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Cam and compression ratio compatibility

That's a nice concise write up detailing some very important engine building details. I can never read enough of that stuff!

I have been pouring over this stuff for years now but really zoned in on camshaft selection this past year as the build of the blown flathead was on the horizon. Swapping a cam in one of those is on par with a full engine teardown. You don't swap one out on the driveway Friday afternoon before the weekend drags. It has to be done right the first time. If you are not familiar with flatheads take a look at this:

 
Good video. I wasn't aware they have two water pumps and 3 main bearings. You're putting a blower on yours- how much HP can it handle?
 
Good video. I wasn't aware they have two water pumps and 3 main bearings. You're putting a blower on yours- how much HP can it handle?
In terms of the cooling system, you could say the old Ford flatheads are like a Siamese twin to the engine world. Yeah, three mains is a real killer when it comes to power potential. Not only is it short a couple support bearings, the crank is one heavy piece of forged iron. Its over 60 lbs. The counter weights are nearly 3" across! If you look how the intake and exhaust is routed its easy to see how difficult it is for this design to even try and breathe. That's where a blower can help a bit by simply forcing the intake charge through the convoluted route it has to follow to get to the cylinders.

I'm spending a good amount on the bottom end to go with stronger billet steel main supports which have a better chance of surviving the additional pressures of a blown application. Also an aftermarket fully forged rotating assembly. Actually, every single component in the engine will be what would normally be considered high end, max competition level stuff. It really has to be to make it work and survive. Best hope is to see something in the low to nearing mid 300's in H.P. The torque will be there from near idle through the rpm range. I'd expect 300's there too. Not bad for an engine design that peaked at 100 H.P. from the factory. But who are we kidding? You don't build one of these for the power output. It's all about the eye candy and exhaust note.
 
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