2.5 camshaft decisions

[llessur]

I'm in the process of stripping down the 2.5 block from my 2500 for a rebuild. As per my other thread this started as a quick thrust washer replacement exercise and has snowballed to something more expensive but hopefully more rewarding.

I took the camshaft out yesterday but unfortunately whilst most of the lobes look OK, there is pitting on the nose of one of the lobes - here is the lobe in question: 

Here are the rest:

Thoughts on re-use of this cam? Is it toast due to the pitting?

If so, my question is what do I replace it with? I'm not a particularly spirited driver so don't want anything too sexy - do I try to source a replacement OEM cam, or is there something better out there? Budget is also an issue so I can't afford to spend big bucks.

I think the OEM camshaft for the 2500S is 307621 - Chris Witor does not seem to stock it but Rimmers do both new and remanufactured. Has anyone had any experience with their camshafts? Any pitfalls around remanufactured ones?

Also, I presume I should fit new followers if I'm fitting a new cam? What about the camshaft bearings? These seem like a specialist job to remove and fit...

 

 

 

[Anglefire]

To me the pittings doesn't look too bad - but temper that with the fact that I know nothing! 

If it were me and I'd got the engine that far into bits, I would change it - I bought a new one for my spitfire from Newmans Cams - not sure if your engine is in this list http://www.erstellen.co.uk/newman-cams/PRICELIST-BROCHURE_2019-TRIUMPH.pdf 

You obviously have the issue of shipping and the price doesn't include the new followers - which will have to be new for the warranty, but not necessarily theirs.

A reprofiled cam is another option - but you have to take into consideration the hardening of the lobes and whether they reharden them after the new profile is cut or not (Or if you can!) becuase if the hardening has been breached, you will be changing it again fairly quickly. 

[Clive]

looks OK to me to re-use. (caveat, if you were racing, or doing massive daily mileages, or a total full engine rebuild etc etc)

When a cam is bad, the pitting would be more like small chunks missing, or teh lobe just not there (had this on a kent cam, 10k miles and teh lobe was almost round)

[llessur]

Cheers both - this will be a near-total rebuild in that it will be rebored, with new pistons, rings, bearing shells, thrusts etc plus the crank will be reground. It was borderline whether or needed it or not but I really fancied it as a project having never done it before so thought I'd dive in. The budget-conscious side of me says reuse it, bit that would seem like a shame given the rest of the work that will be done...

[daverclasper]

2 hours ago, llessur said:

The budget-conscious side of me says reuse it, bit that would seem like a shame given the rest of the work that will be done...

That old conundrum! 

[Clive]

I expect that cam will last at least as long as a new one....

If buying new, I think Wade are in Oz? Heard good things about them. Or  the Witor cams?

[JohnD]

Lessur,

Your old one appears to be from a Saloon engine - one groove on the front.    The 'better' production cam was the TR6 with longer duration and 2 grooves, but you would need to raise compression, flow the head, use an extractor exhaust etc. to see much benefit, as would be  true for a more exotic one.

I know it's a long way, but Rimmers recondition camshafts, and one of those is 'only' £106.    You could ask them with pics if yours is recoverable, thus removing the risk of lowing your deposit, or wasting postage.   Or get advice from an Oz regrinder.

John

[thescrapman]

Get a PI cam which is same profile as Mk2 Vitesse I think.

Basically aim to end up with a 2.5pi engine on HS6.

Needles etc are known, so not too much playing to get it running fairly well out of the box 

 

[NonMember]

The early PI cam is the same as a Mk2 Vitesse. The later one is the same as a late Mk3 GT6 (dome-top piston engine) and slightly milder, but still a better cam than the 2500TC/S. As has, I think, been said, this works best if you also have the head skimmed a bit to get closer to the PI compression ratio.

[Pete Lewis]

llessur,  just seen your post in the 2000register but lost my login,about the rubber steering UJ 

have to say dont know why this was introduced but on converting mine from manual to Pstg, Chris W supplied a shaft of UJ and rubber disc , which is fitted and works ok 

although i have reservations about the amount of idler engagement there is in the lower UJ  its a hollow idler  shaft not easy to judge its length of insertion from inside the UJ clamp

pete

[Steve P]

Just to add i have a 2.5 with a TR5 cam in my Vitesse with HS6 carbs.

Head worked a little along with the inlet manifold and a decent 6-3-1.It makes really good power and bags of torque.

Steve