TR3 engine & box re-build

[iain]

Those steel figure of eight rings gave me no end of trouble. They are coated with a varnish that seals them.......they collapse. I had set mine at 0.004” last time, when out took the engine out to sort rear crankshaft oil leak.....the liners were flush! When I quizzed some suppliers, the sealing varnish came to light and I ditched them for solid copper. C and M have in my humble opinion assumed a greater than possible height reduction under compression. When I rebuilt the engine  for the second time the liners were torqued down as Mick has recommended and the change in height was negligible. This was not a surprise as Hamlin’s had already gone through this exercise to set the liner heights. 
Just a thought Where the copper figure of eights you supplied to Mac and M annealed? If not it might be worth annealing them and seeing if they allow the liners to come down. Revington supplied me with annealed versions which I would never have thought of until I discussed with them.
I will not use steel figure of 8’s again.

Iain

[Motorsport Mickey]

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Edited December 3, 2020 by Motorsport Mickey
Duplicate

[Motorsport Mickey]

3 minutes ago, Motorsport Mickey said:

Bob,

I ALWAYS keep old gudgeon pins, they are excellent for this clamping operation and you can't crush them., to remove any clamping leaning influence when you remove the head measure the liner heights unclamped and then compare (don't lean on them too much when measuring) with the liners when clamped they should be pretty close. Always use the head to clamp the liners into position just as you have done, if you use washers or a "block bar" traversing the block pulling all the liners down it's possible the liners don't pull down square. No harm in retaining the liner clamp afterwards with washers or the block bar.

The copper Fo8 gaskets compress 3/5 ths of bugger all, and when you put 105 lbs on them it serves to remove any "spring" or resistance to downward pressure. I've measured copper Fo8 before and after seasons running and there's no change. they are not thick enough to compress internally (unlike a solid copper head gasket where the 1mm thickness and many hot cold cycles anneals them and it will crush about a thou,...I've rebuilt engines where they've been fitted).

Hamish,

Good thinking but there are only microns of Wellseal left on the Fo8 gaskets after clamping, you can't measure it, the 105 sees to that, if there is a lot left there's something wrong with how the liner is pulling down.

Bob, 

After you have your figures and are happy they are representative, swap No 1 and  No 4 piston and conrods in their bores and check the piston crown heights along the pistons in the block...you know what we are checking...right ? 

The pistons need equalising in the bores, press down with the shaft of a hammer and makes sure the pistons give an equal reading around the circumference. In the axis along the gudgeon pin position it's obviously fixed, the new Max Speeding rods will be straight so rocking the piston along the other axis should allow 4 measurements around the crown the same dimension.   

How C+M can think copper Fo8 of 18 thou thickness can compress 3-5thou (nearly 30% of the gasket thickness !) to reduce the liner heights to the appropriate heights makes me blink  

NEVER trust a machinist, ALWAYS measure the components to confirm the work carried out.

Mick Richards

 

[Ian Vincent]

2 hours ago, 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. ?

My view is that you would only shape the liner to match the gasket if your head had been skimmed to the extent that the shroud on the inlet valves has been removed.  If the shroud is still there, there is little point in shaping the liner.

Rgds Ian

[Lebro]

A fair amount of the shroud was removed earlier this year, as you can see the chamber pretty much follows the gasket edge in that area

Edited January 16, 2021 by Lebro

[Lebro]

2 hours ago, Motorsport Mickey said:

Bob, 

After you have your figures and are happy they are representative, swap No 1 and  No 4 piston and conrods in their bores and check the piston crown heights along the pistons in the block...you know what we are checking...right ? 

The pistons need equalising in the bores, press down with the shaft of a hammer and makes sure the pistons give an equal reading around the circumference. In the axis along the gudgeon pin position it's obviously fixed, the new Max Speeding rods will be straight so rocking the piston along the other axis should allow 4 measurements around the crown the same dimension.   

How C+M can think copper Fo8 of 18 thou thickness can compress 3-5thou (nearly 30% of the gasket thickness !) to reduce the liner heights to the appropriate heights makes me blink  

NEVER trust a machinist, ALWAYS measure the components to confirm the work carried out.

Mick Richards

In your 1st paragraph I assume you mean check that the block surface is parallel to the main bearing centers. Not a lot I can do if it isn't.

Not clear on what you mean by equalising the pistons ? again what to do if wrong.

I am still waiting for shells, so cannot fit the crank yet anyway, or determine what thickness of thrust washers to order, so getting liner height correct is main focus for now. Will see how well I can set them up in my lathe before commiting to DIY !   I may try annealing the copper, re-torqing the head, then & using stiffer tubes measure again before removing any metal. of course if I could find some 15 Thou copper FO8 rings that would be much easier, but none of the suppliers quote the thickness.

Bob.

[BlueTR3A-5EKT]

Supporting TR liners on the smaller lathe.

I have one of these to fit in the tailstock holding my spare chuck.  Not super accurate (+ or - 0.005") but does a nice job of holding odd shaped long items without a steady or ability to use centres.

