double head gaskets

C

chicknlittle

Member
Hi All,
I just got my hands on a 51 merc flat head this engine was rebuilt 23 years ago and never fired it looks like it has double head gaskets I have not seen this before is this normal and should I fire like is or should I tear down and relube it.
Thanks
 
chickn>>>double head gaskets>>is this normal
No.
chickn>>>should I fire like is>>>
Yes
chickn>>>should I tear down and relube it.>>>
No.

Jack E/NJ
 
possibly ford pistons with a 4" merc crank or excessive head and/or deck planning. I would pull a head.
 
I don't see why you could hurt it to fire it up. There on there for some reason like was said above. If it runs alright take a compression test. Let us know. Walt
 
Yep, been there done that and agree pull the head and check clearance.. They will run fine with the double gasket but not the best answer.
 
Didn't someone have problems recently with sticking valves after running an engine that had been built a while ago but not run. I'd prefer to pull it down and reassemble after giving everything a good oiling. Maybe the double gaskets were to cope with some poor fuel? They shouldn't be needed, so the reason why they were fitted should be investigated. Look upon it as a kit of parts that have been loosely assembled.

Mart.
 
Thanks for the help The friend that I got the motor from said the motor was rebuilt by a shop I for got the shops name I will pull the heads off tonight when I get home since the have been removed once and needs new head gaskets anyways Thanks
 
The likely problem would be milling the heads too much or adding a cam with a higher lift, all this can be corrected. Double head gaskets will run OK at best, but performance and economy will be poor.
 
After 23 years, who knows/remembers what quality this "rebuild" really is? In 1990 flatheads were not very popular and most shops, unless run by old timers, didn't know a whole lot about flatheads. Not having a clue as to why double head gaskets were used, I would pull it apart before trying to start. Why ruin good parts? (Especially a 4" crank!) I agree that what you have is basically a bunch of new (hopefully) parts in a sturdy cast iron box!
 
Well I got the heads off everything looks good and clean I think I will get some clay and go from there I do know a little history from the builder He was a old timer that knew his flatheads but has passed on now. Thanks for all the help
 
Man sometimes am not so bright I just got my ****** back from the shop and thought I would start looking more into the flathead as i was looked closer it has a mc1 head and a eac head the eac has double head gasket the other side only has one I just wanted to update you all
 
On the question of re-lube. I think it depends on what lubrication was used during assembly. I put an engine together once with Sta-Lube white lithium grease. It sat for about 3 years before I installed it. It ran fine for about 100 miles and then all the valves stuck open. When I tore it apart again, it was, more or less, obvious that the Sta-Lube had partially dried-out, turned "gummy" and stuck the valves. I do live in a dry climate which probably contributed to the dry-out. Since that incident I have always used the molybdenum based assembly lubes without any problems.
 
chicknlittle said:
Man sometimes am not so bright I just got my ****** back from the shop and thought I would start looking more into the flathead as i was looked closer it has a mc1 head and a eac head the eac has double head gasket the other side only has one I just wanted to update you all
Click to expand...

When you pull both heads and even before 'claying', see if the 'double gasketed ' side has pistons heads ABOVE the block deck. I just went thru a situation (and asked for advice here) where my piston heads were .053 above deck. Now, with the head that I took off (and sold to a friend , before noticing pop up situation) everything fit fine. With new head...no way. I considered double head gasket after advice. Then , I used a 'farmer' type remedy that worked out great. Hey, what the heck..I've farmed alot:cool:
 
As Hardtimes said. check piston to see that they don't pop up above the deck. Chances are the EAB head had been mill and the pistons were hitting on that side. The EAB heads are good heads for raising the compression but it don't take much milling before the pistons will hit the head. Walt
 
I have an engine that I had decked a LOT... Measured the piston to head clearance without the gasket in place by measuring how much the head lifted off the deck by the pistons...

I then carved out the combustion chambers by hand, rotary file and sanding.
Then add gasket to obtain clearance.

Have not fired it yet... Should work out well.

Karl
 
You must log in or register to reply here.
Back
Top