hey guys, I posted up a couple earlier threads floating around the idea of an eaton supercharger on a flathead. couple weeks ago I scored a decent M112 off a jag for $50 that I couldn't pass up. then at fitchburg fate told me I wasn't going to be making my own intake when within 15 minutes I found a sharp 2x2 intake that had been milled flat exactly like I would need. $150 later it was mine, and I sold a few things while I was there so i'm into this intake for $75. so, I'm looking for input from guys who have blown flathead experience. I have the basically stock 239 out of my old roadster that I'm going to test this on. block is cracked and welded with some tiny leaks in the exhaust ports (going to try stop leak) but it's in great running shape with a 77b cam. I have some 8ba heads to put on it instead of the edelbrocks. eventually I plan to build a 3 5/16 X 4 1/4 motor with some added work to really shake things up. anyone have an idea or source for a pulley ratio calculator? the M112 is 112 cubic inches. I want to run 1 or 2 v belts. low boost max of 5-7 psi. what should I look at for ignition?? I know there are electronic boost retards but not sure if I'm running enough PSI to worry about it. good write ups on home made pop off valves?? just general advice on things to do or avoid?? any special jetting to consider on a 97 with a blower?? I checked out the blower and it just needs it's coating stripped off the rotors and new rear needle bearings. like $5 worth of parts then reassemble. soon I will be posting up pictures of how I plan to mount carbs. hoping to fit three, but if I only get 2 that will be plenty for the 239. just a quick mock up to see if things would fit. hadn't even washed the grime off yet lol.
I don’t know anything about flatheads, but I’ve run a couple McCulloch’s on on Yblocks and an Eaton on an OT car. To get the motor to feel right at part throttle (particularly with the centrifugal McCulloch’s) I needed the centrifugal and vacuum advance of a NA motor. Maybe a bit more, due to the lower compresssion ratio. So I needed 2-4 degrees retard under boost. Some vacuum advance units will provide retard under boost, at least the F code Yblock did. I used electronics. The Eaton should make full boost right off idle at WOT, so having good part throttle response and not detonating might be an issue. As I said, I have no clue how flathead distributors work. Great project, you’ll love it when it’s dialed in.
the mcculloch would be different being a blow through though?? most flathead distributors are just straight mechanical advance. not much for off the shelf units with a vaccum advance. flatheads don't need much advance like an overhead do because the inlet path creates lots of turbulence. they use 2 degrees initial and about 22-24 total usually. JWL put dyno time on motors and found that some flatheads benefit from a 5 degree timing retard setup at higher rpm. these are the things I need to check on. I'm guessing this motor will need some sensors on it. maybe see about a knock sensor, a wideband afr setup along with a boost and vacuum gauge. usually these eatons are fitted with a low speed bypass to allow recurculation and bypass the rotors but this unit doesn't include that feature as part of the housing, it is seperate on the back of the inlet. I don't have or plan to use that part as I want to try making it look early even though I am sure it would run much better and be more economical with the bypass in normal traffic.
Cleaned up the blower and reassembled it. Spins smooth now and looks good on the intake. Can't wait to make up the mounting plates Sent from my SM-G965U using The H.A.M.B. mobile app
It's possible to run 5 pounds boost on a stock engine with no modifications especially a flathead which has low compression to begin with. Go over about 7 pounds and you start to have problems with head gaskets and maybe bearings, rods etc if you go even higher. You will need to calculate the ratio of engine displacement vs blower displacement and engine speed vs blower speed to get the right pressure. It does not have to be exact but you need to keep it on the low side for long engine life. A cam with a lot of overlap is not good because it allows blower pressure to blow out the exhaust. So, a mild cam. The supercharger alone, with 5 pounds boost, will give you a 30 - 40% HP increase so you don't need to go wild on the rest of the engine. The supercharger has the added advantage of increasing power throughout the rev range not just on the top end like most hop up parts.
Those jag blowers are nice When I worked at jag I replaced quite a few that the coating would come off and they would knock. Still made lots of power just a bit of noise. It’s the same blower that ford uses on there svt stuff if your looking for pulleys etc You could get a smaller pulley from jag to increase the boost for over $500 bucks !!!!! We took one of the jag pulleys to a local machine shop and he made 50 of them for us at 50 bucks a pop....... the parts dept was REALLY happy with that mark up !
