Rover V8 camshaft wearing a groove in timing chain cover

[Else]

Hello all.

I need a bit of help from Rover V8 engine specialists please.

I've had a strange knocking noise from the front of the engine at idle ever since a new roller cam was fitted and also had a couple of oil leaks underneath timing chain cover. I found one of the bolt holes had cracked which was letting oil leak out so I stripped the cover off this afternoon to investigate. Once i had the cover off i noticed there is a groove worn in the inside of the cover at the top which looks like it was from the timing chain rubbing.




Also the sprockets don't look to be exactly in line. The cam sprocket looks to be a couple of mm further out (away from the block) than the crankshaft sprocket. You can't really see it from this picture but you can see what I'm referring to, hopefully.
There is a little button on the end of the cam that has been in contact with the inside of the timing cover, here is a pic





Could the cam be moving forward in the block at idle allowing it to tap on the inside of the cover when its idling creating the tapping noise??

Thanks Andy

[Boosted LS1]

The cam will move forwards and backwards a tad. The thrust button may help with forwards travel but I doubt any noise will be because of movement. Have you sorted out lifter preloads or lash settings?

You could fit a thrust plate behind the cam sprocket.

[Else]

Thanks for the reply Mike.

What about the groove worn in the cover, surely thats not correct.

Andy

[Else]

Another thought.. what if this cam doesn't have a thrust plate fitted, what if its an early type which doesn't have the groove for the thrust plate.

Theres no distributor or pump putting load on the cam so its free to move back and forth tapping on the inside cover at idle speed?

[paintman]

Quick look at LRcat parts list for RRC & P38.
RRC cam shows a bolt & flat washer (not the domed affair you have)
Earlier RRC doesn't have a camshaft retaining plate: http://new.lrcat.com/#!/1230/73417/75066/6006
Later RRC has a camshaft retaining plate: http://new.lrcat.com/#!/1229/83488/84864/6690/8494...


P38 shows a flanged bolt, again, the flange section is flat FS110301L

P38 has a key to locate the camshaft: http://new.lrcat.com/#!/1234/90127/90555/7160/9057...

Is this new setup the same as what was there before?

[Boosted LS1]

The mark on the cover's from the thrust button. Older rovers had the cam moving in both directions without a button and I don't recall there being big issues with that. Perhaps the knock would go away if you removed the thrust button?

It could be something else though imo, not the button?

Edited by Boosted LS1 on Monday 17th February 00:29

[paintman]

Boosted LS1 said:

The mark on the cover's from the thrust button. Older rovers had the cam moving in both directions without a button and I don't recall there being big issues with that. Perhaps the knock would go away if you removed the thrust button?

It could be something else though imo, not the button?

Edited by Boosted LS1 on Monday 17th February 00:29

Mine's as per my first link. No issues.

[PeterBurgess]

looking at the pic of the complete crank sprocket, chain and cam sprocket I cannot see what prevents the cam sprocket from walking? If it is free to walk it may well allow the chain to chew the front cover as shown. I haven't done cam work on a V8 forever and a day so apologies if I am wrong.A spacer would sort the problem.

Edited by PeterBurgess on Monday 17th February 06:42

[Boosted LS1]

I've just had another look at the pics. The 2 scuffs at the top of the casing will be from the chain because it's a double roller and yes the cam's walking forwards a tad. Maybe a new thrust button would prevent that. One with no wear. They need to be shaved to allow a few thou of clearance.

[Zener]

Why dont this have a 360 thrust plate fitted? rather than the less successful button method , machining the cam to accommodate is a small machining process , like mentioned already the button dont appear to be working too well , the block as the two hole provision for one already

[Boosted LS1]

Later rover engines had the 'C' shaped thrust plate. I'm not sure if it's the same thickness as the TVR plate. Early engines didn't have anything to control the cam walk. Bizarre really but they seemed happy enough.

[Else]

Thanks everyone, really appreciate your comments. I know the previous cam had a thrust plate but I will have to investigate this one further and get the cam machined if it doesn't have the slot.

The cam and followers came from the states, I could ask them but its a pia to get an answer from them. I didn't fit the cam so i don't have any paperwork for it so I have no idea what the spec is. I have tried to find out but got nowhere. It didn't knock before on the old stealth cam so I'm convinced its something to do with this one.

Andy

[Else]

Stripped off the inlet plenum and valley gasket this afternoon to expose the roller followers etc.
I also undid and pulled the cam sprocket off to look for the cam retaining plate or lack of one.
There is definitely no retaining plate so I would like to fit one can’t see how it holds the cam in place.

Has anybody got a picture of the proper cam for a serp?

Thanks Andy

[Else]

I’ve read that when using a roller follower cam it can walk forwards and back when there is no distributor and oil pump drive to put a little load on the cam holding it in the back position. Is this right?
Has any one got an old serp cam that I could have to copy the slot position to get my cam machined to match?

[paintman]

Can't help with the cam but in the absence of any other replies you might get a rough idea of the difference in the front end of the cam by looking at the V8 cam section of Rimmer's website.
https://rimmerbros.com/Item--i-GRID009192 Scroll down & click on the various cams for a bigger picture

What happened to your old cam - as in where is it - as that would seem to be the best option to know what mods you would need to make to the new one.
Also have you managed to get any response/advice from the supplier of the current cam?

[Zener]

TVR fit cams didnt have a thrust groove machined into them either and the thrust plate was very often omitted (I've never witnessed with) thus relying on the cam to dizzy gear to keep things in check here is what your looking for , not mine but Real Steel did my cam before sending out I have the same thrust plate system in this shot

[Else]

Thanks Zener. That’s really helpful. I think I’ll order one of those thrust plates then get the cam machined to fit it as in your pic.

Andy

[Steve_D]

Some engines will already have the fixing holes for the thrust plate. If not you will need to drill and tap a couple.
Also use hex head bolts with reduced the head height otherwise they will foul the back of the cam drive gear.

Steve

[Else]

Hello all.

Going go remove the cam this weekend and get it machined to suit the retaining plate.

I have a collapsed and broken fixing bolt shoulder on the front cover which was leaking oil. My question is do I need to source another interim front cover ie crank driven oil pump with distributor hole or will a gems front cover fit?

Thanks Andy

[Zener]

Get it built up by a competent alloy welder reworked drilled etc IMO,. GEMS front cover won't work sump bolt pattern is wrong for starters and don't clear duplex timing gear IIRC