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Fredell1977

Triumph Cp Tr6 Uprated Camshaft

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Dear all.

I am sure this topic was extensively discussed but I do not some help to decide which camshaft to buy. My tr6 engine is out for a rebuild. I will uprate the engine (modified head,balanced engine Etc) to make it suitable for fast road use/occasional hill climb. My mechanic suggested to fit an uprated Kent cam. I am not sure sure about this since it seems that these Kent cams are best suited for x flow ford engines. I had a look at the moss and revington sites but I got confused. Any suggestions?

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Fredell,

 

Welcome - apologies for not "approving" your post earlier - only just spotted it!

 

There are quite a few camshaft choice threads on here already.  As you are starting with a CP engine, you already have a fairly "sporty" cam.

 

As well as Kent you could also consider Newman.  The PH2 & PH3 profiles are good (PH3 possibly a bit extreme) and some of us are running combination cams with PH3 inlet timing and PH2 exhaust.  This works well.

 

Are you planning to stick with the Lucas PI?  It's certainly capable of providing the fuelling for more aggressive cams but does need fairly specialist knowledge to set it up.

 

Are you UK based?

 

Nick

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Tom Key runs a Newman hybrid cam PH3/PH2 40-80 70-30 - same overlap as a TR5 cam works well on injection and decent exhaust - he uses the TRE 6-3-1 - he has seen 185-195bhp (flywheel estimated) on Vesey dyno

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What is your compression ratio and what RPM range do you want the engine to run in? That's what determines your cam specs should be

Edited by motov8id

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Tom Key runs a Newman hybrid cam PH3/PH2 40-80 70-30 - same overlap as a TR5 cam works well on injection and decent exhaust - he uses the TRE 6-3-1 - he has seen 185-195bhp (flywheel estimated) on Vesey dyno

 

So PH3 inlet timing and PH2 exhaust?  How would that go in contrast to my 307689 in myEFI overbored 2 liter?  I'd like something that revs a little harder/higher than the early Tr5 cam.  Had been looking at the Wishbone Classics

 

WBC559V2 http://www.wishboneclassics.com/content/wbc559v2-camshaft-triumph-gt6-tr250-tr6

 

 

 

But at USD500  it's almost twice the cost of Newmans custom grinding me a Tr6 Cam with 300 degrees duration on the inlet PH3 and 280 degrees on the exhaust.

 

 

Thought from the wise?

 

 

C.

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That's what I'm running in my current 2L Craig.  Goes pretty well though not quite as keen at the top end as it should be I don't think.  Possibly exhaust related.  'Tis a little hard to be sure though as it makes very short work of 1st and 2nd gear and anything over about 5,500 in 3rd is illegal....... :ninja:.  No doubt this means my gearing is too long, but I like the 3000rpm/70mph cruise.

 

Gives a slightly loping idle and some hitchiness at very slight throttle opening on my plenum/single TB inlet which I don't seem to be able to tune out and gets wearing in traffic.  However it's utterly tractable when given any throttle - pulls from 1000 rpm.  Sequential injection might be enough to sort the hitchiness.......

 

James Carruthers has the same cam in his 2000 and that goes very well.

 

Nick

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I´m a bit more conservative with the "asymmetric"  Moss TT Fast Road 89, 290 / 272 degrees.

Pulls from 1500 strong. Flat torque and revs easily above 6000.

Above 5500 in third road legal  :yes:

Martin

Edited by Martin

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I have what I believe is a Kent TH7 cam in my 2ltr. Still quite tractable at low speed, although can be a little 'snatchy' at times

Over 3,500 and it takes off like a scolded cat!!

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Hi guys,

 

Do you think this Newman cam would work with twin SU's on a 2ltr or is it best with PI.?

If you mean the PH2/3 hybrid I think it would be quite grumpy in traffic on SUs.  Ok on tripleWeber/Dellortos or injection.

 

Nick

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Thinks Nick,

 

I'm just looking for a cam replacement. The 2ltr I have, has I believe the mild triumph cam fitted judging by the rolling road figures I got last year.

 

From the Vit6 bit I'm assuming that its a Vitesse 2ltr with the 308778 cam (which isn't actually a bad cam as Stanpart Profiles went) So also assuming that this is the original cam so may be a few years old?   From your comment to Nick I'm also assuming that your not looking to open a vein in your wallet and start on the endless pursuit of power, but rather are looking for a measured improvement.

 

Lots of the more power producing cams tend to rely on some serious improvements in the head, induction, fueling, ignition, exhaust etc, and are likely to be a disapointment.

 

If it was me and I had a nice road 2ltr running Strombergs or SU's and just wanted a bit more oomph without breaking the bank, I'd be looking for a cam near the 308778 profile, with a reworked inlet manifold (around #2 & #5) and if you can run to it a good exhaust manifold. 

 

In my 2ltr I'm actually using a Witor CW3021 cam which is basically a 308778 with higher inlet lift. And whilst there is a lot of other work gone into the engine with that cam its just about maxing out what its possible to make with twin 1.5 Strombergs, and as I think Nick would confirm from Gurston it is on the quick side.

 

Alan

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Depends which cam you have at present.  Is it Mk1 or Mk2 engine?  What is the engine no. prefix?  (not that that is a reliable guide these days!).

 

Assuming that you don't already have a Mk2 Vitesse or GT6 engine, the Triumph 308778 cam was standard fit in those and the "132" PI saloon.  It is a very decent profile that works well with carbs.  With injection, a crappy 6-3-1 and a bit of head work I was getting 120bhp.  Steve Attenborough and Gareth did some extensive messing about with heads, manifolds, exhausts and PI and got nearly 150 bhp

 

As Alan says, Chris Witor does a variant of this with more valve lift on the inlet side and it certainly seems to work in Alan's Vitesse as it goes very well and idles beautifully.  Mind you, this is a very well sorted car with alot of thoughtful development work in it. 

 

Nick

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Gents,

 

From the previous owner its a Mk2 engine from a '73 estate I believe. ME999xxxHEA. So quite low on power. I plan to do some head mods along the line of N.Coll and yourself Nick. later this year. I have also acquired a 6-3-1 manifold that looks like it might be a Mike the Pipe model. Hopefully it will fit the Vitesse. Also a longer inlet manifold inc 1.75" SUs, So am looking for 120 +bhp. So something along the lines of what Alan has done. I had been looking at the Witor cam that Alan has fitted so may well go that route as he has had some success with it.

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Hi All,

 

Just picking this thread back up.

 

I run a special Newman cam with their steel followers, and a few other modifications.

 

Mine produced 196bhp at the flywheel back in 2015 on the Peter Burgess Rolling Road, on Lucas Injection (MU calibrated by Prestige Injection developments).  Went very well.

 

Now on EFI, and yet to get chance to see results based on back to back testing.

 

Cheers.

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