I go away for a couple of weeks & come back to find this excellent discussion! My next assignment will probably be to Kirtland out in Albuquerque - I'll then get to spend loads of time with Joe Abbin & get him to publish more stuff!
Hey Guys, Truely, flatheads are the most like women as far as engines go. A constant source of mystery, misery and suprises lol. The more I think I have got a handle on what makes them run the more they just suprise me by breaking down ahaha. Danny
Hey mate, yeah i put that in on the way back from franks. just curious as to what the max is for a flathead. ive heard it said that the design is a great one for avoiding detonation but ive also said that 6:1 in a flatty is the equiv of 8:1 in a OHV engine. there is also the argument that the smaller combustion champer merly impedes flow and that your better off increasing flow then you are increasing static comp past a certain point. Dan
This is chart for flathead compression ratios with a wide range of heads. What works and may not for higher compression.
Somebody shoot me a PM with an email direct...I find I still have an email that contains a working copy of Jim Leis's INCREDIBLE FH compression chart, a work that took much of a year. Jim collected a ton of info and charted it. I don't know if what I have is the final work...he upgraded it several time before his way-too-early death. It contains his own research and the fruits of my old copy of an incredible Canadian service bulletin that charted all known heads from '32-1950 with compression computed for both 221 and 239, including the Denver and the Canadian heads of all sorts. I suspect that as with all specs, they are not 100% right but do give clues. I noticed slight inconsistencies in Ford of Canada's computations, but they are not too scary. I think Jim must have worn out a stack of calculators building and checking his numbers! I think I can come up with a way to send the thing, if not I will consult a young person who understands electrons. Also...last thing I heard, secret leak from the secret societies out there, is that modern thought is that there is a slight but worth harvesting flow behind the valves and a SMALL clearance at operating temp should be left between valve and roof. Please don't expect speed from me. My wife just died, the second wife I have lost since I went on the HAMB, ans I am a wreck. I am just on here to clear my head from too much reality falling on me.
Sorry to hear of your loss, Bruce. Back in the late '90s my son got into some dirt track go Kart racing, some really fast, serious and expensive stuff, not kids' toys. Of course I had to get involved too, up to my ears! Rules were quite liberal for open class, as long as you started with a 5hp B&S flathead, really just a small, one cylinder version of the Ford FH, except the valve stems were parallel with the cylinder rather than at an angle. Strokers were common, and the B&S "Blockzilla" blocks were also legal and used by some, as they allowed a larger bore. Methanol was the fuel, and most folks slipped in at least some nitro. Last open class engine we built was quite radical, and even though we ran a stock stroke and a regular block which limited bore size, it was unquestionably the fastest thing on the track. Unfortunately son started having some trouble with his neck, and ended up having to quit racing go Karts due to a neck bone problem that could have paralyzed him if he had a wreck that landed him in a certain way. Kart was parked and eventually sold to people who had no clue as to what to do with that motor. Do wish we had been able to put it on a dyno, but none was available where results could be reliably kept confidential. All we know is when it ran "right" nothing on the track could stay with it, and it was still pulling hard at 13,000 rpm on methanol and 10% nitro! We had titanium valves because there wasn't room for enough valve spring to work at those kind of rpms and we needed hardened lash caps on the valve stems to stop the lifters from mushrooming the end of valves and increasing the valve lash, which of course killed the valve lift and duration. This was next on the list when the neck problems grounded him. We worked out a rod length and piston height above pin to get a "pop up" of .200" out of the block, which was as far up as we could get it without popping the top ring out of the bore. The head was a billet piece meant for 1/4 mile Jr. dragsters, which cooled adequately enough for our short races with the cooling effect of methanol. Fly cut the head to give a quench clearance over piston of .040", and over the valves at.100". Then used a die grinder to dig out a flow passage from valves to cylinder, using a head gasket as a template for the sides, and the flycut recessed pockets for valves and piston for the depth, or should I say heigth. Never had access then to CCing equipment to check CR, but I do know it was plenty high from the torque it took to crank it with a rig converted from an automotive starter. With the methanol and mild dose of nitro, detonation never entered the picture. Seems to be along the lines mentioned above about mixture not liking the sharp turn into a relieved block. Got the idea from memories from reading in my teenage years of late '50s when flatheads were fighting for survival in competition against OHV V8s in the fuel classes. Wish we could have finished up that engine to it's full potential and dynoed it!
Dredging up an older thread rather than starting a new one on this topic. I recently snagged an EAB engine. There is an extra capitol B after the EAB. So, EAB B. I also have a pair with a canted D like EAB D. I have another single EAB that is marked much different.there are 2 sets of numbers 38K: and a backward D over this sequence EAB6050D. I am guessing it is all just different foundry ID info. Anyone know what the additional letters and or numbers may signify?
Can anybody tell me how to print the file in post #36?...I’ve never seen PDF in “books”. Forgive me .......I’m old.....Thanks!......Mark
I'm far from a expert but I clicked on the white car with the red background and it downloaded to my computer. I then went to downloads and clicked on that. I found the correct file and clicked on it. when it opened, I would have clicked on print if I wanted to print it.
The Jalopy Journal
