M20 timing gears,timing and FW questions

[tn535i]

My son and are are reviving our old 86 2.7(very well cared for engine) into a different e30 body with numerous changes and here's a couple quick questions for the experts.

First, should we replace the timing gears? These are the old stamped ones and I think I've read to replace the intermediate gear with the updated(sintered) one but the cam sprocket is probably OK as is? He would like to make some mods in the future and so it's up in the air as to if and when the head might come off for an e to i job or turbo or ?? The head and cam bolts were previously upgraded to torx btw. No leaks except for a little out the oil pan we will probably replace that but leave the rear seal alone or would you do the seal as well?

Next, thing is going to be a 5 speed swap. We have a single mass flywheel already but it's heavy and we plan to lighten it up a bit. How light would you guys go on the flywheel as my son thinks 13-14 lbs like the early Euro motors would be the ticket. Sound OK? Currently almost 19 with an 11 lb or so PP. So shedding about 5 lbs is not sounding crazy light to me. He knows how to drive the manuals pretty well and preferes the M6 over the 535. About 5 lb difference there if I'm not mistaken.

This FW seems to balance almost perfectly statically. Is that what we should target for the FW and then FW+PP. This is what I did on my 535 clutch job and I was surprised how much out of balance the new PP made things. I had to drill and remove a good bit on one side. We also measured about .001" axial runout on the FW when bolted to the crank and marked it up since we will try to bring that as close to .000" when we machine. Also not sure about the recommended step on the friction surface and PP surface. Anyone know the specs on all this?

We will also need to add the reference mark for the tdc as the newer FW does not have this. Not a problem to do but would there be any value in moving (advancing) this or even trying to make it adjustable? Would this accomplish nearly the same thing as putting in a chip and switching to premium fuel or does this sound crazy.

Also we noticed when the timing marks are tdc the reference pin on the old ring gear is no where near the actual sensor location. Anybody know how they really trigger the ECM? Is it about 120 or 240 degrees out of sync and the computer does the rest. That's about what it looks like.

Thanks in 'advance' (pun intended)

[TSMacNeil]

I have the upgraded intermediate gear...brand new never installed. Since I'm giving my '88 away shortly, I'll let it go for $25 plus shipping from 85295.

If you're interested.

[winfred]

i always recommend losing the stamped gears because i have seen many of them fold up and throw the belt, caught a few about to go during belt jobs too, not just the cam gear craps but the small one as well.
i have the early euro flywheel and it works nice with a stock 2.5 and my 2.8 stroker, the 13# 323 wheel looks just a like a I wheel but doesn't have the stepped up part on the engine side and is flush with the ring gear
a couple pics

[craigb93]

http://www.nmia.com/~dgnrg/page_41.htm

Down in the fine print it says 0.011 in.
This was the number I saw somewhere else last year.

Look some more though.

-Dick

[tn535i]

TS... I'll consider this but we might be pulling both gears from a later donor car along with a few other goodies we need.

Winfred... My son has shown me those same pictures of how he wants to turn down the flywheel on the engine side.

craig... I thought Bently had all these numbers too but I did not find them on my first glance. That gives me a number to check where it is now though. I've seen that article before too and it is very good resource.

Thanks

Keep the info coming. I'm really curious to know if anyone has ever 'manipulated' the timing?