relieving a flathead

how do you go about relieveing a flathead ford v8 by the valves and piston and how much thanks

 

Ill get the ball rolling...

 

im talking about bet twin thevalves and pistons on a flathead ford v8

 

Very little on the deck surface. But it depends on the head. Maybe some more info...

 

There are newer theories on how to do it, but here is the traditional method.

From the 1952 Fawcett Books "How to Build Hot Rods"

 

Check out Joe Abblin's book "335hp Flathead Ford v8 Performance Handbook "
It deals maily with supercharged flatheads but gives very good advise on porting and relieiving flatheads - Also check out Tex Smith's COmplete flathead ford maunal - I prefer Joe's method -

 

Good stuff. The more you take from the deck surface the more you lower compression. Flow.

 

thanks i will have to find couple books

 

must help with the air flow to the valves

 

Very true.. But Flatheads don't breathe very well at all - More flow yeilds more power even after the compression loss. Acording to Joe Abblin a constant depth releif of .125 yeilds 14-18% more flow on high compression heads and 7-8% on low compression heads - but only lowers compression .2 - .3 of a point which only causes about a 1% power loss - but the power gain from the increase in flow is much more substantial 14% flow would translate to roughly 14% more power. ( aprox )

 

www.roadrunnerengineering.com for Joe's Book
eBay For Tex Smith book - ( You should buy them both )

 

Might have to do some reading. Interesting. Is this based on a supercharged engine or a carbureted engine?

 

Could be of some interest to you. I liked reading it.

http://midstateantiquestockcarclub.com/flat_heads1.html

Its part of this website.
http://midstateantiquestockcarclub.com/

 

Granted a supercharged engine can be carbureted. But would out forced air induction.

 

According to Joe ( I have talked to him about this on the phone for hour on end ) It's an advantage weither blown or naturally aspriated. And it you think about it, The more air/fuel you have to compress the more power you're gonna get, a blower is just gonna amplify that. I also HAve talked to a couple old timers that raced dirt track they both swore by releif cuts- and denver heads ( slightly higher compression ) And they were restricted to 1 carb - Said the releif made a huge difference .

 

Joes 335 hp motor ( blown ) still made 217 with 3x2's - it is a 4" merc crand and a .125 over bore - a 276 -- isky 400 cam - Joe's Flathead improvements are centered on improving air flow - 1.6 pro flow valves, port & releif - in fact he modified the offy heads aand cut them for bigger chambers - compression was 8.2 - 1 - According to his reasearch Air flow is the key -

 

Very true, many people try to apply OHV techniques and technology to Flatheads, and it just doesn't work. More compression in a Flathead actually hurts airflow because it makes the transition area smaller and more restrictive.

 

good info thanks

 

Don't do it; you may run across a set of Ardun heads at the next garage sale you stop at.

 

yea right