Engine Knock/rattle

[cliftyhanger]

I did go and chew the fat at my local Triumph Meeting last night, which is always good and encouraging.
Plus I have an autosolo to enter (in the spitfire!) and today I am staying out of the garage.
Need to go shopping to buy cakes and bacon for the visit tomorrow.

[tony g]

My first thought when reading this was a big end rattle. When under slight load it wont make the noise as its being "pushed" slightly by the pressure above it. When lifting off the throttle it goes into neutral ie no pushing or not much pulling and can float about a bit. The noise can then appear more clearly defined. If youre convinced its not chain or head, sump off and check the rods

Tony

[cliftyhanger]

My first thought when reading this was a big end rattle. When under slight load it wont make the noise as its being "pushed" slightly by the pressure above it. When lifting off the throttle it goes into neutral ie no pushing or not much pulling and can float about a bit. The noise can then appear more clearly defined. If youre convinced its not chain or head, sump off and check the rods

Tony

Trust me Tony, I know a big end noise, and this definitely isn't.

[tony g]

Ok

[cliftyhanger]

Ok

Tony, I apologise, my reply could be interpreted as rude. It was not meant to be.
I appreciate any thoughts. And sort of quoting Sherlock, once all the possible suspects have been eliminated, what is left, however impossible, is the culprit.

So at some point, unless the problem is identified, the engine will be out again and stripped with internals checked. oh joy.

[tony g]

None taken Clive

Tony

[dollyman]

My first thought when reading this was a big end rattle. When under slight load it wont make the noise as its being "pushed" slightly by the pressure above it. When lifting off the throttle it goes into neutral ie no pushing or not much pulling and can float about a bit. The noise can then appear more clearly defined. If youre convinced its not chain or head, sump off and check the rods

Tony

Trust me Tony, I know a big end noise, and this definitely isn't.

That's why i was suggesting the plug lead Clive, it rules out big end, little end or broken piston as you have found
Tony.

[yorkshire_spam]

Are the oil pump and dizzy off the shelf or from the older worn engine? I'm wondering if "lash" between those and the jackshaft/drive is giving a chatter on run-down?
(Clutching at straws as all the obvious stuff is ruled out)

The provenance of the head seems to rule it out but I'd also consider tired/cracked valve springs?

And while we are on million to one shots, bolt/nut/washer somewhere in the inlet tract?

[cliftyhanger]

Sam, had the inlets off and checked backlash in the pump and dizzy. Both seem large to what I would expect, but the jackshaft has correct play, no wear evident in the journals either. And all gears lined up.
The jackshaft, dizzy, water and oil pumps all off the old engine.

I ran the engine with no water pump, no difference.

Running out of ideas, but I have yet to pull the cam. That is next. As is pulling the shaft that drives teh oil pump, somebdy mentioned they can round off and clatter.

[yorkshire_spam]

Have you got an oil pressure gauge plumbed in or are you just going off the warning light to indicate pressure?
My gut feeling is something oil pump related, but I could be a million miles off.

[cliftyhanger]

Have you got an oil pressure gauge plumbed in or are you just going off the warning light to indicate pressure?
My gut feeling is something oil pump related, but I could be a million miles off.

I think I have an oil gauge somewhere I could plumb in. May need to venture into the loft, but will try that.

[cliftyhanger]

Oil pressure good. 50psi hot (with cheap p1$$y oil for running in) and 30lb hot at idle.
Yesterday checked a lot of stuff. valve gaps seem to increase by 1-2thou when hot! And the Rolon timing chain tensioner that I reused seems to have the OE plate behind it, with teh oil jet squirting onto the chain just before it reaches the pad, so the better type. However, it was sitting almost fully compressed with the new chain and new straight guide. Looking at the new guide, it appeared to be incorrectly positioned but no adjustment, it was pushing against the chain unnecessarily. So removed, holes slotted and refitted so the chain can JUST sit straight between the cam and crank sprockets. That sat the tensioner better too.
Various stuff was poked and listened too, and the noise seemed to be loud around teh bellhousing....

Today, engine pulled. Swapped the newly fitted lightened flywheel so check for contact and tried to refit the original flywheel.
This is where things got "interesting".
The old engine came from a board contributor, and ran beautifully for years. So no complaints. I was from a TR7, and I was given all sorts of stuff with it. But what I didn't realise that it was a late TR7 engine, so the backplate and flywheel are different. In that the backplate is fitted wit countersunk screws and teh flywheel is thicker, or certainly runs very close to the backplate. But the countersunk screws were all damaged during removal. And hex head bolts used to refit the plate (located on dowels so not an issue). When the new lightened flywheel was fitted, it all turned fine. However, it seems when hot , there is very (and I mean very) slight contact. In one area, between the lightening slots, hence the knocking sound. Depressing the clutch made no difference to the noise, so that is odd, would expect it to be worse?

Anyway, I truly hope this is the issue. I will call Robsport for new countersunk bolts/screws on Monday morning.
If this doesn't sort it, expect a Toledo-sized bonfire in Brighton next weekend!