hi, i have a rebuilt 1937 flathead 21 stud, is it possible to supercharge this? any known suppliers of blowers, manifolds etc,thanks
Really, if you want to build a performance motor you should start with a 24 stud motor. Besides, the 21 stud motors have very limited speed equipment availabiltiy anyway. I would pick up a book called Blown Flathead, by Joe Abbin of Roadrunner Engineering in Albuquerque, NM. Another good one is Street Supercharging by Pat Ganahl. It will give you a lot on information and tell you exactly how to build the motor. I along with other people of this forum are using Joe's kit. The full kit is around $2500/3000, then you will some good open chamber heads, reworked rods, steel mains, good headers............................$$$$. Bottom line, if you want to put a supercharger/blower on a flathead, use the 42/48 24 stud, not your 37 21 stud. IMHO
Are you doing this for looks or a cool factor? I dont think for the money your going to gain much horse power
My brother in law use to polish out the blowers for Joe's out of his garage for extra money. He even designed his first website and updated it from Germany when he got restationed.
I have sold several of Joes blowers and had great success. I did one for myself with serp belt using one of my 348 WP kits and it would turn the 700-16 tires in the first three gears. (was that on gravel?)
thanks chopped coupe for reply, have ordered the joe abbin book, take your point about the equipment available, although don orosco does 36 ally heads, means moving water pump from block to head, is this a step forward? would look ok thou, mudslinger prob going for looks if honest,should i wait and get a later engine,thanks.
Joe's kit is hard to beat. Bang for the buck, he's got the best street kit out there. If you want/need full-out performance, you might look at 4-71 on a Navarro intake (H&H) or something similar. But if you're even asking about it for a 21-studder, you probably just want decent street performance - go with Joe's kit.
36coupe In my estimation moving the waterpump from the block to head is two giant steps backward. Just like the pumps down low and not up in the way of your generator/alternator............... Maybe Mudslinger has never taken a ride in a healthy blown flatmotor, but a blower like Joe's will add some 30/45% power increase depending on how you build the motor............what type of cam, heads, chamber, headers, on and on. Certainly by todays standard, a 300hp Flathead falls short of most new V8's from the factory, but compared to 30/40 years ago...............it is giant! Joe has made over 300hp on the dyno and we will see what mine will do. My guess is that I could sure scare the pants off a new Mustang GT at least from one stoplight to the other. I didn't build mine to race with, but I will take it to the drag strip here in Redding, CA and would also like to take it to El Mirage or even Bonniville. The WOW factor is good, but nothing sounds sweeter than a blown flatmotor with open headers!!!!!!!!!!!!!! IMHO
Hi Guys, Last year at the Hot Rod Reunion in Bakersfield, CA the '34 went 107.6 mph in 12.41 seconds. You can see a movie of one of the runs on www.roadrunnerengineering.com . 0-60 in 3.5 seconds. Ref a Viper can do it in 3.8 and a Z06 Vette in 4.1 secs. per magazines. The '34 kills my own 2007 GT Mustang. Don't count the flathead out yet!
We run a 4-71 on a flatmotor in a land speed roadster and , as much as I hate to say it, it is just old tech. Joe's stuff is well designed, tested and proven. we had the record up until last year and then some guys with big check books went after us. They not only got the record, they shattered it by 15 mph. That is a shit load in land speed racing. The new blowers take less horsepower to spin which makes all the difference in the world.Anyway, the 4-71 really is high on the cool factor for a street car, but there are much better options for performance.Cubic dollars come into play, though.This crap is REALLY getting expensive.I think we are just going to put a motor together that will live, let everybody drive it and just have fun.Hey, that's how it's supposed to be anyway, right?Good luck with your project!!!
Hey Flatheadjunk. You just need to ask your "Magic 8Ball" what you need to do. It has all the answers. (GRIN) Wayno
You need to first supercharge your wallet to increase the flow of DPMs...dollars per minutes... ....then the engine. It can get expensive very quick ...
You can get Navaro 21 stud heads for some pretty quids, but if you use the 31-36 heads just keep the 37 pumps and run late ohv ford or chebby thermastats in place of the 31-36 pumps!... and then they will clear the blower no prob...Roach.
Seems like an appropriate place to pose this question...... On a stock 42-48 239" motor. With a Max-1 cam and OE heads how much hp (crank) will a Roadrunner blown Flatty make on straight pump gas?
joe is a hell of a nice guy spent a long time talking to me about what work`s and what dosen`t ! and why. the man is very smart and will not try to sell you something you don`t want . I want to put a Whipple on mine and he agreed on all my reasons . but said it will be hard to make work ! I like a challenge !
Here is a post from last year I started. It has some good blower info, I'm not sure how much of it will apply to your 21 stud engine though. Todd http://jalopyjournal.com/forum/showthread.php?t=148441&highlight=bore+stroke
If you are going for a blower, don't get hung up on the availability of ali heads for the 21 stud motor you don't need compression to make HP with a blower. A couple of days on your block with a die grinder porting to get the mixture to flow is the way to go. Properly balanced and with good bearings you should be fine with a post pump in head motor just don't turn the boost up to much. Should give you 40% more than a stock motor with torque all the way through the rev range. Yes you will make more power with a later 24 stud motor but why be a sheep? Stu Hilbourne laid down some good times back in the day as did Isky both on 21 stud motors. If you are not looking for period correct an Eaton blower of a Mustang or Jaguar will be about the right size and more efficienty than an old roots design. Rich
Rich - have you figured out a decent way to mount & plumb them? Their funky inlet (at the back of the case) makes it challenging from a packaging perspective. I looked into these in the past as they're plentiful, relatively cheap, & spares are easy to come by, but couldn't see a decent way to set up the intake side - without going EFI...
A fellow named Whitehead in Arkansas is running the Eatons on several of his flatheads and his approach is really neat. Take a four barrell flathead intake and mount a flat plate on it. Remove the air box fromn the Eaton and mount it on the plate. He then does the carbs one of two ways. Mount a carb directly over the back cover by welding a two barrell adapter to it or for two carbs just cut a round hole directly in the center of the top of the housing and either weld in the adapter or as he does, just JB weld them in. Yes, JB weld They don't leak, it runs like a spotted ape and they don't need an overboost relief , just watch your pulley sizes. The guy knows his shit!
Well, after searching high and low I can't pics of the unit. Surely someone from the Bella Vista, Arkansas area NW of Fayetteville has seen Robert Whiteheads turbo setup. Of the dozen or so cars he has at least four or more are running the Eaton M90 supercharger. Anyone with pics please run these on this thread if you would. Thanks!
Flat Ernie. I have an eaton. I plan to make a little plenum for two carbs that sits on top of the blower to "look" right but at the back it will extend past the back of the case and down to bolt onto the inlet. It won't be the best for airflow should work. In reality by the time air and fuel enter the manifold under the blower it is a complete mess anyway. I also think with some time and a die grinder I can make the little Eaton look a lot better than it looks in stock form. I have seen Robert Whitehead's flattie with an Eaton. He just built a one carb manifold that puts the carb behind and above the blower. I am sure it looks fine but I thought it looked retarded. Brad
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