Afternoon gents!
So iv just bought another engine, its just been rebuilt with the usual bits n bobs including a t25, however the guy is unsure if it has been cammed. whats the best way to check this? I went up to see it running but didnt sound lumpy, but want to be sure before i buy new ones for it. I saw a similar post on here regarding this but couldnt find it. I beleve a DTI guage was involved? and if it does turn out to be standard, then a 285 should do the trick??
Cheers
1. 9 out of 10 times if the last owner says he dosnt know means its not..
2. Has the timing cover been off?
3. Is there a vernier pulley beneath the cover?
4. And if it is cammed I would change the HG while the engine is out anyway because you know it's had it's arse ragged.. Better safe than sorry and cheap and easy todo this first..
no point changing the headgasket if theres no fault
There might be a way of checking the lift from the followers? but I don't have that info
or whip off timing cover, lift cam followers up and tilt them so they stay up and don't fall down. remover timing chain and camshaft and see whats stamped on it
Originally Posted by gttjames
get a dti gauge.
rotate the engine so that number 1 inlet valve is shut.
use the dti off the top of the pushrod.
set the dti to zero.
rotate engine slowly. - every 10 degrees or so take the measurement of the dti gauge.
write the results down - maybe even draw a graph.
the compare it with this:
https://www.rtoc.org/cam/
(make sure you set the rocker ratio to 1:1 and valve clearance to zero, as you are measuring straight off the pushrod.)
the answer should be there somewhere....
As above don't get me wrong but its a dam sir easier todo with the head off.. That's how I found it recently.. The engines out now do it now. Easy
As an indication, check and see if the tappet adjusting nuts are towards the end of their travel.
or you could remove the round plate at the opposite end of the engine to the timing cover (usually gets half covered by the gearbox). tap it in one corner - should spin out. then read the info at the end of the cam. then tap the cover back into place ( dont forget to use silicone on its edges)....
not all cams have anything written on them. Do what sparkie suggested, but just check peak lift, I haven't come across a modified GTT cam with standard lift. Note that there are at least 2 versions of the standard cam.
Alot of great information here guys! Thanks alot! Just shows the knowledge we have in this forum! Thanks again! Il let you know how i get on!
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