Rattle

[Greybeard]

They look so much like the old ones that I wondered if you had accidentally grabbed the old ones during reassembly. I say this with the hope that I haven't insulted a friend

AH yes, difficult to suggest anyone other than one self, would make similar mistakes to our own (cause I'm hoping it not just me)

But if so the SRM ones would still be around - yes

Of course I doubted myself over this but as you say, the new followers would still be on my bench.

I don't think the new followers had SRM lasered onto them, as shown on their web-shop image. If they did, it's all worn off now. I wish I'd taken a picture of them before I used them.
http://www.shop.srmclassicbikes.com/product/a10-cam-follower-set-stellite-hard-faced-set-4

I haven't yet got around to contacting SRM but I'll let you know what transpires.

[Greybeard]

G'day GB.
Sounds great mate. Just one tappet. The exhaust pulses sound pretty close. Ready for the DGR.
You deserve a medal 
Cheers

Thanks bud. I set all tappets to 8 thou. I'm still using the lash-caps. If that worn follower was the cause of needing to screw the adjuster right in how about the other inlet valve, that doesn't have a worn follower? Re. the current slight tappet noise: I reckon there's every chance of grease/oil under the caps fooling the feelers. I'll whip the tank off and recheck the gaps.
If I start to hear that nasty rattle again I may be removing the rest of my hair!

The new cam gives the exhaust note a real snap.

[berger]

i have not been to the pub, Greybeard the followers I have with SRM on them are LIKE glass and the SRM logo bit will not be touched with said file it just glides off, so I can't see it wearing off in the barrels maybe they sent you some they got from elsewhere. PS she sounds well, she's got a growl.

[Greybeard]

...maybe they sent you some they got from elsewhere...

You have to wonder about that. Would SRM risk their reputation by selling junk?

[berger]

hahahahaha they sold me those horrible excuse of 50p pieces errr piston rings

[UncleD]

I realise this thread has been quiet but having read it am wondering what the response from SRM was?

[Greybeard]

I realise this thread has been quiet but having read it am wondering what the response from SRM was?

Thank you for remembering this topic.
My bike engine has been partially stripped since my last post. Weather has not been suitable for riding so I've not rushed. Also, loads of family related stuff has needed my attention. So, I have not moved on the problem since then.

[Greybeard]

I realise this thread has been quiet but having read it am wondering what the response from SRM was?

When I contacted SRM, (by email) I got this reply:


Gary Hearl <gary@srmclassicbikes.com>
   
Wed, 26 Sep 2018, 10:48
   
to me

Hello Neil,

Looking at your pictures of the damaged cam follower, this is a classic case of valve springs coil binding.

The valve springs should have a fitted free length on a 356 Super Rocket camshaft of minimum 1.395” (Measured between top and lower cup) and be able to be compressed a further 0.080” ( 2.0mm) before they coil bind. If a valve seat has been replaced in the past, its possible the seat has not been cut down to its correct position, in effect holding the valve further down which would make the valve springs wrong fitted length, also pattern valve springs with wrong wire section and number of coils could cause the same issue. I would check all the valve springs for this problem, if it isn’t checked and rectified , any other cam followers fitted will have the same wear issue. Also look for bent pushrods and excessive wear on top of the valve stem, these will all be a result of coil binding valve springs.

If you could measure the fitted length of each set of springs, and then remove them, and put the outer spring in a vice and fully compress until coil bound and give me that measurement as well, also the free length of each spring , I can then determine if the valve springs are correct or bad pattern ones. A photo of the head with the springs insitu with caps and collets will also help so I can see what type of caps and collets you have.

The cam follower were our own manufactured part, not all batches were etched with our Logo, we have blanks made, and we then build up the end face with a hard Stellite type material and grind the radius to suit. I have seen so many engines with the same issue as yours and its always down to the valve spring coil binding issue. Checking the valve springs free fitted length is an important stage of the engine assembly process.

If you can get back to me with the info I have asked for, I will look through it all and get back to you.

Regards Gary

[Greybeard]

I'm in the shed today wondering what to do next. I cannot see any evidence of hammering on any part of the valve gear.

[Swarfcut]

GB.   A very interesting reply from SRM.  Without knowing if you have had other contact with them in this matter, I can see no indication on their part for you to return the followers for any sort of quality assessment. I can understand their request for photographic evidence, but I would have considered any customer difficulty concerning their brand of parts would need to be quickly investigated to avoid any adverse repercussions. Business is all a matter of confidence, and it is easier for any retail business to keep an existing customer than get new ones.

