3a engine figure of 8 gaskets

[Wsl]

Before rebuilding my 3a engine I asked Daryl at Racetorations, and he informed me that they do not use figure of 8 gaskets, and haven’t done so for over 30 years, with no problems at al all. Any thoughts on this.

John

[RogerH]

How do they get the top of the liner to sit apprx 0.004" high.?

Do it properly and fit the Fo8's

 

Roger

[John Morrison]

12 minutes ago, Wsl said:

Before rebuilding my 3a engine I asked Daryl at Racetorations, and he informed me that they do not use figure of 8 gaskets, and haven’t done so for over 30 years, with no problems at al all. Any thoughts on this.

John

What do they use instead?

John

[Wsl]

Thanks roger, They (Racetorations) just Welseal the liners in compress them down, machine the block, and liners flush, and treat it like a standard conventional engine. They have been doing it this way, with no problems for over 30 years. Racetorations have an excellent reputation, and long experience, in the TR world. After all why does the TR engine need .004 cylinder protrusion, maybe it’s fo8 compression problems, I have left mine out, and gone along with the Racetorations line.

John

 

 

[RogerH]

Hi John,

I can see that would remove one area of concern. The Fo8's are always a worry.

The 0.004" liner protrusion gives a good grip on the head gasket/liner to ensure a water tight fit.

Keep us updated on your journey.

 

Roger

[trchris]

Makes some sense doing this however if they machine the block and liners flush how do the achieve a clamping force to seal the lower liner face and block?

Chris

 

[Motorsport Mickey]

Darryl has great knowledge and is very innovative especially with race engines.

As we know if the liner size goes over 89mm piston size (92mm has been used on race engines…and admitted too) the liner skirt below the shoulder becomes very thin and “crystal” like and easy to damage. Liners of the largest dia often are different having the skirt machined off and are “glued” into position, having the bottom dia a closer fit than the standard “ easy slide” and then fixed into position.
The liner shoulders in a standard 50 year old block have settled/lifted/twisted and present the liners when inserted to the block surface…like Ken Dodds teeth !
This requires block machining also to ensure the shoulder presents the liner shoulder square in both planes.
I have had the block shoulders machined a couple of blocks on the shoulders, about 1 hour set up for the block and 15 mins each bore to remove about 2 thou and remake them all square. 

Triumph did a great job originally, the wet liner kits allow individual replacement and the standard copper/ asbestos/ copper gasket a wide compression range. It goes in new at 40 thou and comes out compressed at 30 thou which allows a generous spread to get an individual clamp onto and around either liner.

Bottom line if you fit liners without a protrusion after removing the Figure of 8 gaskets ( there to ease “ batch machining practice” ) you need a gasket with a fire ring to give a good compression seal of the 180 lbs or thereabouts liner compressions. That also ( hopefully) will transfer enough clamping pressure through the liners into the shoulders and blocks. The copper Fo8 gaskets are obviously softer than the block material and so encourage a sealing face there. 
It wouldn’t frighten me to run a flush block but unless your block is better than most I’ve seen, to achieve over 100k like I have on 2 engines currently running,  without prior preparation I’d be “ gum sucking”.

Mick Richards

Edited August 13, 2023 by Motorsport Mickey

[Hamish]

A few are machining the block to do away with the fig 8 mine is. 
i think going this route is the block machining that is critical. 
 

without this accurate work stick with the fig 8’s and standard practice you only have to do the job every 40 or 50 years. 

[Wsl]

Thank you so much for all your ideas, interesting to hear different views. I have no f08 gaskets fitted, and the liners are machined flush with the block. I am now on my second gasket failure, one might think that this is the reason for the failures. I have just removed the head again. But the failure appears to be at a different point on  the gasket each time,  not around the fire ring. The gaskets that I have used are Payen (black colour) non copper, with steel fire ring, the actual gasket material, the black coating, seems to have failed, I have 87mm liners, and these gaskets seem to have an overly large bore size. Anyone had trouble with these gaskets?  Maybe better to go back to the 60’s and use an 83mm standard gasket, as long as it doesn’t encroach into the bore + a head skim (don’t think it’s ever been skimmed). Will report back, thanks for all your ideas, please keep them coming.

