Now I'm in the market for some take-off cylinders, since so many just buy the big-bore kits complete and then sell their original cylinders. Once again, I'm seeing a lot of 88 parts for sale.

Are there any differences that will keep those cylinders from fitting my cases and heads?

 

Good question. Know the difference is in the stroke. Bores are the same. I has seen some good deals the other way (Brand new take off's from a 96 (cylinder, pistons rings) for as little as $200. Never could get some accurate outside measurments. Check some part numbers like at bike bandit fish. Be sure to post back here for furture reference. Harley went to the 96 because they needed a little more torque for the 6 speed I think. Sales demanded 6 speed I guess.

 

Well, from what I found, a lot of 88" cylinder casting #'s are 16593-99, and I just found a kit that's supposed to be take-offs from an '09 Street Glide for $89. eBay 380343997602. The casting numbers are the same, according to the ad.

If I'm wrong, then I just bought a bundle of parts that won't do me any good. If I'm right, then I have my cylinders to get bored for a 107" build. I also have cams to leave sitting in the garage, just looking cool, a pair of aluminum ashtrays, a set of lifters, a derby cover, and pushrod tubes.

There are other cylinder sets on eBay for a bit less, but this bundle spoke to me. It said, "Buy it now".

 

FWIW, I also found a couple more pairs of late-model 96" take-offs with the same casting numbers. Looks to me like they're all the same.

 

They are the same. You did good.

 

TC88 cylinders and heads will fit on the 96" cases; however, the pistons must be the "stroker" pistons for the 96"; 88" pistons althought the same bore have shorter skirt and pin location.

 

So I think you are saying that a take off 96 cylinder will fit but not the piston on my 88.? Guess if you think about it that the cylinder is the same length, so with the longer stroke in the 96, the piston must be lower (centerline of pin to piston top is less) The longer stroke allows more air volume to rush in . I would think the 96 pistons in reality would have less skirt length from the pin down to bottom of skirt since on down stroke it need to go into crankcase. We are talking about pretty much here (I think 3/8" or .375) If you ran the 96 cylinder and piston on a 88 you could probably run regular gas. What do you think the compression ratio would be. Is the pin difference 3/8

'CJ' Not sure you can just go by a casting number. You probably should do some measuring. It would be pretty easy for Harley to take less off a face to make cylinder longer.

 

Forget about 96 vs 88 cylinders; they are the same. The 96" stroker piston does have a shorter skirt and the pin has been relocated. By that I mean the pin location in the conecting rod, not the piston. The con rods are the same lenght in the 88 and 96 but the pin in the 06 has been relocated .1875" which is 1/2 the .3750' stroke. I am not certain but believe the shorter skirt is necessary to avoid piston to piston contact ABDC.

If deck height is 0.00, the only change in compression would be attributed to the increase in bore, the piston pin location and/or stroke has nothing to do with compression.

 

Piston to valve contact, maybe, not piston to piston. Of course, .1875 is probably enough to have the piston contacting the head.

Yes, ladies and gentlemen, we can lay this one to rest. The casting numbers are the same on the cylinders, whether they're from an 88 or a 96.

This has been confirmed (probably hundreds of times before I asked).

If you just want to do an overbore, there are plenty of inexpensive take-offs out there for the taking.

 

Not quite; time for a geometry lesson. The 96" cylinders and con rods are the same length as the 88"; perhaps you missed that in my previous post. Neither of those contribute to the .375" stroke increase in the 96" which is the result of the .3750" outboard relocation of the crank pin from the crankshaft centerline. Therefore piston to valve contact is no more an issue in a 96" than in a 88" because the piston pin location in the rod has been raised 1/2 that distance because the crank wheels move in a circle. However, when the pin location is raised in the rod to compensate for the stroke increase it pulls the piston deeper into the crankcase and piston to piston contact does become an issue and that is why the stroker piston has a shorter skirt.