Problems with 89mm liners and FO 8 gaskets

[Benstag]

Hi I'm a newbie and after some help and advice please,

 

I'm rebuilding my engine on my 1962 TR4 but have hit a problem with getting the correct liner protrusion with my new 89mm liners.

I've done some measurements of new liner versus old placed in the block with no FO 8 gasket just to try and determine what thickness of gasket I would need. with the old liners they sit 0.012" below the surface of the block and the new liners 0.017 below the surface.

The steel FO 8 gaskets I received in my gasket set are 0.014" so give 0.002" protrusion with the old liners, but -0.003" below the surface with the new liners. The original copper FO 8 gaskets are I believe around 0.018" thick but compress down so would start out at 0.006" protrusion with the old liners, but 0.001" with the new liners so I guess would probably blow the head gasket.

 

Would the Wellseal add any measurable thickness to a copper FO8 gasket ???

The vendor who supplied the liners suggested machining the top of the block !! but also claim they can source 0.023" steel FO 8's but won't have them at their warehouse in Germany until some time in Jan, by the time these arrive in the UK I'm guessing it will be Feb and I was hoping to complete the build over the Christmas break. Also I'm concerned that 0.023" FO 8 gaskets will give us too much protrusion (0.006") ?

 

Also does any one know a factory tolerance for the height of the liners ? (My original liners measure 4.485 " from the top to the shoulder)

 

Any thought or ideas greatly appreciated.

 

Thanks Jeff

[Motorsport Mickey]

Hi Jeff,

 

Well unless very fortunate you'll not be completing the build during the Xmas break.

 

Carry out a search in the Forum section "Liner height protrusion" and you'll find about 8 threads (with comprehensive postings from myself and others) on how to carry out the liners resetting. Doesn't matter if the liners are 86/87 or 89mm liners all will be to the same dimensions (other than bores), but you need to actually fit the liners on FO8 gaskets dry (doesn't matter which gaskets, you need dimensions to make decisions). I would always use copper, they don't compress a buqqer and more importantly don't corrode.

 

Have a read and then post again (I'm here all night) and we'll go through the process in easytime.

 

Mick Richards

Edited December 22, 2015 by Motorsport Mickey

[RogerH]

Hi Jeff,

the Welseal will add nothing to the Fo8 thickness.

I'm not a fan of steel gaskets.

TRy and get Copper if you can.

 

I'm sure I have read somewhere that Revingotns or Racetorations do various thicknesses.

 

When I get back form my Chrissy hols I'll measure my old and new liners and see if they mimic yours at all.

 

Roger

Edited December 22, 2015 by RogerH

[Motorsport Mickey]

In case you have difficulties finding one of the threads, here's one I made.

 

 

 

Lots of variations there, I never trust liner heights until they are built up (dry fitted) and clamped with head and old gasket.

Select which FO8s you want steel or copper and do the build (dry) and clamp into position with head and gasket. Remove the head and gasket and clamp the liners with large washers and old gudgeon pins on the studs in between the liners, torque to 40lb ft. Then measure at 4 points around the liners (unless you are good with feeler gauges (I am) use a depth micrometer instead (I do, you can get repeatable numbers easily and quickly). You are looking for between 3 and 5 thou as the liner heights for all liners. If you have 5.5.5.5. you are good to go, if you are 5.5.3.5. it's likely the reduction in clamp pressure where it shows only 3 may give you a blown gasket in the future. If you have 5.5.5.3. it's possible to get away with it, the end liners have no support for the head and it will deform and increase the clamping force there and help compensate for the low height.

 

HOWEVER this all depends what the top of the block is like. Too many imponderables, I would skim the block first 5 thou before the dry build then you know it's parallel to the crank centre line (assuming your engineering firm doesn't just clock the top surface). Then you can make decisions as the dimensions are established when building.

If you want to cut out a process fit the liners (dry) on your chosen FO8s (steel or copper)and clamp into position as above with head and old gasket, IF the liners are then solid when head is removed without any retaining clamps then ask engineering shop to skim 8 thou from top of the liners and block. Then remove the liners after marking their position 1.2.3.4. and orientation Front marked, (I used to get the engineering shop to phone me and I'd do it whilst the block was on their miller) with pullers, and ask them to skim another 5 thou from the top.

Take it all back home and rebuild the engine with the same components but now with sealer at the FO8 position, clamp with head and old gasket, remove head clamp liners into position at 40 lb ft and fit rods with pistons, measure piston tops from top of liners, remove rods and pistons, deck your pistons and you are on your way.

 

Mick Richards

[Motorsport Mickey]

And another posting with similar but some additional info.

 

 

Quite common for the gasket to fail at number 4, check the search facility for details.

