Oh dear - Engine rattle getting worse.

[Antonnick]

We went for a nice drive in the Rhön at the Weekend - highly recommended lovely scenery. A round trip of 200km and at the end the engine rumble was getting worse and worse. The old Trouble, you drive at 60 or 70 thereabouts and with the slightest bit of acceleration , the rumble starts.

I drove this afternoon to our local mechanic - who listened and is convinced it is a bearing, either big end or the main.

Now I did replace the bigend bearings last year with Standard new ones although the condition of the old ones as viewed hier in the Forum was considered to be ok. I also replaced the main bearing in the middle and at the rear end - again their condition was viewed to be ok. However the front main bearing I did not replace. It was mentioned that other Problems with sealing the plate which has to be removed for Access  makes this a bit risky and anyway given the good condition of the other two was unlikely to be bad.

I am also now unsure whether the thrust bearings I installed were put in the right way around. 😐

Thus I am about to get organised to do this bearing and check the thrust washers. I would appreciate some advice on what to look out for and perhaps any other thoughts in case this last bearing is not the noise culprit.

Car is 1970 13/60 convertible.

 

[glang]

oh dear you havent had much luck have you! Honestly it is possible to get these cars to a state where they are reliable and repair free at least for a few thousand kms.

Dont be worried about taking the sealing block out - if its put back with a bit of care and aligned ok theres no reason why it shouldnt seal well afterwards.

Big ends are always described as a rattle when reving the engine stationary (although thats when quite bad) and mains a rumble. Your oil pressure will drop as bearings wear so thats another indicator. I forget now but I assume the crank was confirmed as standard size when you worked on it previously but were the journals checked for ovality? They can go out of round at high mileages or bearing failure and then of course new bearings wont last very long.

Although there didnt seem to be much wear on the original bearings this is always difficult to judge by eye until the underlayer starts to appear and of course youve got to be lucky to catch them at this stage before they fail completely.....

Does the end float of the crank feel any different from when you replaced the thrusts?

Finally how about running the engine without the fan belt to discount the alternator/dynamo and water pump just in case?

[Antonnick]

I have drained all the oil out now , so I will replace the front main anyway tomorrow. I will check the free Play for the thrust bearings too, before I take them out to check.

One question, does the sealing block have some sort of gasket ?

 

[glang]

yes it has two little wood wedges (yes wood!) and two little gaskets although have a look at yours when you dismantle it because Im not sure these gaskets are always required.

When removing the seal block hopefully you can get it out without damaging the gasket between the engine block and front plate then when replacing it ensure its flat with both the front face and the sump face before doing up its fixing screws.

[Antonnick]

I wonder what sort of Wood it is? I see that the Wood and gaskets yu mention are avaialble from the normal suppliers. I will remove the seal block tomorrow and if necessary order the parts ( and some others ) at the time.

[nang]

You make no mention of having measured the bearing diameters. This is necessary as you can't tell the condition by just looking. You'll need access to a micrometer to do this. 

Tony.

[glang]

It shouldnt be difficult to find them but I didnt need the gaskets (none fitted and would have raised the sealing block to high) and found fitting the wood wedges too complicated so reused the originals.

Remember to try to carefully separate it from the front plate gasket - use a feeler gauge if its stuck....

[Bitumen Boy]

Quoted from Antonnick-

I wonder what sort of Wood it is? I see that the Wood and gaskets yu mention are avaialble from the normal suppliers. I will remove the seal block tomorrow and if necessary order the parts ( and some others ) at the time.

Just a very ordinary softwood IIRC, it's there to seal rather than take any load.

[Antonnick]

IIRC   ????

 

[Clive]

I have removed the front sealing blocks on a few engines to  replace the front main bearing. Without removing the front plate.

I reused the wood wedges, in fact the stayed on the sealing block. On reassembly just a smear of quality "instant gasket" to reseal where the old gasket fitted and the faces of the wood wedges, but do make sure the area is oil free (I use aerosol brake cleaner, ideal for degreasing)

For instant gaskets, I have just used some Victor Reinz "Reinzosil" which is very good...

[glang]

Did you find those little corner gaskets were required Clive? 

and IIRC = If I remember correctly

[Antonnick]

Thankyou for that Clive, it answers a question I was going to make.

So I took off the sealing plate carefully this morning and it seems that previously someone had used liquid sealing compound alongsside the Wood wedges. I will try to put it back as suggested - the front gasket to the front plate is quite good.

I removed first the front main bearing to have a look. If I had not had new bearings to Hand I would have re-used the old ones - they showed hardly any signs of wear or Scratching. Presumably therefore, the main bearing is not the cause of my knocking Sound.

The crankcase movement though looked quite large when I pulled at it. I do not have a dial test indicator today but I thought I would try to measure the movement using my digital calipers, ( is it called that?) I read 1,2mm which is rather large. So, I removed main bearing no3  and checked the thrust washers to see if I had previously put them in wrongly. No, they were correctly positioned, smooth face against the main bearing.

I have some new oversize thrust washers from last years work so I have temporarily at least installed a pair of +0,01 Inch just to see what the result is. My measurement now gives a free Play of 0,3mm which is in tolerance.

