The Ford Barn

ford6man27 · 08-29-2013, 09:19 PM

Will the valves have enough clearance in stock 8RT heads with an L100 cam? I think the L100 has .375 lift. These heads have never been milled.
thanks.

Andy

Ol' Ron · 08-29-2013, 09:31 PM

The 8RT heads are the lowest compression ratio of all the Ford heads. The net lift of the L-100 cam is .360". Depending on the displacement it would be better to use EAB heads. Have them milled for .050" piston clearance and have the valve pockets clearanced at 5 degrees. To answer your question Yes it might, you can check with clay. But why not do it right?

quickchange34 · 08-29-2013, 09:53 PM

There are different ways to right .

4tford · 08-29-2013, 10:22 PM

tin foil peas!! Use clay the same way

JWL · 08-29-2013, 10:47 PM

Checking should be done in at least 4 positions on each valve and 5 positions on each piston if you are trying to achieve maximum performance by "fitting" each chamber.

Ol' Ron · 08-30-2013, 08:08 AM

Sponsored Links (Register now to hide all advertisements)

When milling the heads to gain piston clearance, the dome area in the head becomes smaller and can toucth the piston. I use a head gasket to mark the bore and blend this area into the rest of the dome. Yes those little alum peas work well.

GOSFAST · 08-30-2013, 10:05 AM

Quote:

Originally Posted by 4tford

tin foil peas!! Use clay the same way

I would be somewhat leery of that "fire-ring" on that head gasket sitting inside that bore!!

Thanks, Gary in N.Y.

P.S. It may only a be "photo" issue, but it looks real close?? You don't want that ring in the bore.

El Rat · 08-30-2013, 10:29 AM

How about place the head on the motor without a gasket. Turn it over... if you can you will be just fine once the heads are bolted on with a gasket. Again this is probably not a race motor.

HP Hunter · 08-30-2013, 10:43 AM

The ross pistons sure look nice.

Harry

Ol' Ron · 08-30-2013, 10:36 PM

The issue here is to get the best performance and economy out of what you have. A good example is putting a set of 61A heads on a 239 of any year. Have the heads milled for 40-50 thou piston to head clearance and improve both performance and economy. It doesn't cost much to do.

Russ/40 · 08-31-2013, 11:40 AM

Quote:

Originally Posted by 4tford

tin foil peas!! Use clay the same way

FYI, that is not where the clay or foil peas should be on the valves. You want them at the very top rim of the valve, due to the angle at which the valves approach the head. The location pictured will give irrelevant information.

Ol' Ron · 08-31-2013, 01:39 PM

I usually cut the valve clearance at a 5 degree angle. that way you don't remove buck material or reduce the CR much. .050 clearance for a street engine.

Chuck Sea/Tac · 08-31-2013, 11:32 PM

Quote:

Originally Posted by Ol' Ron

I usually cut the valve clearance at a 5 degree angle. that way you don't remove buck material or reduce the CR much. .050 clearance for a street engine.

Ron, I understand "doing it right", however, I'm curious, what noticeable improvement do you get from the .050" head clearance ? I would think, smoother running for one, but what economy/ performance benefits? Seems negligible, but again what do I know! Chuck

Ol' Ron · 09-01-2013, 09:59 AM

The Flathead has a very large combustion chamber, compaired to an OHV engine. This causes a large flame front which can build a very high pressure in the cylinder. This can cause detination at avery low static compression. Most OHV engines have a 30-40 thou piston to head clearance. In the case of the Flathead closing up this area effectively shortens the combustion chamber and forcing all the air/fuel mixture into the spark plug area. This turbulence also creates a better combustible mixture..
Back in the old days we'd take our heads down to have them milled, taking 20-30 thou off after installing them back on the engine the engine preformed better. We thought we;d raised the CR but in fact all we did was nake a more turbulent combustion chamber.

Chuck Sea/Tac · 09-01-2013, 11:16 AM

Thank you

ford6man27 · 09-03-2013, 10:07 AM

Ron,
This is what the engine is going in. I have been racing this old car in vintage dirt track races. I am 71 years old and have decided its time to hang up my helmet so I am making it street legal. this engine will only be driven down to the coffee shop in the mornings now and then and maybe a parade or two. I am not looking for horse power, just something that sounds good. I raced with this car in 1967 so don't want to sell it but would like for it to still be used for something. I am just an old man who wants to keep this old car, I guess you would say for just a toy.

Andy

Ol' Ron · 09-03-2013, 07:24 PM

God love you, yes keep it. The #8 at Danbury was driven by Bones Sevens a good friend. These flatheads are reat engines, I JUST LOVE THEM. Always try to get the best out of them. Take care

ken ct · 09-03-2013, 07:58 PM

Quote:

Originally Posted by ol' ron

god love you, yes keep it. The #8 at danbury was driven by bones sevens a good friend. These flatheads are reat engines, i just love them. Always try to get the best out of them. Take care

hi ron are you sure of the spelling of bones,you sure it wasen't stevens,did he have any brothers named buggsey stevens that raced in seeconk ma track in the 50's???? Ken ct. ron iPOSTED THIS IN CAPS FOR YOU DONT KNOW WHAT HAPPENED KEN CT.

