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Hello All

             What is the considered opinion about camshaft bearings in a 1500 engine?

 

I am just deciding about parts for my next engine!

 

I have decided on a Newman PH2 camshaft! I have asked them and they will grind one on a small bearing camshaft.

 

So I thought I would measure the block so I made a gauge about 30mm long with 1.968"(Go) on one end and  1.9695"(no go) other end.

 

When tried in the block only the 'go' end will fit(just) so all bores are within Triumph specs!

 

So now I am wondering if it is worth fitting bearings(bought cheap) and I do not know how good the fit will be until fitted?

 

So what,s the considered opinion?(experience)

 

Roger

 

ps do you need the expensive followers to go with the PH2 camshaft? EN40,s  or will chilled iron do? I shall only run single springs I think(jaguar type)

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Camshaft bearings are not really needed if your block is good.

 

No great hardship to fit on a 4 pot though if you have a small journal cam.

 

I think Newman advise steel followers for all but the PH1, but call them to discuss, David is very pleasant and helpful

 

Nick

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Thought you said you wanted reliability, single spring? I wouldn't.

 

Alan

Hello Alan

                 I have had jag springs in this engine for 27,000miles and Triumph fitted single as do lots of other makes?

 

I am not going sprinting like you,I just want to build a new engine with a bit more puff!

 

I will not be red lining it every time out!

 

If I can get to 5000rpm in top overdrive I would be doing 115mph which is quick enough for me!

 

I would just like to push the cruising revs up to 3500rpm which is 80mph with my 28% overdrive

 

Its only a project to pass the winter months away(Boys and Toys!)

 

Roger

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I'm fairly certain single springs were/are have a manufacturing cost factor. Regardless of rev limits I work on the theory: single - spring cracks, cap falls off, valve drops, big bang! double - spring cracks, well not much apart from probable loss of compression and valve bounce at above low revs. 

 

I always find it interesting how often people striping Rover V8's report find more than one broken spring but no damage done, and those engines aren't exactly high reving!

 

Alan

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Double springs aren't to do with reliabilty, in the sense of not breaking.

They are to help prevent valve bounce.

 

Any spring will have a "fundamental frequency", the frequency at which it will 'ring' if struck.

If the input frequency is a whole number multiple or divisor of that frequency then the spring will resonate, vibrate at that fundamental, allowing the valve to bounce on its seat and seal poorly.

A 'stronger' = stiffer spring will have  a higher fundamental so the input frequency must go higher to cause resonance.  If that is higher than the RPM of the engine, job done.Bu the input - in this case the half the RPM as a valve opens once in But the the stiffer spring will load the valve train.

My SofS came with a 'race -prepared' engine, but the builder had fallen for this fallacy, and the ultra stiff spring made the cam shaft eat the block!    It wore right through the bores in the block, and the valve gaps opened up in a few laps on our first test session.    One ruined engine.

 

But Physics is your friend!     If two springs work "in parallel", for instance one inside the other, then their individual stiffnesses add.  Two springs the same will be twice as stiff.

So two relatively weak springs can be used, with the same combined stiffness as a single spring.

If those springs have different stiffnesses and so frequencies, any input cannot make them both resonate at the same time.

In fact it can, but only by an input that stimulates both at the same time, by frequency 1 TIMES frequency 2, which means a very high frequency, way beyond an engine's rpm.

 

That's why two springs are sometimes used.

Look at a pair of springs deisgned to be used as valve springs,  One is almost as stiff as a single;  the other is compressible between your fingers.

John

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Hello All

             I have decided to fit the camshaft bearings and have a small cam ground.(As someone said it saves ruining the block)

 

I will fit them and make a Go & No Go gauge before I have the cam ground.

 

Still not sure about valve springs now? Newman Cams list single for PH1 to 3 cams?

 

I have also bought Peter Burgess book on Cylinder heads(Cheap) I have cleaned up a few ports in my life but just by looks!

