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TR3 engine & box re-build


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My usage is fastish road, not racing. When I modified the head earlier this year I was aiming for 10:1 with the 87mm liners I will be fitting.  Only other mods are tubular exhaust (Phoenix) & Newman PH1 cam.

Perhaps the question should have been what height would the pistons have been from the factory?

I will wait till I know what height they come to unmodified, if they are above the liners then I will need to do something, if not, probably leave as is. I don't yet know how much will be taken off the block.

Bob.

Edited by Lebro
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Why not ask your machine shop what they mean. I think they have told you to deck the pistons? One assumes the block has been faced, liners test fitted with new figure of 8 gaskets pulled down and machined to height accordingly? Therefore the pistons are too high.......now back to the question, liner height or deck height? 
Cheers

Iain

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When I rebuild my stock engine earlier this year, I measured the "deck height" from the top of the clamped liners to the top of the pistons. They were all within a range of 8-10 thou clearance (piston below liner) so left them as they were. So far, so good, done about 1700 miles, including 25 today as the sun was out.

Mick

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According to Mick's technical article, (TRaction 299 pages 40-41) for a standard road going engine,

pistons should be 40 thou below liner top.

A comprehensive article, which I shall follow, apart from the order of things to do near the end e.g. fitting cylinder head & cam followers before the cam. 

I assume the last column of jobs was just to illustrate the time required to do them.

Bob.

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Hi Bob,

The deck height of the pistons needs considering along with the equipment and use of the car.  The reason I said that a "one size deck height" can sometimes be wrong is that depending upon the crank, conrods, pistons  and very importantly head gasket the deck height clearance between piston top and the head can be eroded. This is the reason the liners are used as the deck height setting point, not any superficial increase in compression.

Using a standard crank and Carillo rods with Forged pistons and a Steel head gasket which is compressed down to 20thou crush (that's about it's initial thickness but it has ridged compression rings pressed into it) when the head is torqued down, I observed "piston shadows" (discolouration but no contact) on the head when stripped at the end of the season.

I ran very disciplined on revs normally self limiting to 6000 revs, and with a 6500 rev limiter which I used occasionally extending use between short straights, despite that the 8 thou deck (top of the liner) to piston clearance down from the liner lip was eroded. From your comments you'll not be using the car aggressively or at these higher revs, but this will be countered by your equipment obviously not competition quality (but those Maxspeeding Rods you bought will stand in good stead) and you can expect the standard crank (as I used) and cast pistons to expand not withstanding the excess bearing wear experienced over many more road miles covered allowing more lift.

Reading other racers deck heights (Christian Marx's amongst them) they experience similar results as myself,

...........................................................................................

If any of you are fairly new at this, be warned...With my modified stock crank, Carillo rods, forged Wiseco pistons, and steel-shim head gasket, my piston "kissed" the head at high RPM and I spun a bearing.

This happened at the end of a loooooong straight at Auto Club Speedway. There went $1,000 and a bunch of hours.  I was trying to achieve close to zero deck height.

On the bench, the pistons came up to .003 from the top of the sleeve (this isconsidered the deck, not the top of the block)Now I'm running one of Mordy's .032 head gaskets for a little more Piston to Head clearance. 

In one of the older posts, Greg Solow recommends at least .026 total P to H clearance because the stock crank will stretch a little at high rpm and the piston will reach up higher than it does on the engine stand in the garage.

STEVE

From: TR4 Tony Sent: Jan 23, 2013 4:52 AM

To: Kas Kastner

Subject: Re: [Fot] TR4 deck height

>Hi all

 >We run 8 thou with a steel crank , carillo rods. Flat top Venoila pistons and

>a very modified head on my TR4.

>As a consequence the engine 'drinks' a little and now and again when fresh and

>a tiny water seepage can be seen on the middle head studs where there is a bit

>more pressure, but its a small price to pay. This beds in after a while via

>gunge movement but teaches you to monitor the levels in the header tanks in

>the meantime.

Regards Tony 

On 23 Jan 2013, at 02:32, Kas Kastner wrote:

 Impression in the carbon is just right.

"Never be beaten by equipment"

 Date: Wed, 23 Jan 2013 00:38:35 +0000

 Subject: Re: [Fot] TR4 deck height

 With a billet crank and Pauter rods I use a 0.010 inch deck height, plus

allow 0.022 for the head gasket.  I have run as little as 0.007 deck, but had

impressions of the head on top of the pistons.  Joe(B)

................................................................................................

so a standard engine which runs on a composite copper gasket which compresses to 30 thou can still give good flame front progression across the chamber and adequate clearance between piston and head if the piston is decked flush with the liner top, but not as much in hand maybe as you thought.

Mick Richards

Edited by Motorsport Mickey
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Thanks for that very good explanation Mick, much clearer now. So I should aim to be below liner top, but not as much as 40 thou, 10 thou sound like a good compromise.

Bob.

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11 minutes ago, Lebro said:

Thanks for that very good explanation Mick, much clearer now. So I should aim to be below liner top, but not as much as 40 thou, 10 thou sound like a good compromise.

