If this is the wrong board for this post please direct me to the right one, I feel like this could be a fun topic. I have recently come into possession of a solid 1953 8BA flatty I build engines for hotrods and resto mods for a living so I’m not afraid of doing my own work on this thing but it is my first flathead. I’ve been trying to do some research on what can be done to this engine platform to build a little more HP than 95 on a good day. Turns out there’s really not much from this decade on the topic (at least that I can find and yes I used the search function so don’t be an asshole.) I’m thinking bored and stroked: how far can I go overbore, I’m thinking 4.125 stroke? Navarro heads with a little work don’t to the chambers, spark plug spacer? Flat top or domed pistons? Isky racing cam (I mean obviously) multi 97’s is super cool so I may look at that set up too MSD ignition S10 T5 and a ford 8 inch with some tall gears? What do you guys think the best combos are, what ideas do you have, what advice do you have? I don’t want the “just build a SBF or BBF instead” answer either This engine is either going in a period HotRod like a shoebox or late 20’s early 30’s car or truck or I wanna build a lakester and go for 200mph on the salt flats
If you look hard enough on this forum, there is a lot of information about just this subject; it is a little disorganized though. Another good source is "The Ford Barn" forum. Several members there are really on top of the game about this. I would start researching "pop-up" pistons and porting if you really want to get serious about this. The secret is getting them to breath while retaining compression.
There is a ton of info on this board and in several books out there. As @tubman said, I feel the key is the balance between breathing and compression. When building a good reliable hotrod flatty, doing all the little things really adds up.
Ron's book will prove very helpful. Plus go over to www.fordbarn.com and post your question. This has been discussed at length.
The main difference between working on a flathead to get extra performance out of it and working on a later overhead is time . Primarily the valve train is going to take more time to deal with than a sbc or sbf. I think I have five or six flathead books including the Tex Smith - Ron Ceridono one that I have had for probably 40 years. up on the shelf behind me. That one is easy to read and great for a guy building a mild street motor but a couple of he others might be better for a much higher performance level.
John W. Lawson ("JWL") was the man. He started with a bone stock rebuild (making a little over 80 HP) and went from there.
A lot of knowledge doesn't just transfer over. Only a flathead requires the block to be modified in regards to the engines breathing ability.
My last flathead(have built over 10 just for myself) was a .080 over bore with stock stroke,mild cam/.350 lift,Edelbrock slingshot with 2 —97’s and a big oversized K & N air filter for a 6 cylinder Porsche(3 cyl on each bank). I spent extra time enlarging the exhaust ports particularly on the ends where they exited the block and purchased a big port intake gasket and enlarged both on the block and on the matching intake. Dyno results showed I did well as had 150 h.p. At the flywheel and my no fendered 32 cabriolet highboy with t 5–5 spd and 3:89 Detroit locker nine inch Ford with coil overs ran 80 mph in the 1/8 at the drags. All this from a 73 year old man and no stroker. Flatheads Forever!!! P. S. I only relieve the intake side on the block approx .080 and don’t touch the exhaust side because it is expelled under pressure;I feel this is better than a “true” full relief. The intake and exhaust valves were both 1.6 and not the standard 1.5. (ATTACH=full]6237700[/ATTACH]
Flatheads need superchargers like a Jew needs a yamaka. I'm not talking about Frenzels or McCullochs, Either the big ScOT or 471. Oh, and buy the book from Joe Abbin and follow it like the Torah. He used the little Holley/Weiand induction blower and still made north of 300 HP. Oy vey, and loosen the purse strings, this is going to get expensive. Shalom!
What @Bandit Billy said ^^^^^^. The whole premise of building any performance engine is to find the best way to get air to flow into it. Thats why a simple change in valve angle and replicated ports enable an LS Chevy to perform much better than a Gen 1 smallblock. You can do a lot of modification to the Flathead to improve breathing and get somewhat minimal reward for all the work. On the other hand, without going to extremes trying to get every single HP naturally aspirated......you can generally improve the intake tract reasonably well and then a blower will pack more air into it anyway. I'd go with a more common 4-71 or one of the later aftermarket roots style on top. If you really want to do some disguising, you could modify some aftermarket throttle bodies to look like mechanical fuel injection on top of it.......or just go with some carbs if you like tinkering with them.
