A couple of tappet setting questions
Discussion
Checked my tappets today as one sounded a little noisy, indeed, found them all more or less correct except for one which was at 19 thou.
I have the cerb manual but wanted to check a couple of things:
1) I have no "special tools" - in order to maintain the cam timing will it be sufficient to cable tie the chain to the sprocket and hold the whole thing up in the correct position with a length of coathanger wire?!
2) Looking at my sprocket, it appears that the bolt holes are slotted. I don't want to move the cam timing, therefore, will it be OK to remove the cam with the front two lobes on equal lift rather than backing it off 1.5 teeth as per the manual (I won't rotate the crank or cam whilst in this position - just remove the cam and then replace it).
3) The cam chain tensioner - presumeably this is the (17mm?) bolt in the nearside head? Do I just unwind it a bit - if so, how far and how do I know how much to retighten it afterwards?
4) A couple of valve clearances are tight, can I just use a stone to lap a thou or so off the shims?
5) Finally - what sealant should I use to reseal the cam covers?
I have the cerb manual but wanted to check a couple of things:
1) I have no "special tools" - in order to maintain the cam timing will it be sufficient to cable tie the chain to the sprocket and hold the whole thing up in the correct position with a length of coathanger wire?!
2) Looking at my sprocket, it appears that the bolt holes are slotted. I don't want to move the cam timing, therefore, will it be OK to remove the cam with the front two lobes on equal lift rather than backing it off 1.5 teeth as per the manual (I won't rotate the crank or cam whilst in this position - just remove the cam and then replace it).
3) The cam chain tensioner - presumeably this is the (17mm?) bolt in the nearside head? Do I just unwind it a bit - if so, how far and how do I know how much to retighten it afterwards?
4) A couple of valve clearances are tight, can I just use a stone to lap a thou or so off the shims?
5) Finally - what sealant should I use to reseal the cam covers?
this is very tricky, i tried it this way and it ended up with heads coming off as i lost the timing.
is the engine out or not?
tensioner bolt is on passenger side of the timing cover and it is a 16/17mm bolt.
if i were to do it all over again, i would make a cam sproket retaining tool to keep the cam and chain taught but off the cam. there is a picture thread on here where someone used a extension bar or similar thing that was held in place by a plate bolted over the top of it, using the rocker cover bolt holes. simply mark the sprocket position on the cam shaft, undo bolts and slide it onto the extension bar or similar, then the cam can be extracted (providing you have rotated the engine Prior to all this to the safe position, where cyliner1 and 8 are on overlap iirc)
im sure someone will be along soon to give better advice.
is the engine out or not?
tensioner bolt is on passenger side of the timing cover and it is a 16/17mm bolt.
if i were to do it all over again, i would make a cam sproket retaining tool to keep the cam and chain taught but off the cam. there is a picture thread on here where someone used a extension bar or similar thing that was held in place by a plate bolted over the top of it, using the rocker cover bolt holes. simply mark the sprocket position on the cam shaft, undo bolts and slide it onto the extension bar or similar, then the cam can be extracted (providing you have rotated the engine Prior to all this to the safe position, where cyliner1 and 8 are on overlap iirc)
im sure someone will be along soon to give better advice.
itiejim said:
Checked my tappets today as one sounded a little noisy, indeed, found them all more or less correct except for one which was at 19 thou.
I have the cerb manual but wanted to check a couple of things:
1) I have no "special tools" - in order to maintain the cam timing will it be sufficient to cable tie the chain to the sprocket and hold the whole thing up in the correct position with a length of coathanger wire?!
2) Looking at my sprocket, it appears that the bolt holes are slotted. I don't want to move the cam timing, therefore, will it be OK to remove the cam with the front two lobes on equal lift rather than backing it off 1.5 teeth as per the manual (I won't rotate the crank or cam whilst in this position - just remove the cam and then replace it).
3) The cam chain tensioner - presumeably this is the (17mm?) bolt in the nearside head? Do I just unwind it a bit - if so, how far and how do I know how much to retighten it afterwards?
4) A couple of valve clearances are tight, can I just use a stone to lap a thou or so off the shims?
5) Finally - what sealant should I use to reseal the cam covers?
1) Yes, although accidently moving a tooth on the sprocket will cause you a headache. Dropping anything not held properly will be engine out I have the cerb manual but wanted to check a couple of things:
1) I have no "special tools" - in order to maintain the cam timing will it be sufficient to cable tie the chain to the sprocket and hold the whole thing up in the correct position with a length of coathanger wire?!