Bob.

0.010" clearance piston to liner top is what I set the County 86mm pistons with standard copper asbestos head gasket on last engine.  That had standard crank and con rods.

Peter W

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Thanks for the explaination MIck.
So my engine  has Mahle 86mm pistons decked to the block, liner height at 0.005” and a solid copper gasket at 1.0mm, 0.040” .

What are you observations?

Thanks

Iain
 

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11 hours ago, iain said:

Thanks for the explaination MIck.
So my engine  has Mahle 86mm pistons decked to the block, liner height at 0.005” and a solid copper gasket at 1.0mm, 0.040” .

What are you observations?

Thanks

Iain
 

Hi Iain,

If the pistons are at the block deck height and not the liner to head deck height, with the solid copper gasket at 40 thou thick you're effectively running a 45 thou clearance piston to head.

The standard crank will flex and stretch and even those quality Mahle pistons will plasticise and grow a little in bore and the standard rods will also contribute towards some thou increase of lengths. Maybe 4-5 thou max.

I don't expect the solid copper gasket to lose much in thickness when pulled down and run through many heat cycles (maybe a thou ?) so the set up should be very safe. However the excess piston crown clearance down the bore will slow the advance of the mix across the piston which will not help the fuel burn and complete combustion, but it's a road going engine, who will notice ?

The solid copper gaskets are well known but mysterious to use. There are some who swear by them and those who swear at them, eg I remember Christian (Marx) saying he'd tried the solid coppers 4 or 5 times and couldn't keep the engine sealed. * I respect Christians engineering approach so you can expect all clearances and fitments to be correct, which means something else could be the problem.

The solid copper gasket is obviously less flexible than the original copper/asbestos/copper gaskets of yore which takes up inconsistencies in surface heights nicely. So if the liner heights are towards the max (...err 5 thou maybe) the solid copper has more difficulty in deforming and overcoming the stretch necessary for sealing around the less proud surfaces...water jacket and head to block water transference holes. Meanwhile the liners with their inboard 140-180 lbs compression remain faithfully sealed having the mighty hand of 105 "big ones" crushing the head down onto the the solid copper gasket and underneath the liner top circumference . The water jacket conversely only has the water pressure to contain limited by the rad cap 4/7/20lbs whatever you are running which gives the solid copper gasket a chance no matter how far it has to stretch. 

If you are running a 20 lb cap I'd consider using a 7 or 4lb which may help if the gasket seal is problematical, obviously changing it early rather than later gives the best chance of maintaining the seal. On the other hand I could be talking bumfluff and everything will remain sealed anyway.

*PS: Just to declare I've never run with a solid copper gasket. Went straight from copper/gasket/copper to steel competition with pressed fire rings.

Mick Richards  

 

Edited by Motorsport Mickey
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Thanks for your thoughts Mick
I have run solid copper for a while, without issue, famous last words. 4lb cap. CR is now 10:1 so we will see how it goes. Previously it was 10.75:1.

 Cheers

Iain


 

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Picked up block, crank, flywheel etc from C & M today, 1st job, is clean out all the oilways, then insert the plugs.  15 Thou was skimmed from the block & liner seats, & uncompressed liner height was 8 thou using new copper FO8 gaskets.

Will be checking with head torqued down once all has been cleaned, & on the engine stand.

Edited by Lebro
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My engine was a factory reconditioned one (TSA709FRE) the FRE plate was removed by C&M (I still have it) to reveal the original engine No. underneath. it had been partially erased by overstamping, but still readable as  TS35867E   which, according to the attached chart puts it to be originally fitted to a 1958 TR3A.

This means it can't have been reconditioned, & fitted to my car until later in 1958, but probably a fair bit later than that.  The numbers suggest that the factory had reconditioned 709 engines between 1953, & 1958.  I have always guessed that the FRE engine was put in mid '60s so that was probably the case.

Bob.

Commision No. chart.pdf    

20201202_162710.thumb.jpg.a3170e30c4446bda283000156abe2390.jpg

Edited by Lebro
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Don’t you just love this thread. I can see it being pinned as a go to engine build resource. 
 

I'm learning so much - mostly about my limitations -  if I had previously thought I could put together an engine to go sprinting I was clearly wrong :D

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20 minutes ago, Hamish said:

Don’t you just love this thread. I can see it being pinned as a go to engine build resource. 
 

I'm learning so much - mostly about my limitations -  if I had previously thought I could put together an engine to go sprinting I was clearly wrong :D

It's my morning read.

 

Look at the number of views!!

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1 hour ago, Hamish said:

Don’t you just love this thread. I can see it being pinned as a go to engine build resource. 
 

I'm learning so much - mostly about my limitations -  if I had previously thought I could put together an engine to go sprinting I was clearly wrong :D

It’s not too difficult if you ask the machine/ engineering shop to do some of the tricky bits. I got the shop to do all the bits that Bob had his do plus I asked them to remove the plugs in the crankshaft, clean it and replace plus do the same with the block so that I was just left to put it all back together. Checking on the way!

