Should I be worried???

[peteracs]

Hi All

Not sure if this is coincidental after fixing my blowing exhaust on the downpipes/manifold, but I noticed the other day a 'knocking' when I rev up from just above idle to around 2000 rpm, above that nothing obvious. I have tried to capture on audio below, not sure how useful it is. I have rechecked the value clearances and all is well as as expected. I did notice the oil pressure was a tad lower than recently, but just put that down to hot engine, but maybe not..... So thoughts on if I should drop the sump and check the big ends as a start? Note oil changed a couple of months ago with no obvious issues.

https://ashlyn.co.uk/Downloads/Spider_Engine.m4a

Peter

[rossocorsa]

Sounds to me more like something external is catching on something? But with recordings it is difficult to identify sometimes. If oil pressure is really low it could be the relief valve on the pump sticking. I'm really not expert enough I'm sure someone else will know. Is the engine rocking and the new exhaust arrangement causing it to catch on something?

[Nigel]

Sorry to say but that sounds like a big end.
Not unlike what mine did very early on.

I found #3 shell bad and #2 getting there.
Crank looked fine, fitted a set of std shells, good ever since. No
cause found.

Nigel

[peteracs]

Hi Guy

Nothing external causing it and the engine is rock solid on its mounts. Noise is more evident at the rear, though possibly just my imagination….

Peter

[peteracs]

Hi Nigel

I do think so, my worry is the 1600 crank is not hardened unlike the 2l so if that is gone then will probably mean 2L upgrade…

Peter

[rossocorsa]

Did you use a different oil or oil filter brand? I'd be tempted to at try a different oil filter, if not oil, before struggling to take the sump off. Had this once with a 2000HF years ago and it cured it.

[peteracs]

Hi Alan

No, same brand, 3rd time from memory, Bosch filter and 10W50 oil. I have a set of bearings and the weather is good this week, and an excuse to use the tipper lift. I have had the sump off before so that should not be a big deal. Issue will be if the crank is out of spec, then it is decision time.

Peter

[rossocorsa]

Hi Alan

No, same brand, 3rd time from memory, Bosch filter and 10W50 oil. I have a set of bearings and the weather is good this week, and an excuse to use the tipper lift. I have had the sump off before so that should not be a big deal. Issue will be if the crank is out of spec, then it is decision time.

Peter

GC told me that you can get away with one journal being very slightly under and oil pressure will still be ok.. Being GC that will mean very close to spec mind. I believe number 3 is usually the worst due to starvation whilst cornering. I'd take the oil pump off whilst your in there and give it a clean up and check over but they are usually good.

[peteracs]

Hi Alan

When I took the sump off originally, I cleaned and checked the oil pump which was all pretty good. One thing which I did not know is the origin of the engine in the car. When I got the car it had a print of a photo in the glovebox showing what looked like a failed piston or something which lead me to believe the engine was not original to the car. At the time the car hand done around 25k miles, so engine should have been pretty fresh, but if there was a swapped in engine, this one could have done significantly more miles.

Anyway going to bite the bullet today and get started removing the sump etc to see what the big ends look like.

Peter

[rossocorsa]

Good luck hopefully you will find something that's an easier fix than expected.

[HFStuart]

https://ashlyn.co.uk/Downloads/Spider_Engine.m4a

I'd have to agree  - that's a light big end knock. If I had to guess though I'd say the crank will need nothing more than a clean-up. So you might be able to get away with a set of shells

[peteracs]

Hi Stuart

Hopefully so.

Car up on the new tilting lift (only about 10% lift) and then using a jack installed a pair of stands. This gives me plenty of room to get at everything. Quite liking the lift, albeit pretty heavy after extending it To fit the car. Only issue was using a drill is useless, reverted to ratchet wrench which albeit slow is easy enough.

Managed to get the oil drained, no obvious issue, and managed to remove all the bolts from the sump, but now need to raise the engine high enough at the crank end to clear the subframe and oil pump. So far removed bolts from the engine mount and the top steady bar, but need to disconnect the drive shaft to allow it to go high enough. That is tomorrow's job, so hope I will get to check the big ends after that.

Peter

[Ferrit]

Watching this!  I want to do the same this Autumn

[HFStuart]

Only issue was using a drill is useless, reverted to ratchet wrench which albeit slow is easy enough.

Some of the 'drill powered' stuff works OK with a big drill in low gear but then you need arms like Garth to hold the drill without breaking a wrist. Ratchet power is much safer.

Good luck with it, fingers crossed for you.

[peteracs]

Hmm, well after disconnecting the crank end mount, the crank end driveshaft, the front mount bolt and three of the subframe bolts (leaving the rear one near the gearbox I managed to remove the sump and the oil pump.

So on with taking the big end caps and looking at the bearings, my only comment is that it appears a non event, there is wear, but you expect that, but no obvious excessive wear, so is it just a tolerance issue? The journals also all look prefect, no scoring.

My first idea was to try plastigage, but can I find my stock of it, obviously put away really safely.......

Next I realised the bearings I have do not have the oil way holes for these rods, they are for the new rods for the HPE, so need to buy some as well as a new sump gasket. Tomorrow will get the micrometer out and check each of the journals and look again for the plastigage!

Peter

[betabuoy]

Hi Peter,
Not yet found the cause of knocking then, but the bearing conditions must have been a positive find as at least it appears you’re not going to have to deal with an engine full of bearing fragments too!
Good luck with next stage. Fingers crossed for you.
Chris

[lancialulu]

Hi Peter,
Not yet found the cause of knocking then, but the bearing conditions must have been a positive find as at least it appears you’re not going to have to deal with an engine full of bearing fragments too!
Good luck with next stage. Fingers crossed for you.
Chris

It may be just piston slap. Did it go away when hot?

[WestonE]

Hi Peter perhaps check the Aux DS position. It could be the dreaded Fuel pump lobe knocking Number 2 conrod. BTW you might see a witness mark on the conrod as you have the sump off.

[peteracs]

Hi Tim

I have been considering that given my results below, did it go away when hot, not sure tbh, but think it did not.

Hi Eric

I was not sure if the 1600 had this issue, but I will check. I would also have thought the noise would be constant through the Rev range, but will check.

So I managed to find my plastigage, put away all very safe in a box of injection parts.....

I first used a micrometer to best check the journal and although hard to check in situ, they all appear to be well within spec. I then used the plastigage and the results varied from approx 1 thou through 3 thou, my understanding is that a gap of 1-2 thou is specified. This was done with the lower bearing dry, but the upper still with film of oil, so these would be the best values, ie could be slightly wider. Obviously plastigage is a guide, but it gives me confidence in using new bearings, which I will test again, and that will rule out the big ends. Just waiting for new bearings from Mark (hopefully).

[lancialulu]

I use plastiguage and get 1.5-2mm all the time mostly nearer 2mm on rebuilt Fulvia nitrided cranks (not reground) and is perfectly acceptable. When I rebuilt my TR6 it had 2-3mm and I questioned the 3mm with my machinist (not really wanting to regrind the unblemished journals) and he said 3mm is OK, but when hot oil pressure drops off max whereas the Fulvia engines stay on spec. The two oil pump systems are curiously the same principle but the Lampredi (Beta) is slightly different in that it it gets to max (release valve) at much lower revs and is stable whereas Fulvia is very dynamic.
What does it measure with new shells?