94mm P&C on 1800 cranks with 1700 heads

[Knyda828]

Hi,

Am currently building a new engine for my bus and while this is happening I want to keep my old one going. I have an 1800 setup currently with dropped valve seat and some worn out 93mm P&Cs.
I have laying around a set of pretty nice 94mm P&C and two nice 1700 heads that have been taken out to fit 94mm P&Cs.

The question is, can i use the 94mm kit on a 1800 crank and 1700 heads? I do know that the stroke is 66m vs 71.

Thanks for the help.

[sideshow]

Too long, you need a 71mm version of those pistons.
When you change the crank you also change the rods and need the higher wrist pin height to make things work.

[Type 4 Unleashed]

The 94mm P&C would work, but you would have to cut a lot off the bottom of the cyl's for them to work, then you run into push rods & tubes needing cut, cooling system sheet metal & fan shroud too wide now.

There are 96mm pistons for the 66mm crank making it a 1900, but the cyl's would have to be bored for them to fit, which would be the better way. But still some expense involved.

[Marc]

Too long, you need a 71mm version of those pistons.
When you change the crank you also change the rods and need the higher wrist pin height to make things work.

Opposite situation.

[Type 4 Unleashed]

He said he wanted to use the 1800 crank.
So actually it's not the opposite situation, there are only 71mm stroke 94mm pistons and there are only 66mm stroke 93mm pistons, 96mm pistons come in both 66mm & 71mm. I've have been thru the actual opposite situation, which was to use the 71mm stroke & 5.160" rod with new 93mm pistons, where I had to make about .100" thick spacers to go under the cyl's.

He also could go a 71mm crank and rods & just make it a 2 ltr, if he could find them reasonable enough. It's still about how much money he wants to spend while he's rebuilding his other motor.

[Piledriver]

If you can have the rods rebushed to 22mm T1 94As are almost right, assuming the jugs are OK.

Some places want really stupid money for that task, some places closer to beer money.

If already having the rods rebuilt it should be ~free, as the cost includes replacing the bushings, and all you are doing is reaming them out LESS. (The bushings are quite thick so they can be pressed in, then get machined to size)

Compression heights (t1a 39.8 vs 42 t4 1.7) for best results trimming the jugs would be needed, the case probably needs decked anyway, but .010" usually works for that.
AA jugs used to be 3mm too long anyway, not sure if they fixed that.
The stock 1.8 pistons usually run ~.020 in the hole, if you haven't had the deck cut.

Turing it into a 2L would be easy if you can find a decent 2L crank and rods for a not stupid price.
The alternative would be to sell the 2L P&L (if new) and just buy the right parts.