Cambelt position 2.0 blacktop
AndyW - 5/12/11 at 10:30 PM
Hi guys,
A quick question for the locost massive! Now I have got my engine turning over, I have noticed the cambelt seems to run very close to the edge of the
pulleys. You can see where the old belt ran as there is a clean section on the pulley's. I slackened off the belt re-positioned it and it then
runs out again. The first picture shows its current position and you can see the "clean" bit where it used to run. Second picture shows how
close the the edge of the pulley. Any idea's as to what Ive done wrong? The timing is spot on and the tensioner is correct so Im a bit
lost....
Thanks in advance
Andy
rhinopower - 5/12/11 at 10:45 PM
Is the bottom crank pulley on all the way?
dray13dad - 5/12/11 at 10:46 PM
can see the prob,you got timing wrong! by using painted marks. take cam cover of and set to tdc. you need timing pin for crank and plate to go though
slots in rear of cam.you have to slacken front cam pulley bolts and have both pulleys free on cam taper then set tension you will find that the slack
side of belt will turn both pulleys anticlockwise.tighten tensioner then both pulleys. turn engine over a few times and recheck.
rhinopower - 5/12/11 at 11:02 PM
quote:
Originally posted by dray13dad
can see the prob,you got timing wrong! by using painted marks. take cam cover of and set to tdc. you need timing pin for crank and plate to go though
slots in rear of cam.you have to slacken front cam pulley bolts and have both pulleys free on cam taper then set tension you will find that the slack
side of belt will turn both pulleys anticlockwise.tighten tensioner then both pulleys. turn engine over a few times and recheck.
Doesn't matter how far out the timing is, the belt is overhanging the pulley where it was obviously previously on correctly when the timing was
set. It must be something to do with the crank pulley imo
daviep - 5/12/11 at 11:03 PM
quote:
Originally posted by dray13dad
can see the prob,you got timing wrong! by using painted marks. take cam cover of and set to tdc. you need timing pin for crank and plate to go though
slots in rear of cam.you have to slacken front cam pulley bolts and have both pulleys free on cam taper then set tension you will find that the slack
side of belt will turn both pulleys anticlockwise.tighten tensioner then both pulleys. turn engine over a few times and recheck.
Why would not resetting the cams cause the belt to run to the front of the pulleys?
Have you checked that all the other pulleys and tensioners are all running true.
Davie
AndyRead - 5/12/11 at 11:03 PM
I would go with the bottom crank pulley as well, make sure its all the way on!
dray13dad - 5/12/11 at 11:15 PM
Because you can get the belt to fit with out moving the cam pulley wheels and tensioned up.but there is just a bit of slack 1 between front cam and
crank.2 slight slack between both cams when you turn engine over as there to slight slack in belt moves the belt will run off. will never run out on
crank as crank pulley/ alternator drive pulley will hold it back..
honest been there. have got away with it in the past of just slacking off rear cam (on tensioner side)..
mrwibble - 6/12/11 at 01:45 PM
have you tried turning the engine over to see if it settles?
pretty sure mine did after a couple of turns.
[Edited on 6/12/11 by mrwibble]
dray13dad - 6/12/11 at 06:06 PM
Don't think i was too clear last nite,bit to mush beer.
Would guess you didn't take cam cover of to check cams set right first (ie rocking cyl four,firing cyl one) cos you paint marked pulley.
so you could have been at tdc on crank and firing cyl four. there for be load on cams wrong for belt tension at diferant palces when turning over .so
therfore your belt will run offf
big_wasa - 6/12/11 at 06:32 PM
quote:
Originally posted by mrwibble
have you tried turning the engine over to see if it settles?
pretty sure mine did after a couple of turns.
[Edited on 6/12/11 by mrwibble]
Yep I had one that run up to the edge but not over and it settled back after I ran it up. The timming kit is so cheap for these that its not worth not
using it. Its just a pin and a 5mm bar.
AndyW - 6/12/11 at 06:50 PM
Just to make things clear here.....
I used the proper timing kit, flat bar across the cams and pin to lock crank so it IS timed right, the red marks were from someone else I assume who
ever owned the donor.
I will check bottom pulley although Im sure thats on all the way, and I will report back what I find
daviep - 6/12/11 at 07:41 PM
quote:
Originally posted by dray13dad
Don't think i was too clear last nite,bit to mush beer.
Would guess you didn't take cam cover of to check cams set right first (ie rocking cyl four,firing cyl one) cos you paint marked pulley.
so you could have been at tdc on crank and firing cyl four. there for be load on cams wrong for belt tension at diferant palces when turning over .so
therfore your belt will run offf
I'm still not convinced.
Regardless of which cylinder is firing the load on the cams is exactly the same, everytime any cylinder is at TDC There will we 1 cylinder "on
the rock", 1 cylinder firing , 1 cylinder at the end of an induction stroke and the last cylinder will be at the begining of an exhaust stroke.
I'm not saying you shouldn't set the cams properly but failure to do so only means that your cam timing may be out by a tiny amount, there
is no reason that it should cause the belt to run off the pulleys.
Davie