100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

[p38arover]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

A dead bug.

A comment was made to me that is it possible that turbodave's engine had been overheated by the previous owner and would this have had an effect on the liners?

 

[turbodave]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

Anything's possible.

However - what does overheating actually do? it doesn't magically change the propeties of alloy to grow, (and stay at this increased size) by a certain percentage in a uniform direction (radially outwards from each cylinder bore) whilst retaining perfect concentricity of these bores...

If these things were designed to slide freely, and now they don't because the block is slightly twisted, would make sense.

But to say the situation seen here is because the block was overheated, simply suggests to me that your buddy hasn't thought too long about the basic engineering or metalurgy fundamentals behind his comment

From my own experience of the engine - it had all the original hoses, rad, thermostat, hose clamps, water pump, etc. There was nothing in there that suggested to me that there was anything amiss. Also - has an overheated Rover ever not needed head gaskets? I am very confident that those heads had never come off before I got into it.

All I can suggest is that if anyone else has a spare block (ideally a 2003/2004) then stick it on your grill and see what happens - the more inputs the greater the knowledge.
Perhaps someone also has a spare (scrap) alloy block with iron liners from a different manufacturer - that could be a benchmark of how hot the block needs to be for the liners to slide out...

 

[Bosbefok]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

I believe that overheating the engine is the root cause of the liners slipping. We had basically the same experience with my 2003 block, heated it in the shop and pulled the liner out by hand before it was too hot to hold by hand. I just put it down to the block being worn down by the liner moving up and down. We never thought about trying any of the other liners.

 

[SNAFU]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

Great work! The question for me now is, what dose that mean for the truck you think? Will it keep on going another 10, 20 or 100K with there is a tapping/ticking and all else is running smooth?
Also, any chance you have a sound clip of it before the tear down?
Thanks!

 

[lforgue8]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

All i have to say dave is bravo! great thinking out of the box for sure.....ive been with rovers for 10+ yrs and have dealt with the ticking for all of them and this is great news for sure.....my buddy is in the process of rebuilding a block for his 03 and his is as loud as you describe and i will try and heat up the block as you did and report back what i find.....we may even "pin" his new block too!


PT you safety wired the 4 bolts along the side to each other? any pics of how they are wired?

 

[turbodave]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

I just put it down to the block being worn down by the liner moving up and down. quote]


Good call. I hadn't thought of that as a 'cause'. It seems plausible. That can be easilly established by seeing if there are machining marks in the remaining bores - these will have been wiped clean by the much harder sleeve. I'll take a good look tonight (along with checking the ductility of the liner).

The one thing that I can't explain, is why I managed to easilly pull out five sleeves, all as easily as each other. But two were making heavy gouges in the firing rings, two making light impressions, and the last was making no markings at all.

 

[Roverfire]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

So are slipping liners only for the 03'-04' 4.6's? What about the 4.0?

 

[dcarr1971]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

So are slipping liners only for the 03'-04' 4.6's? What about the 4.0?

This would potentially be a problem for all of us...basically any vehicle with a Rover v8 based on the design that LR bought from GM (a.k.a.- the Buick 215)...

 

[ptschram]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

PT you safety wired the 4 bolts along the side to each other? any pics of how they are wired?

I wired them together in groups of two.

Pics are here somewhere, I posted them up when I did it as there was so much interest-or so I thought at the time.

 

[Chazza]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

Dave,
What about cleaning the block bores and the outside of the Cylinder liners and reinstalling them with either Loctite 680 (safe to 150deg.C), or Loctite 620 (230 deg. C).

My experience of Loctite is that it will not fail and even in the hottest part of the liners - if it fails there - I imagine that at the bottom of the liner there will always be a cooler part still gripping.

I proffer this as a cheaper alternative to re-boring and top-hatting the block,

Cheers Charlie

 

[nosivad_bor]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

Very interesting. I can't see the hoop stress being an issue as it would put the liner into compression, which should be able to withstand tons of pressure. The idea that once a liner starts to get loose because its running hot and loose, it would essentially hone the bore and keep opening up the tolerance. Give that enough time and I'm sure it would result in the describe phenomenon. I think glueing the liners is kind of a hokey move. Top hat or the set screw/ SHCS method described above sounds very logical and safe.

I'm happy not to hear any tapping in my engine

 

[p m]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

I do hear some tapping from a couple of engines, but hope it's rocker arm shaft or lifters.
If it is from liners, I definitely see a liner pinning party in my future.

 

[p38arover]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

The pic I posted of a slipped liner is from a 3.9.

I do have a spare early 4.6 block here (minus main bearing caps - I bought it for the crankshaft) so I could strip it down and heat it up. The block was replaced in a P38A under warranty.

 

[MarkP]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

The issue goes all the way back to 3.5 blocks. Granted it might be worse for later engines but the basic design flaw existed from day 1.

 

[turbodave]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

Looking at my block last night, the first thing that is obvious to me is that I was I was looking at the block wrong when counting the affected cylinders!

#1 & #2 and #7 are the ones that did not move.

The surface finish on the inside of the block bores appears to be consistent across all of the five that are open (including the one that wasn't marking the head gasket).

With the block now cool, I can insert any of the liners about 1/2" into the hole (by hand) before they get too tight; no one seems tighter (or looser) than the next.

I can also confirm the liners can definately not in any way be regarded as ductile. They are very brittle. I broke a half-nickel sized piece off one end with very little force from a set of side-cutters, so that option for retention is definately out!

 

[Bosbefok]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

I took my block to a company that rebuilds Jeep V8s, they are big on stroking V8s to 5.0.
Anyway the guy looked at it and his first comment was "that's dumb, the tapered liner will work it's way through the head gasket". He recons that plain liners machined flush with the block surface will solve the problem.

 

[ptschram]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

The issue goes all the way back to 3.5 blocks. Granted it might be worse for later engines but the basic design flaw existed from day 1.

Curious. Supposedly one of the improvements Rover made was to the casting process to improve the liner issue.

 

[crown14]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

What is the vin from the truck this engine came from and what is the engine serial number.

 

[wheelen disco]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

I thought that Buick had "cast in" liner's. And they were having to high of a rejection rate at the factory .

 

[ptschram]

Re: 100% Proof that liners are moving at 'normal' operating temps & causing the tapping!

I thought that Buick had "cast in" liner's. And they were having to high of a rejection rate at the factory .

That was my understanding as well. Too much migration of the liners during the casting process.