Cheers

Peter W

https://www.warco.co.uk/lathe-centres/303272-lathe-centre-2mt-boxford-thread.html

[Motorsport Mickey]

 

In your 1st paragraph I assume you mean check that the block surface is parallel to the main bearing centers. Not a lot I can do if it isn't.

If it isn't I would ask the machine shop to remedy it, that's how blocks are supposed to be decked...parallel to the main centres and crankline. 

Not clear on what you mean by equalising the pistons ? again what to do if wrong.

The gudgeon pins will help show up any mismatching of the deck surface to the vertical piston...they obviously share the same axis and project that line up close to the deck surface...that can be measured. Apart from bearing clearance (and they are new and tight) they will give you a good indication. The piston runs square in use, the compression pressing down evenly over the surface, the gudgeon pin axis is a "gimme" mimicking the crank, the other axis across the block can vary by piston tilt so that can be "equalised" by pressing down on either side with a hammer handle, you know it's right when all 4 dimensions are the same...or not 

Removing the shroud ? this is where you can go and why it makes a difference, you can even do this on a roadgoing head to remove the flow obstruction

Mick Richards

 

 

Edited December 3, 2020 by Motorsport Mickey

[Motorsport Mickey]

Here you go Bob,

"of course if I could find some 15 Thou copper FO8 rings that would be much easier, but none of the suppliers quote the thickness."

I've pinched some photos off Uncle Jacks engine building tips, pretty much what I used to do when I was building multiple 4 cylinders every year. Buy some copper sheet from suppliers at 15 thou or closest derivative and cut in a pillar drill or miller to suit. I used to do 4 a time trapped between thin ply layers and cut the inner dia on the machine and hand cut the circumference on the outside (not hard).

 

Mick Richards

 

 

 

Edited December 4, 2020 by Motorsport Mickey
clarification

[Lebro]

Thanks Mick, 0.4mm (16 thou) is easy to find on ebay, may go that way.

Bob.

[Ian Vincent]

Bob, if you are interested, I can post details of how I have made FO8 gaskets in the past. Very similar to Mick’s but my trepanning device wasn’t nearly as sophisticated and I didn’t make them as individual items I kept the FO8 configuration. 

Rgds Ian

[Lebro]

Yes please Ian, the more options the better !  Going to try annealing, then a better clamping arrangement first, then decide whether to take 3 thou off liner bottoms, or make thinner FO8 seals. the latter sounds less risky !

Bob.

[rcreweread]

What I don't understand is if a manufacturer can make the figure of eights in steel, why can't they also make them in copper - can't the same tooling be used?

And secondly, if there are no 15 thou copper ones available, why ever not ?(SDF????). Because why have steel which WILL  corrode when you can have copper which doesn't, or am I being too simplistic

Cheers a confused Rich

[Lebro]

A good question. 0.4mm A4 sheet on order. Whether I use it or not.

Bob

[Ian Vincent]

Hi Bob,

Attached are photos of the tool I used to cut the holes, they are available from Screwfix for not a lot of money.  In case you can't read the writing it is a 92mm dia hole saw, which is just about bang on for cutting the centres out.  The cylinder pairs are at exactly 100mm centres.  I used a standard pair of aviation snips to trim around the outside as per Mick but I made it more tricky by keeping the FO8 configuration.

I didn't anneal the gasket after cutting but it would probably be a good idea as there is bound to be a degree of work hardening.

The sheet I used was 0.55mm copper, probably bought from the same ebay place as you and fixed down to a piece of 3/4" plywood with several screws around the outside and with the plywood firmly clamped to my bench drill.

The trick is to keep the drill going slowly and with very light pressure.

If you need any more info, let me know and for what its worth, the hole saw is ideal for making a plywood spanner for tightening wire wheel spinners, it is the same diameter as the centre part of the spinner.

Rgds Ian

PS if you want to borrow my hole cutter, send me a PM.

Edited December 4, 2020 by Ian Vincent

[Charlie D]

 

2 hours ago, Ian Vincent said:

The cylinder pairs are at exactly 100mm centres.

Hello,

I wonder if any TR owners have made their own seals out of PLASTIC sheet. I guess it would be easier to make and cheaper to buy.
What got me thinking was Ian remarking that the FO8 centres were 100mm and I remembered that I'd read somewhere that the design for the TR engine was "Borrowed" from Citroen (I think that is why the measurement is metric.)

I looked up to see how Citroen sealed the bottom of their liners and I discovered these sites.
Interesting that diferent coloured plastic is used for different thicknesses. Also there seems to be a much wider variation in thicknesses available for the Citroen than for the TR.

https://www.yellowboxengineering.co.uk/store/Cylinder-Liner-Gasket-Ring-0-15mm-p129740701

 

http://btwsk.nl/citroen4/files/cylinder_sleeves_2015/2015-10-20 (cylinder lining leakage).pdf

 

 

Charlie.

