from gates to OEM mitsu T-belt

[turboglenn]

Sorry if this is dumb, but i can't recall if there's a difference in the way they align really. And it's been 3 years sincemy last timingbelt install (and yes i did search but can't find a mention of the tick markes not all being perfect )

I used gates belts too much really but i know how they line up when i put them on, i'm putting an OEM mitsu timing belt on my car now and although i've done this a million and one times, right now i either end up with the crank disc/pulley being about 1/2 the notch width off in a counter clock direction, or i get it where the notch in the crank disc is past the pointer on the case to where the case is pointing at where the notch has completely ended (as if the notch rotated to far). No matter how many times i reset it (done it at least 23 times tonight) i either end up a what looks like would be a tooth advanced or a half tooth retarded at the crank but an actuall tooth would be much more rotation.. For some reason i seam to recall they wouldn't line up perfectly or soemthing but it's been 3 years since i've done a t-belt becauyse of my back

 

[steve]

Who makes the belt shouldn't make any difference in installing the belt unless one is junk.

The tooth pitch has to be the same.

If you head and block have been milled that will affect how the cam and crank marks line up since you've changed the distance between the two centerlines.

Are you sure you're not just leaving too much slack in the belt and having the crank move when you tension the belt?

 

[turboglenn]

Yea, i'm sure the install is going correctly. I've even so much as loosened the belt and only rotated the crank and cams one tooth at a time based on which one needed moved. and no matter what if i move the crank it only goes further out. I'm using fidanza gears but that shouldnt really matter. I did have the head milled .005 but should it make that big of a difference? I've never personally had to have my head or deck surfaced on my 4g63, but for some reason like i said before i feel like there was something i was supposed to remember about the notches not being perfect (and when i say perfect, please keep in mind that i'm a long time hobby mahcininst, and have been selling my machinist services for a living the last several years, so my idea of perfect is withing .002 - .005" on somethign like this and even that's being "loose" by my standards

I knew the belt maker shouldn't matter in a perfect world, but from what i've been seeing and hearing about gates in the last few years their quality has severely gone down hill. I told my machinist that my belt failed at just over 30k miles and he said that's about what he's been seeeing when it comes to using gatres belts (and mentioned they made a change to their belt construction in the last few years which i hadn't heard)

It really feels/looks like if i had a few miles on the belt to stretch it just a haor everything would be just fine)To be more descriptive, when i have the belt on and everything is in line, when i appply tension through the eccentric pulley, it was pulling the crank clockwise enough that the complete "tick" mark on the crank was just past the pointer. If i rotate it back a tooth it's way too far backwards, and if i apply the belt from the other direction (wrapping the crank instead of the cams first) then when i apply pressure the tick mark is maybe 3/4ths of it's own width before the pointer on the case (like if i put 10 miles on the belt it would all be perfect... does that make sense? ) I'm alsmot thinking of running it that way for a wfew miles and seeing if the thing doesn't line up perfectly witha little use on the belt

 

[steve]

I've never found the marks to be machinist perfect. Without adjustable sprockets the best you could do was move a tooth so if the marks were less than a tooth off they were right. It's not like the crankshaft sprocket flange has a precision fit and I've never been a fan of the engraving positioning on aftermarket cam sprockets.

Where is the crank mark when you know your at TDC?

When you have belt on where the crank closest, where does that put the cam marks if you move the crank to on it's mark? (or to where you found TDC to be)

 

[turboglenn]

I'll post some pics in a bit, I have another friend over who i've helped and he's helpoed me many times on this, If we can't get them right i'll hav epics up in a short bit

thanks
Glennh