 

So thought I will have a read on how it should be done(I do not think I will build a flow bench!)

 

But the first thing he says is fit the 36.4mm inlet valves! just after I have bought 35mm!!!!!!

 

I am not sure if I could do that with the seats that are factory fitted?(I may just go with the 35mm ones)

 

After all I am not after the very last bit of power! a nice 80 to 90bhp would do and hopefully be reliable?

 

It keeps the old brain active!

 

Roger

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  • 4 months later...

Hello All

              I have decided (rightly or wrongly?) to have the block decked.

I took it in yesterday and the man said it would need at least 0.010" off to get a good surface and he can not re-cut the recess.

So I am having the recess removed about 0.030" the old pistons came to 0.020 below the deck and the new ones would have been 0.024" below.

So I should get a pop up of 0.005" approximately (I would rather the block surfaced and there will be less to come off the New head!)  plus these blocks are common/cheap

I have bought a set of valve springs off Chris Witor the TR5 type as I could not find any Jaguar springs anywhere.

https://www.chriswitor.com/proddetail.php?prod=CW2906

I thought I would try and compare the spring rates and this is what I found

New red (county springs about 34lbs @ 35mm and 110lbs @ 0.405" compression with 0.150" spacer(105lbs without)

White Jaguar  40lbs @ 35mm and 120lbs @ 0.405" compression'

The Newman single springs are rated @ 160lbs ??? So I think over kill for a 1500!

So what is all your opinions? (I promise not to get upset or cry) still time to change my mind as the man is busy and job will not be done until January

This is how I did it a bit crude but it was for comparison more than accuracy!

All tests with out bottom Triumph collar, I will make the 0.150" spacers in steel I do not fancy aluminium and will make them a good fit inside the outer spring to stop it moving around!

 

Roger

 

 

 

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1 hour ago, rogerguzzi said:

So what is all your opinions? (I promise not to get upset or cry) still time to change my mind as the man is busy and job will not be done until January

This is how I did it a bit crude but it was for comparison more than accuracy!

All tests with out bottom Triumph collar, I will make the 0.150" spacers in steel I do not fancy aluminium and will make them a good fit inside the outer spring to stop it moving around!

 

I'll let others comment on your decking issue!

I like the TR5 Red Spring sets, 1) safer than a single spring, 2) Dual springs and especially as they are different strength and wound in opposite directions stops a sympathetic vibration/bounce building up. Good opinion says no Triumph engine unless at the extremes of operation requires anything stronger.

The bottom spring spacers locate on the valve guide so I'd make sure that they aren't a tight fit in the outer spring.

Double springs use a different valve spring cap to the single springs, I think?

.030 shouldn't make too much difference, but with a skimmed head as well, you might want to check push rod length.

Alan

  

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I run a pop-up of 0.005" in the Vitesse engine (2L 6 obviously).  No issues.  Any advantages?  Don't know....... goes well enough and runs very lean at cruise without pinking/hitching so maybe the squish is working!

I did have to machine the piston crowns a little to achieve this as the numbers didn't quite work.  Pretty sure I had to remove a bit more than 0.030" to fully clean up the fire-ring areas.  The advantage was that after a couple of test builds to determine the most equal piston/rod combinations and some careful measuring I ended up with dead even pop-up across all 6.

On the PI (2.5 6 obviously) I wasn't looking for zero-deck or pop-up, but the deck did have a very light skim.  Initially to see how flat it was and then a bit more to get it flat.  Total removal 0.005" ish.  Didn't re-cut the recesses, which did give me some concern about head gasket sealing, but in the event it worked just fine.

Nothing to add on the valve springs.  Pretty sure that the TR5/red set is what I have in the Vitesse.  PI I re-used the OE ones as they were all still the same length.........

 

Nick

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Hello All

               Now first this will make you laugh! 

I have been carrying 2 inlet and 2 exhaust valves,springs and collets along with a head gasket in the boot on all our trips.