 

However bottom line is No 4 runs the hottest (furthest from the water pump and is fed hotter water because of it). The excess heat allows deformation of the rear of the block after many hundreds and thousands of stop start cycles and hot/cold/hot cause the studs to lift the block material at the rear. This reduces the clearance on the rear liner to the block and also it's clamping force, hence it blows the gasket.

As Ian says clamp the liners in position using tubes or old gudgeon pins and washers on the studs inbetween where the conjoined liners are. Apply a minimum of 40lbs ft here and then measure the liner protrudences around the liners to the block face.

Measure in 4 positions around the liner top (depth micrometer if possible but a straight edge and feeler gauges if you can use them well) and write it on the liners tops in permanent marker. You are looking for an even measurement in between 3 and 5 thou around each liner and equal if possible along them all ie 4 4 4 4. You can get away with a small run out ie 4 4 4 3 tapering to one of the ends, because the seemingly massive head casting can and will deform under torqueing, (there are no other liners at the ends the same height to prevent it) and take it up. But if the height reduction in a liner clamp is between two liners in the centre of the block eg 4 4 3 4 they prevent the head deforming and correspondingly the pressure and liner clamp is reduced and allows a future possible gasket blow.

Check the head inbetween the valves for cracks and also the waterway in the centre of the block on the web and the corresponding holes close together in the centre of the head.

 

Mick Richards

[Motorsport Mickey]

And another, as I said there is about 8 threads under Liner Height with this and other information on it, but there's a fair bit of measuring and decision making to be done before you can progress successfully.

 

 

 

 

If you have a low liner between +3 and +5 dimension you have to machine the other taller liners to the same dimension. +3 will give an acceptable "clamp" by the head onto the gasket and then the cylinder liner, if you have taller liners alongside it (ie +5) then the clamp pressure would be compromised and this is a weak spot on the gasket seal.

 

If you have had the liners out recently and cleaned the block (like you have) then this operation is easy.

 

1) Make your measurements and mark on the liners in felt tip, mark the liners for position and orientation.

 

2) No need to clamp liners they are being removed, drop sump, undo caps, push out pistons, protect journals and crank against water and ****.

 

3) Push out liners from below in pairs, or use a puller as described before, should be easy. Mark the liners with permanent marker (inside bore is good) with the amount to be taken off them (probably only a thou or 2 max).

 

4) Take the liners to the engineering shop and ask them to remove enough material from the top of the bigger liners to make them sit the same height up as the lowest liner. Grab the machine shop receptionist by the lapels and shout at him... ONLY TAKE THE AMOUNT OFF THE LINERS I HAVE TOLD YOU, DO NOT MEASURE THE HEIGHT OF THE LINERS FROM TOP TO THE SHOULDER ON EACH AND MAKE THEM ALL THE SAME, IT IS UNLIKELY THAT THEY NOW ALL SIT THE SAME AMOUNT DOWN IN THE BLOCK. You only provide all the liners to give them a datum for measuring and comparison.

 

5) Upon receipt of machined liners clean the block internals, fit liners in block in their correct order and in their correct orientation as per manual with new F of 8 gaskets the same thickness as before upon your choice of sealing gasket goo.

 

6) Fit cylinder head and torque down to the correct 105lb ft figures using the correct tightening sequence. Remove the cylinder head, fit retaining washers over the siamesed area of the liners or how you want to and retorque down these washers to at least 40/50lbs to keep the liners seated.

 

7) Measure the liner height protrusion with a depth micrometer along the cylinder block over and around the liners in 4 positions around liners 1/2/3/4 which should all now be sitting between +3 to +5 high. A figure of +3 will give satisfactory clamping force as long as it is replicated over the other liners also.

 

8) If you have a weird reading on one of the liner heights plus a couple of thou on one of the measuring points you should suspect a piece of grit has fallen onto the F of 8 sealing face, pull the liner (pair)clean off and refit as before.

 

9) As long as the cylinder block face in flat and the cylinder head studs have not pulled up the surface of the block (check, if the block has swelled around a stud you can hand relieve in that area to remove a couple of thou so that the gasket clamp is not compromised) the gasket will seal. Make sure cylinder head does not rest on the water pump, it can stop the head torqueing up.

 

Carry out rest of rebuild, go for drive check fluids, retorque engine after 500 miles as per manual.

 

Mick Richards

[Benstag]

Hi Mick and Roger,

 

Many thanks for your advice and information,

 

I'm still a little apprehensive about taking the block and having it machined to suit the low liners, and at the moment I'm considering obtaining some of the copper FO8's and conducting a dry fit as you suggest above and if that ends up with not reaching between the 0.003 and 0.005 protrusion then waiting for the 0.023" FO8's from the original liner vendor. Though I'll also try Revingtons or Racetorations, as you suggested Roger, to see what they can offer.

 

It's just frustrating that the new liners are 0.005" shorter than the originals, though I guess they would probably be within the original factory tolerances if I could find that detailed somewhere.

