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Question for the assembled gurus here.

Where did the Newman Hybrid cam come from (aside from the blatantly obvious answer please)?

I know Nick runs it, and I have seen mention of others running it. But Newman don't mention it on their website, and I have never seen any info as too why it came into being?

Also, this cam is PH3/PH2 mix. Would a PH5/PH3 also work, give more of a "Fast Road" cam without being full race?

This is curiosity more than anything else, too much watchkeeping with nothing to do allows the brain to run away.

Cheers

Phil

 

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I think the asymmetrical cam idea has been around for decades, but I suspect GT was the original advocate in the Triumph context.  IIRC he was offering a such a cam about 10 -- 12 years ago (maybe even a little longer), but was a bit coy with the details (specs, price, delivery etc).  Possibly someone even bought one  and found it worked as advertised.

Where the actual idea of getting Newman to produce a cam that mixed their PH2/PH3 profiles came from I'm not sure.  That it was Newman who actually make them was an obvious choice as they are very flexible and helpful and had suitable range of profiles "on the shelf".  If you wanted one, you can just ring up and ask for one and it'll cost the same as the ones they advertise.  I'm also not sure how close a resemblance this cam bears to GTs original concept either as I don't recall every seeing specs for that, but I suspect it's a bit less wild.

Seems to have been a good idea though as it gives a pretty bright mid-range and top end while still being pretty tractable low down - though I have to say that I don't know anyone with one that isn't on injection and most are EFI'd.  Not sure it would play all that well with twin SUs or Strombergs as it certainly represents the outer edge of what you can get away with on a plenum manifold inject setup.

Should also maybe mention that "asymmetrical" can means different things.  In this context it is that the inlet and exhaust profiles are different, but cams with profiles where the shape of each cam is assymetric (different on opening and closing sides) while the inlet and exhaust remain the same also exist.  Pipe used to make such things in the late 80s and I had one in a 1500 engine in my Herald for a while.  It did go quite well but was notable for being very clattery.

Why do you ask Phil?  What are you plotting?

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4 hours ago, Nick Jones said:

Not sure it would play all that well with twin SUs or Strombergs as it certainly represents the outer edge of what you can get away with on a plenum manifold inject setup.

Okay, so you reckon individual throttle bodies should behave better than a plenum setup?

5 hours ago, Nick Jones said:

Why do you ask Phil?  What are you plotting?

Well, as mentioned before I need to build a new engine for the 2000. Most probably this will get the "standard" hybrid cam, as this is really going to be my daily driver. Fingers crossed the cylinder head is sorted, so just got to get a block (Chic Doig has some, I just need to actually collect one from him! Been planning to collect for about 2 years now). After that exhaust and intake.

However, I also have various other project cars going (2 Heralds and GT6 Chassis), and at least one of these is simply going to be bonkers. I have a 1500 block (NOS), my intention is to get a one off crank made with a throw half way between the 1.3 and 1.5. Reason behind this comes from a conversation with GT many years ago when he did my OD on my first Spitfire, where it was suggested that a 1.4 engine would possibly be able to combine the revability of the 1300 with the torque of the 1500. As far as I know, never been done, I have the means so plan to do it! This might be a good candidate to try a PH5/PH3 cam?

This second project will not happen soon though, I have been thinking about it for over a decade so far, and I really need to get the 2000 done first. It's simply that I am stuck onboard with too much thinking time on my hands lol!!

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Phil, you have stirred my memory. Many many years ago, Chris Witor had an engine in his mk1 saloon. He had an offset grind on the crank, and for some reason I think used VW pistons (possible nonsense, this was 25+ years ago so memory could be corrupted) so a just thought.

Saying that, a steel crank would be good and strong.

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54 minutes ago, zetecspit said:

Saying that, a steel crank would be good and strong.

I had asked a wee while back about steel cranks, the consensus at the time was a steel crank was not required on the saloon engine, the original is good to at least 7k (testified by oldtuckunder, who was regularly testing this out on his Vitesse!). I do have a full set of maxspeeding Conrods and a shackford lightened flywheel (actually I have two flywheels, as I wasn't certain which one I would need between long back and short back, so bought both).

The 4 pot will be a steel crank when it is done however.

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Sorry, I was thinking of the 4 pot.

Wondering if it is possible to do an offset grind on a 1300 crank. The 1300 in the mk3 we have pulls like a train. OK, not quite as much as a 1500, but then again the engine revs so freely. If you are ever down this way (!) you are welcome to try it. 