However, before tightening everything up, I will check tomorrow properly with the dial test indicator.

I am trying not to be too optimistic that the large amount of free Play was really the cause of the rattle.

 

[RobPearce]

I'd be surprised if undersized thrust washers resulted in rumbling as they only really do any work with the clutch pressed. I suppose it's possible, though.

[glang]

As was commented the journals could be out of round which is impossible to know without measuring however if they are the bearings normally show signs of damage with a few miles of use and as yours looked good I dont think this is the problem.

I dont think the measurements you give on the thrust bearing add up so as you say need confirming with a dial gauge (end float is ideally 6 - 8 thou). What did the old thrust bearings look like? Just to confirm the face of the thrust with an oil slot in it goes against the crank.

Will you be looking at the bigends?

 

[Antonnick]

The bigends I replaced last year - at that time I could download Pictures and the Consensus of opinion was that they did not look bad at all. I replaced them anyway.

The thrustwashers I replaced as well at that time using Standard ones. Only the one at the rear Looks a Little worn but hardly anything.

In the Manual, it refers to the "thickness of thrust washers"  with "clearances" from 0,15 to 0,35 mm. The Manual also notes the "crankshaft end float" to be 0,10 to 0,20 mm. Which should I aim for?

Once the thrustwasher issue is settled and the rattle is still there then at least this has ruled out the bottom end so to speak. The next check will be the head gasket - I have ordered a compression tester - they are cheap enough. There is also the possibility of a worn Distributor where the Timing curve at Speed no longar matches and for that I have it in mind to send it to the "doctor" anyway.

Postscript - wow - I can download Pictures!! Is this the new update of the Website? Wonderful!

[glang]

according to Rimmers theres two types of thrusts (part numbers 104820 and BHM1366) with 5 and 10 thou available for early 13/60 and 5, 10 and 15 thou for late cars. I dont know what the difference is or if they are interchangeable.

The end float should be as your manual says 4 - 8 thou not the 0.3mm (12 thou) that your initial measurement has shown. However if the dial gauge confirms this and no bigger thrust is available then I dont think its a major disaster to leave it like that....

[glang]

One thing, is the sound the same as last time? If I remember correctly all the work you did previously cured the noise?

[Antonnick]

Last time it reduced the noise but did not eliminate it.

..and just to Show that I do not always work on the car ...

[nang]

I still think that you need to get the crankshaft bearing journals accurately measured so you discount  the bearing problems.

Tony.

[RobPearce]

Quoted from glang-

according to Rimmers theres two types of thrusts (part numbers 104820 and BHM1366) <snip>. I dont know what the difference is or if they are interchangeable.

Early 13/60 (GE) engines are small bearing while the very late (GK) ones are large bearing, the same as the Mk3 to MkIV Spitfire engine change. The inner diameter of the thrust would have changed accordingly. Not interchangeable.

[Antonnick]

Mine is GE. So the 0,01 Inch are the largest available it seems.

I do not think it is possible to measure for ovalness of the main bearing unless you remove the crank - which to do, you have to take the engine out of the car. I am not ready for that.

The big end ovalness I measured last year already and all 4 were ok.

 

[sparky_spit]

One thing you can do with the crank in the car, is to measure bearing clearance figures using Plastigauge.  It is pretty accurate if you follow the instructions properly and take care when doing it. You should be able to use it to measure for ovality as well if you do 4 tests per main bearing at 90degs rotation for each test.

It is a good product and I use it a lot.

https://plastigauge.co.uk/

[Antonnick]

I could not get hold of a DTI today so had to revert to using feeler gauges. After much Trial and error the clearance was measured as 0,25mm so then I tried to put the bearing cap back. It would not seat properly but fortunately I saw this before trying to tighten the bolts up. It ranspired that one of the thrust washers had come out! The 0,1 Inch oversize ones I could not get back in but I had 0,05 Inch ones which did go in. The movement was then measured at only 0,15mm and before anything else could go wrong I put the bearing cap back on and torqued it to 70Nm as specified.

Next Task is the sealing Piece. I Need to make new Wood wedges and get hold of the high temperature liquid gasket and sealant. I also Need to put the sump back on a lot better than last time because it leaked oil all over the place. I have a new gasket for this.

 

[glang]

I had a strange thing happen with the thrusts on my engine, same as you, where an oversize went in and then when I came to replace them I could only fit the std size.....

Anyway if your happy youve got that end float reading, perfect. Now are you sure the threads are all good in the sealing block? Its only aluminium and prone to stripping of the threads both from the sump and front cover. New blocks are available in both ally and steel or you could drill and tap the holes for slightly bigger metric bolts.

Then with the sump check that its sealing face is flat and not raised around the bolt holes where theyve been over tightened. If they are you can gently tap them flat.

Soon be driving it again and now you can post pics of that as well😊

[Antonnick]

Al back together again but the test drive showed no Change to the engine rattle when lightly accelerating at 6ß to 70kmh. At least it has now ruled out the bearings. And I forgot to redo the sealing plate front bolt which I knew was a loose fit. So it leaks a bit.

Next steps? Check the cylinder compressions I think to rule out a head gasket. Interestingly, I had to top up the Radiator a bit. That could mean something.......