Edited December 4, 2020 by Charlie D

[Motorsport Mickey]

1 hour ago, Charlie D said:

 

Hello,

I wonder if any TR owners have made their own seals out of PLASTIC sheet. I guess it would be easier to make and cheaper to buy.
What got me thinking was Ian remarking that the FO8 centres were 100mm and I remembered that I'd read somewhere that the design for the TR engine was "Borrowed" from Citroen (I think that is why the measurement is metric.)

I looked up to see how Citroen sealed the bottom of their liners and I discovered these sites.
Interesting that diferent coloured plastic is used for different thicknesses. Also there seems to be a much wider variation in thicknesses available for the Citroen than for the TR.

https://www.yellowboxengineering.co.uk/store/Cylinder-Liner-Gasket-Ring-0-15mm-p129740701

 

http://btwsk.nl/citroen4/files/cylinder_sleeves_2015/2015-10-20 (cylinder lining leakage).pdf

 

 

Charlie.

Hi Charlie,

That's interesting and finding out at what lbs the plastic stops compressing at would be informative, ...but these plastic seals are only torqued to 40 lbs ft (54 NM). I'm not sure they would take another 65 lbs ft on top to make the 105 total. Would the plastic start splitting or deform ? the liners form an integral part of the block stiffness and would the softer material compromise it ?....Hmm.

Mick Richards 

[Charlie D]

Mick,

I understand what you mean about the pressure put on the seal. It may well deform, but then again there is not much space around the seal for it to deform into.

The seal sizes that are supplied range from

0.05 mm === 2 thou inch

to

0.125 mm === 5 thou inch

A lot thinner than the TR metal ones and I guess at that thickness the deforming would be minimal.

I get the impression, from the article, that the original ones were made of paper impregnated with linseed oil.

Different to the TR, but it is amazing how similar the set up is when you look at the Citroen pictures.

 

Also interesting is the way the guy uses an old liner to hone the liner seat in the block. If you have the patience( and its not tooo corroded) it’s a lot cheaper than having a machine shop do it.

 

Charlie.

[BlueTR3A-5EKT]

3 minutes ago, Charlie D said:

Mick,

I understand what you mean about the pressure put on the seal. It may well deform, but then again there is not much space around the seal for it to deform into.

The seal sizes that are supplied range from

0.05 mm === 2 thou inch

to

0.125 mm === 5 thou inch

A lot thinner than the TR metal ones and I guess at that thickness the deforming would be minimal.

I get the impression, from the article, that the original ones were made of paper impregnated with linseed oil.

Different to the TR, but it is amazing how similar the set up is when you look at the Citroen pictures.

 

Also interesting is the way the guy uses an old liner to hone the liner seat in the block. If you have the patience( and its not tooo corroded) it’s a lot cheaper than having a machine shop do it.

 

Charlie.

Renault 4 used wet liners sat on what looked like impregnated paper.  R4 Conrods being the “trick” mod for Austin  7.

Peter W

[Lebro]

Pulled the liners out today, along with the seals, measured tham, & as Mick said they do not compress. they were 19.4 thou before I started, & are still 19.4 !.

Have ordered an A4 sheet of 0.4mm (16 thou) copper, but will be a week or so before I get that, so, wishing to get on, I fitted the steel seals (temporarily), & liners, then made a better way of clamping them evenly, & checked the heights again:

  

front two were 3 thou all round, 3rd was 3.5 - 4 thou, & 4th was 3 thou all round, so with a 16 thou gasket that will be nicely within the range.  next I clamped all 4 liners down, so that I can move on & fit the crank, & pistons etc.

Will fit onto engine stand tomorrow.

Bob.

Edited January 16, 2021 by Lebro

[Motorsport Mickey]

Good progress Bob.

 Just to say when copper received  I wouldn't dare fit the liners without a dry run of head onto block with the copper Fo8s dry fitted and then clamped and measure the heights, it would turbocharge my OCD.

Mick Richards 

[iain]

:-)

me too!

Iain

[Lebro]

Just been reading up on the oil circulation in my original red hardback Triumph TR2 workshop manual (to make sure I had not missed cleaning any oilways - I hadn't), in passing I read that the FO8 seals are "steel with a plastic coating".   Yet my FRE engine, which I know has not been apart since being fitted had copper ones.

I tried to see what TR4's were fitted with (I have that manual too) but there is no detailed description of  the engine in that one.

Bob.

[Lebro]

.

Edited December 5, 2020 by Lebro

[Ralph Whitaker]

23 hours ago, rcreweread said:

What I don't understand is if a manufacturer can make the figure of eights in steel, why can't they also make them in copper - can't the same tooling be used?

And secondly, if there are no 15 thou copper ones available, why ever not ?(SDF????). Because why have steel which WILL  corrode when you can have copper which doesn't, or am I being too simplistic

Cheers a confused Rich

Both Revington and Moss list copper FO8 seals, but only in the one size 18thou. I expect the idea is that the copper will compress slightly and end up at the same as steel 15thou.

Ralph