves are at the heart of the matter. Anyway, plenty more to do and I'll check compression again before too long with the dry/wet method. I had a leaky sparkplug tonight which reminded me to ask...what plug is recommended? AC 44 are on it now (looks like from 1960) and I guess I didn't tighten it enough from the last compression reading...are compression ring plugs never used?
|
|
| supereal | -- 12-23-2009 @ 10:36 AM |
|
There are as many recommendations of spark plugs as there are car owners. We use Champion RJ14YC in place of the original H-10's. They have the compression washer seals. You can't use the taper seal plugs in engines not set up for them. Carefully inspect the spark plug holes, particularly if the plug has come loose. It is not unusual to find that the hole has been cross threaded, damaging the threads, or someone got carried away when tightening. If so, they can be Helicoiled by a competent shop.
|
|
| parrish | -- 12-23-2009 @ 8:27 PM |
|
thanks Supereal! I always baby the plugs back in (actually a Ford guy many years ago showed me that you should alway first turn any threaded piece counter-clockwise until the two threads mate and "fall just a bit", then turn clockwise) and I think the loose plug was me being a little too careful about over-tightening the taper fit. Anyway, all the threads look good, so I'll switch over to the RJ14YC brand.
|
|
| supereal | -- 12-24-2009 @ 7:30 AM |
|
That is good advice. Usually, if we find a damaged head, it was done long ago, as most owners today are careful as you are. There hasn't been much progress in spark plug technology in the area of replacement. Many manufacturers specify 100K miles before they are changed. By then, a carbon ring has formed on the piston end of the plug, and if a special technique isn't observed, the threads in the aluminum head can be ruined quickly, particularly in Fords. It just isn't a DIY job anymore.
|
|
| EFV-8 Club Forum : | https://www.earlyfordv8.org/forum |
| Topic: | https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=483 |