A or B Flywheel

M

mollydog

Member
Can anyone tell me if the is a difference between the A and B flywheels? I'm new to this and am not trying to make stupid mistakes.

Mollydog
 
The motor in my 31 A is being rebuilt. Since it is out of the car this is a good time to address the clutch/flywheel assembly.

I plan on switching to a touring cam but haven't decided if I should go with the standard A flywheel, the lightened A flywheel or the B flywheel.
Additionally what it the advantage of the V8 clutch and what modifications are needed?

PS I am doing this on a tight budget so I need to spend money wisely.
 
The first thing I would do (even on a tight budget) is use a crankshaft with counterweights, and a 5.5 head.

If you have money left over, then lighten the flywheel and/or use the V8 clutch.
 
If you are on a tight budget and already have a good model B flywheel, that is what I did and am very happy with the results. The lighter flywheel takes weight of the rear main bearing and the babbitt will be under less strain. Not only that but you won't run the risk of a botched up job on a lightened model A flywheel. No need for a V8 clutch . The B flywheel uses the same clutch as the model A. You are no doubt interested in improved performance. The model B flywheel will make a big difference in throttle response and accelleration . The lighter flywheel will also help with less clash with the gears because it spools up and down quicker . Now would be a good time to install a higher compression head. You can probably save enough by using the B flywheel and clutch to buy a better head. If you can't afford a new head, If you have a model B head with heart shaped combustion chamber it will be an improvement over the model A head. Just my thoughts, its your choice.
 
Thank you for the info - Unfortunately $1,500 for a counterbalanced crankshaft and $300 for a hight compression head uses most of the money I have for this rebuild. I have to keep it simple!

The biggest issue is hoping that the main bearing babbit and current crank is OK then boring for oversized pistons, changing the cam gears, getting the valves right, and maybe a touring cam. The lightened flywheel would be nice if it makes sense and spending a little on a clutch is wise.

I am looking for a low cost but logical way to get the model A on the road. After all this is a hobby !
 
I've never really saw the need for a heavy counterbalanced crankshaft. I've got by real good with original model A crankshafts , in some cases for over fifty years and never had one fail . Some seem to think that they are an absolute necessity and everybody is entitled to their opinion. A heavy rotating assembly causes throttle response to be slow and labored. If enough money is spent on other mods, this can be overcome. A good cam is the Super street Winfield 3/4 race cam that Bill Stipe grinds.This cam is only $125.00 exchange. It may be too late to get this cam. Acceptable cam cores are hard to come by for a good regrind. Good luck , Peppy model A engines can be a learning experience or an expensive escapade. I never tried to build an all out race engine. I mostly have been intrested in a peppy faster than stock engine that I could do myself, sometimes with a little machine work that I could farm out.
 
nhusa said:
Thank you for the info - Unfortunately $1,500 for a counterbalanced crankshaft and $300 for a hight compression head uses most of the money I have for this rebuild. I have to keep it simple!

The biggest issue is hoping that the main bearing babbit and current crank is OK then boring for oversized pistons, changing the cam gears, getting the valves right, and maybe a touring cam. The lightened flywheel would be nice if it makes sense and spending a little on a clutch is wise.

I am looking for a low cost but logical way to get the model A on the road. After all this is a hobby !
Click to expand...
So what you are saying is, you are doing an overhaul not a rebuild. An overhaul uses components that are already in the motor but may be usable and a rebuild replaces all the components including the main bearings, rods and babbitt, cam, pistons, rings and any other moving components of the engine. I have a paint can rebuild in the shop right now.
 
Rebuild, refresh, overhaul, build a race motor - call it whatever you want. All I need is a damn Model A motor that runs well enough for my wife to have fun with a completely original Model A that has been in our family since the late 50's and been in storage since 64. I just want to do what is smart and have something that runs OK and does not burn too much oil.

The motor that is in the car is truly stuck solid and not a good candidate for a rebuild or whatever. I pulled the head and the pan and found that it had water in the bottom so I got another one that may be better - at least it is not stuck!

