hi, i'm working on a 8ba flathead and i want to put in a new clutch before i install it in my 51 vic. measured the old one and it's 11". i know there are many opinions on this subject. i'm thinking of going to a 10 or 9 1/2. i'd welcome any feedback, if i do so, will that mean a new flywheel? how about the bell housing? are there different sizes for different clutches? the trans is a B.W. 3 speed with O.D. also from looking at catalogs, it seems that the throw out bearing is two pieces. is that correct? i'm new to the flatheads so any info would be great! thanks
Less is more, in terms of throttle response. The heavier wheel helps to launch a heavier vehicle ( truck ) Yes you could drill a larger wheel to accept the smaller clutch,,, but let's not do that
I think that might be the only option? Not that I have much FH knowledge, but the few I’ve had with different sized clutches, the flywheel was the same diameter.
Stock 49-51 Ford passenger car clutch setups were 9.5” diameter with an option for 10” diameter. They never offered anything bigger than 10” until years later (on larger displacement V8 types). I’m fairly sure that an 11” pressure plate wouldn’t fit in the 49-51 Ford V8 bell housing. A larger clutch would be overkill with this car. The throw out bearing is two parts….the inner hub and the sealed bearing itself. They are simply pressed together. They are sometimes sold separately and also can be found as a set. The 11” clutches of that era were generally found in trucks only.
I had an 11 inch clutch in my 41 when I took it out and the flywheel was coming apart at the ring gear so I had a 49 shoe box flywheel that was drilled for the nine and a half and I had it drilled for 10 in and put that in. And it has Wicked clutch shatter. I bought the clutch and pressure plate new from CNG Ford parts, your results May Vary. I'm going to get a clutch from somewhere else soon enough to replace it
ok thanks for the input and suggestions. what i have is a 8ba that has a 11' clutch and PP. the flywheel is not drilled for a smaller size. i have also bought a bell housing and 3 speed OD which i have enclosed pics of. i don't have the adapter engine stand plate yet so i have only been able to check if the bell housing and 11" clutch will work with the 8ba and trans. all the holes seem to line up but i have read that some bell housings won't work with a 11" clutch. on the floor, they seem to fit together but that really won't matter if they don't bolt together. so based on these photos, i was hoping someone would know if they will go together or maybe advise me on where to look for numbers on the housing or if there is a way to measure them off the car. i also have a 59a with a smaller pressure plate. would that flywheel work on the 8ba if i need to go to a smaller clutch? thanks for any input. i'm new to these flatheads and seem to be collecting stuff that won't work together so any suggestions will be greatly appreciated. thanks again
The 59a flywheel will not work properly on an 8ba style engine...the starter ring will be in an incorrect location and the flywheel may rub the rear of the block as well.
I had no idea the flathead flywheels are different! I'll have to make sure I've got the right junk to go with each one.
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