John 

 

[RogerH]

Hi John,

Why not just fit an  ordinary copper/composite gasket for an 87mm piston. Unless of course if the engine is a little uprated.

 

Roger

[Motorsport Mickey]

If it’s not failing on the 180 lb compression seal on the fire ring, then it shouldn’t fail on the 14 lb (or whatever your rad cap is) pressure being applied around the water jacket sealing areas.

However it’s not to be underestimated how much beneficial block stressing 4 thou liner protrusion puts into the block, helping prevent fretting.

This is a block that only has a thinnish web ( often cracked) in the centre top to tie both sides of the block together. This why the factory designed 4 steel cast towers under lot’s of compression, running top to bottom trapped between head and the liner shoulders machined into the block base… it is not accidental.
If the block liner shoulders have been machined square in both planes it should be fine.
If it was my engine I would pull the liners, mark each one inside each bore with permanent marker pen 1.2.3.4. and F to show the front of each liner when fitted. Buy copper Figure of 8 gaskets. Measure the Fo8 thickness, have the liners skimmed off by the appropriate amount, ( do it yourself even with a granite surface and stick on wet and dry sandpaper.
DRY fit the Fo8 gaskets and fit an old head gasket and the head, and pull down the liners to 105 lb. Remove the head and old head gasket and retain the liners with big washers where the liner siameses like this OO OO torqued to about 40 lbs ft ( not critical).Measure the liner protrusion at 2 positions each side on each liner to the block top surface. If you get 3.3.3.3. Or 4.4.4.4. Or 5.5.5.5. You are good to go. 
Pull the liners and apply Wellseal to each surface, liner shoulder on the block, also the mating underneath surface of the copper Fo8 gasket, and the topside of the Fo8 gasket, and then the underside of the liner shoulder which goes on top of the Fo8 gasket. I don’t worry about the combined thickness of Wellseal, 105 lb ft torque will see bugger all (microns) remain on the gaskets, just enough to retard corrosion.

Refit the liners in the appropriate orientation as shown on your permanent marker and to the front. Use a standard copper/asbestos/copper composite gasket which will allow 87mm piston Dias, DON’T USE AN 83mm HEAD GASKET, and apply Wellseal to ALL MATING SURFACES. Cylinder head surface, block and liner top surface, and both sides of the head gasket. Line the gasket up on the block for the cylinder head studs ( try not to squirm the gasket about), and screw the cleaned studs down through the gasket into the block. The fit the cylinder head over the studs and torque the head in the appropriate sequence as per manual. Use 3 torque figures, say 40/80/105 lbs ft and then refit all the other parts for engine running.
Then I'd complete 200 miles and carry out a retorque on the head, undo all the nuts ONE flat to avoid sticking friction when tightening, and retorque up to 105 lb ft in the recommended sequence. Fit all other bits and drive engine. Works for me, …over 23 engines.

Mick Richards

Edited December 6, 2023 by Motorsport Mickey

[Wsl]

Hmmm.. Thank you Mick for that very detailed approach, which I think will solve the problem. However I was hoping to do this work without pulling the liners out, although I did not have the liner seat machined, I just Welsealed them in and had the top of the block/ liners machined. To be honest, the top of the liners look ok and have remained flush with the top of the block. I am concerned though with the head, it does have a large crack along the centre web, I will have a word with Peter Burgess this morning to see if this can be repaired (correctly). I will also consider Roger’s suggestion, fitting a standard copper composite gasket. Incidentally, my bores are 87mm. But the bore size of the Payen (black) gaskets are 91.5 mm, seems a little too large to me, possibly because the Payen gasket bores are circular, whereas the bore of the standard copper gaskets are shaped, more or less, to fit the combustion chambers. 

Once again thank you for all your advice, especially Mick’s very detailed, and informative approach. I’ve been around TR3’s for forty years and still leaning obout them.

John

[Lebro]

I fitted standard TR4 composite 86mm head gasket to my 87mm engine  even though I had opened up the area around the inlet valves it still covered ok.

