1500 Camshaft

[rogerguzzi]

Hello All

             I am toying with building a replacement engine for my 1500 spitfire.

 

My present engine has 9.5 to 1 comp ratio and hardened valve seats and a reprofiled MK3 camshaft from canley classics, polished ports and modified combustion chambers, 4 branch mainfold ,K&N's and Megajolt ignition.

 

The reason I am thinking of building a new engine is this one has a slight death rattle at about 2750 to 3000rpm.

 

My question is what camshaft have people fitted to give a bit more power but not to race type and can camshaft bearings be fitted to block?

 

Roger

[KevinR]

The same cam bearings as fitted to the MKIII and early MKIV Spitfire can be fitted, and then you can use a genuine Spit MKIII / Early MKIV camshaft, which is a well respected camshaft that gives a good compromise of performance, economy and driveability.

[Clive]

TR5 profile is the next step. make sure you match the CR of the head.

Be warned, having destroyed several 1500 cranks you need to take great care and take no liberties. An oil cooler (with thermostat) and very good quality oil are a must. I think setting the rev limit at a safe level would be wise too......

And get everything balanced. And IF you can find them, VP1 big end bearings....same as TR6, 2000 etc etc

[p7rider]

Your death rattle , do you think it is the cam in the engine block ?

[rogerguzzi]

Hello p7rider

                     No I think it is a bit of slack in the centre main bearing as I re shelled it and checked with plasti guage, but thinking about it maybe camshaft bearings are worn(non fitted late block) and oil pressure is slow to come up when been stood for a while!

 

Roger

[rogerguzzi]

Hello All

             Just reviving this thread as I am close to deciding on camshaft! after looking at all the reports I can find on line(confusing?)

I am coming around to the Newman PH2 profile(if they will grind one on a small bearing shaft)

 

So is any one running this cam? and what is it like?

 

Roger

[John Bonnett]

I shall be very interested Roger to hear which camshaft you finally decide upon. And when the engine is together what results you get on the rolling road.

 

Please do keep us posted.

[rogerguzzi]

Hello John

                David Newman has said they will grind one with small journals.

 

I think the PH2 profile is the same as the old Triumph V175 or known as B which is a 30/70  70/30  280degs 0.409" lift (0.405" Newman) and running 0.014" clearance (so not to tappety)

 

I run the Mk3 profile at the moment 25/65  65/25  270degs  about 0.350 lift

 

All that I have read seems to suggest Triumph,s benefit from more lift (to compensate small valves)

 

So I think I will order a Newman one as I still want a road car that still pulls from say 2000ish RPM but a bit more grunt at 3500+(well that's the theory unless some one tells me different?

 

I have been looking at the rocker gear and the shaft is worn as expected and a couple of rockers have scored bores and all tips are worn(I could re profile these!)

but I was thinking of fitting the bushed type as supplied by Rimmers and Moss etc and making solid spacers instead of the springs(they say it helps keep the oil in?)

What do people think?

 

Roger

 

ps It get very involved when you start but I only want to do it ONCE!!!

 

Roger

[rogerguzzi]

Hello All

             I have decided on the Newman PH2 cam(at last) on further looking it has the same lobe angles as all the Triumph ones.

 

What about cam followers? Triumph never listed any different ones from what I can find! and the Newman steel ones seem expensive (£88 + vat a set, £40 +vat chilled iron type)

I have run just ordinary ones on the Mk3 prifile for 10,000+ miles and all seems ok? (Thoughts)

 

As to the rocker arms I have been reading reports on the TR register and a fair few people seem to have had trouble with them(poor maching and soft tips)

So I am going to have a go at drilling them out and bushing them with Phosphor Bronze(I found a lenght in the workshop) and re profiling them and a new shaft(if they wear it is not to much trouble to change them.

 

I have made a jig to hold them for re drilling and I have a 9/16" reamer(so its just my time and all winter)

 

Roger

[John Bonnett]

Hello All

             I have decided on the Newman PH2 cam(at last) on further looking it has the same lobe angles as all the Triumph ones.

 

What about cam followers? Triumph never listed any different ones from what I can find! and the Newman steel ones seem expensive (£88 + vat a set, £40 +vat chilled iron type)

I have run just ordinary ones on the Mk3 prifile for 10,000+ miles and all seems ok? (Thoughts)

 

As to the rocker arms I have been reading reports on the TR register and a fair few people seem to have had trouble with them(poor maching and soft tips)

So I am going to have a go at drilling them out and bushing them with Phosphor Bronze(I found a lenght in the workshop) and re profiling them and a new shaft(if they wear it is not to much trouble to change them.

 

I have made a jig to hold them for re drilling and I have a 9/16" reamer(so its just my time and all winter)

 

Roger

 

A good project Roger. Please let us know how you get on.

 

John

[rogerguzzi]

Hello All

             I have made start on bushing the rockers(knackered the first one) drilled it out to 11/16"dia but the drill cut over size about 10thou!!!!

 

But I did not like the look of a 11/16"dia? hole (to big and looked to have weakened the rocker)so drilled and REAMED the next one 5/8"dia and it looks much better!

 

I made a bush and reamed it and its tight on the unworn part of the old shaft but a nice fit on an unworn part of a TR6 shaft?

 

So I will get a new shaft before doing any more(one short now unless I strip the existing engine or if some kind person has some old ones going spare to play with?)

 

Still it keeps me off the streets?

 

Just the jig to re profile faces to make now?(and before you ask the answer is no? if I charged 50p an hour you still could not afford me to do yours Sorry)

 

Roger

[John Bonnett]

Nice piece of work Roger. Isn't it good to have time to play? Lucky we are not trying to make a living at this. Nobody could afford the prices for a realistic hourly rate. I've not costed up the inner wings I've just made but I reckon a thousand pounds wouldn't be unreasonable given the hours I spent. But who would spend that on a pair of inner wings?