I know in overheads you can get away with a full point of compression more with aluminum heads on same fuel so wouldnt putting iron heads handicap more than help?.. I have heard guys liking the iron heads because they seem to hold gaskets better or atleast that is opinion of some
Ever notice how many late models with aluminum heads seem to need head gaskets? It's the dissimilar metals that heat & cool at different rates that causes the head gaskets to fail and why they use copper gaskets with aluminum heads on Flatheads.
Porkenbener I do not know how to take you. I took my first ride down the Quarter in 1958, ya I,m 75 years old and don,t spell good. Most guys have made good suggestions. I was not looking for a bunch of HORSE SHIT from a word fanatic.
Thirty Two I have a four and three eights stroke and three and three eights bore and most likely 9.5 compression and was looking to loose some comp. and gain some breathing with stock heads. I have no idea if I would loose or gain power.
Yes I got it ...my flathead is pretty close to that according to the charts also and it hates anything less than 91 octane .. I'm no ace motor builder or anything but my guess was if I put iron heads on mine unless it lower compression from say 9.5:1 to 8.5:1 it is going to be even more unhappy with iron heads unless I add more octane
Thirtytwo Mine is not a street car and I changed over to E85 and it ran good but we are always looking for more.
Then fuckin pay attention to my suggestion first. Unless of course my suggestion was way over your head. Maybe you didn't notice this post: You do have one other option, go to my profile in the upper right hand corner there is a little button "IGNORE". Unlike the pits if you click it you will never ever have to see me again.
Beaner As I said I do not know how to take you, however the block is relieved and am going to try iron heads. Your suggestion is not above my pay grade level and I will take your advice as it did not cost a penny, just don,t be such a horse,s ass in posting. I,m getting a lot of likes on this.
To add another variable to the equation, I have become VERY enamored with Edmunds heads. They have the spark plug relocated so it is not over the exhaust valve, thus allowing the use of extended tip spark plugs. I have put them on my last two builds and the results have been very positive. I know I'm not in your guys league with 314 inch engines, but for street motor, these (set to the proper squish) they add power and economy, and I have never had a flathead run as well as with these. I have read of instances where some folks have done welding and re-drilling to get the same results. Beaner : Keep up the good work! If you don't get the opportunity to putt up to Minnesota, I may have to stop in Missouri the next time I go to Florida.
I got to play with an old merc in the later '60s. Played with a lot of head combos, Evans, Stock, Canadian. Rocky mountains. Relieving the block gave us out biggest gain and it seemed to do better with the Canadian heads than any other heads. I did shave the heads .010. They were almost as hard to come by back then as they are now and you should have seen the grimace when I told everyone I was going to cut 'em. I did have to make a minor cut in the valve pockets for clearance (about .003 with a fly cutter and a little dremel work to take the sharp edges off). The cam was a custom Isky grind, I don't recall the numbers on it, but it was healthy enough. The engine was in a '53 post car so it was a pretty heavy car and perhaps the mods would not make power in the right place for your little car. You been around long enough to know that too much torque in the wrong place will kill your run. I may take a little longer and clay both sets of heads and see if just a minor unshrouding will make it or break it. But I am as curious as I am goofy.
The aluminum dissipates heat faster than the iron heads do, less heat means you can turn the stove up a bit, thus the higher compression allowance when running aluminum heads . I like the nostalgia look of the ford heads but watch detonation issues, the bane of the flathead. I went with Navarro blower heads on my .125 punched, merc cranked, 8BA. At start up with minimal air blowing across the radiator it ran cool and revved faster than any motor I've ever built (coolest sounding too). Make sure you keep us informed on how your change works out.
Got one head preped for valve cleranced and on and all seems well and will finish the second head today and soon fire it up and if all is well will be ready to make some passes. The rest of the car checked out OK and new seat belts are coming.
You're already running at the upper limit of most performance flatheads... At this point you're in fine tuning mode, and in that respect anything you do is probably going to be a case of trial and error. Theory is probably not going to be super useful in your 'environment.' You're probably going to need to just try it and see where you are... If I had to guess, I'd bet swapping the heads for steel would be an initial let down for you, but it might be a case of the steel heads might provide a little more room to grow... A better foundation for future tuning... Basically, I think a head swap rewrites the book a little on any engine... Maybe less so with a flathead, and if you were just running a basic street motor, maybe it wouldn't matter a whole lot... But you're attaining performance levels a lot of flathead guys salivate over already.
2nd head installed and new belts installed and fired up and sounds good, however you never know till trans brake is released on the green, then we will know. Will let you know in a couple days.
Great! I really like that you really test that. Cant wait to see the results. In theory it should run better as it should breath better
OK guys here,s the scoop E85 and to the track we went. Previous best in 1/8 was 8.17 5 yrs ago. 8.05 1st pass and reset timing to 27 deg and a 8.01 next then shut electric fan off and took water pump belt off so we could make some heat beyond the thermoastat taking the temp to 230 7.92 and then a 7.88 The biggest difference was in the 4 to 6 thousand range in low gear and a couple mph on the top end.
Possibly why this worked for me is the 4.375 stroke which helps make up for some of the lost compression. The E85 runs so cool you have to figure how to get some extra heat in the engine.
The Jalopy Journal