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54 minutes ago, zetecspit said:

Sorry, I was thinking of the 4 pot.

Wondering if it is possible to do an offset grind on a 1300 crank. The 1300 in the mk3 we have pulls like a train. OK, not quite as much as a 1500, but then again the engine revs so freely. If you are ever down this way (!) you are welcome to try it. 

Ahh, yeah the 4 pot will be a custom crank, so guess I can do what I wanted with it. I am thinking to stick to original, and simply go for the stroked 1300/destroked 1500 just to see what happens. GT reckoned (and I can't recall if this was in the yellow book, or something he said to me) that was the engine Triumph should have made.

If I am ever down your way, and stay long enough in one place I may well take you up on that offer! It is the staying in one place long enough that is the issue, I only ever seen to do flying visits!

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2 hours ago, thebrookster said:

I had asked a wee while back about steel cranks, the consensus at the time was a steel crank was not required on the saloon engine, the original is good to at least 7k (testified by oldtuckunder, who was regularly testing this out on his Vitesse!).r.

Is this 2L saloon, or 2.5, Phil?     Stroking the larger engine for the extra 500cc, means that the mean piston speed exceeds 20meters/sec above 6.5K

This rule of thumb indicates loss of reliability, unless more exotic materials are used, such as a billet steel crank, and forged pistons.

2.5L      Stroke(mm) =    95    
        Rpm MPS
   5000    15.83
    5500    17.42
    6000    19.00
    6500    20.58
    7000    22.17
    7500    23.75

Edited by JohnD
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Interesting idea Phil - what sort of price does a custom crank command?!

On the 1300 engine revability - is any of that to do with the smaller journals as well as stroke? I've heard it said but don't know if true. And having driven a late mkIV I didn't notice any reluctance to rev compared to my mk3.

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1 hour ago, PeteStupps said:

Interesting idea Phil - what sort of price does a custom crank command?!

On the 1300 engine revability - is any of that to do with the smaller journals as well as stroke? I've heard it said but don't know if true. And having driven a late mkIV I didn't notice any reluctance to rev compared to my mk3.

Price - from what I have gleaned in various places looking at a few thousand? There are companies whom have already done 4 cyl cranks, so not a huge adjustment needed apparently.

Revability - as you say, this is primarily down to stroke really. Journal size shouldn't affect how high the engine can rev, just how fast it gets there (bigger journals equals more friction). However if your oil pressure is good, and oil is in good condition and at proper heat again this will be negligible. This may be of consequence to a racer, on a road car I doubt you will see any difference.

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10 hours ago, thebrookster said:

Okay, so you reckon individual throttle bodies should behave better than a plenum setup?

For the PH2/PH3 hybrid, I do currently run a plenum manifold. It’s about 90% ok. It’s hitchy below 2000rpm on very light throttle  but clears immediately with more throttle. I’ve spent a lot of time trying to tune this out and it’s almost acceptable (still soon gets wearing in slow traffic), but at the expense of having it fairly rich down there, making pottering-about economy relatively poor. I think reversion is the issues (also why I think it wouldn’t play that well with shared CD carbs) and have started on a set of ITBs based on BMW K1100 parts.

My other comment is that when choosing cams...... it’s very easy to overdo it. Done it myself more than once. The current one in the Vitesse is too much really. I get away with it because of the engine management and because the car is fairly light.  I certainly wouldn’t go any further and if choosing again I might actually pick something milder.  

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14 minutes ago, Nick Jones said:

it’s very easy to overdo it.

I hear you!

This is part of the reasoning behind building a second engine and keeping the original as it is, I have a get out clause if I need it. However I still consider myself young and foolish enough to go a bit wild for the time being :banana:

I am watching your ITB thread with interest, most likely I will be toddling down a similar one myself.

The 4 pot idea, in theory at least, should be capable of a serious dunt of power. Ideally I would have used one of GT's wilder cams, however this is unlikely so another option is needed. Hence wondering about a hybrid wild cam.

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Hello All

              As you all know I have Alan's(oldtucker) Mk1 2lt Vitesse

I am leaving all the lower engine as is but I have decided to fit a more standard cylinder head for longer life etc.

Now the camshaft that is fitted is a Chris Witor one with the extra lift but was ground onto the exhaust instead of the inlet!

But the engine still made 122 BHP.

Alan had another one ground but with the extra lift on both valves and seeing as the cylinder head is off I thought I might fit it!

I had this 25/65/65/25 cam in Spittys first engine (without the extra lift) and I liked it.