So to day I got the spares out as I wanted the spare crank sensor to see about mounting it on the timing cover.

I do not know why but I decided to check the valves and I found they had longer stems than the ones on the bench!!!! ready to go in Spiity,s new head

Funny I thought(HA bloody HA) the penny droped then I had rebuild the brother in laws TR6 cylinder head at about the same time I put them in the boot(well they look the same on their own)

Now the next discovery the old valves I have which I had taken out of a spare head I bought for a tenner had a larger head???

So I had a look at that head and of course(you are in front of me now) it is a 1300 large inlet valve  head 218141( 36.5 mm  dia not the 35 mm)

So B****r I have acquired a TKC1155  with the 35 mm inlet and Burgess says fit the 36.5 mm  for best flow (but it has seat inserts) and I have done all that porting on it!!!!!

So do I rework the tenner head? and by the time I have cleaned up the combustion chambers it will probably give me the 9.5 to 1+ that I want or see if I can have the hard seats opened up to 36.5 mm dia and have a light skim to get the right compression ratio?

Now I have come this far it seems a shame not to get the extra BHP they give

Cheapest option is rework the tenner head and get a set of inlet valves and I will have a standard spare head in case it goes T**s up !

Roger

ps its not light at the end of the tunnel its another bloody train coming!!!!

Still better than an old mate that we sent off to the Big Triumph Club in the sky today?

So will stop my moaning and think how lucky I am?

 

 

 

 

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Edited by rogerguzzi
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Sorry about your mate......  Looks like you gave him a good send-off though.  Topless in the snow?!  Respect is due!

Carry the wrong spares?  You wouldn't be the first.  Discovered in my prep for this years 10CR that I've been carrying the wrong bottom hose and fan belt for the last n years....... So much better to find these things out at home rather than half-way up an Alp though.

Re valve sizes:

1. Check combustion chamber depths.  I have it in my little monkey brain that the big valve heads were only ever 1300s from the factory (or at least that 1500 versions were very rare).

2. Rather than port another head, you may well find that there is enough meat in the inserts to open up the valve throats and recut the seats - it's only 1.5mm.

3. Measure the chamber volume properly after all valve work has been done and final valve height makes a big difference

 

Nick

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10 hours ago, Nick Jones said:

Sorry about your mate......  Looks like you gave him a good send-off though.  Topless in the snow?!  Respect is due!

Carry the wrong spares?  You wouldn't be the first.  Discovered in my prep for this years 10CR that I've been carrying the wrong bottom hose and fan belt for the last n years....... So much better to find these things out at home rather than half-way up an Alp though.

Re valve sizes:

1. Check combustion chamber depths.  I have it in my little monkey brain that the big valve heads were only ever 1300s from the factory (or at least that 1500 versions were very rare).

2. Rather than port another head, you may well find that there is enough meat in the inserts to open up the valve throats and recut the seats - it's only 1.5mm.

3. Measure the chamber volume properly after all valve work has been done and final valve height makes a big difference

 

Nick

Hello Nick

                  Yes it is a 1300cc head whith about 36/37cc chamber!

So if I can find 2cc(39cc) plus 4cc in gasket plus 378.4 cc = 421.4  divide by 43cc = 9.8 to 1

Or is that to high?

The 1500cc head  insert is 37.76mm o/d  and 31.75mm i/d(1 1/4") = 6mm so 3mm wall thickness (118")

To get to 36.5mm valve it would be bored to 33.33mm i/d (1 5/16") = 4.5mm so 2.25mm wall thickness(0.088")

Not sure about that sounds a bit thin?

I think I will get a set of valves or I could just modify one chamber and use and old valve to measure chamber and see what I get?

Then I still have the 1500cc head untouched!

