Well here’s what I found so far, 48 flat head Edmunds 52 era heads. Found a small water drip at driver corner of head. Isolated it between head and block just a slight leak. Decided to pull head. I could tell on copper Best Gasket (speedway) #1550 with added copper coat upon installation. I could see the darkness on copper of leak. Head and gasket latterly just came off easy. I laid every thing out on bench itching my head. Looking for why. Then bang the light came on. The water jack holes were really reduced in size on copper gasket very restrictive. Thinking this right here could be lots of my wonders and whys. I’ve purchased fel-pro #7548 since the water passages are matched to block. Now to pull passenger side and give it a run. I just can’t believe I did not catch this on build. I’ve taken photos of gaskets and head and block to give reference. I’ll give a heads up further down the road folks.
Not a flathead guy but I don’t see the size of the gasket holes as a factor, they match the size of the holes in your Edmunds heads as well as factory heads. I’d be checking block and head flatness as well as the integrity of the stud threads.
I prefer any COPPER gasket over a “fiber” gasket because if u DON’T use any sealant or spray, the gasket can be reused even on another block. As long as the block and head are “flat” I have reused the gasket over and over many times when I had three engines all operable at the same time. Flatheads Forever!!
Here’s some better photos so you’ll understand and understand flow restriction. I’ve got a twenty degree warmer running built motor. Thinking this could be the ticket. Look closely you can see the whitish rings around gasket reducing flow to block to head note reduced in these areas and not a hole creates hot spots.
There was another thread about this a few months ago. Yes, absolutely you should open up the Best gaskets to the size of the holes on your heads. It is really odd why they did this. Someone on the thread even called Best and they didn't know why either. I used stones and thin carbide to open my gaskets up. Out of the box, it is certainly causing a restriction of water flow and allowing overheated water to remain in the block longer.
Thanks, I felt stupid not noticing. That’s today’s world of parts. It’s slipped beyond return. Live & Rod well !!! Good day
Don't feel stupid. I didn't know this either until a well known builder and racer clued me in on it as well. Makes perfect sense. Those "stock" holes that Best punched are a little bigger than pinholes. Makes no sense.
Reduced hole size in head gaskets is common to force coolant to flow only where you want it to flow - sometimes a very small hole is there just to let steam or air out, but that's it. I don't know the coolant path in the flathead V8, but in many engines the pump pushes coolant into the front of the block, it then flows all the way to the back where a couple of large openings let it up into the head, where it comes all the way to the front where it goes out to the radiator. Lots of people have seen the large openings in block/head all the way from front to back, and the small/missing openings in the gasket, and had an eureka moment when they think making large holes everywhere will improve flow and cooling. Well, the flow now goes into the block, straight up into the head, and out the radiator, there's no movement in the rear of the block and head so now your "improved" flow makes the engine overheat - and usually people can't figure out why. The large openings in block and head are usually related to holding the casting cores when the part is made, and then getting all the casting sand out. As I said, I don't know the correct coolant path inside that engine, but I do know that the people that designed an engine usually have a pretty good idea what they are doing. Before changing an original design you really want to think about what that modification will bring with it. And that said, it may be worth researching how the original gaskets for that engine looked.
In 49 Ford made the water ports at the rear of the deck much larger to make more flow happen in the rear. Not sure what they did with the lower row of holes.
Original gaskets have the correct sized holes. Original poster has a picture comparing the different between the two gaskets as well. I've also compared them. I needed big bore so I couldn't use OE copper gaskets. It's a known issue if you want to ensure your flathead cools properly. There is no reason to keep heated water in the block except to raise the coolant temp which is not needed on a flathead.
UPDATE!?! Took my ride out. Once warmed up. I ran it 1hr in 91 degree Florida heat in country keeping 24-2600 RPM gage stayed at 190 degrees. This gage is off but better than zero idea. Actual temp about 179 with gun. Had a bite then blew out a different direction longer Cruz 25-2800 RPMs still holding temp well. So hands down if running a best copper head gasket be sure to match head & block water jacket holes up with zero restriction. I installed a felt pro this time around holes were exact dead on! My over temp situation is poof gone. Happy Rodding Good Day
I opened up the coolant holes on a Pontiac block, starting at the front going back. It ran hot from then on. Back of engine was much hotter then the front. I learned to leave them alone. Glad it worked out, not needing to watch the temp gauge all the time sure makes driving more fun.
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