8ba/8rt Flywheel and Clutch Help Needed

1

1950F1

Member
I need clarification regarding flywheel/pressure plate set ups on 8ba/8rt engines.

I thought 8ba/rt flywheels flywheels were drilled for 9", 10", or 11" clutches; 9" in cars, 10 and 11 in trucks depending on transmission. I have a flywheel and pressure plate set up that I thought was a 9 inch car setup until I measured and looked at the pressure plate and it says right on it; 9-1/2 inch. Do the measurement given in the ford book refer to the disc size or are there really 9-1/2, 10-1/2 and maybe 11-1/2 sizes also? And is ther any reason I can't or shouldn't use the 9-1/2 inch setup in front of my T-87 truck ****** in my F-1 pickup? Any easy way to tell what a flywheel might be drilled for in terms of clutch size?

Thanks in advance for sharing wisdom. Carl
 
I agree with jdl, there is 9, 9.5, 10 and 11 inch clutches. I don't have an easy way to tell you how to tell without having a pressure plate to measure against. 11 and 10 inch are kinda easy to tell by eyeballing the flywheel holes but 9 and 9.5 are tougher. Maybe somebody has taken measurements and will chime in on here.
 
The 8BA had 9-1/2--10--11. the 9in. was the old 32-42 in 46 the 59AB came out with a 10in. If you have a 9-1/2 it will work fine behind an 8BA in an F-1. Don't try to use a 48 or older wheel behind an 8AB, trouble. Walt
 
9" don't exist on stock late flathead flywheels, only on prewar applications in fact, so you don't need to make that distinction. 10" was a heavy duty option on passenger cars, very rare, but common on 1/2 tons.
 
9.5 Long type is the most common. 10 inch Long type not so much but they were on F1s, station wagons, and police cars. The 11 inch is for big trucks. They are way heavy. It takes the engine a bit to rev with an 11 but my pops old F5 would pull a full load of wheat with no problems.
 
The 9 1/2" Pressure plate on the 8BA will not work with an early top load transmission throw out sleeve. Zeke
 
The 9.5 inch clutch disks are 1 inch 10 spline too. These will only work with the three speed side shifters & overdrive trannys from 49 to 53 Ford cars & some pick ups
 
To clarify on the pressure plates...'32-48 and the related '49-50 Merc and F series plates all have fingers spaced for the very large throwout bearing used on those vehicles. If you use the '49 up Ford passenger plate with early type trans, the fingers will not line up with the throwout at all. Pressure plates must match up to the throwout bearings that will fit on whatever trans you are using...
 
ALL HANDS; I have an 8ba flywheel 10 inch...for trade,, need 10 inch wheel for 59ab engine, in good order, we each pay shipping to each-other, fair ?? PM me at zippss@gmail.com .... or call 707-768-1905 ... OLD...BILL
 
Yes, there is an easy way to check what a flywheel is drilled for.
The distance between the close drilled holes, and the distance between them and the next set is as follows.

9 1/2" = 3" and 7 9/16"

10" = 3 1/8 and 7 7/8"

11" = 3 3/8 and 8 1/2"
 
Thank you all for the wonderful education on 9.5, 10 and 11 inch clutch setups. I now realize I have a beautifully resurfaced flywheel with new pilot bearing, a researfaced/rebuilt pressure plate and new clutch disc all 9.5 "- for a car . . . Problem is I happen to have a truck . . . :-)
 
1950F1 said:
Thank you all for the wonderful education on 9.5, 10 and 11 inch clutch setups. I now realize I have a beautifully resurfaced flywheel with new pilot bearing, a researfaced/rebuilt pressure plate and new clutch disc all 9.5 "- for a car . . . Problem is I happen to have a truck . . . :-)
Click to expand...
wondering if you still have that 9.5" combo? I have an 8BA, ready to change my clutch and pressure plate. phil @ auldridge.org
 
Yes I do. The flywheel and pressure plate have been resurfaced and the disc is new. I figure shipping is about $40 to $45 Bucks. With that in mind. Tell me what sounds reasonable via Private Email. You will not be dissapointed in this set up. Regards, Carl
 
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