I have a Newman PH2 in now but am running ITB,s EFI and that is good and still pulls well from 2000 rpm

So the question is what does the collective brain think should I fit the double lift one(I have the new followers and pushrods)

I am going down to CD 150,s but with a Chris Witor gas flowed manifold.

Roger

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Andy T got me on the Newman hybrid cam back in 2010. (Thanks Andy). That was installed in 2011 on a completely rebuilt engine, along with the EN40 steel followers on Lucas fuel injection.  It was absolutely tractable from idle, and would pull from 1000rpm in 4th gear without complaint. Idle was also smoother than all the CP 150 bhp cams I have heard and driven.  Not sure that is anything to do with having the entire engine balancing (crank, crank pulley, rods, pistons, cam, flywheel and clutch cover).

I am now on EFI with Jenvey throttle bodies, coil back, K6 ECU, etc.  

As Nick says, not sure suitability on twin carbs with this cam.

Next cam on engine refresh is a Newman PH5 race. 

Will keep you posted on progress.

 

Cheers.

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59 minutes ago, rogerguzzi said:

So the question is what does the collective brain think should I fit the double lift one(I have the new followers and pushrods)

I am going down to CD 150,s but with a Chris Witor gas flowed manifold.

I would use the double lift cam, after all there must have been good reasons for Alan & Chris to decide on that one?

I think for your usage, CD150's are a good choice, I remember Alan saying that these were generally the better carb, they simply lacked at the top end? As this not something we often encounter on the open road? I was running them on my 2000, nice and reliable and certainly worked with the PI cam that was fitted on that engine.

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56 minutes ago, TRTOM2498EFI said:

Andy T got me on the Newman hybrid cam back in 2010. (Thanks Andy). That was installed in 2011 on a completely rebuilt engine, along with the EN40 steel followers on Lucas fuel injection.  It was absolutely tractable from idle, and would pull from 1000rpm in 4th gear without complaint. Idle was also smoother than all the CP 150 bhp cams I have heard and driven.  Not sure that is anything to do with having the entire engine balancing (crank, crank pulley, rods, pistons, cam, flywheel and clutch cover).

I am now on EFI with Jenvey throttle bodies, coil back, K6 ECU, etc.  

As Nick says, not sure suitability on twin carbs with this cam.

Next cam on engine refresh is a Newman PH5 race. 

Will keep you posted on progress.

 

Cheers.

I will be very interested to hear your thoughts on the PH5 when it is fitted.

How easy did you find the K6/Jenvey install?

Cheers,

Phil

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Roger

Good to see Alan's Vitesse has gone to a good home. Alan was kind enough to offer some advice to me and donated some of his spare carbs.

I have a 1969 Mk2 GT6 with a CTM head running 9.9:1 CR, the CW version of the standard 308778 cam shaft with +0.030" increased lift on the inlets (at least I hope it is...didn't check), a flowed inlet manifold and 175 CD2 carbs. Currently running on a Pertronix 2 Ignitor electronic ignition with their 0.6 Ohm 45,000V coil.

Running pretty well, revving freely and getting good economy (+35mpg on the last two RBRRs).

Ian

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Hello All

                I have been thinking again(dangerous hobby!)

Is a good idea to drill and tap the cylinder block to 7/16" UNF ?

The head would be easy and It would be easy enough to make a jig to keep the drill and tap upright.

At the moment Alan had replaced the studs with high tensile cap heads screws for the short ones and bolts for the long ones with just one long stud at each end>

I am not keen on screws and bolts into the block I would rather a stud fail in some way and not block thread!

If not where is the best place to buy a set of 3/8" unf studs (unless one of you have a good set of Triumph ones to sell me?)

Roger

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Hello Nick

                  I can not see any in the ARP range(may just me!)

Chris Witor does a kit of 7/16" for £67 inc vat (would cost more for 3/8"!) 

He recommends 50lb/ft outer bolts and 65lb/ft centre ones (still uses bolts for outer ones!)

I have sorted out how to make a drilling/tapping jig

The annoying thing is I ordered 20 of the mini ones that arrived today!!!! Hey Ho

Roger

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11 minutes ago, AB|W said:

Roger,

Have you looked in the ARP catalogue instead of just for kits

something like this:-

https://arpcatalog.com/120/index.html

Alan

Hello Alan

                   Thanks' for that but I think I will probably go for the Chris Witor ones as I think the ARP ones are a bit OTT!

I have ordered 2  x  7/16" UNF taps so will probably make the jig tomorrow(that will keep my quiet for a while)

Roger

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