 

Another TR4 owner did mention that his 89mm piston and liner kit was supplied a set of FO8 gaskets which is curious as you would need a bottom end gasket set which contains FO8's anyway to fit them so I wondered if this was because a thicker FO8 gasket is needed as the norm with 89mm liner kits.

 

Also for the dry fit I don't have an old head gasket to use and don't want to use the new gasket I have, I was considering using a sheet of 2mm thick polypropylene and cutting the stud holes in it, do you see any problems with this ?

[Motorsport Mickey]

Jeff,

 

The block is quite likely to have stretched or relaxed in the last 50 or so years and as some of the posts suggest the liners are likely to be seating slightly differently. It's quite common either to be machining the block top or the liners individually, in fact because of the hundreds of thousands of hot/cold cycles it's not unusual for the rear of the block to have lifted by a couple of thou and by so doing releasing the gasket clamp there.

 

No need to be apprehensive about any of the machining work, it's all easily achieved by a good engineering firm but you have to have a datum to work from. If you follow the advice on the posts above regarding fitting the liners and measuring you can then be assured that your decisions of what to machine will be correct and the engine will go back together reliably. The dynamic nature of an engine including gaskets and stretching components means for a reliable build you can't measure the components first and by juggling the clearances arrive at a dry figure which is correct.

 

Take it one step at a time, liners upon copper FO8 gaskets fitted dry, don't worry about not having a head gasket I'd rather the head pushed the liners onto the FO8s reliably than use polypropylene which may allow the liners to impress into it on the top. Then measure the liner height as described at 4 points around the circumference of each liner and record it on the top, Note: mark each liner with front towards the front of the engine and number them 1.2.3.4. (normally I do it inside on the bores) and keep the liners in that orientation.

When you have measured the liner protrusion (1 thou as you think, but I wouldn't be surprised to see different figures) you can start to make sensible decisions. If you can get the 23thou FO8 gaskets to do this it would be good allowing a few more thou clearance for measuring purposes in case the liners push down further than you think. Taking 5 thou off the top of the block is not difficult and helps true the face up removing any lifted surfaces to allow accurate fitting which then also allows the liners to be measured and machined accurately.

 

Mick Richards

Edited December 23, 2015 by Motorsport Mickey

[graeme]

Jeff,

 

Welcome to the Forum. When I fitted 89mm liners I used Revingtons copper Fo8 gaskets which are .018" thick which gave me the correct deck/liner height. As others have said, don't be tempted to use steel Fo8 gaskets as they corrode rapidly.

 

http://www.revingtontr.com/shop/product_display.asp?mscssid=TALM52GW2MHJ8HQT6S3P5SCWWLR13A7F&CarType=TR4A&ProductID=112789

 

Cheers

Graeme

[PeteT]

Hi Jeff,

 

Listen to Mick Richards. He's the dogs danglies on this topic. Followed his advice with my rebuild including skimming the block and pistons and my engine is fabulous. Goes like the clappers and torque up from 117 to 130. The guys a genius.

 

Regards, Pete

[Benstag]

Thank you all for the warm welcome to the club forum, and special thanks to Mick and Roger for their invaluable advice and technical support.

 

I've been out of action for the last few days after picking up the dreaded lurgy (Man Flu as my wife puts it) but did manage to talk to TR Shop on the copper FO8's, they were extremely helpful and went and measured some of their stock which looks like its 0.019" to 0.020". The plan is to go and visit their shop next Tuesday / Wednesday and pick up the copper FO8's (The post could take forever and I need to pick up other parts anyway).

 

I'll then follow the procedure Mick has outlined and if required will take the block to be decked at the machine shop that worked on the crank for us, assuming they have the right equipment to perform the work.

 

The TR4 engine rebuild is starting to feel like far more work than when I rebuilt my Stag engine, or Spitfire / GT6 engines in the past.

 

Anyway I wish you all a very Merry Christmas and a Happy new Year, and will keep you updated on progress as I move forward on the project.

 

Regards

 

Jeff

[Motorsport Mickey]

Hi Jeff,

 

Sounds like a plan.

The 4 cylinder TR engine is of a design of it's time and although different with it's removable liners has the major advantage of being almost ultimately rebuildable. It also has the major advantage of once being rebuilt correctly will last for decades and many thousands of miles with the absolute minimum of servicing, whilst some of the other cars of classic status are more like "babies in a high chair" meaning you can never leave them alone they always require attention !

The attention TRs enjoy most is of being driven and I'm sure yours will come together well, when you've made your measurements if you want to discuss which way to go drop me a Personal Message (click my avatar picture and select send me a message from the options) and we'll discuss your best method to suit what you've got.

Have a Merry Christmas and New Year confident in the knowledge that the engine can be sorted to an excellent standard.

 

Mick Richards