 As for your motor, the basics need a reality check, such as the valve lengths, valve springs, spring cap, collet position on the valve stem, bottom cup. Are all these parts the right parts for the head? Your engine should not have valve lash caps in standard trim.

 I have a feeling that the answer will be a big yes, knowing that you know a lot about engines (by chance found your amazing Ford Consul story).

 So, it is all down to those high quality followers and the camshaft profile.

 If it were my bike, I would put in a low lift 334 cam, some tired springs and a set of reasonable genuine followers. That would get you back in the saddle.   Sorry if it is all back together, I thought it was still awaiting reassembly.

 Meanwhile, have a word with David Newman Camshafts in Farnborough, Kent.  Nice people to deal with, and they understand  older engines.

 Swarfy.

 Additional.. Rare example of levitation on your new stainless worktop, and your phone is off the hook.

[Greybeard]

Swarfy,

Thanks for the flattery but this bugger has me stumped!

To be honest I've been stalling on the task of getting the engine back together because without a clear indication of the problem, I'm worried that the same thing will happen again. Those SRM followers cost £175!!!

It would be an easy assumption to make that the trouble I've had started after fitting the pattern 356 camshaft in 2017. The first strange thing I noticed was that the tappet adjusters on the inlet side needed to be screwed right down before I got the right clearance. I did try lash caps but removed them on the next strip-down as I was worried about what they were doing to the valve geometry.

I don't really want to completely strip the engine again, but I'm worried about removing all the debris from the worn follower.

Maybe, as you suggest I should buy the correct camshaft for this machine and give the bottom end a thorough clean.

Today I tried applying the sharp edge of a triangular file to the unworn edge of all the SRM tappets. In Picture 1 you can see that on the badly worn follower the file bit in easily. I've sent this photo to SRM. One thing that puzzles me is that if the Stellite has worn through on the cam follower how come my camshaft has survived, (picture 2)?

Another thing is, why is it that only the left-hand inlet follower is affected? When I changed the SRM one for one of the previous, cheaper jobbies, that also wore badly. This would seem to indicate the problem is not a faulty follower.

Ok, another thunk. Valve collets: I was using the type that has an annular ring that engages with a groove in the valve stem. I put new valves in last year that do not have the groove and I made the mistake of using the old collets. I bought a set of new wedge type collets but I think they might be wrong. They don't seem to snug into the cap tightly. Did someone here say that there are two types of wedgy collets? If the collets are wrong, they might be causing the valve to bottom. But as I said I can see no evidence of hammering. Again, why only one follower?

[RDfella]

There's an easier - albeit cruder - way to check all this without measuring spring wire size, number of coils, valve seat position etc etc. With the engine assembled, turn it until one valve is fully open. Then try to open the valve further by prising on the rocker. Sould open at least a 1/16 more.

[Greybeard]

There's an easier - albeit cruder - way to check all this without measuring spring wire size, number of coils, valve seat position etc etc. With the engine assembled, turn it until one valve is fully open. Then try to open the valve further by prising on the rocker. Sould open at least a 1/16 more.

Yes, I could put another one of the El Cheapo, not-worn-as-badly-as-that-one followers in to replace the duff one purely to test that theory. I'm not sure I can bear to strip it down again just to clean the bottom end though so I'll have to do the best I can to clean it first. Thank you for giving me a way to move forward! Surprisingly I do not see any metallic particles around the cam trough or in the sump filter. I have an external filter so maybe it's doing a good job.

[RDfella]

Greybeard - thinking about this a bit more, whilst spring length, coils, collets etc may well cause coils to binding at max cam lift, your need for valve caps is another, almost disconnected,  issue. As I see it, the main issues which could cause that are: base circle of cam too small, followers or pushrods too short, or valves too short / valve seat inserts not cut deep enough. Wrong collets or spring retainers may cause coil binding or other mischief but will not create valve clearance issues (the valve stem end is not affected).

[Swarfcut]

 If we go along with SRM's reasoning, then anything which will cause excessive loading on the follower has to be investigated. Also worth a check that the rocker arms are not distorted.

 GB.. if you can hang on a few days, I will dig out a standard wide fin iron head and measure the valves. From memory the standard valves have a single wide groove and plain collets.

 The other SRM followers look OK, so I suspect the cam lobe on the baddie may hold the key, easy to measure and compare the lift on the lobes with the cam exposed. Otherwise it must be down to something amiss with the inlet valve, as outlined by RD.  With the barrel off, a wipe round the cam trough and a gallon of some noxious hydrocarbon sloshed over the bottom end should do the job of a spring clean. As you say, the major particulates are safely in the filter.


 Swarfy.