Well, I spent the evening swapping out my old EAB heads for some nice, polished and milled Edmunds heads I just acquired. After claying the valves and checking all the clearances, getting everything nice and clean, replacing all the studs with nice new hardened ones(complete with thread sealer, no cutting corners this time!), and hitting the gaskets with some sticky spray paint...I was ready to torque them down and go. After doing all this, I filled her up with coolant, re-timed her, bolted on this sweet old chrome oil filter, and went. The car ran exactly the same as before. I have had a few different sets of heads on this car...is it just me, or is there really even that big of a difference between stockers and the more common finned aluminum varieties? I really see no difference at all with these Edmunds heads...aside from the fact that they look cool and old-timey, but so do the Merc. heads I had on before. The car even stayed at the same temperature as before...176 degrees. No real moral to this story...just annoyed with myself because I always have to change things and end up liking the way it was before...that '32 grill shell for example, and now these heads. Oh well...
really depends on the compression. at first I thought this was an old thread as I remember you deciding to go back to the stock heads. so now put the A model grille back on!
There are a lot of different heads out there and each is a little different. Most of them, like FLATOZ said, have the cylinder top relieved to run with a certain compression ratio. If you change just the heads and do not match them with the appropriate high top pistons, chances are you will actually lower the compression ratio of the engine as opposed to the stop heads. While the heads may have a more performance oriented cylinder top shape, without properly shaped pistons, the cylinder pressure and intake and exhaust velocity will all go down, giving you little or no net change. So, unless you are tearing into the bottom end too, in most cases, swapping cylinder heads turns out to be purely cosmetic. Hope that helps clear it up.
I also agree and the Ford EAB heads are the highest compression of all the stock heads, so you would see less change with those as opposed to say 8BA OR 8RT heads. Oh, by the way, I love ModelA grill shells
I asked a similar question a few months ago and came to the conclusion that besides weight the aluminum heads didn't give much back without the supporting parts. ie... pistons, cam, intake...etc. But the stock heads work well with the supporting parts too. And in a twisted kind of way I kinda like the look of the stock head better.
For an otherwise stock engine, the finned aluminum heads are a dress-up part. The Edmunds, were always meant to be bolted onto a stock engine - they use stock studs even (one of the very few heads to do so). I ran a set on my '34 - mostly because I had an Edmunds intake - otherwise, I'd have run Edelbrocks or Offys as they're a tiny bit cheaper. I don't know that you need pistons to match, per se. Very few heads are set up to accept pop-up pistons of any type. I set them up with .050-.060" piston-to-head clearance - just like stockers. Most of your aftermarket heads will provide a slight edge on compression by themselves, but 1/2 to 1 point of CR isn't going to be noticeable. Enjoy your effort though - Edmunds are a nice looking head! But if it really torques you off, just take 'em off, put your EAB heads back on, & send the Edmunds to me!
What are you running for cam,Ing ,intake, carb,exhaust. A good running flatmotor can be a challend to optain.
.060 bore, 4" Merc. crank(works out to 265 ci), two Strombergs on an Offy regular dual, old Mallory dual point distributor(centrifugal adv., with the two piece cap), lakes-style headers. I have it running perfect now...and yes, it was a challenge to obtain!
Haha, I already did! Have the '32 shell and insert hanging in the garage, right next to the EAB heads. Maybe I will start building another car!
You're right. The heads went right on, no problem with stud lengths or anything. The combustion chambers of the EAB's and Edmunds were very, very similar...clearances, shape, etc. I thought I may get a little more noticeable power with a potential CR increase, but I think it may be almost exact between the two.
Adam, If you decide to get rid of those heads, you know i'm first in line homey, plus they'll go with my 2 X 2 Edmunds intake! Your ride looked way better with the stock heads you had on before
We put some new pricey offy heads on an old beater engine, replaced the steel 8ba's, and it felt like the engine was rebuilt! customer/friend was stoked! We put some EAB heads on my old beater engine, replaced the steel 8ba's, and it felt like the engine was rebuilt too! I am still stoked! With the torturous heat I run my RPU at, no fan, little mercy (I met you at Pats after Asphalt Invite last year) I don't know if aluminum heads would be as durable for my use. Anyway drive the piss out of that thing. TP
Put a set of Offy "400" heads on my '50 PU. Installed a Isky cam, Offy 2x2 intake, two Holley 64's and newer Mallory dual point. Thing runs like a scalded *** ape! But your right! I have a set of stock 8BA heads on a '50 Industrial Flatmotor in a '23 T bucket, Offy intake and 2 -94's and it runs just as good. Not as flashy as the finned heads but just as good!! _______________________________________ I've seen bored and stroked...But never popped a rod!
i think the total unmodified cc's of an Edmunds head is fairly close to that of an EAB head (both have less cc's than the stock heads.) this would mean that the compression ratio in both are higher than stock, but i believe in stock form similar to eachother. i think a lot of guys looking for better head performance ported reliefs around the valves to get better flow (which would create more cc volume, but better flow) and then machine the deck to increase compression ratio back up. there's not much to a flathead head. not much more to it for performance than chamber shape, compression ratio and efficiency to cool. what do you have for a cam in that beast? the right cam and valve train makes all the difference... -scott noteboom
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