Bob

[Motorsport Mickey]

John, 

The liners need to be fixed by force in a downward direction. Example:

Some owners try and pull the liners down by using the securing large washers in the siamesed positions ie OO OO instead of using the cylinder head… it don’t work…I experimented and tried measuring heights with and without head clamping.
The head clamping method on liners sitting approx 4 thou high, consistently pushes down the liners further than the washers do until the liner and Fo8 gaskets are compressed below correctly. This gives the block rigidity tying the head and block together on sealing surfaces.

My comment on my other post, regarding the original seats liner presentation as being like Ken Dodds teeth, is a humorous description ( I hope) giving a mental picture of their orientation to vertical in 2 planes. They are nowhere near vertical. The past 50 years of the engine being driven and the block getting hot and then cold has stress relieved it, and moved the internal liner shoulders. The liners now are likely only sitting on 3/4 of the liner shoulder machined in the block. The liner spigots are a slide fit ( about 2 thou clearance) in the block, which allows the liners to “ self centre” and seal when pressed down firmly ( 105 lb ft on a 4 thou liner height does it). Your liners are loosely placed in the block directly on the block shoulders and then were presumably machined flat along with the block deck ? The liners will have moved… there is nothing preventing that, when they are in position thrust your fist into the bores and pull and push the liners… they will move and lean in different directions. You now have not only no liner compressive securing, but the outside liner bores in the block that is attached to the block liner shoulder is a loose fit on the liners. Your flat deck top with no protrusion is spreading the 105 lb ft across the block and the liner is shuffling aroundwards . See the problem ? That's why your water leak is from different places on the waterjacket from deck top to the head.

Mick Richards

PS: The cracked web in the top of the block is likely still sound, the crack being superficial. If we are talking a road engine without humongous power going to be extracted it wouldn’t bother me. I’ve rebuilt 6 or 7 like that after pointing it out to owners, none appear to have problems.

Edited August 18, 2023 by Motorsport Mickey
Clarification.

[Wsl]

Thanks Mick

Do you think that this could be done with the engine in situ? Because taking it out is such a painful process, apron off etc…been there before . Also, are the f08 washers expected to take up all of the unevenness of the liner shoulders ?

regards John 

[Drewmotty]

I’ve changed FO8s with the block in situe but I don’t think it was worth it. The efforts required to keep the crank clean just aren’t worth it. 

[RogerH]

Hi John,

taking the  engine out with the GB makes life easy to  do the delicate/precision work.

The block shoulder that holds the liners need to be clean and as flat  as possible.  Any deep corrosion can be filled with JBWeld to help support the Fo8

I made a crazy tool that allowed the shoulder to be rubbed down with wet&dry and being held square.

Ideally the shoulders should be machined flat

Do try and get the liners set as per Motorsport Mickey's instruction.

I use a length of 1/2" diameter silver steel and feeler gauges to measure the liner protrusion.

 

Roger

[Hamish]

Gudgeon pins are useful spacers to hold liners in place with big washers. 

[Drewmotty]

Good advice above.
Be especially diligent in cleaning out the corners of liner locations in block. Even a small fillet of rust or debris will make a difference. 

[Chilliman]

11 minutes ago, Drewmotty said:

Be especially diligent in cleaning out the corners of liner locations in block. Even a small fillet of rust or debris will make a difference. 

Especially if you are using the thicker liners supplied by Daryl or indeed the ones Moss now provide at 2mm thicker, I've just built an engine with a set of these & it took a lot of effort fitting & refitting to get them sat completely down in order to get the protrusion precise. the lower outer edge tends to snag just a minute amount which is enough to throw everything out even using the head to torque down each time.

[Motorsport Mickey]

5 hours ago, Wsl said:

Thanks Mick

Do you think that this could be done with the engine in situ? Because taking it out is such a painful process, apron off etc…been there before . Also, are the f08 washers expected to take up all of the unevenness of the liner shoulders ?

regards John 

Piece of cake.

Place-car on ramps or jackstands.

 Drop oil from sump

Drop sump, drop oil pump. mop conrods and crank inside crankcase with non fluffy rag to remove worst of standing oil.

Undo big ends and push conrods up past and around the crankshaft and out of the top of the liners… carefully, no broken piston rings here or dings put into ground crank surfaces.

