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Brian Eldred

Cam lobe wear, replacement?

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Wouldn't disagree with using the correct assembly lube, but I think i l'll stick with using an oil with the correct Zinc content ( as ZDDP). Oil is much cheaper than an engine rebuild.

Iain

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As regards new camshaft and tappet fitments it's a given that they are fitted with the correct assembly lube.

That's not to say the same used in every case, I'm a strong believer in using the lube supplied or recommended by the supplying camshaft firm. You can be assured if you use a different product to that supplied or recommended and experience ANY problems with camshaft or tappets the immediate response will be "AAAaaahh that's not what we use/say and that's the reason you've got a problem". Just as using a camshaft from one supplier and cam followers from a different supplier, it's like putting 2 cats' in a barrel, "it's their fault,...no... no, it's your fault" etc... etc, entirely normal reactions from opposing firms and you are stuck in the middle, don't do it.

For the record when I build ANY engine race or road I use the combined products of one camshaft supplier and also their lube or recommendation for lube, I also use a good quality oil of correct ZDDP and after 200 miles using no less than 2000 revs (strange looks are garnered at traffic lights from other road users) and no more than about 3000 revs do an oil change to remove any contaminants flushed from the engine system, and carry out a head retorque at the same time. Then refill with the same high ZDDP oil and you are good to go, whatever remains of the camshaft lube is still adhered to the camshaft just as when you stop the engine normally, and I'm sure mixes in with the high ZDDP oil.

I can't honestly tell you that this is the correct way to fit camshafts and break in engines, it's the way I do it after taking various advice from firms and other builders and I've never had a camshaft or cam follower failure in multiple race engine (4 cylinder and V8) and over 20 road going 4 cylinder rebuilds. (No...I don't wear out engines quickly, but back in the 80s/90s I built a number of engines for other people/entities).

Iain,

Difficult to give a comparison because I've not run a roadgoing TR for some considerable time, (my everyday classic is a Stag), but when I raced a TR I used either Millers or Penrite, again because of the high ZDDP content. The Stag I used to run on common or garden 20-50 oil and Halfords was amongst the mix at oil changes. When I discovered the Classic Oils product (some years ago) and I moved onto that, the oil pressure remained at normal levels on the Stag and I never noticed a variation in pressure, not that I'm too bothered about pressure. Flow is what I demand from the engines and as long as the pressure remains broadly within the original range I'll run with it, driving is more fun than fixing.

Mick Richards

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Before I discovered this problem I'd just changed the oil. I'll consider a higher zinc content oil next time! I've got some assembly lube....

I discovered today after doing some de-carbonising that it's fitted with +40 pistons, so the engine has been rebuilt sometime pre-1995 (I have all the records since then.) It's done just over 30k miles since then, so it's good for a few more yet. Just want to get her back on the road now the sun's come out B)

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"Before I discovered this problem I'd just changed the oil. I'll consider a higher zinc content oil next time! "

So you are leaving the same oil and filter complete with camshaft and follower iron filings in the engine when you are just about to fit a new camshaft and new followers ? That may be taking thriftiness to unheard of levels . 

Mick Richards

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Hi Mick, between changing the oil and filter and adjusting the tappets, which is when I noticed the issue, I'd been out for one run of maybe 50 miles. Surely the wear and consequent oil contamination would have occurred over a much longer period? 

If you think there's a risk of iron filings remaining I have no problem with changing it again! 

Brian

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Sorry Brian but I think there will be filings lurking within oilways and in the sump.

I'd regard it as a small investment and drain the oil and put in new filter before new camshaft is run, and then stick with the 200 miles running and again drain off and new filter and retorque the head. Up to you what oil you want to use but I'd do all I could to get those shavings and metal slivers out, the longer inside the engine the more associated damage to bearings crankshaft etc

Mick Richards 

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Just an update - started to fit the new cam today but when I bolted on the camshaft sprocket it all locked up. No end float. After much googling I found that it's best to trial assemble the camshaft, front bearing and sprocket off the car and then it's easy to measure end float. Now I have to machine a few thou off the back of the bearing.

Oh and I've bought some Classic Oils oil...

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But the passenger in the car in the brochure isn't holding up a brochure :ph34r:

Bob.

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1 hour ago, Lebro said:

But the passenger in the car in the brochure isn't holding up a brochure :ph34r:

Bob.

When I was very little I had a dolls pram like that. It had an outline of a dolls pram on the side, it should have been like a Russian Doll but it wasn’t, I contemplated this and what’s beyond the universe often at such a young age.

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2 hours ago, Lebro said:

But the passenger in the car in the brochure isn't holding up a brochure :ph34r:

Bob.

 

TR4-2.png

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:D:D  That's better,  but the passenger in the brochure held by the passenger in the brochure  -------------------------------------

Bob.

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4 hours ago, Lebro said:

:D:D  That's better,  but the passenger in the brochure held by the passenger in the brochure  -------------------------------------

Bob.

Talk to Pogo, I have exhausted my photo editing skills !

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It was a great picture Brian. TR4, open road and that very pretty TR4 cockpit.

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