Roger

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Hello All

              Will these seal fit with perhaps some maching of the guides(I have a lathe)

http://www.theengineshop.info/acatalog/Valve-Stem-Seal-8mm-026109675.html#SID=52

And how about these just need shortening?

http://www.thewedgeshopstore.com/valve-guide-set-bronze-spitfire-mki-mkii/

I have done a bit of cleaning up one chamber and its only 36cc so way to small! can I chamfer the side opposite the spark plug like a 6 cylinder head?

The 1500cc engine is the same bore as TR6 and valve sizes are the same!

I could just machine a bit out of the bottom of the chamber!

Roger

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Those seals will probably fit.  There are a whole bunch of very similar seals available. Witor uses one listed for some Austin Rover engine. 

http://www.chriswitor.com/proddetail.php?prod=CW2903

Others use ones intended for VAG.  Pretty much anything that looks like that and is intended for an 8mm valve should work though some are fat enough to be a marginal fit inside the inner valve spring.

Witor does some lovely guides too.  I have some in the Vitesse.  They are now more than 3 x the price I paid though, so the ones you suggest and a bit of simple lathe work seems like the way to go.  That's what I did on the PI head also.

This is information out there on how to do the 1300/1500 head properly.  Some of it says to grind away the shape by the spark plug.  Other say that the shape is there for a reason and is to concentrate the charge near the plug and thus left more or less alone.  What can be done is to grind back the chamber wall around the inlet valve (including at the base of the plug ramp) to unshroud the valve.  Obviously care is needed not to undercut the head gasket sealing area.  This could be done on the exhaust side too if you still need more volume.  Don't machine out the bottom of the chamber.

Must be a later TR6 (CR) with the small exhaust valve.  The earlier ones have the valves almost touching and cracking between the valves can be a problem.

Nick

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Hello All

               Kas   Kastner shows this for the 1500 cylinder head which would be easy on my milling machine and burrs.

So now I am getting even more confused(not to difficult!)

They were running 12 to 1 compression ratio and probably avgas or similar?

There are more power gains by
modifying the combustion chamber.
The section that needs attention is the
area around the inlet valve. Grind away
the cast iron around the inlet valve as
shown in the drawings. This simple bit
of grinding will improve the flow
considerably and consequently the
power. My test engine was running a
12.0 compression ratio and has shown
no ill effects from the modification. It is
mandatory that an oil cooler be fitted
when you go to this higher compression
ratio. We have had no failures, but as a matter of good maintenance we checked the rod
bearings after several hours of running time. We found that the bearings were all in good
condition. It is only a matter of good sense though, to check after a hard race to see firsthand
how the situation appears. Since the original time of this writing many owners have reported
the great success they have had with this modification.
If you are using a gasket other than the compressed stock .035'' head gasket be sure to
measure the thickness so that all your calculations are true to the parts used. After all the
grinding and machine work has been finished, assemble the head with the valves and valve

Roger

 

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Don't forget that the compression ratios they were using were for racing, and with some now regarded legacy cam profiles, probably nothing tractable below 4K rpm.

That doesn't denigrate the concepts on good head work, the porting on my MK1 head was done by some who took Kastner's port & throat work, plus Vizard's chamber work and said "Wimps" fortunately he did it on a thicker saloon head, and I got it before anyone had ever used it/skimmed it, so I was able to keep compression ratio in the sane tractable band.  If I could afford to I'd love to see what skimming it to around 10:1 would do, might be very exciting above 5K but I think would ruin the over all balance of the engine.  

Alan

 

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Also, some of the compression ratios (for 6 cylinder for sure, maybe not so much with the 4) were the result of Kastner having to run 150 Strombergs, limiting flow and I think he was tuning in a similar way to the restricted inlet series with a high CR to compensate for never getting a truly full charge at high rpm.  Dunno how he got round the carb issues you were fighting Alan....?

I don't understand the combustion chamber you've posted Roger.  Doesn't look like a 4 cyl chamber to start with - where's the spark plug?

Nick

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Hello Alan and Nick

                                   Alan I am in a more fortunate position than you as I have 3 cylinder heads(4 if I count the original one with a burnt exhaust seat! cam timing was wrong and opening to early I think it was!)

