threepots head job

[London_Phil]

Hope were not sucking eggs here, but Please, please, protect the cylinder head mating surface before levering anything against anything, but I'm sure you knew that anyway, I'm just getting very anxious about this, sorry

[threepot]

Got them out! Took about 2hrs. Don't know if there is a orderly way,but took the outside ones out first. I used two nylon faced hammers with rubber handles as levers,and used the middle liner as a fulcrum. A friend helped,and I think this helped,both either side,levering in turn,and some gentle tapping,and plenty of wd40 helps? The middle one was more of a challenge. But we decided to use two thin,angled metal brackets between the liner,and the block,and used two old wood chisels of all things as levers,rocking back and forth,and it did the trick!! This job proves how important regular coolant changes are,as there is hardly any corrosion on the liners,or bolts. Deciding now whether to get liners honed,and fit new rings??

[Sin_Tiger]

So is there an indication of what was holding them?

[Sparky]

Got them out! Took about 2hrs. Don't know if there is a orderly way,but took the outside ones out first. I used two nylon faced hammers with rubber handles as levers,and used the middle liner as a fulcrum. A friend helped,and I think this helped,both either side,levering in turn,and some gentle tapping,and plenty of wd40 helps? The middle one was more of a challenge. But we decided to use two thin,angled metal brackets between the liner,and the block,and used two old wood chisels of all things as levers,rocking back and forth,and it did the trick!! This job proves how important regular coolant changes are,as there is hardly any corrosion on the liners,or bolts. Deciding now whether to get liners honed,and fit new rings??

My .02

I would get the liners honed, new rings, wrist pins and circlips then you're good for a while.

[JayDub]

Deciding now whether to get liners honed,and fit new rings??

Well done Mark,  give her a treat, she's served you well... but the bores sound OK, if they're not glazed and are still cross-hatched like you say, maybe just rings and gudgeons etc.  Saves a job in the future.

[Sin_Tiger]

Wipe the bores with a clean white cloth soaked in white vinegar. Run the back of your finger nail over the surface, if you can juuuuust detect the surface you're good to go.

Enthusiasm, rotary stones and a power drill = disaster. If it wasn't burning oil before, it won't now.

[threepot]

Swansea Auto,a local auto machine shop,quoted £5 per liner to hone. Not done a full examination,but some xhatch does seem to have worn away?

[JayDub]

Swansea Auto,a local auto machine shop,quoted £5 per liner to hone. Not done a full examination,but some xhatch does seem to have worn away?

For the sake of 15 quid?

[Sin_Tiger]

My advice, if you can still see the cross hatch, leave it. I've never come across anyone with proper line boring machines that charge the service out at £15 an hour, stay well away 

[threepot]

My advice, if you can still see the cross hatch, leave it. I've never come across anyone with proper line boring machines that charge the service out at £15 an hour, stay well away 

When I phoned for a price,he did ask me the mileage. I told him 50k,he said not to bother. Not having it done will save me about £140. I could still check the ring gap inside the bores?

[Sin_Tiger]

Apologies now if I'm beginning to sound like a stuck record on this subject but I feel it's important that anyone considering going at the surface of any cylinder liner understands the implications of what they do. It just so happens that I'm doing this in your thread, nothing personal  :icon_wink:

Cast iron / steel cylinder bores (chromed and Nikasil are a different kettle of fish) are machined with a fine matrix of grooves designed to aid distribution and retention of oil as cylinder lubricant for the pistons and rings, commonly referred to as "Honing". The pattern may appear random but is actually precisely carried out on a rigid line boring machine, with the pattern, angle, depth and pitch carefully calculated based on the average piston speeds, mean cylinder effective pressure (MEP), piston ring material and pressure, fuel ratings and lubrication and it's additive pack to mention just a few factors involved.

"Glazing" as a built up coating that can appear in use on the cylinder surface, is a chemically created deposit as a result of reaction between the cylinder lubricant and fuel during the combustion cycle, the results are rarely remotely similar even in identical engines. This deposit can adversely affect the effectiveness of the cylinder lubrication, so if it's above a certain level it should be removed, restoring the efficiency of combustion and lubrication can reduce lighter coatings in many cases without resort to mechanical intervention.

Lighter "glaze" coatings can often be removed with the use of a mild acid. If mechanical removal of a "glaze" coating is found necessary, it must be carried out very carefully to prevent damage to the original cylinder bore surface. Once the interface between the "glaze" and the bore surface has been breached, the abrasive material will begin to affect the surface finish. If the end result leaves you with a dull mat finish that is smooth and the "honing" marks cannot be seen and detected by touch, you might as well scrap the liner as back in use that cylinder will not produce it's full power and wear will be greatly accelerated.

In short, this is not something I would undertake unless absolutely certain of the circumstances. It would be unfair to cast aspersions on a workshop without knowing a lot more of the circumstances but consider this, as a minimum I would carry out glaze removal using a lathe, very slowly so as to monitor the surface carefully. I wouldn't expect to take less than an hour on each liner, what's the minimum wage?

Said my piece, I hope some of it is informative to someone, I'll get my anorak and go for a brew now 

[threepot]

So is there an indication of what was holding them?

Just put it down to them being a 'snug' fit? And the fact that any effort exerted needs to be upward,which is not easy. Surprised Triumph didn't come up with a tool? Some good ideas on here if you do search You could use an engineers clamp on the middle liner using the 2 flat edges just to give them a twist to break the seal?
I checked the 'top' rings in their relevant liners earlier,and ring gaps ranged from 0.4 - 0.43 top and bottom of the bore.
Haynes state the gap spec 0.2 - 0.41. But also states the end gap is not critical unless it exceeds 1mm?


Tried to buy a 'rubber test plug' yesterday,but couldn't get one within bore size. Plumbers use them for blocking waste pipes etc. But I have seen them on eBay within size. Could be adapted to use as a tool?

[Timbox2]

Just put it down to them being a 'snug' fit? And the fact that any effort exerted needs to be upward,which is not easy. Surprised Triumph didn't come up with a tool? Some good ideas on here if you do search You could use an engineers clamp on the middle liner using the 2 flat edges just to give them a twist to break the seal?
I checked the 'top' ring in its relevant liner earlier,and ring gaps ranged from 0.4 - 0.43 top and bottom of the bore.
Haynes state the gap spec 0.2 - 0.41. But also states the end gap is not critical unless it exceeds 1mm?

They did a tool for the 955 Engine, T3880315, but the 955 engine has a 3mm larger bore so I guess it doesnt fit. Interestingly I have a T300 service manual and it does say remove using "Hand force only"

[threepot]

From my experience,I'd think you'd struggle to get the liners out by hand only??  I did notice a small amount of carbon build up where the liners fit into the engine block? Hundreds of heat cycles must have some effect?
My 'gripe' about this situation is,that Triumph must know about the about the 'soft' valve issue that can effect early bikes,but they don't seem to recognise it,and still charge a 'premium' on parts to resolve it!

[Bixxer Bob]

Worth a try ST? Their so 'snug',I'm sure I could've left them? But after trying to get them out,got my doubts now? Not sure how much movement breaks the seal?     Also,Didn't expect the pistons to clean up so well in situ.

Clive covered prising them out on the course but i'm buggered if I can remember now.  Why not just drop him an email?

I think it was left right then centre so you can lever against the centre one for the other two then have plenty of room around it to work it loose.  And I think it involved a large flat blade screwdriver under the lip at the top and a packing piece to stop it marking the block, if you get my drift