hi all, im gonna whip my cambelt off this weekend and pop a new one on cus im taking my head off, but how do you know when the correct tension is reached with the adjustable tensioner pulley jobbie? is there any rules to follow etc when working on the sei fire engine?

The general consensus for tensioning cambelts on FIRE engines is that when its correctly tensioned you should be able to twist the belt by 90 degrees in the middle of it's longest run, using just your forefinger and thumb. Assuming, of course, that you're not a bodybuilder with freakishly strong fingers...

shop 4 parts has a special on the cam belt and tensioner just now if your looking to buy

thought that might be bout what it wud be!

the other thing is im changing my valve springs, im gonna take cam off but leave cam sprocket on to make life easier! shud i make marks on cam and crank sprockets in relation to the engine with tippex at the point the engine has stopped or shud i re time the engine with the tdc markings already made with the notches on the engine??

don't mess with your own marks.
The new belt has the marks corresponding with the marks on the pulley.
Change the tensioner at the same time.

so what your saying is no matter what point the engine stops at, re time the engine so the timing marks already made on the engine shud be used???? ie, turn the crankshaft and camshaft so the marks on them align with the marks on the block and head then pop the new belt on?

Correct!
Just align the cam pulley mark with the mark on the head (behind the puklley) and then line up with the bottom pulley.

righty, got u all, but how do you adjust the tensioner? do u need a special tool for the job?

MintySport said:

righty, got u all, but how do you adjust the tensioner? do u need a special tool for the job?

Click to expand...

Nope, but 4 hands, a huge bar and a 13mm spanner usually sorts that. One person at the top levering the pulley towards the front of the engine, another person, again from the top to do up the nut

Nah, its only a 1 man job, one hand on yer crowbar and the other on yer spanner! Pull it tight, tighten the bolt, check the tension, adjust as necessary

cheers lads,
but one thing im stuck on.

i get all my marks lined up......take rocker cover off, but can i just remove the cam with sprocket attached after removing cam bearing caps or do i have to remove sprocket in case it screws timing up.......... cus i might have to replace some shims?

Hi,
Sometimes best to align the timing marks before you remove the cam belt, because the valve could be at half lift and want to spring back to its closed position, which in turn will cause the cam pulley to rotate, and its a pain in the @rse to re-align them when they are not connected by the belt.

Hope you all follow that

Thanks
Paul T

i follow wot u saying, but once i got tdc, do i have to remove sprocket from cam first before i remove cam or can i just remove cam bearings and remove cam and sprocket as 1 unit????

there should be an oil seal behind that pulley so yes you will need to remove it so you can fit a new one.

replace the cam oil seal then? isn't it a bitch to get the cam pulley off though??

Nah, they're not that tight. Hold the cam with a big spanner and put a socket on the pulley nut.

cool cool.

I'll only replace it if I can get my hands on a 75 cam. Best get searching the breakers on Thursday:chin:

Hi I recently changed cam oil seal and its a piece of cake to remove the sprocket and just a little trickier to remove the oil seal because you need to be carefull not to cause any damage the head. and its easy to fit new seal too.

how did you get the oil seal out then?

If you don't have a seal puller, you can insert a self tapping screw into the old seal, not too deeply now, and use that to pull it out.

Cheers

D