16v motor questions

[89TC-16V]

I have a running 16v commonblock motor from my old 90 TC. Questions I have is in regards to rebuilding or building a new bottomend for it. I know that there are no main bearings available for it I have heard. Is it possible to use the stock pistons with new rings on standard T2 rods with a T2 commonblock crank in a commonblock bottomend as to save money on having custom pistons made for a new bottomend build? Pistons alone are 500+ a set to have made and was looking for a way to build a cheap bottom end that would still have the same compression ratio as stock but have the replacement options available that any T2 commonblock motor has. I would imagine Alan know the answer to my questions

[Guest sy2206]

I'm not 100% sure, but I would say like 90% sure. LOL. As far as I know, the wrist pin, rod bearings, and crank bearings are all over sized from a standard common block. I know for a fact the rod bearings and crank bearings are over sized. The wrist pins are either over sized, or the wrist pin-to-rod bearing length is different from a standard common block.

So it is my understanding that when the Masi bottom end is wore out, broken, or tired, it's completely junk. It's is pretty much not serviceable at all, and the parts from inside can not be switched over into a standard common block.

I too am contemplating building a standard (non-Masi) forged common block bottom end for my 16v motor. If I go that route, my stock masi bottom end would be for sale. Runs great, 58k miles.

[89TC-16V]

My understanding is that the crank bearings were slightly slimmer than the commonblock stock bearings and that somebody had a set plained down to fit. If was asking more about the pin bushing hole diameter and maybe using the pistons on stock rods with correct pins and bushing possibly or having the small end of the rod made to fit some way eliminating need to buy custom 2.2l forged pistons with the correct valve reliefs and a 7:5:1 compression ratio

[Guest pnsurfin]

You can't use stock pistons because they have to have the cut-outs for multi-valves. You will bend the valves if you don't use 16 valve pistons.

If you try to modify the original set-up to avoid this by shortening the piston travel, you will also lose horsepower.

Patrick

Edited August 7, 2010 by pnsurfin (see edit history)

[Guest sy2206]

I think what 89TC-16V is trying to say, is he wants to use stock Masi 16v pistons, and a standard non-Masi common block bottom end.

As far as I know, that is not possible.

The bearings/journals at all three locations(crank-to-block main bearings, rod-to-crank bearings(bottom of rod), and piston wrist pin bearings(top of rod)) are all unique to the Masi bottom end. When it comes to the stock Masi bottom end, you either use all of it, or none of it.

[89TC-16V]

Yes so I guess its use masi bottomend or don't bother. Gotcha. Or there is always innovate and blaze own trail. I have a nice TIII bottomend that maybe with a cam driven distributor can be used in place of it. Scratch, that, better idea, TIII internals in stock T2 commonblock so I can run a distributor and I would imagine the T3 pistons 4 valve reliefs might cover that but compression will be around 8:1:1 which won't hurt anything

Edited August 7, 2010 by 89TC-16V (see edit history)