We're putting the finishing touches on a '52 flathead. I'm wondering what spark plugs everyone use? I'm probably opening up a can of worm on that question. Also what temp thermostat would be best for breaking in the engine? Dale

 

180 degree T-stats is usual recommendation. I use NGK plugs.

 

I use champion H-10 in my 51 flathead

 

I prefer Autolite 216's.

I thought I had 180 deg stats in my engine. It runs right around 180 in mild weather and 190 on the hottest days. When I pulled them out, they turned out to be 160's. I'd recommend starting with them, kick up to 180's if it doesn't stay warm enough.

 

Champion H10 & 160 degree stats .

 

Autolite 437 and 160 thermostats.

 

Look's like I have a couple of plugs to chose from. I will see whats available up town. I will start with the 160 thermostat. Thank's for the info

 

I use Autolite plugs with 160 ℉ thermostat. Remember that the thermostat is really only functional as the engine warms up. Initially your choke should control drivability and after the engine is warmed up you thermostat should be wide open and your fan and radiator will control the heat assuming that your timing and carb are set correctly. Just because you put in a 160 ℉ thermostat doesn't mean that your engine will then run at 160 ℉.

 

Not exactly. At "normal" conditions, the stat will be partly open. When you pull a long hill, in hot weather, with a heavy load, and temps rise, it will open further to dissipate the extra heat. Here is an interview with a Stant thermostat engineer that is very enlightening.

https://www.ford-trucks.com/forums/3...ml#post2366044

 

Theoretically you are correct Ross . . . But I don't know how old that article is and as you read it you can get confused. It is like asking and engineer what time it is and he will go through all the variables including how to build the watch.

On our old trucks things are pretty simple. Any basic thermostat that I have ever tested is supposed to start to open at the rated temp and as the article says within 5-7 degrees it will be fully open. Oh, but this small amount can vary thermostat to thermostat and even somewhat within the same part number/manufacturer. Now if you are designing a calibrated cooling system that works on the ragged design edge balancing "cost, weight and timing" then maybe this might be important. But with our old trucks and all they have been through and the changes that we have made I don't see that difference as significant to any of us.

I think that you will find that our thermostats are fully open after about 10 minutes of starting and stay that way while we drive.

 

What type heads do you have on it? That can make a difference on what plug to use.

 

It has the original EAB heads

 

When I received my '49 last summer we went for a ride and the temp went to H. I got spooked and put in 2 160 F thermostats, well as it turned out the truck had come from MN and someone had put in 205F thermostats. I eventually went with the 180F thermostats as it seems to run a little better and not make such a mess around the tailpipes at operating temp.

The Autolites are preferred, although I currently have a set of NGK in and can't tell the difference. I do have the pertronix ignition (it was already 12 volt when I bought it) and have been playing with the spark plug gap. The truck has been put away since Nov., but I think I'm at .032.