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Sprint cam sprocket bracket
http://forum.triumphdolomite.co.uk/viewtopic.php?t=37379		 Page 1 of 2
Author:  Matt Cotton [ Sat May 21, 2022 11:47 am ]
Post subject:  Sprint cam sprocket bracket
Hello all.
Last year I replaced the timing chain on my Sprint. It has been running well since. Last night I took off the cam cover to have a brief inspection. I notice that the cam sprocket bracket is not aligned to the sprocket?
When I changed the chain, I didn't need to use the bracket, but in future I may remove the head.. So will need to utilise the bracket to hold the sprocket and keep chain tension.

I'm sure I refitted correctly and don't remember there being any adjustment for this bracket.. Just two bolts.

Anyone have any idea what I may have overlooked?

Many thanks.
Matt.
Image
Author:  xvivalve [ Sat May 21, 2022 11:51 am ]
Post subject:  Re: Sprint cam sprocket bracket
Is there any movement in it? An obvious answer would be one bolt dropped out and it has rotated about the other...
Author:  Matt Cotton [ Sat May 21, 2022 12:03 pm ]
Post subject:  Re: Sprint cam sprocket bracket
No movement at all Alun.. Very odd.
Author:  dursley92 [ Sat May 21, 2022 2:47 pm ]
Post subject:  Re: Sprint cam sprocket bracket
Is it the wrong bracket? Wondering if an 1850 or TR7 one has crept in maybe?
Author:  Matt Cotton [ Sat May 21, 2022 3:36 pm ]
Post subject:  Re: Sprint cam sprocket bracket
Quite possibly Russ. The engine has had work in the past. I had a look earlier and the Sprint and 1850 do have different brackets.. So quite possible.

A nuisance that will be though.
Author:  BobM [ Mon May 23, 2022 9:38 am ]
Post subject:  Re: Sprint cam sprocket bracket
The 1850 and Sprint brackets are not interchangeable. Your problem is caused by the bolt holes in the bracket having a generous clearance. This allows the bracket to rest to one side as you tighten. I find it necessary to ensure alignment before final tightening when building up after fitting the chain.

BobM
Author:  xvivalve [ Mon May 23, 2022 10:19 am ]
Post subject:  Re: Sprint cam sprocket bracket
I can't think of any benefit (or for that matter detriment) until such time you need to remove the head, at which point remove the timing cover prior.

I think the risk of tearing the sump gasket would prevent me touching it until I need to...
Author:  Matt Cotton [ Mon May 23, 2022 10:59 am ]
Post subject:  Re: Sprint cam sprocket bracket
Thanks Bob for confirming this - you live and learn!

The head may come off at some point for inspection as it is very 'clattery' at the top end, so I can address my misalignment then. A nuisance, but one of those things.

Thanks for the advice - always appreciated.

BW

MC
Author:  BobM [ Mon May 23, 2022 9:05 pm ]
Post subject:  Re: Sprint cam sprocket bracket
Hi,
Sorry Matt. Just looked properly at your photo. I believe it can only be that far out by having one of the two bolts missing. Which also suggests one of the two chain guides is only secured with one bolt. That said, I would expect with a little leverage the bracket would rotate. the excessive clearance I spoke of allows only about 5/16in movement.

Unless a hard setting sealant has been used, the sump gasket should remain intact when removing the front cover. If it breaks dropping the sump is a pain but possible.

You say the top end is noisy. Is this tappets or more of a knocking. The cam sprocket can slacken despite the tabs. The two 1/4in unf set screws are some what marginal for powering 16 valves.
Author:  Matt Cotton [ Tue May 24, 2022 8:52 am ]
Post subject:  Re: Sprint cam sprocket bracket
Morning Bob. Thanks for your ongoing thoughts on this one.

I know the bolts you refer to. There are two and they bolt this bracket and also the top chain guide in place - I am sure both are still in place and definitely refitted the two when I did the chain.
The bracket really is solid, I've put a small pry bar through to see if there is any movement, and it doesn't move at all.

I have ordered a bracket from Rimmers. As they are less that £10 and look NOS, I thought it would be useful to be able to compare against the one fitted to my car. Who knows if someone has deformed it in the past for some reason?

The noise I refer to is very much a 'clattery' sound. Initially, I thought it was the chain - hence the replacement, but following refit, it hasn't made any real difference, although possibly a bit quieter at idle. The original chain did have some stretch however and the tensioner was fully extended, so the replacement wasn't a totally wasted task.
The valve clearances seem fine, so I think it is possibly the buckets, or worn valve gear. I am hoping Mad Mart may be able to take a look sometime for me when he is able.
Richard Old and I checked the oil pressure recently and that was good. I intend to check the compressions too when I get a moment.

Aside from the clattering, it runs nicely.

I did post this on the club F.B page, and some of the group quite correctly pulled me up on my tardiness regarding the tabs. I have since made sure the bolts are still tight and peened over the remaining tabs.

I will keep you posted on this one!

Kind Regards

Matt.
Author:  BobM [ Tue May 24, 2022 9:19 am ]
Post subject:  Re: Sprint cam sprocket bracket
It seems the bracket must be distorted.

BobM
Author:  new to this [ Tue May 24, 2022 10:14 am ]
Post subject:  Re: Sprint cam sprocket bracket
Is it possible to fit the bracket back to front, if you know what i mean ?

Dave
Author:  Mad Mart [ Tue May 24, 2022 10:16 am ]
Post subject:  Re: Sprint cam sprocket bracket
Quote:
I did post this on the club F.B page, and some of the group quite correctly pulled me up on my tardiness regarding the tabs. I have since made sure the bolts are still tight and peened over the remaining tabs.
You only need to peen over one tab per bolt. The idea is the tab washer can be reused, using a different tab each time you remove it.
Author:  Matt Cotton [ Tue May 24, 2022 11:56 am ]
Post subject:  Re: Sprint cam sprocket bracket
Quote:
Is it possible to fit the bracket back to front, if you know what i mean ?

Dave
I don't think it is Dave. One side is flat (which sits on the block face) the other is flanged, I guess for rigidity?
Author:  Matt Cotton [ Tue May 24, 2022 11:57 am ]
Post subject:  Re: Sprint cam sprocket bracket
Quote:
Quote:
I did post this on the club F.B page, and some of the group quite correctly pulled me up on my tardiness regarding the tabs. I have since made sure the bolts are still tight and peened over the remaining tabs.
You only need to peen over one tab per bolt. The idea is the tab washer can be reused, using a different tab each time you remove it.
That makes me feel a bit better Mart - The one I took off only had one tab peened over, so I just replicated that on refit.
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