I am looking for information on real world blown flathead engines, guys that have one and drive them a lot. If you don't mind could you list your engine specs I have listed below to get a idea of what really works. I think that I and many others here could benefit from this information. Thanks, T displacement heads compression ratio boost blower type ignition system timing curve boost retard, if so how much carburation cam, specs if you have them other engine mods, i.e. rods, bearing cap, etc. any other significant things I have forgot to ask...
I'll start displacement 268 cu/in heads Offie .425 compression ratio ~8:1 boost 6# Max blower type Weiand ignition system Mallory YZ timing curve 4 static 16 adv total 20 by 2K boost retard, if so how much none carburation Holley 4150 4-barrel cam, specs if you have them Isky 400 JR. other engine mods, i.e. rods, bearing cap, etc. None any other significant things I have forgot to ask... Installed 5 years ago around 17K miles with zero problems <!-- / message --><!-- sig -->
Have you called Joe Abbin at Roadrunner Engineering? http://roadrunnerengineering.com/ He's got flow info backed up with dyno runs backed up with dragstrip runs...get his book soon. He's not reprinting them anymore & working on a new book...
Got it, read it, practically have it memorized. Joe's book is very good with a lot of information and how to, but it doesn't cover every blower out there, and the tuning specifics for them. I'm pretty sure his information is accurate, but I would like some opinions and end user information from someone who isn't selling a supercharger kit. T
I understand. I've been editing his new book & the one thing I keep telling him is to provide more examples of different blowers - even bad examples - otherwise it looks like a fancy sales brochure. The fact is, he researched blowers & sizing for flatheads (street) for a long time before settling on the Weiand - in fact, he ran a Camden on the first generation of his flatty. It has more to do with sizing and parts availability than anything else - just so happens, somewhere between 140" and 180" is about right for a street-driven flatty blower...a 3-53 & 4-53 would work well, but drive parts are hard to find (old B&M stuff can be adapted). As an example of what I've suggested he include, a 4-71 is actually not a great blower for a street-driven flatty due to its displacement. You end up under-driving it to prevent overboost at higher RPMs and it will actually turn slower than if the rotors free-wheeled based on engine draw, so it will generate vacuum for a long time before it hits boost. I've asked him to include that in his new book - more of a "here's why it isn't the best" vs "here's why mine is the best" approach... BTW, he's getting out of the blower business... But call & talk to him - he'll talk your ear off - I had lunch with him yesterday and it was about 3hrs! All good stuff though!
50 Ford 1963, Are you planning on setting up a blown flathead in the future? The only reason I ask is because I am going to be doing this soon, and I can't find much information on my application. What type of blower/supercharger will you be using? Thanks in advance! -Nick
Here is my intent based off of my own questions. displacement 276 heads reworked mercury 8CM compression ratio 7 to 8 :1 boost max of 6 blower type undecided, but leaning towards a 4-71 ignition system MSD timing curve 4 initial, 18 by 2 k for a total of 22 boost retard, if so how much yes, 1 degree per psi of boost carburation a 3x2 set up or a 4 barrel cam, specs if you have them I have a Potvin super 3/4 I may use other engine mods, i.e. rods, bearing cap, etc. stock rods, center bearing cap. any other significant things I have forgot to ask... I still have some undecided parts here, hence the question to those who actually have a blown flathead they drive. T
My setup on my coupe is: displacement 255 cu/in heads edelbrock .425 compression ratio ~8.25:1 boost 6# Max blower type roots 4/71 ignition system moded chevy with pertronix 2 timing curve 4 static to 22 at 2200rpm carburation Holley 94 x2 cam, specs if you have them Isky max 1 mod on short block, porting, isky single springs, full flow oil system. shorty speedway exhaust lightweigt flywheel M21 gear box winters quick change 3,78. better1/4 mile 14.35s third years with it, and only had one blown head gasket, and it was my fault , I think I did not recheck the head bolts... good luck
I think you might find my new book, 335HP Flathead Ford V-8 Performance Handbook, helpful in deciding what kind of flathead buildup makes sense. You can get the book from Amazon, Speedway or at www.roadrunnerengineering.com . Lots of dyno tests. Joe Abbin
I am a total newbie when it comes to flatheads, but I concur with the opinion that it is worth getting a blower that you can get parts and information for. My son and I are attempting to resurrect my dad's '41 2dr that he built in the 80's with a Camden supercharger. The car sat for a long time, the engine and blower seized. We have the blower partially dis***embled and free, but parts and information on this unit appear to be nonexistent. If it just turns over and makes that awful screeching sound it used to, my son will be happy. It will probably be a net loss of HP. The engine was a 286 with Edelbrock heads, maybe 8:1 compression. He ran about 6 lbs. boost. He had cast pistons in it at first, I was driving behind him when he goosed it and one exploded. After he rebuilt it again he drove it for years from Minneapolis to OK City, Columbus, etc.
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