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Fitting a cylinder liner

keebo

Aluminum
Joined
Dec 31, 2007
Location
Lanc's UK
Hey up
I have to fit and repair a cylinder liner from a motor bike it is a three cylinder engine
1st of all there is a discrepancy in the other two liner heights one is
1.08mm & the other is 1.20mm above the top face of the cylinder barrels

2nd the counter bore that takes the new liner is to deep don't ask me why by 0.75mm our .087mm depending on which of the other two liner I try to match up to

"are you with me up to now"

So I am going to make a spacer to get the liner to the correct height
What material would be best suited for this job
Also would it be best to skim the top of the highest liner and make all three the same height

There are some pictures of the culprits bellow

Kevin
 

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What engine is it?

First, I'd check the manufacturers tolerance on liner protrusion, and make any spacers out of the same material as the block.

FWIW some liner heights are obtained by shimming DESPITE what the manufacturers state,.... they probably don't want to admit to inaccuracies in the basic machining.
 
Hi thanks for the replies
The engine is a Triumph Trident with a big bore kit 1000cc
Iv'e just spoke to my customer he said I must fit and then sort the hight out after
I think I will go for the mean dimension with ally as you said
but still open to sugestions

Kevin
PS with a longer stroke as well
 
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Just a guess Sami but my guess is ether a Trident or Rocket 3. Keebo Is the liner from SRM?

I would think that if the new liner did not match the hight of the other two there would be a problem with the head sealing and might cause it to leak.

James
 
Just a guess Sami but my guess is ether a Trident or Rocket 3. Keebo Is the liner from SRM?

I would think that if the new liner did not match the hight of the other two there would be a problem with the head sealing and might cause it to leak.

James
Thanks guy's
I'm on a mission tomorrow with my customer some sort of alignment job on a paper machine, I will enquire about SRM and get back
As for now I'm out on the lash for next 3 hrs
Thanks kevin
 
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Diesel truck and tractor engines use brass shims under at the top counterbore to set liner protrusion. I would think the motor cycle manufacturer supplies shims.
 
Stupid question :- You have not managed to get the shims / liners in the wrong pots? I just thought I would float this because the discrepancies would make me doubt that the head would seal and the engine would run.
Frank
 
Stupid question :- You have not managed to get the shims / liners in the wrong pots? I just thought I would float this because the discrepancies would make me doubt that the head would seal and the engine would run.
Frank
Hi not sure about mixing things up but the item's came to me with one liner to fit, probably all three liner would have the same dimensions
Kevin
 
I've never heard of shimming liners in ref to motorcycles, or seen anyone offering shims. AFAIK after you install the new liners you just deck the entire assembly to true them up.

I gave up on my R3/T150 projects a couple of years ago and found them a new home. I suspect that I made a wise move. :)

cheers,
Michael
 
I have used cast iron piston rings as spacers for jobs like this. Cut the counter bore to square things up. Install an iron piston ring that is in the ballpark. If the ring presses in correctly you can bore it to size after installation. That is the ID, not the depth. Install all the liners "proud" and mill the block after the install. If the liners require a protrusion for gasket seal then get the counter bores right first.
 
With the spigot type liners you have, it suggests that the top land bears against the head with no gasket, then is surrounded by a composition gasket which crush at torque and seals the compression. If so the top land should be even between the three cylinders, and the gasket will take up the small differences in liner protrusion.
 
One thing that might be worth doing is check the liner heights from the bottom of the cylinder, and not the top. While it's unlikely, there is a "chance" that the aluminum "deck" of the top of the cylinder is not square with the bores.

Of course if one liner is truly "protruding" more (the entire top edge is higher than the entire top edge of the other liner), then there is obviously a height problem that must be solved.
 
These 1000 cc big bore kits for trident/rocket 3 motors are a pain, the bore size does not leave enough material around the liner to hold it in place properly, and you will encounter problems with liners moving inside the cylinder casting.
Check that the two liners that are already fitted are both pressed in fully, and do not be tempted to use too much interference when you fit the other liner.
I would ask the customer for the head gasket and deck the cylinder to suit after all liners are fitted and properly home.
If you are considering building the complete motor for him, don't, unless you have had a lot of experience with these motors.
To say they have reliability problems is an understatement, remember they started out as a 750, and they weren't that reliable at that capacity.
 
These 1000 cc big bore kits for trident/rocket 3 motors are a pain, the bore size does not leave enough material around the liner to hold it in place properly, and you will encounter problems with liners moving inside the cylinder casting.
Check that the two liners that are already fitted are both pressed in fully, and do not be tempted to use too much interference when you fit the other liner.
I would ask the customer for the head gasket and deck the cylinder to suit after all liners are fitted and properly home.
If you are considering building the complete motor for him, don't, unless you have had a lot of experience with these motors.
To say they have reliability problems is an understatement, remember they started out as a 750, and they weren't that reliable at that capacity.
Hi guy's thanks for the replies once again
Tony you say
"do not be tempted to use too much interference when you fit the other liner."
I will be using Nitro -200 deg C to shrink the liner before I fit it
I would think that would help regarding line movenent
Also the liner has a shoulder at the top + protrusion would this not eradicate any movement
Thanks Kevin
PS back in 10 hrs
 
Hi guy's thanks for the replies once again
Tony you say
"do not be tempted to use too much interference when you fit the other liner."
I will be using Nitro -200 deg C to shrink the liner before I fit it
I would think that would help regarding line movenent
Also the liner has a shoulder at the top + protrusion would this not eradicate any movement
Thanks Kevin
PS back in 10 hrs

Kevin I'd be surprised if you need to go to the lengths of -200 deg c Nitro, IME most dry liners are quite an easy drive fit ( heat barrel to say 170c in oven and pull in with a piece of allthread at the most) and are basicly held in place by the top hat.

I'd be concerned the ally might be too thin in places for a super tight fit and cause distortion if not crack.
As has been stated, I agree, IMHO these engines weren't at their best at standard, big bores can only be one thing .... TROUBLE.

Not wishing to rain on your parade, but ''where angels fear to tread'' comes to mind.

ON EDIT another thought, don't try and press out liners on blocks like these, IME the only safe way is to machine them out,....... TIP set the boring bar to leave say a .015 wall then move center .008 - .010 and peel out the strip and collapse the rest.
 
Hi guy's thanks for the replies once again
Tony you say
"do not be tempted to use too much interference when you fit the other liner."
I will be using Nitro -200 deg C to shrink the liner before I fit it
I would think that would help regarding line movenent
Also the liner has a shoulder at the top + protrusion would this not eradicate any movement
Thanks Kevin
PS back in 10 hrs

I should have said distortion, not movement, although I have seen them rotate in the block as well.
I once made a billet cylinder block and used nikasil bores to eradicate this problem, but the problems just moved on to the next weakest point, ie the crank cases.
Even with todays technologies, it is still hard to make them reliable.
I see you are from Lancashire, I don't know how old you are, but the most reliable ones I have ever seen where raced by the bee bee brothers racing team in the 70's and early eighties, and if I remember rightly, they where from your area.
 








 
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