Ok you 20b freeks! Is a light weight flywheel really necessary? Could I continue to use the stock one? I know on a 13b that throttle responce is increased but what about the differances on a 20b? These are just a few questions I'll ask before I start my conversion. Thx in advance

 

Uh, there are no factory stock flywheels for the 20B. They don't exist! The 20B came with a flexplate stock.

This can turn into a good thread to discuss 20B flywheel conversions. I'll start by saying that I'm getting a 215-225mm Racing Beat light steel flywheel for my 20B. I'm not getting the T2 240mm version because I'm sticking with a '76-'78 ribcase 5 speed tranny. My engine is NA, so it's not going to break the tranny very soon, or at all if I drive it like I bought it.

There are other flywheels out there, like from Australia that work well and may be cheaper than RB products. Also, Tilton twin disc stuff is stronger, but more expensive.

That's my .03 cents worth.

 

Oooops, I ment the stock flywheel from my Fd

 

It won't work.

I'm suprised this thread hasn't gotten more posts in it by now.

 

Um, yeah, low-inertia flywheels only reduce inertia on 13B engines. For all other engines, the laws of physics don't apply, and the low-inertia flywheel won't change anything.

I think Pettit was running a 20B with a flex plate and a Hewland transmission, so you may want to give them a call. If you price a Hewland transmission first, then you may forget about making the call, lol. It may be possible to use a flex plate on other transmissions, though.

You may be able to use the FD flywheel if you do some milling work. You need to balance the whole rotating assembly, which isn't going to be cheap.

My 20B has the 3.1 lb Quarter Master flywheel for the Quarter Master universal 5.5" 2-disk clutch pack. The counterweight needs milling work for this conversion. Fortunately, this is a common setup for GT1 RX-7's, so the appropriate milling plans are available from Mazdaspeed.

If I remember correctly, the 20B came with a flywheel. I don't remember what kind, but it was most likely a Billington or Quarter Master flywheel. The 20B-REW came with a flex plate.

What's the point of installing a 20B if you are going to down-tune it to 200 lb-ft torque and putt around town with it?

 

Ah, yes I should have mentioned 20B-REW. D'oh!

What's the point? Wouldn't you like to know. Hehehaha!

Seriously though, I say we should put other stuff on hold to finish our 20Bs as soon as possible. Mine will be done hopefully in time for sevenstock. That's what I'm shooting for anyway. I've got like 3 months and very little budget. I think I can do it (the light at the end of the tunnel is looking really bright these days). Then I can always upgrade in the future. At least it won't just sit there in the meantime.

If you're interested in the details of my project, you're more than welcome to read some of my threads here and there. I crave feedback.

 

my friend with the 87 pickup 20b, has to use the same bellhousing as jeff because they are tilted like the truck

mike

 

Cool! That 20º tilt makes room for the starter. It worked like a charm in my Midget. It can be R&R'd with a couple mm to spare even. No notching of the frame.

Could you tell me if T2 trannies are also tilted?

 

they are but not nearly as much, maybe 10degrees tops

mike

 

I've heard people can use old ribcase bellhousings on T2 trannies, but maybe they were pulling my leg? What's required? A little slotting of each hole?

 

well i think it went right onto the truck tranny (its like a t2 box)

mike

 

That's interesting. Now I know it's good to hang on to those bellhousings long after the ribcases grind themselves to oblivion.

 

yes, keep those things, they crack. i had a customer who was looking high and low for one for a long time

mike