Flywheel locked up engine???

B

boo

Senior Member
i'm putting an 8ba eng in my 27T. i bought a 51 8ba rebuilt eng w/flywheel and clutch for the 51 trans. i'm using a 39 trans w/ 50 merc stamped bellhousing, so i took a flywheel and clutch off another 8ba truck eng , also the oil pan , i wanted the pan to bellhousing boltup bracket. PROBLEM..when i bolted the 8ba truck fly/w to the car 8ba eng. the flywheel hit the block and locked the eng???? why would there be a difference??? what solution/? machine back of fl/whl? spacer behind fl/whl? any ideas, thanks Boo
 
The late 8BA car/truck/Merc flywheels are all the same (to the best of my knowledge) except for clutch sizes/types/bolt patterns. What exactly is causing the lockup? Are you sure the flywheel taken from the 8BA truck was the correct (not 59A) flywheel?
One possibility may be too long pressure plate bolts. Another may be trying to use the HD alloy truck clutch seal with the flat starter plate, instead of the indented plate.
 
The 11-inch truck clutch is usually used with the truck cast iron half bell. It may be making contact with the stamped half bell. I would get the flywheel drilled for the old 10-inch long type clutch. It's the easiest one to get that has the 1 3/8" 10-spline set up and it has a lot less pedal pressure than the big 11-inch if that is in fact what you have.
 
not sure if the flywhl is 59a type or not, was on later 8ba eng, has 10'' clutch. 51 flyw is 5/8'' from ring gr to clut face, truck flwh is 3/4 from rng gr to clut face ??? back of flywh, 8ba flwhl is about 1/16+ less from crank shft recess than the trk one. that is what i think might have to be taken off. the dust plate has a recess dimple in it but ring gear had been rubbing. joys of mix & match
 
boo said:
not sure if the flywhl is 59a type or not, was on later 8ba eng, has 10'' clutch. 51 flyw is 5/8'' from ring gr to clut face, truck flwh is 3/4 from rng gr to clut face ??? back of flywh, 8ba flwhl is about 1/16+ less from crank shft recess than the trk one. that is what i think might have to be taken off. the dust plate has a recess dimple in it but ring gear had been rubbing. joys of mix & match
Click to expand...

Your measurements indicate the "truck" flywheel is from a 59A, as my 59A flywheel measures 3/4" from the ring gear, and an 8BA measures about 5/8". Get/borrow a known late flywheel and see if your problem is solved.
Rotorwrench pointed out a good point, and that's the 11" Long pressure plate should not clear the Merc stamped 3" 1/2 bell. You need the truck cast iron 1/2 bell, or better yet, use a smaller 9 1/2"-10" Long, B&B or diaphragm clutch.
 
The early flywheel is somewhere near 1/4" different in where the starter ring is located as compared to the later 8BA family of flywheels. The starter rings are different too. You will need an 8BA type flywheel to allow the starter to function correctly. There are 10 inch Long type clutches in the 8BA family but they are getting hard to find now days. They were used in some F1 pickups, police cars, and station wagons. The Mercury cars have a 10-inch but it is the Borg & Beck type with 6 equally spaced mount bolts for the clutch cover. The rest of the 8BA cars have the 9.5-inch and big trucks have the 11-inch.

The 59A flywheel will bolt on but it won't work.
 
I have 8 ba truck flywheel (11") and a Mercury (Borg and Beck clutch) car flywheels off and measured both. They both measure .178-.180 from the bell-shaped lip on bak to the crank mounting surface. Truck wheel measures ~.585 from ring gear to clutch surface, car measures ~.565, but it has just been turned and don't know how many times before.
 
Boo, I don't know if this will help. but when I installed an 8BA engine up against my stock 40 Ford trans. I used the 1950 Merc stamped steel bell housing, Merc 10 inch clutch and pressure plate and and flywheel and the 40 throw out bearing. I am pretty sure the same set up will work with the 39 Ford trans.
 
The backplate holding the starter has different offset between truck and passenger pans.

Mixing a truckpan and a passenger flywheel gives you a lockup between the plate and flywheel.

Or if it was the other way around...been there done that...
 
i will take more measurmens tomrrow. the mistery to me is that i have aother car that a friend gave me the motor out of his 50 pkup, is a merc engine, ibolted a ''auborn'' clutch to the flywheel [just because in 50's they were hot setup??], w/39 trans, dont remember clutch size but have been running for15 yrs, no problem. also has stamped steel blhsg???? will ma
easure 8ba starter ring to block and measure trk startrng to blk and see if i can turn trk flywhl to match 8ba wheel. the 10'' preasure blate just clears the stamped blhsng, that is not the hangup.
 
From what you suggested, is the flywheel any bigger then normal?. You can drill out a flywheel to except a 10, 10 1/2, or maybe a 11 inch. Not really versed in a flathead or even a later ford 11 inch clutch. Is it needed? Outside the large big trucks?
 
No, the 11 inch clutch is not needed in all most any application. They are for very heavy loads or heavy towing. I would not use anything larger than a 10 inch.
 
WELL, i went to my shop today and measured everything. called a friend w/machine shop,says he can fix it. the ring gear are the same diameter, the recess on face @ bolts same, have to move ringear forward 3/16'', cut 1/8'' off back that goes over crank, then tapod backside out to ringear, should match the 8ba flywheel then. will get it balanced then..hopfully thats the last problem, trying to get car done for ROG
 
WELL, you're the first I've heard of to turn a 59 flywheel into an 8BA. Helps to have friends with machine tooling!

Lonnie
 
i have an 8ba flywheel, the problem was that it is drilled for the 9 1/2'' clutch and the clutch disk and the pressure plate won't work w/early transmission. different splines and throut bering size. no supplier could give me what i needed to use the 8ba car flywheel, also i had already had the tk flywheel resurfaced and new ringear, could brobly have 8ba wheel redriled for 10'' clutch and resurfaced and new ringear, brobily cost about the same at this point.
 
It would be a lot easier to drill & tap the 8BA flywheel for a 10-inch Long type clutch. These were the only clutches that made it over to the 8BA family after 1947 but the flywheels are scarce now days since they were a special use item. Some folks use the old early Ford 9-inch and they work fine on a light body car. There is plenty of room on the 8BA type wheels to drill for what ever you want. The old after market wheels were drilled that way from the manufacturer so you could use different clutches.
 
If you have a 8BA flywheel and drilled for 9 1/2 use that Pressure Plate.
And get a 9" disk. 10 spline.
Its best to deal with a Ford suppler like macs. NY
 
I used a 9" early type clutch as Rotorwrench suggests from Ft Wayne with a re drilled 8ba flywheel on my AV8 and it works great. Engine has a lot of snap to it when revved with that smaller clutch. And like you say, you can match up the splines, t.o. bearing, etc easily going that way.
 
thanks for all the info, took both flwhls to machineshop and we decided to redrill 8ba flwhl for my 10'' cl&pp that i have and resurface it. thanks again
 
You must log in or register to reply here.
Back
Top