1) is a standard 1500 with hard seats(and ported by me!)swooped for a American spec differential(my Brother in laws but he has since sold the car after I got it going well for him)Pr**t

1) is the one I bought for £10 a 218141 1300cc Toledo with the bigger inlet valve.

Plus the one on the car at the moment is a KC1156 1300cc Dolomite smaller inlet valve which I cleaned up the ports and machined the step in the combustion chamber away between the inlet and exhaust valves opposite the plug! to get the compression ratio down to about 9.5 to 1(I wish I could find the article that said do that!) and had hard exhaust seats fitted.

This head has done 25,000+ miles with no problems.

So I think I will port the Toledo one as it has the bigger inlet open the chamber up a bit but not go to the expense of hard exhaust seats in case its a dog! and I can put the 1500cc head on if it is

Plus the face looks good and I think I can cut the 3 angle valve seats myself on the milling machine as it is only cast iron!

Nick

         I assume the plug is opposite the grind area ie by B

I have ordered a set of inlet valves and bronze guides (valves are nos Triumph/Leyland ones) from these people.

http://www.leacyclassics.com/

Does that sound like a good plan ???

Roger

ps I have been servicing our old Lister generator this morning a SOM 8-1 built in 1958 runs at a nice steady 850 rpm(very restful) not like the modern ones at 3,000 rpm!!

I will post some photos later in a new heading

 

 

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3 hours ago, Nick Jones said:

  Dunno how he got round the carb issues you were fighting Alan....?

 

And as far as I can find never published, a few hints from Steve, and a piece by Tony Drew indicates that apart from bevelling the front of the piston, which it now appears from later flow bench test to be a waste, that the 150 CD (and the SU HS6) although nominally 1.5" .they aren't, the bore tapers from about 1.35 inlet to 1.5 outlet. So if you bore the carb out to 1.5" right the way through, it bugg.rs the choke mechanism (but who needs a choke) and rebuild a new bridge, you can get them to flow more, and still be a 1.5" carb.

From AFR logging the 1.5 carbs on the 6 have a tendency to go rich and stay rich above 6K, and as I think (correct me if I'm wrong) that high compressions love rich mixtures, I think that's how they got to claimed 8K.

As with the 1.5's and my fiddling I could get 6.5+K  and with the 1.75 it will pull 7K (for the briefest of periods I let it), I think if you could afford the engine rebuilds I think a highly modified pair of 1.5's might just fuel a high compression 2ltr towards 8K,  Not sure if it would be street drivable though!

Alan  

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2 hours ago, oldtuckunder said:

And as far as I can find never published, a few hints from Steve, and a piece by Tony Drew indicates that apart from bevelling the front of the piston, which it now appears from later flow bench test to be a waste, that the 150 CD (and the SU HS6) although nominally 1.5" .they aren't, the bore tapers from about 1.35 inlet to 1.5 outlet. So if you bore the carb out to 1.5" right the way through, it bugg.rs the choke mechanism (but who needs a choke) and rebuild a new bridge, you can get them to flow more, and still be a 1.5" carb.

From AFR logging the 1.5 carbs on the 6 have a tendency to go rich and stay rich above 6K, and as I think (correct me if I'm wrong) that high compressions love rich mixtures, I think that's how they got to claimed 8K.

As with the 1.5's and my fiddling I could get 6.5+K  and with the 1.75 it will pull 7K (for the briefest of periods I let it), I think if you could afford the engine rebuilds I think a highly modified pair of 1.5's might just fuel a high compression 2ltr towards 8K,  Not sure if it would be street drivable though!

Alan  

Seem to remember Vizard having something to say on the subject of boring out CD carbs (SU & Stromberg).  Not sure it was all that positive though.  I think combined with a lairy cam "street driving" would be tricky!  Airflow difference between 6k and 8k is substantial mind.....

Nick

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