Yeah, the Ford guys strip the coating off whenever they take them apart as when you spin them harder the coating flakes off and scars the case. This one had just started flaking so I stripped the rest off. I'm using a v belt drive so it will be custom made. Diameter will actually have to be larger than stock to keep the boost down to manageable flathead levels. Sent from my SM-G965U using The H.A.M.B. mobile app
I’m in. I have an eaton M90 that I got for free and a stock Aluminum intake for $10.00. I built a new 276” motor and I’m running it with the 2 carb setup this year while I sort out the setup. Looks great, Cliff
Rule of thumb for ignition retard if your stilll wondering is 1 degree of retard for every 1 pound of boost Sent from my iPad using The H.A.M.B. mobile app
hey guys, I have been puttering a bit with the blower. i have a couple plates to make the adapter to the intake, cover the rear and adapt the carbs. the picture I put up earlier shows the standard spacing of a 97 from most intakes. I would like to put 3 97's on top as it seems that's about where I should be CFM wise... gets me about 480 or so. two seems like it may be just a little shy?? with the plate i have in place it seems like I can fit 3 carbs with about 1/8" in between them with a little massage of the rear cover. anyone have a reason why I shouldn't run 97's that close? Hemi 4x2 intakes seem to run them really close like I'm thinking. also, has anyone run a supercharged flathead with 2 vs 3 carbs and seen much of a difference?? seems most of the actual dyno runs that Joe abbin shows are running various 4bbls. hope to get some pictures of the layout tonight. I think I can get all that to fit and still be able to run a stock 8ba fuel pump.
I’m thinking of going with the 2 carbs, a pair of Model 59’s like the ones I run now. I’m not one for welding on the blower so I’m looking at making an adapter for the rear of the blower and then using a 2 carb side by side setup. Might look non traditional unlike the two you have on top of your case now, we’ll see. Cliff Ramsdell
I run three 97's on top of a 471. Made just north of 350 HP. 8 pounds of boost, 8:1 compression. I also have a 4 barrel plate for the blower but I decided not to go that route. Just a recommendation, I set mine up to run progressive linkage and I think that was an error. The flathead needs more than that center carb off the idle. I have mine adjusted now to open all three pretty fast. It is a hand full though!
yeah, the 90 is a lot harder to do a top mount carb without extensive rework. this blower is just two little beads of weld I ran on the back side of the case in line with the ribs. going to get the back milled flat and the top lengthwise ribs milled down to mount the plate to. show some pictures later. yeah, my motor isn't going to be that stout!! I'm looking for 3-5 psi. something in the 225hp range would be plenty for me. especially since the test motor is small. next motor will get a solid 5psi. definitely no progressive linkage. in a light car you should be able to run it without an issue. what's your motor got internally to be running 8psi with 8:1 compression. that's a pretty heavy combo. you must have a retard box or race gas.....
Joe Abbin's book How to build a Supercharged Flathead Ford. Everything you need to know about blowers and were afraid to ask. To answer your Q's. There's a formula in the book on how to calculate pulley rations. Two carbs would be enough to provide fuel. If you want the look of three you could always blank one off. You can use a Chevy dizzy and have Bubba cut it down for you to fit. This gives you alot of options. They are plentiful and cheap, you can have tach drive. The main body will be up higher that will give more belt clearance if you need it. I would work on the pulleys first, this is going to be your major expense make sure you can get things to line up. H & H flathead may be able to help you with pulleys
Yes, MSD BTM-6 and matching MSD distributor. Internally; Relieved, Ported, Ross Pistons, Merc crank, HandH main caps, chevy valves, Indexed, zero decked, Navarro blower heads and intake, aluminum fly wheel, hi volume oil pump, reds headers, 97's from Clive in England, It is overkill probably but I had to go there on this car. You are correct, at 225 hp your flatty will run all day, every day for years. I just had too many SBC buddies that said they were going to run circles around me. I couldn't have that!
350hp flathead is nuts. my next motor will be bigger displacement. probably a 293. strapped center, bigger cam etc. to get me in the upper 200's. wish I had someone close to me that had some real experience in porting. I want to make that one a really nice driver.
Here's the pics of the little welds I did on the back of the case. Just enough to enable me to cover the back of the case when we machine up what I have marked out. The three carb setup will just fit with some extra work. Sent from my SM-G965U using The H.A.M.B. mobile app
still looking to plan and gather parts for this setup. i'm trying to go with as many ford OEM parts as I can to make the drive. I have a dual groove wide belt crank pulley I want to use. I know many 59a trucks came with dual groove waterpumps and generators, does anyone know if the 8ba/8rt did as well?? Also a generator pulley for the same.
Cool stuff! Keep the updates coming. Interested in the transition from top mounted carbs to blower case intake (at the rear?)
believe it or not, that is the easiest part. block the back and make a V-shaped slot between the two lengthwise runners.
Been a while but figured you guys might like to see the latest update. I'm teaching myself to tig weld so here is the blower plate I made for the intake. Next up is a meeting with the Bridgeport to clean up the plenum and deck it. Sent from my SM-G965U using The H.A.M.B. mobile app
I didn't try it but I can tell you that all three idling was a smoky, smelly, plug fouling, cylinder washing, inefficient nightmare. It has been a year of driving since I was on this thread but I have actually found that just running around town I keep it on the center Stromberg 90% of the time. The other 10% of the time is more fun though.
Two carbs is plenty for a stock cube engine .use 3.5 power valves to keep it from dumping too much fuel .
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