EJ25 Timing Help

[crazymilk]

Over the weekend I started stripping back my EJ25 Subaru engine which I am using for my first conversion into my 85 T25.

My pan is to replace all the seals, HG’s, Cam Belt ect ect ect.
Now this being my first foray into a conversion I have a slight concern/question.

When I took the existing cambelt off before I did I lined up the timing marks no problem, however as soon as I took the belt of the right side (while looking at it front on) cam pulley the pulley kind of moved on its own anticlockwise about 30˚.
I continued on and got bot heads off ready for skimming at my local engineers.
However I am now worried/confused as to why is done that and if it is going to be a problem when reinstalling the cambelt?
Looking at both heads the valves are seated nice a flush in the head, not sure if that makes any difference.

Thanks for your help.

[Dollytony]

It's because 1 of the cam lobes is at full or near full lift, so it can snap back.

Getting the cam pulley on the right hand side lined up can be a bit of a pain, it took me a good few attempts, if you do a search on youtube there are some good tutorials with some good tips.

The timing is not done at TDC on any of the pistons, so you cannot do any damage when fitting the new belt. you just need to make sure all the timing marks line up.

[crazymilk]

Great - thank you.

So basically as long as I have all the marks lined up when I reinstall the belt ect then it should all be OK..(famous last words )

[Aidan]

is this a quad cam 2.5 ?

if so you need a lot of care or the proper tool to hold the cam cogs in place when removing the belt to stop the two tensioned cams rotating in opposite directions and the valves banging into each other which can bend the stems, had to replace the head on mine as it had been previously f'd up on one of the three recorded belt changes it had had before I bought it

[Domino]

is this a quad cam 2.5 ?

if so you need a lot of care or the proper tool to hold the cam cogs in place when removing the belt to stop the two tensioned cams rotating in opposite directions and the valves banging into each other which can bend the stems, had to replace the head on mine as it had been previously f'd up on one of the three recorded belt changes it had had before I bought it

Iv prob changed over 100 timing belts on turbo quad cam Scoobs and iv never once used a proper tool ,, easiest way is to lock the tensioned cams is to gently grip them with a set of mole grips and then change the belt , they have to be put on gently as you don't want to damage the cam pulleys but like iv said iv done more than I can remember and never had one problem with using mole grips

[syncroandy]

Interesting, but I can't help thinking you must have three hands

To OP, on a SOHC engine it really is quite simple, however it is worth getting a manual as that has info you really do need need such as torques, wear limits, machining limits etc. I'm just doing some heads on an EJ251 and the specified skimming limit is only 4 thou.

[Domino]

Interesting, but I can't help thinking you must have three hands

To OP, on a SOHC engine it really is quite simple, however it is worth getting a manual as that has info you really do need need such as torques, wear limits, machining limits etc. I'm just doing some heads on an EJ251 and the specified skimming limit is only 4 thou.

i get lots of practice as I change my 2009 2.5 sti belt every couple of months regardless of mileage and the same goes with my close mates as we all drive high power Scoobs lol , iv got a lot of used belts hanging in my garage I can tell you but rarther safe than sorry when it comes to the timing belt

[crazymilk]

Great thanks you guy
Yes sorry its a 2000 SOHC.
So as long as I have the crank lined up and the cam pulleys lined up when I install the belt I should be good?

Getting the heads machined at a local engineers at £18 + VAT each which seems pretty good to me.