TR6 hammering sound from engine...

[villa.1]

Thanks fo the suggestions, hopefully something simple!

[villa.1]

Hi Steve,

 

Nobodies asked, is the knocking synchronised in time with crankshaft revolution or much faster (likely camshaft ).

 

Micky

The noise is higher pitched and fast, in time with tapets at tick over. As you go up the revs it slows to more like crank speed and becomes a much louder banging noise.

[Motorsport Mickey]

Compression test, wet and dry.

Sorry you've done that, obviously from the readings it looks like No 2 cylinder has a problem and from what you describe with the noise there's something impacting upon one another.

If the tappet clearances remain correct and there is no evidence of obvious problems with the rocker arms maybe a cylinder inspection with a small "snake head " camera through the plug hole may show the problem. To state the obvious, the only other ways of further investigation are head off or sump off, and because of the difference in compressions it sounds as if it's on the top end that's a problem. I fear Markus at be on the mark with a loose valve seat (if any are fitted), I'd bite the bullet and remove head and see what you find, at least it will move you forward with evidence or lack of.

Mick Richards

Edited March 2, 2017 by Motorsport Mickey

[Peter Cobbold]

Wouldn't a valve seat shifting show up on valve clearance?

[Motorsport Mickey]

Depends upon how it's sitting Peter.

 

I won a race with the engine ( TR 7 V 8) running perfectly, and after the garland presentation and restarting the engine, immediately heard a " chock chook" noise and drove the car off the circuit (200 yards) for recovery. A valve seat had dropped but was still providing closure against the valve and dropping neatly back into it's machined recess. When I stripped the engine down the valve clearances were within a couple of thou, probably within the setting range.

Saved the head, no damage just remachine another valve seat into it.

 

Mick Richards

[GT6M]

Wouldn't a valve seat shifting show up on valve clearance?

Mickeys got it aboot right,

Butt, in my case, cos the insert was ..deeper in, and I peened the top over, so it would,nt

dropp oot, then wot was happening was that the thing was,nt full home,

so it was working up an doon 20 odd thou.

 

no much, but enough t,mek a nice tapping,clicking noise

that rose wid revs

 

The old RPC Deisels wer really bad for it,

the pree chamber come loose, { steel in a alloy heed }

 

it was tight, that one could shift it wid yer hand / fingers

Butt, boy did it mek one hell of a racket

esp if a few had gon,

which generally happend after they overheated, so all 4 would be rattling away

 

M

[Peter Cobbold]

Thanks Mick, Markus. Beginning to wish I hadn't had inserts on the rebuilt head.....Peter

[oldtuckunder]

Beginning to wish I hadn't had inserts on the rebuilt head.

 

Never saw much point to them on a classic with a cast iron head, that doesn't do much mileage.

 

If its a competition engine why risk it, and you are going to be checking for any recession tappet clearances fairly regularly.

 

On a road car doing a few thousand miles a year if you ever do get a recession problem after n+years then you still have it as an option.

 

Never seen any sign of a problem on my engine and its often sees 6.5K+, and I just give them a quick lap in each rebuild for no other reason than why not I have the head off.

 

Alan

[Peter Cobbold]

 

Never saw much point to them on a classic with a cast iron head, that doesn't do much mileage.

 

If its a competition engine why risk it, and you are going to be checking for any recession tappet clearances fairly regularly.

 

On a road car doing a few thousand miles a year if you ever do get a recession problem after n+years then you still have it as an option.

 

Never seen any sign of a problem on my engine and its often sees 6.5K+, and I just give them a quick lap in each rebuild for no other reason than why not I have the head off.

 

Alan

Alan, I was being over-cautious, and would not fit them to a standard engine. My reasoning was the blower adds about 50C at cruise to the intake temperature, 80-90C under boost. So I went for belt and braces, probably unnecessarily, but the supercharge makes it unknown territory.

Peter

[villa.1]

so I think im getting closer to the knocking issue, I took the sump off and found lots of bits of shedded metal in the bottom!!! which i assume is the remains of my thrust washers rather than a bearing? both top halves of the thrust washers are still in place. Im keen to know if this means something major or has anyone had this happen and not seriously damaged anyother bits? Also what sequence would you suggest I should be working to for further inspections.

 

Thanks in advance,

 

Steve

Edited March 2, 2017 by villa.1

[Richard71]

Hi Steve,

 

Perhaps you could post a pic of the debris found in the sump? The reason I ask is if unless you've had thrustwasher modification work, well you should only have (if my memory serves me well) two top halves of thrustwasher.......a bit of a failing on the 6cyl TR engine design.

 

I would suspect the debris may well be other material.

 

Regards,

Richard.

[villa.1]

A couple of photos,

 

[villa.1]

dont realyy know what im looking for in terms of wear.

[Richard71]

Could possibly be small end bush material, circlip retaining the gudgeon pin broken causing scoring on your #2 cyl and the subsequent low compression therein???

 

Just a thought, but as other have already suggested, it may be wise to remove the cyl head or at the very least a boro-scope inspection down the spark plug holes.

 

Regards,

Richard.

[Richard71]

dont realyy know what im looking for in terms of wear.

 

That to me doesn't look excessively worn. Have you removed & checked #2 big end bearing, it may show symptoms of the little end in trouble?

 

Regards,

Richard.

[oldtuckunder]

A couple of photos,

 

 

I'm making a guess at a trashed BE bearing shell, only because I have seen similar scrap in my sump :-(

 

Try looking at #5 next (only because it and I have been in a personal battle for a couple of years that I may just have won)

 

Alan

[villa.1]

I assume there should have been a bottom half to my thrust washers and not just the top half?

[Blue cedar]

No. There are 2 TWs. Both half moon and sit opposite sides of the rear crankshaft bearing, just as yours are .....correctly fitted. There is no bottom half.

[villa.1]

No. There are 2 TWs. Both half moon and sit opposite sides of the rear crankshaft bearing, just as yours are .....correctly fitted. There is no bottom half.

ahh thank you for that, I guess im going to be missing the internals of big/little end or main bearings judging by the debris in the sump.

[Blue cedar]

I' d want to look at number 2 bearing, look at cylinder 2 wall for scoring and also if there is any play in the little end.

[Guest ntc]

ahh thank you for that, I guess im going to be missing the internals of big/little end or main bearings judging by the debris in the sump.

Or something you put in the inlet manifold.

[GT6M]

Cant see hoo some thing left in inlet mani,

can fin its way to sump

Unless, its wacked a biggg hole int piston, !!!

 

If im seeing OK, them bits look like brass bitts,

are they magnetic.

 

Only thing I can think of inside engine, that could get into sump

thats a brassy shade, ist Wee end bush.

 

Butt, if that had gone, there be one hell of a racket,

bit like a windy gun rattle/bang.

 

Can ye shine a torch up int engine, look at cam,an followers.

as still think its in there,!

 

most odd.

 

 

M

[Motorsport Mickey]

Undo No 2 big end, check bearing, if ok grab hold of conrod and see if excessive play in small end.

by pushing/twisting the piston UP the bore.

 

Not scientific. but if you do or don't find play I think now you'll end up pulling the head.

 

Micky

[Guest ntc]

It is engine out because it is knackerd.Needs a full mark one eyeball.

Edited March 3, 2017 by ntc

[poolboy]

In the pictures that were posted, something looks odd, kind of chewed up, about that protruding section of the hollow dowel in the connecting rod thru which the bolt passes.

I wonder if that could be related somehow.