Repeat after me… Cling film ( sandwich wrap) is my friend.
Tear 8 pieces off big enough to wrap each big end in 2 pieces, offset so the film joints are hidden. also cover the joins around the crank into mains bearings etc with wrap to avoid dirt ingress.

If you have liners in situ for more than2 or 3 years they often form the opinion they are now part of the block…and want to stay there. However at under 12 months fitted you can make a small extractor from an alloy plug about 3/4” thick and -10 thou down on the liner inner dia and with an outer dia of -10 on the block bore and feed a 1/2” threaded rod down the liner and fit through the centre of the plugs with 2 nuts behind it, and through a heavy duty channel on the block deck draw the liners up vertical about 2” and then wiggle them out. (On holiday at present, will post photo of tool on Friday).
Obviously keep the pistons and conrods oriented And numbered 1-4.

Buy your copper Fo8 gaskets and fit dry onto the cleaned Fo8 shoulders machined into the block that you’ve now got Wellseal on. Refit the cleaned liners in order and orientation and use an old cleaned head gasket under the head and torque down to 105 lb ft.

Remove the head and measure in 2 position on each side of the liners down the cylinders and mark on the liners. Remove the liners, mark 1.2.3.4 and the front ( leave the fo8 in the block.) and have the liners machined down to leave 4 thou protrudence. Refit the liners in their position and orientation on the prefitted DRY Fo8s and using the old clean head gasket and the head retorque down again to 105 lb ft. To avoid rippling the new gasket ( when you fit it) torque it in 3 stages, 40/80/105 lb ft or similar, get in the habit.

Then recheck the liner heights, NEVER trust a machine shop. We are looking for 3.3.3.3 OR 4.4.4.4 OR 5.5.5.5 all will give a good clamping force with a copper/asbestos/copper Payen standard gasket at up to 87mm piston dia. Because of the pre noted block heat stress releasing you often find an odd thou mismatch caused by the aforementioned liner lean. Depending where it is depends upon how and if it needs attending to. Measure and advise and we can decide.

When dimensions are good refer to above posts regarding Wellseal applying, and how to refit the head.

Remove the clingfilm and inspect for dirt before replacing pistons and oil pump and sump. I reckon to do this work within a couple of days depending upon liner alteration.

If you don’t have the block liner shoulders recut square that’s the reason for measuring around the liner in 4 places ( 2 each side). You will give instructions to the machine shop ( or skim yourself with wet and dry) to skim an uneven amount off, tailoring the top surface to give an even liner protrusion around it’s circumference. That’s how I hand fettle my engines together.

Mick Richards

Edited August 14, 2023 by Motorsport Mickey

[stuart]

FWIW with reference to Racetorations not using FO8s Stanwood engineering in Bawtry do their blocks and they glue the liners in once everything is machined. I know Alan Coote had his TR2 engine done there and he was very sceptical about it but it worked fine and it was a great engine.

Stuart.

[Wsl]

Thanks Stuart, interesting Daryl omitted to inform me that I needed to rework the shoulders.

Thank you Mick, collected my copper fo8 gaskets from Moss, said to be 18 thou. Tomorrow car over my pit, drop sump, remove oil pump, and pistons, cling film crank ( top tip that ). I will then try to remove the liners. These liners have been in for about 5 or 6 years, but I don’t think I will have a big problem because I use Ford 100% Superplus coolant, and there will be no corrosion at all or any sludge, it is really good. I am going to follow your instructions, one exception, when I dry fit the liners 40.80.105, I will probably leave them for a few days, check clearance’s , and take off what I need by hand, with 600/400 grit wet/dry. Will keep you posted. Thanks Mick for all your help and advice.

regards John

 

[Nigel C]

Roger "I made a crazy tool that allowed the shoulder to be rubbed down with wet&dry and being held square"

I did too, worked a treat......

Very informative as always Motorsport Mickey 

[Wsl]

Hi Nigel C. Just what does this tool look like, because I am about to embark on this. Today I have the car over my pit, dropped the sump off and the oil pump off. Tomorrow pistons out, clingfilm crank; I am now trying to improvise a tool for extracting the liners - trying to cobble something up from the bits lying around the workshop. So any ideas would be appreciated.

John