2) Looking at my sprocket, it appears that the bolt holes are slotted. I don't want to move the cam timing, therefore, will it be OK to remove the cam with the front two lobes on equal lift rather than backing it off 1.5 teeth as per the manual (I won't rotate the crank or cam whilst in this position - just remove the cam and then replace it).
3) The cam chain tensioner - presumeably this is the (17mm?) bolt in the nearside head? Do I just unwind it a bit - if so, how far and how do I know how much to retighten it afterwards?
4) A couple of valve clearances are tight, can I just use a stone to lap a thou or so off the shims?
5) Finally - what sealant should I use to reseal the cam covers?
.2) Not sure how equal lift will help you, as you will still move the sprocket by taking the two slotted bolts out. You then need to know TDC at the same time as equal lift or the 1.5 thou difference. Do a search for TDC on the forum to find out that all TVR engineers used crystal balls.
3) Yes, you can just loosen it but its not much hassle to completely remove it. To tighten it back up you screw it up and at the same time take the oil filler neck off. This will give you a good view of the chain. using a screwdriver you see if you can move the chain more than half an inch. Bit like a bycycle or motorcycle chain.
This in itself will negate you trying not to move your sprocket bolts, because if you tension the chain to anything other than it previously was you've effectievly changed your cam timing
.4) Yes, emery cloth vigourously until you can't hold the shim with bare fingers cos its too hot is about 2 thou.
Stone might be a bit too vicious.5) I used a normal gasket sealant. Nothing special needed apart from make sure its the non setting variety (usually organe), and use half the amount you'll think you should. Excess gasket sealant all over the cams is bad, and much easier to do than you think. I know, I did
.Shayne, cheers for the help. The engine is in - and I really dont want to have to take it out!
I intend to cable tie the chain to the sprocket in order to hold it in place there, then I have used a bit of stiff wire to hold the chain up - hopefully this will be enough...
What about the tensioner? Do I just loosen off the outer bolt - if so, how much. Should I just count the turns out and return it to the same position?
I intend to cable tie the chain to the sprocket in order to hold it in place there, then I have used a bit of stiff wire to hold the chain up - hopefully this will be enough...
What about the tensioner? Do I just loosen off the outer bolt - if so, how much. Should I just count the turns out and return it to the same position?
take the oil filler neck off, 3 allen head bolts, you will need some gasket sealer to seal it back on.
get a torch and shine it inside the oil filler neck hole, yuo will see the chain tensioner plate. I would undo the tensionor bolt slighlty so you can undo the cam etc. once you've held the sprocket and chain up then remove then wind out the tensioner bolt.
what you dont want to do is let the chain go slack as it will drop of the teeth on the bottom sprocket and thats when you start getting 1 tooth out on timing etc.
have you got the AJP engine maunal (not the stuff from dave hinns website)
whe re-tensioning just wind the bolt in, use a screw driver to lift the plate, i cant rember how much the plate is allowed to move but tighten the bolt until the plate can only move the amount that someone else can confirm. i cant remember how i did mint.
get a torch and shine it inside the oil filler neck hole, yuo will see the chain tensioner plate. I would undo the tensionor bolt slighlty so you can undo the cam etc. once you've held the sprocket and chain up then remove then wind out the tensioner bolt.
what you dont want to do is let the chain go slack as it will drop of the teeth on the bottom sprocket and thats when you start getting 1 tooth out on timing etc.
have you got the AJP engine maunal (not the stuff from dave hinns website)
whe re-tensioning just wind the bolt in, use a screw driver to lift the plate, i cant rember how much the plate is allowed to move but tighten the bolt until the plate can only move the amount that someone else can confirm. i cant remember how i did mint.
Edited by plumAJP on Sunday 7th June 17:27
Thanks Shayne - I think I have got away with keeping the chain in the right place - it's currently held up by a bit of wire and a screwdriver poked through the hole...
If it had slipped a tooth though the cam wouldn't go back on though would it?
Fingers crossed, it's one of those jobs that I can't wait to finish just to know that it's right.
If it had slipped a tooth though the cam wouldn't go back on though would it?
Fingers crossed, it's one of those jobs that I can't wait to finish just to know that it's right.
Have a mooch around my pics - most have narratives on the bottom explaining what is going on. There are quite a few which relate to timing/cams/shims etc.
http://rides.webshots.com/photo/288917015006117098...
Although it isn't difficult per se, you don't want to be making silly mistakes when doing the timing/tappets.
http://rides.webshots.com/photo/288917015006117098...
Although it isn't difficult per se, you don't want to be making silly mistakes when doing the timing/tappets.
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