Rgds Ian

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37 minutes ago, Ian Vincent said:

It’s not too difficult if you ask the machine/ engineering shop to do some of the tricky bits. I got the shop to do all the bits that Bob had his do plus I asked them to remove the plugs in the crankshaft, clean it and replace plus do the same with the block so that I was just left to put it all back together. Checking on the way!

Rgds Ian

Here’s some removed earlier.......   TR 2 crank. Plugs removed **** found.

Peter W

 

F5AAECAC-9B0F-4DCF-AE43-86A8EEF0CF15.jpeg

EC4926F4-8506-42B7-89E1-C5EEB99F482F.jpeg

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That's the second time I have seen those photos today ! (Toby was explaining why it is worth doing while I was collecting my stuff) I had a look at your block too, a fair bit of undercutting corrosion around a couple of the liner seats, going to be "laser welded" apparently.

Bob.

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Those photos do show why  its perhaps a false economy not to remove the plugs.

Laser welding does seem to be the in thing for block repairs. Hamlins send theirs off to a company in Portsmouth area to repair liner figure of 8 seats, cracked block stud holes etc.

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So, today I cleaned out all the oilways, checked that cam bearing holes were in the right place (they were)

cleaned all aspects of the block. my old gun cleaning brushes came in handy for the oilways, & cam follower holes.  Then inserted the oil gallery plugs using locktite. these were supplied by C & M & were steel with allen key heads. the front one had been machined to clear the front face.

20201203_144915.thumb.jpg.3daa9048cc2f53c51c7a0464b02566d8.jpg  20201203_145552.thumb.jpg.ba3a13b3f6f836c9e899aa185da27545.jpg  IMG-20201203-WA0008.thumb.jpeg.560eb8033b70eb6b1d9caf2b4a43b1d0.jpeg

Next job was to check liner heights. dropped in the FO8 rings, followed by the numbered liners.

C & M had set the height to 8 thou without compressing the rings, saying that under compression they should go down to 3 - 5 thou.

IMG-20201203-WA0010.thumb.jpeg.d171beb0cb43ac3a4a6d1ae130f1d6d5.jpeg

Torqued up to 105ft LB (not easy when on a trolley) then removed the head & gasket, & added 4 clamps as per the manual to hold the liners in place. the tube spacers I made from aluminium, & they would not take 40 ft lb before starting to crush, so I did them up as hard as they would allow.

1st set of measurements (using M & W depth gauge)

 7     3  6     7  7     7.5  4     7

6.5   6  4    7  9      8    8     8

Not happy with these, and figured that the liners were leaning over a bit due to being clamped on 1 side only.  re-arranged the clamps :

20201203_165511.thumb.jpg.f52fefdcf549f909899ec4d6e2fe4390.jpg

so as to clamp each liner diagonally to eliminate any "lean"

new measurement:

7     6  7     7  6      7  6     7.5

6     6  7    7  8      8  8      7

Happier with those, but still too high. Tomorrow I will make some stronger tubes, & torque down to 40ft lb to see if the numbers come down, if not I will have to take a couple of thou off the liner seat.

Edited by Lebro
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I'm surprised that C&M don't clamp the liners to set them.  The people who did mine had a bar/block that they clamped onto the FO8s to measure everything up.  When I collected everything they pointed out that if the liners sere a bit high, it was because they might have relaxed slightly from when they set them.  Sure enough, when I clamped them down hard they came back into spec.

Rgds Ian

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Well done Bob. You certainly get on with it when you get the chance. 
 

can I ask if there is merit in shaping the liner to match the gasket. ?

5209E33B-D998-4F15-8B84-F883BABCD9C3.jpeg

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The FO8 gaskets I used were copper, & measured at 18 Thou before use, I suspect they have not squashed down as much as C & M thought they would. Apparently C & M always use steel FO8 gaskets, I do have a set of those (came with the liners) & they measure at 15 Thou, so an easy fix would be to use those which would bring the measurements in to spec, but I'm not happy with using steel, unless someone can persuede me that they are OK.

Bob.

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On 12/3/2020 at 6:31 PM, Hamish said:

Well done Bob. You certainly get on with it when you get the chance. 
 

can I ask if there is merit in shaping the liner to match the gasket. ?

5209E33B-D998-4F15-8B84-F883BABCD9C3.jpeg

I did with the previous liners:

20200505_160051.thumb.jpg.4b8cc628a23b914ef9ac52a18d81dbe9.jpg

And may do so with these

Edited by Lebro
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8 minutes ago, Lebro said:

The FO8 gaskets I used were copper, & measured at 18 Thou before use, I suspect they have not squashed down as much as C & M thought they would. Apparently C & M always use steel FO8 gaskets, I do have a set of those (came with the liners) & they measure at 15 Thou, so an easy fix would be to use those which would bring the measurements in to spec, but I'm not happy with using steel, unless someone can persuede me that they are OK.

Bob.

A Smear coating of welseal type stuff. Would protect them enough surely,? without adding too much thickness. 
and thanks for the clarification above.

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