Club Triumph

Hello John,

I seem to remember it was machining the end of the body so that the difference between it's depth and the rotors length was as small as possible, i.e. minimise the end float and also ensure the end plate is flat.

Alec

The Vizard book also talks about mixing and matching pump parts to get the closest fit between the moving parts. I'll have to dig that book out.

Witor's website seems to suggest he no longer modifies the oil pumps, as the new pumps are coming within spec.

See here: http://www.chriswitor.com/proddetail.php?prod=217488RP

Phil

Endfloat is only part of the story. Clearances between the gears and between gears and housing can be a problem, as can the finish on the gears.

The last two "new" pumps I've had were both rubbish and I ended re-using the originals with a bit of fettling.

Bottom line, if your old pump measures ok and was giving good pressure, there is no reason to change it for one that may not be any better and could be worse!

Nick

Chris would mix and match internals and machine them to ensure that everything came within original spec.  

Nick were those new pumps from CW because if they were I am sure he would like to here about it.

MUT

No, they weren't from Chris.  One came with a rebuilt engine I bought, the other I don't remember - possibly with another pile of parts I bought.  I did try swapping bits around but couldn't get a decent result.

Nick

I had a good chat to the recommended local engine builder this afternoon and he was very receptive. A lot of the things I thought he may baulk at he was really keen on. For example I asked if he would cut three angle valve seats for me and he said no, he would rather do seven! He can do all the machining I need in house including lightening the flywheel.
He also reckons my cam may not be stuffed after all, but we'll know when he sees it.
Im pretty excited now as Im taking the lot down to him on monday for cleaning and measuring and to assess whether I can hone and ring and also if the crank will be ok with just a polish.
The only thing that I'll have to farm out is the extra thrust shell in the rear main cap, which I will send to Greg Tunstall in Brisbane.
Cheers
Josh

Hello Josh,

all I can comment on with regard to thrust bearings is my experience on my own cars and having had an engineering training. I have re fitted the same thrust bearings back in my engine after nearly 50,000 miles when I had it apart recently. Also in thirty years or more of running big saloons I've never had a thrust bearing failure, i.e. the shells dropping out. I know that there are plenty of people who have had failures and I can't comment on those never having seen them.

One thing I have come across time and again in my work is that a failure occurs and the common reaction is to modify to cure the problem but a little investigation showed that there was a problem that was not a weakness of design but usually of maintenance.
The idea of making a full circle of the thrust bearing sounds a good one but the main bearing cap is designed to accept load vertically and is not really designed to have horizontal force on it. Four bolt mains caps would probably be fine but a two bolt is not that strong in a horizontal plane. Maybe I'm being a bit theoretical rather than practical, I don't know? I'm sure that there was a good reason that half circle bearings were fitted, incidentally, so does the Jaguar XK engine.

What do others think?

Alec

Thanks Alec. It seems to be a pretty popular mod though, and I replaced my thrusts not too long ago and the end float is back.
They would probably be fine if driven sedately or backed with an auto but I give my car and my clutch hell and I'm not about to stop. People who know a lot more about Triumphs than me have recommended the mod so I'll be going that way.
Cheers

Custom solid bronze thrusts from some bloke in the US seem like a good option - they can't wear through to steel and pick up  

Also make sure the thrust faces on the crank are mint - micro polish if necessary

Cheers Andy, Ive seen them before too. I'll see what the engine builder reckons about the thrust faces when he inspects it.

On another note, what's the verdict on having cam bearings installed?

Hello Josh,

Autos don't apply to any of my cars, nor are they given a gentle life although driven with mechanical sympathy.  The only thing I have done is to pin the bearings in, but that doesn't affect how quickly they wear?

Alec

P.S. I just had cam bearings installed, more a sort of insurance rather than necessity. The Tadek Marec Aston Martin six cylinder engine has no cam bearings either, the cams run in aluminium.

Alec

Really?? I don't disbelieve you Alec, but we all know Aluminium is a crap bearing surface...

No disrespect meant Alec. I have just heard so many times that the thrust bearings are a big weak point of the engine need to be modded for hard use.
The custom ones from the states might be a better option possibly
Cheers
Josh

Cam Bearing are good insurance policy if using high lift cam and lots of revs - 2000's definitely need them in fast road - race tune. Triumph sort of conceded this and fitted them to Spitfire 1300's. You will probably get away with it without cam bearings if you use the mildest springs you can and good oil - I have seen a 2.5 with a seized cam journal (no bearings , race cam)

Quoted from andy thompson

Custom solid bronze thrusts from some bloke in the US seem like a good option - they can't wear through to steel and pick up  

Also make sure the thrust faces on the crank are mint - micro polish if necessary

Quoted from josh18

On another note, what's the verdict on having cam bearings installed?

^^^^  This, absolutely this^^^^^

There is (in UK at least) a serious shortage of shops with big enough machines to do the 6 in one go.  This stops some of them, but not all.  Doing it in two passes......    I have cam bearings in the Vitesse now..... but it took two blocks.

If you can find a shop with a big enough machine to do it in one go, fine.  If not.... probably best avoided.

Nick

I was  going to get this done, but Toms mchine was done in.

So, after some consideration, I just got the front bearing done.
as this frunt one was showing moer  wear / elongation that all the others. others had virtually no wear.
the frunt,n one gets the ..pull,  frae the timing sprocket,
so maybe this why it wore moer.

maybe some thing to think of

M

That's a good idea Marcus. I have noticed some wear on my front one in the direction of pull- at least in as much as it's shinier towards the crank sprocket side. I dont know if this would take the measurements out though.
Cheers