Timing chain

[joe37705]

I'm putting a new head on my 22r and the timing chain is so tight I'm afraid it's going to bind up and break when it's running. I measured the diference in the head heights and the new one is taller. I'm guessing it's never been machined or anything like that. Are there any longer chains I can look for or what?

 

[NotMatt]

What year head/block? There are two different styles of heads and blocks... early 22r heads are about 1/4" taller than the late model ones... and they don't interchange because the blocks are different as well. If you put an early head on a late block, the timing chain would end up being really tight to almost impossible to get on.

 

[joe37705]

I bet that's it then. I thought the ports were round on the intake side of the early ones though and square on the later year ones? The 2 heads look the same except for height. It's an 87 block at least.

 

[NotMatt]

I forget what the differences were... I think the exhaust ports are pear shaped on the later heads and just round on the early ones, but I'm unsure of that. Either way, it sounds like you have an early head... which is a bum deal.

It will run if you put it together with an early (longer) timing chain, but it will miss and generally run like ass, since the compression will be low and the timing will be off due to the difference in the later and earlier blocks (the timing chain will actually be too long if you use an earlier one, since the early blocks were a hair taller as well).

I personally tore down a motor that was built like this by someone who was a supposed "toyota mechanic"... we drove it from Milton-Freewater, OR and made it as far as Yakima before it spun a rod bearing. :masturbanana[1]: