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TR3 engine & box re-build


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Took a look at my new Newman's camshaft today, & the :chilled iron followers. Slightly disappointed to see that they had a hole near the base. I have read that this is not a good idea ?

Any comments on these.

Bob

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The hole(s) are to allow returning oil passed, which in turn then goes onto the camshaft.  As far as I can see it's a good thing, and indeed when I rebuilt a Norton Commando engine a few years ago - did the same on the advice of one of their (1970's Norton) work's race team members.

Pete.

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Not convinced it’s a good thing as previously written, unless the clearances are good. I would suggest measuring all follower bores with a slip gauge, numbering each follower and then measuring each follower in two planes. Then fit each follower to each bore, with your desired clearance. For ref all of the bores on my engine were 0.9735”. Again measured at two points at right angles. 
I aimed for a minimum of 0.001” clearance.

Having run the engine up for 20 minutes, so far there is no sign(audible) of sticking, which was very evident previously.

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Ok, so I measured the new chilled iron followers from Newman today:

.93615    .93685    .93625    .93650    .93615    .93610    .93630    .93620

I decided I didn't want them any bigger than .93630, so took Nos. 2 & 4 & after making a simple internal holder from a scrap ali bar applied some abrasive paper to them while spinning in the lathe.

they are both now around the .93625 mark, (& nice and shiney !) The others are black.

No more progress today on TR, but did help a friend to check out his overdrive gearbox (from a Sunbeam Alpine) on the bench. Solenoid high current plunger switch was sticking, a few prods with a screwdriver sorted that out, the solenoid to lever adjustment is similar to 'A' type in that you use a rod (or drill) to pass through the lever end, & into a drilling in the case, & like our "worn in" units, we had to adjust it a little past the hole to get a good engagement. Anyway it worked, so no strip down required.

Bob.

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I know they are marginal variations in the follower  diameters but I’m surprised there are any. Mine were almost all bang on the same. 

Also, the black coating led me to believe they were the phosphated ones and not basic chilled iron. 

Rgds Ian

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If the coating is anything like the Usual suspects Phophate hardened variety, you perhaps should consider soaking in meths and making scrupulously clean. This was advice I was given............eventually.

Iain

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A couple of photos of the Newman chilled iron followers, one as supplied (ok on size), & 1 which was 0.93685, before polishing down to 0.93630.

20201121_090648.jpg.df9388c61050b30711da98a5f7978570.jpg    20201121_090720.jpg.4aeedb4f27f02f58de332d6c1350fa51.jpg

 

I note from the TR4 workshop manual (the TR2/3A one does not have any dimension info) that the diameter should be 0.9367 - 0.9371, & the bores should be 0.9373 - 0.9380

Clearance should be 0.0002 - 0.0013 with a wear limit of 0.0016

I have no way of measuring my bores, so what will be will be ! at least all the lollowers are in the same ballpark now, & are on average about the same as the TRiumph ones I took out.

Edited by Lebro
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Hi Bob, That minimum dimension suggests that my followers (at 0.9362) are half a thou undersize but even at that size when I fitted them into bores that had been thorougly cleaned, first at the engineering shop and then by me with a 25mm dia brass bottle brush in an electric drill, the followers were a very close fit in the bores.

Having previously had problems with them sticking, I'm happy with what I have ended up with.

Incidentally, I agree with your comment about there not being very much offset on some of the cam lobes vis-a-vis the base of the follower and that could contribute to some of them not rotating properly - as demonstrated by the witness marks on the face of some of the followers.

Rgds Ian

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2 hours ago, Ian Vincent said:

 

Incidentally, I agree with your comment about there not being very much offset on some of the cam lobes vis-a-vis the base of the follower and that could contribute to some of them not rotating properly - as demonstrated by the witness marks on the face of some of the followers.

Rgds Ian

Not my comment ?

Bob

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The cam lobes do need to be offset to rotate the followers, Neil R advised me to check this as a matter of course. There have been cams around that have lobes that are not really in the right place.

Iain

PS.Thats useful data on the followers and bores Bob.

PPS . Those followers look remarkably like the usual suspects variety....... I wonder? 

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I did.......I put fine valve grinding paste on piece of leather on a piece of machined oak and polished them all. Time will tell if this was the right thing to do :-)

Iain

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3 hours ago, Lebro said:

The thing is, should I lightly polish the rest of the to remove the black ?

Bob.

 

So did I.  Using 1200 grit paper with the follower held on a home made arbor in my bench drill.

Rgds Ian

PS The comment about the alignment of the cam lobes was Iain's.  It as age thing.

Edited by Ian Vincent
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Remaining 6 followers now lightly polished to remove the black coating (whatever that was).

Only other TR progress today was to check out the grease channels in my water pump.

Must TRy harder tomorrow

Bob.

Oh & I watched most of the AGM

Edited by Lebro
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26 minutes ago, Lebro said:

Remaining 6 followers now lightly polished to remove the black coating (whatever that was).

Only other TR progress today was to check out the grease channels in my water pump.

Must TRy harder tomorrow

Bob.

That’s good progress for a chill out day. 
 

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Running out of things I can do now, waiting for block & crank to come back.

I did modify the lower radiator mounting so I now insert the 3/8" bolts from the top instead of the bottom.

I cut 2 X steel plates ¼" thick to fit under the rad mounting platforms, & drilled & tapped them 3/8" UNF.

then secured them under the mounts with a single 5mm pop rivet. Then drilled out the captive nuts on the rad to 7/16" to give clearance.

466647059_Captivethreadedplateforradiator.thumb.jpg.c1963abca03bf522adbeb1a6728bc4da.jpg

Only other progress was to balance the new 87mm pistons (see other thread on H section rods in the general TR technical area

Bob.

Edited by Lebro
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On 11/20/2020 at 5:16 PM, Lebro said:

Ok, so I measured the new chilled iron followers from Newman today:

.93615    .93685    .93625    .93650    .93615    .93610    .93630    .93620

I decided I didn't want them any bigger than .93630, so took Nos. 2 & 4 & after making a simple internal holder from a scrap ali bar applied some abrasive paper to them while spinning in the lathe.

they are both now around the .93625 mark, (& nice and shiney !) The others are black.

No more progress today on TR, but did help a friend to check out his overdrive gearbox (from a Sunbeam Alpine) on the bench. Solenoid high current plunger switch was sticking, a few prods with a screwdriver sorted that out, the solenoid to lever adjustment is similar to 'A' type in that you use a rod (or drill) to pass through the lever end, & into a drilling in the case, & like our "worn in" units, we had to adjust it a little past the hole to get a good engagement. Anyway it worked, so no strip down required.

Bob.

You must have more accurate measuring instruments than me.  I can only get to 1/10 of a thou with my dti.

How did you do the diameter check? I would roll them on a surface plate with dti on a stand to work as a comparator having identified the smallest diameter one with a micrometer.

Cheers

Peter W

 

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Mitutoyo digital 0 - 1" micrometer.   I don't have a surface plate unfortunately. I did work around (& up & down) each one to find the largest dia.

Phones M & C today, they say my stuff will be ready this week, so I presume so will yours.

Bob

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Been checking out valve clearances / spring rates etc today, to make sure they comply with The Newman PH1 camshaft requirements.

Cam spec:

Valve lift =  0.405" (both) lift at TDC =  0.060" 

Measured gap between Exhaust valve & head face = 0.495"

Measured lift at which springs become coil bound = 0.512"

Recommended force to open valve to full lift = 160lb (6000 RPM max) or 200lb (8000 RPM max)

Measured force to open exhaust valve to full lift 175lb

(to do this I placed a 90 thou washer between a hard flat floor surface & an exhaust valve, then balanced a lightweight bar across the valve head, & stood on it while holding onto a 30lb spring balance suspended from garage roof. My weight (plus that of the bar) almost exactly took the valve down to the washer, pulling on the spring balance even a bit lifted me off the washer.)

Well sometimes you have to think outside the box !

Called Newman cams, & discussed my findings, they said it will be just fine.

On to some engine parts painting now.

Bob.

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1 hour ago, Lebro said:

Been checking out valve clearances / spring rates etc today, to make sure they comply with The Newman PH1 camshaft requirements.

Cam spec:

Valve lift =  0.405" (both) lift at TDC =  0.060" 

Measured gap between Exhaust valve & head face = 0.495"

Measured lift at which springs become coil bound = 0.512"

Recommended force to open valve to full lift = 160lb (6000 RPM max) or 200lb (8000 RPM max)

Measured force to open exhaust valve to full lift 175lb

(to do this I placed a 90 thou washer between a hard flat floor surface & an exhaust valve, then balanced a lightweight bar across the valve head, & stood on it while holding onto a 30lb spring balance suspended from garage roof. My weight (plus that of the bar) almost exactly took the valve down to the washer, pulling on the spring balance even a bit lifted me off the washer.)

Well sometimes you have to think outside the box !

Called Newman cams, & discussed my findings, they said it will be just fine.

On to some engine parts painting now.

Bob.

We need pictures of this test Bob. 
 

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Just now, Hamish said:

We need pictures of this test Bob. 
 

I did it with the lathe using the apron longitudinal traverse.

Attach luggage balance to the chuck pull the spring with a hook through the centre with the base of spring sat on the tool post.  Apron wheel applies the pull.

Cheers

Peter W

spring pull test.jpg

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I did look at using the luggage weighing thingy that I have, but it did not go high enough (110LB)

were you measuring standard springs, & if so what did they come out as ?

Bob.

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