The new one will most likely need to be bored because the pistons are sloppy and the crank has a bit of endplay. Boring with new pistons isn't a problem as long as the crank and mains are OK. If not I'll have to do a rethink - maybe the crank in the old motor will be OK But I certainly will not spend $1500 for another.

I will do what makes sense for the flywheel, valves, cam, etc. to ensure that it is reliable but will not go overboard. I am here asking for opinions from people that have been down this road with their A's so i can learn from them.

The flywheel is interesting - a lightened A or B makes some sense if there is enough money - In fact I just saw that a B flywheel can be purchased from JC Whitney for around $100 but don't know if it will work.

BTW - I also have a 1919 T that has been in our family since the mid 50's that I use almost every weekend. It has the original motor that has not been rebuilt but I have a back up 26 motor/transmission that has been rebuilt refurbished or whatever you want to call it that will go in it so I can refresh the real motor. The backup motor has new aluminum pistons, single piece stainless valves, new main bering cap to eliminate excessive crank endplay, bushings in the triple gears, kevlar bands, etc. so i am not a complete newbie to older Fords. Additionally I have been involved in drag racing, nascar and sports cars for close to 50 years so I know a little about motors and cars. At least I know enough to ask questions!

I would not be proud to say that I was doing a "Paint Can rebuild" because that sounds like something a slick used car salesman would do to make a beater look like a cream puff. Something akin to putting sawdust in a rear end.
 
Last edited:
How old is that JC Whitney catalog with the hundred dollar model B flywheel??? I need to find a catalog like that if its up to date. I overhaul my engines and have whatever machine work is needed done. I've tried to answer your questions. It sounds like you have answered them yourself and I've got to wonder why you bothered to ask in the first place.
 
On line yesterday. I did a search on a model B Ford flywheel and it came up near the top. They say either aluminum or steel. I would not purchase one unless someone with experience said it is OK
 
Yes that is what showed up in the quick search I did last night
- I was surprised to see that JC Whitney still existed and I am not surprised that their part is not even close.

Today I spent a bit more time and saw that Model B flywheels are almost nonexistent but I might be looking in the wrong places.
 
Thanks Benson, That clears that up !!! I knew something didn't sound right. JC use to sell a lot of used model A stuff back in the sixties but I figured that all that stuff was long gone . I remember that they offered used model A block assemblies guaranteed to be free of cracks for forty dollars . I wish they still offered stuff like that. Back then I didn't have enough money to take advantage of such great offers.
 
From experience just because an engine is stuck doesn't mean it isn't a choice for a rebuild. The engine in my CCPU looked like it came out of the bottom of a lake when I got it and took a sledge hammer and a 2x4 to get the pistons out. However, once it was apart had it magnafluxed....no cracks and bored the cylinders. The engine came out fantastic and you would never think it would have been a usable block. Lots of time, energy and below grease got it done!
 
nhusa said:
Yes that is what showed up in the quick search I did last night
- I was surprised to see that JC Whitney still existed and I am not surprised that their part is not even close.

Today I spent a bit more time and saw that Model B flywheels are almost nonexistent but I might be looking in the wrong places.
Click to expand...
If you really want one, James Rogers usually has a few. Stock or lightened.
FWIW, with the goals you listed, I dont see where you need a new crank either.Good Luck:)
 
1930 coupe said:
Changing to a light flywheel is a highly controversial subject, some people say it is good, some say it is bad, and some say they cannot tell any difference. If you are just going to drive your car around town and occasional short club tours, I would put whatever flywheel you have back on and your car will run just fine.
Click to expand...

I took the motor to a guy that works on both T and A to see what it needs. He agrees that the std flywheel will be OK for my needs and will only change the cam if it is needed. we will do the timing gear. The big question is the crank and babbit. We already know that it will need boring and most likely rods.
 
You must log in or register to reply here.
Back
Top