The Ford Barn

Ol' Ron · 09-04-2020, 10:53 PM

Think about it?? at least start with the smllest stock head, I;d suggest the EAB head, but they are getting scarce, but 8ba heads are a die a dozen. Mec ans 8RT have the biggest stock chambers

tubman · 09-05-2020, 10:07 AM

I am of the opinion that just about any head can be brought "up to spec" with the proper combination of milling and chamber modification. Just remember that cast iron is much harder to work with than aluminum.

Ol' Ron · 09-05-2020, 04:35 PM

I was thinking of a simple way to increas CR, At presenI move the spark plug in the 8ba head, by pluging the original and drilling a hole at an amgle that comes out where thee original plug eas pluging thid hole and drilling snd tspping it for s power timplug thst comes out in the transfer area. So far it hasn't worked very well, but it's getting better and I think the next head might work. If it does?? I can make a fixture to do any head.. Now why do you think this might make a diffferance?

Pete · 09-05-2020, 06:56 PM

Quote:

Originally Posted by Ol' Ron

I was thinking of a simple way to increas CR, At presenI move the spark plug in the 8ba head, by pluging the original and drilling a hole at an amgle that comes out where thee original plug eas pluging thid hole and drilling snd tspping it for s power timplug thst comes out in the transfer area. So far it hasn't worked very well, but it's getting better and I think the next head might work. If it does?? I can make a fixture to do any head.. Now why do you think this might make a diffferance?

Many theories have been advanced and tried on plug location in a flathead.
Some work, some don't. Even heads with 2 plugs have been tried with various locations of the plugs. Mediocre results. Most all mods have been tried on race engines though.
One theory on having the plug in the transfer area has 2 possible problems.
1- The plug will cause a vortex in the mixture flow in a critical area that will be detrimental.
2- The plug being closer to the cylinder will cause a distorted flame front due to less travel time. More time gives it a chance to equal out across the area.

I am still waiting for someone else to come up with something better than what we have now. It is too expensive to fiddle with. We are not racing for money any more.

Ol' Ron · 09-06-2020, 08:18 AM

In a way I agree with Pete. However, at 87, it's something to do. Putting the plug in the transfer area allows the use of a power tip plug, which is right in the middle of the combustion chamber when the plug fires. If you have a .050" piston to head clearance te AF in the chamber is in a turbulent state during combustion and all or most of the fuel is burent. At least that's my reasoning. Better than watching re runs on TV and it mIGHT work

mfirth · 09-06-2020, 08:48 AM

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Quote:

Originally Posted by Ol' Ron

In a way I agree with Pete. However, at 87, it's something to do. Putting the plug in the transfer area allows the use of a power tip plug, which is right in the middle of the combustion chamber when the plug fires. If you have a .050" piston to head clearance te AF in the chamber is in a turbulent state during combustion and all or most of the fuel is burent. At least that's my reasoning. Better than watching re runs on TV and it mIGHT work

Ron, you are amazing........keep on keep'n on !!!!!

tubman · 09-06-2020, 09:04 AM

I agree with the use of power tip plugs. As mentioned many times before, I like Edmunds heads because the plug location is mover juuuust enough to get it away from the valve, which allows their use. Wouldn't moving it that slight amount be better than putting it smack dab in the middle of the transfer area?

09-04-2020, 10:53 PM	#21
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,855	Re: 255 merc engine Think about it?? at least start with the smllest stock head, I;d suggest the EAB head, but they are getting scarce, but 8ba heads are a die a dozen. Mec ans 8RT have the biggest stock chambers

09-05-2020, 10:07 AM	#22
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,303	Re: 255 merc engine I am of the opinion that just about any head can be brought "up to spec" with the proper combination of milling and chamber modification. Just remember that cast iron is much harder to work with than aluminum.

09-05-2020, 04:35 PM	#23
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,855	Re: 255 merc engine I was thinking of a simple way to increas CR, At presenI move the spark plug in the 8ba head, by pluging the original and drilling a hole at an amgle that comes out where thee original plug eas pluging thid hole and drilling snd tspping it for s power timplug thst comes out in the transfer area. So far it hasn't worked very well, but it's getting better and I think the next head might work. If it does?? I can make a fixture to do any head.. Now why do you think this might make a diffferance?

09-06-2020, 08:18 AM	#25
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,855	Re: 255 merc engine In a way I agree with Pete. However, at 87, it's something to do. Putting the plug in the transfer area allows the use of a power tip plug, which is right in the middle of the combustion chamber when the plug fires. If you have a .050" piston to head clearance te AF in the chamber is in a turbulent state during combustion and all or most of the fuel is burent. At least that's my reasoning. Better than watching re runs on TV and it mIGHT work

09-06-2020, 09:04 AM	#27
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,303	Re: 255 merc engine I agree with the use of power tip plugs. As mentioned many times before, I like Edmunds heads because the plug location is mover juuuust enough to get it away from the valve, which allows their use. Wouldn't moving it that slight amount be better than putting it smack dab in the middle of the transfer area?