Vern is currently building my '51 Merc 8BA. 4" stroke. .125 over, ported and polished. Balanced. Chevy SS valves, Edelbrock heads, Eddie Meyer intake, 2X 97's. Isky 400 Jr. Mallory dual point dist. He's not planning to dyno the engine when he's done, but he thinks it will be good for ~150hp. I don't plan to dyno it either, but I can give you my butt dyno review when I've got it going.
That sounds like very realistic expectations if not a bit conservative. Strap that thing in a frame, wheel it down to the dyne, put er across the rollers. But take my advice, go for a coffee and a slice of Jameson while they beat on it. I couldn't watch. Inquiring minds want to know.
Sorry, gotta be the a hole. IF you work on engine machining for a living, you would know that you sonic check the block you have to see what's possible. You can have any piston you want custom made, but if this isn't in the plans, you check what's available. Those are the limitations. The parts, machining and care taken for a street driven car is going to be a whole different game compared to a top speed engine. This sounds like dreaming. It's okay to dream, just don't yank our chains.
The first time I read this I interpreted it as "a Jew needs a Yamaha". In my mind I saw a Hasidic Jew on a crotch rocket.
Some interesting input from the HAMB members. Being one guy who has actually accomplished a bit with some flatheads all of which have been machined and built by my son and I. There's a lot that's possible to making good power without adding a blower. Our experimenting at Speedweek 2024 has shown what's possible when rookie driver Carley Moody set a record doing such a thing at just under 160 MPH with the outside air temperature over 100 degrees and the density altitude almost 8000 feet. To get the required speed needed to run fast you need to figure out how to get the engine to pull RPM. Most flatheads running on the salt have a limit to what they pull for RPM. If your able to get a combination that pulls at least 5500 RPM at the third mile with at least 160 MPH speed your now getting someplace. Very few Ford flathead V-8s can do this finding someone able to build an engine for the street and possibly for a 200 MPH lakester is a very difficult task to find and unfortunately will be very expensive. Now if a blower is added then 200 is possible but to do it you need to have an engine that will survive for four or more miles each pass turning 6500 RPM. Example at Speedweek 2024 mile five exit speed was 221 MPH our little stock block Ford flathead ran a total 34 miles this year setting 3 records with 25 of those miles all over 200 MPH. The engine survived to run again. It can be done but it takes many months of work and years of dedication. Ronnieroadster
Congratulations on your Speedweek success. The OP has proposed doing two things : a period hot rod (street) or a lakester (race) Both require different considerations, especially due to the small displacement and limited breathing ability. As you say, with proper mods the flathead can produce some ligitimate speed on a long straightaway.........but it most likely won't have much low end driveability and rely on rpms for proper power. Driving on the street is going to be better with good low end and mid range power, so different camshaft requirements. In a larger capacity overhead valve engine, its less critical because there usually is a broader and more powerful torque curve. Adding a supercharger would provide a decent powerband across a broad range for the street and not require near as much cam. It is probably the single best way to increase power for a small and intake limited engine like a flathead. A lot of money can be spent trying to extract power from a flathead with limited results. In the fifties, extracting a few extra hp was great, but today a stroker flathead in a shoebox isn't going to outrun even a soccer mom. If he choses to go for the lakester and racing, the flathead naturally aspirated will be fine because he will be competing against others similar to his combo. I think he needs to decide which type of build he is going to do before moving forward, because with a small engine his choices will be more important.
2-3 deuces look good but for reliability and horse power, a single four barrel is my favorite go to . Get some good books , build torque .
Good point. Many people don't realize that you have to increase torque at a given rpm in order to have more HP at that rpm.
IMO, a cam is the biggest "seat of the pants" improvement you can make. just don't get carried away. if you're looking at a daily driver, a max1 should be plenty. hotter ones will run great at high speeds, but are gutless around town.
Middle of the road build for a good street pounder. 4" Merc Crank is a must. Isky 1007b grind, its a 400jr without the issues in the lower midrange where the torque is dead. Johnson adjustable lifters Relieved block from valves to cylinder Flat top pistons .125 over bore. Minor port work, mainly exhaust and gasket match. 9" Clutch with larger springs, cut down flywheel for less weight to spin. Do not run a Max1 cam, they are a waste of money if you want it to sound like it has any balls at all. This is my 59ab stock stroke with a 1007b cam. Straight piped. With the exhaust its even better. https://youtube.com/shorts/uuNMTibl_ss?si=AZCvq2jNNcsoK_-O
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