Anyone know of a shop in the Rochester MN area that has shaved or milled a flathead head? I could drive up to Minneapolis, especially with planning and same day service. I would like to get heads shaved on my 8BA for the bump in compression and efficiency. Might as well take advantage of today’s bottom of the barrel gas which can support a compression ratio of 7.5:1 easily.

 

I'd contact the local Early Ford V8 Club, they will know who has the experience.

Before you have the heads cut, check to see how much they've already been cut. Few heads have made it 70+ years without at least one cut. You can gauge whether they've been cut by looking at the front underside of the heads, near the thermostat housing. See how much of a ledge is left, see pics.

This head has not been shaved, or very little:



This head has been shaved quite a bit, enough that there is no ledge left:

 

I’ll have to have a look under the hood and see what I can see. I’ll have to do a google search, town I live in has a population of maybe 2500, no early ford club I’m aware of.

 

This is the only chapter in MN:

 

With a flathead the more you cut the worse the engine breathes because it reduces the transfer area and this reduces power. Breathing is a much bigger problem than compression so most of the time the bigger the better combustion chamber volume wise.

 

A mild camshaft upgrade will be a better bang for the buck.😃

 

A cam could be a later project, looking for low hanging fruit that is easier and an easy weekend project. Want to take Henry to Cruisin the Coast in Mississippi in October. Getting front end tight and my 1985 S10 T5 installed are my priorities.

looks like an L100 grind could be in my future.

 

Flathead V8 cores are very high quality and easy to regrind too.

 

One of the guys on Ford Barn, KiWinUS, who works at Roush is regrinding stock cams to the 8CM grind, which has great torque and better breathing.

 

I don't have masters for a stock Merc cam but I've got one that's 213 @ .050 with .313 lift which would work well too. The last one I did for a guy with a street rod I used a 224@ ,050 lobe with .302 lift.

 

I would want something with good low and mid torque. This is where I want to end up for interstate cruising. I have a pertronix ignition now to replace points. May end up with a mechanical/ vacuum advance distributor to get full advance or close by that point.

 

Flathead engine cams are sort of weird because even stock cams seem really big for the engine size. There are a couple of reasons for this; there is no rocker arm so the cam duration is the same as the duration at the valve. Also because the ports are very restrictive it needs quite a bit of duration to achieve adequate breathing at any reasonable RPM.. I'm not so sure that the engine responds to gross lift much at all. It might but probably not.

 

Personal opinion a 3.50 axle ratio with a T5 won't be great for highway speeds. These trucks have the aerodynamics of a barn door, and 239 c.i. isn't a lot of engine. They don't mind spinning in the upper 2000's for extended periods. Except on flat ground you'd be down to 4th quite a bit. An overall ratio from 3.50 to 3.73 is where I'd shoot for. Your overall ratio in 5th will be 2.52, which for reference is what BobbyTNM runs in his truck with a 500 c.i. Caddy engine. (Also depends on tire size, of course)

 

Good to know, truck has what I think is a 4.27:1 rear end gear ratio in it now. I live in the Midwest and it is flat around here. Plan on T5 then drive it and see what I think. That should put me around 2500 RPM at 70 and 2700 at 75 on interstate. Trying to find a 9” from a slightly newer truck so I can change gears a bit easier if I want. Maybe a set for interstate and a set for around home. Changing out third member should be about 2-4 hours.

 

I'm running a 3.50 with the stock 3-sp, which gives 2500 at 60 mph. I am at mile-high altitude and lots of big hills, and I wouldn't want any taller gears. I also wouldn't want to go 70 or 75 with stock brakes and steering.