Ol' Ron · 09-03-2013, 09:56 PM

Yes It was Stevens. You'll have to excuse my typing. Not sure about the other.

Joe/Ct · 09-03-2013, 10:51 PM

Ken/Ron,
Do you remember a driver at Riverside Park named Jocko Maggiacomo (Sr)? What car and engine was he running back in the day?

08-29-2013, 09:19 PM	#1
ford6man27 Junior Member Join Date: Aug 2013 Posts: 3	8RT heads Will the valves have enough clearance in stock 8RT heads with an L100 cam? I think the L100 has .375 lift. These heads have never been milled. thanks. Andy

08-29-2013, 09:31 PM	#2
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 8RT heads The 8RT heads are the lowest compression ratio of all the Ford heads. The net lift of the L-100 cam is .360". Depending on the displacement it would be better to use EAB heads. Have them milled for .050" piston clearance and have the valve pockets clearanced at 5 degrees. To answer your question Yes it might, you can check with clay. But why not do it right?

08-29-2013, 09:53 PM	#3
quickchange34 Senior Member Join Date: May 2010 Location: charlottesville, Va. Posts: 589	Re: 8RT heads There are different ways to right .

08-29-2013, 10:22 PM	#4
4tford Senior Member Join Date: May 2010 Location: Regina Canada Posts: 1,335	Re: 8RT heads tin foil peas!! Use clay the same way

08-29-2013, 10:47 PM	#5
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: 8RT heads Checking should be done in at least 4 positions on each valve and 5 positions on each piston if you are trying to achieve maximum performance by "fitting" each chamber.

08-30-2013, 08:08 AM	#6
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 8RT heads Sponsored Links (Register now to hide all advertisements) When milling the heads to gain piston clearance, the dome area in the head becomes smaller and can toucth the piston. I use a head gasket to mark the bore and blend this area into the rest of the dome. Yes those little alum peas work well.

08-30-2013, 10:29 AM	#8
El Rat Senior Member Join Date: Nov 2010 Posts: 260	Re: 8RT heads How about place the head on the motor without a gasket. Turn it over... if you can you will be just fine once the heads are bolted on with a gasket. Again this is probably not a race motor.

08-30-2013, 10:43 AM	#9
HP Hunter Member Join Date: Jan 2011 Posts: 78	Re: 8RT heads The ross pistons sure look nice. Harry

08-30-2013, 10:36 PM	#10
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 8RT heads The issue here is to get the best performance and economy out of what you have. A good example is putting a set of 61A heads on a 239 of any year. Have the heads milled for 40-50 thou piston to head clearance and improve both performance and economy. It doesn't cost much to do.

08-31-2013, 01:39 PM	#12
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 8RT heads I usually cut the valve clearance at a 5 degree angle. that way you don't remove buck material or reduce the CR much. .050 clearance for a street engine.

09-01-2013, 09:59 AM	#14
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 8RT heads The Flathead has a very large combustion chamber, compaired to an OHV engine. This causes a large flame front which can build a very high pressure in the cylinder. This can cause detination at avery low static compression. Most OHV engines have a 30-40 thou piston to head clearance. In the case of the Flathead closing up this area effectively shortens the combustion chamber and forcing all the air/fuel mixture into the spark plug area. This turbulence also creates a better combustible mixture.. Back in the old days we'd take our heads down to have them milled, taking 20-30 thou off after installing them back on the engine the engine preformed better. We thought we;d raised the CR but in fact all we did was nake a more turbulent combustion chamber.

09-01-2013, 11:16 AM	#15
Chuck Sea/Tac Senior Member Join Date: May 2010 Location: Between Seattle & Tacoma Posts: 2,354	Re: 8RT heads Thank you

09-03-2013, 10:07 AM	#16
ford6man27 Junior Member Join Date: Aug 2013 Posts: 3	Re: 8RT heads Ron, This is what the engine is going in. I have been racing this old car in vintage dirt track races. I am 71 years old and have decided its time to hang up my helmet so I am making it street legal. this engine will only be driven down to the coffee shop in the mornings now and then and maybe a parade or two. I am not looking for horse power, just something that sounds good. I raced with this car in 1967 so don't want to sell it but would like for it to still be used for something. I am just an old man who wants to keep this old car, I guess you would say for just a toy. Andy

09-03-2013, 07:24 PM	#17
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 8RT heads God love you, yes keep it. The #8 at Danbury was driven by Bones Sevens a good friend. These flatheads are reat engines, I JUST LOVE THEM. Always try to get the best out of them. Take care

09-03-2013, 09:56 PM	#19
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 8RT heads Yes It was Stevens. You'll have to excuse my typing. Not sure about the other.

09-03-2013, 10:51 PM	#20
Joe/Ct Senior Member Join Date: May 2010 Location: Waterford, CT Posts: 250	Re: 8RT heads Ken/Ron, Do you remember a driver at Riverside Park named Jocko Maggiacomo (Sr)? What car and engine was he running back in the day? __________________ Joe/Ct "The older I get, the better I was"