'26 engine knock

[R.White]

Not so much a new topic but a return to something that I thought was sorted but most definitely is not. .

 

Avid 4 cylinder car readers will recall that I was experiencing a distinct tapping sound coming from my engine.  This regular knock was coming from No.1 cylinder on the firing stroke.  Investigation revealed historic damage to the bore which also turned out to be a cracked so I had a liner fitted.  The engine was treated to a rebore and new + 0.040"  pistons installed.  I also replaced the valves guides and springs at the same time. Unfortunately, despite assurances from the engine repair guy that the noise would have been from a piston ring hitting the damaged bore,  on restarting the reassembled engine the noise is still there!  The tapping sound is most noticeable at tick over but if I short out the sparking plug on No.1 cylinder, it disappears.  I have checked the connecting rod big end bearings and the white metal looks to be in good condition and has an even clearance (with Plastigauge) of 0.0015") which I would have thought would be correct.  I guess there is a solution to the problem but I am not sure what to do now.

 

Ray.

[Spinneyhill]

What did you do with the small end when fitting the new piston?

[R.White]

The gudgeon pins that came with the new pistons are a perfect fit to the little end of the rods.  The bushing in the rod shows no signs of wear.   The set up is of the modern fully floating type with cir clip retaining clips.  The engineer was also happy with the fit. 

[Bloo]

Assuming there is no problem with the small end (I was also wondering about that), you could try tightening the big end a little.

 

I have used plastigage on almost everything I have ever worked on, but was reading the other day on the VCCA, and discovered that the 4 cylinder Chevy enthusiasts do not trust plastigage, and speak of tapping the big end sideways with a tiny hammer to check for clearance. They also turn the engine by hand to make sure the bearing being adjusted is not dragging to much.  Apparently .0015 on those engines is on the high end of acceptable, and might make noise.

 

Those Chevrolet engines are splash oilers. Is your Dodge splash oiled? Here are a couple of threads:

 

http://vcca.org/forum/ubbthreads.php/topics/306467/Re:_Adjusting_tightness_of_'30

http://vcca.org/forum/ubbthreads.php/topics/243425/Connector_rod_clearance

 

There are others over there as well. Another thing I have seen recommended is to turn the crank 90 degrees and recheck in case the crankshaft is a little less than round. This is to make sure it doesn't tighten up. Good luck.

[R.White]

I haven't read those threads yet but I thank you for them.  Yes, the 4 cylinder Dodge Brothers engine is splash fed.  I made sure the bearing cap was on the right way so that the oil gets scooped up.  I too have always used plastigauge and never had reason to doubt it - but you are right in looking for an out of round journal.  I am surprised that 0.0015 is seen as a big clearance given that it is not pressure fed.  I can of course take up the bearing clearance a bit more and see if  that cures the knock.  It might be worth mentioning that the other bearings are adjusted the same and remain quiet.

If there is a slight out of round wear pattern on the journal, how much is considered to be too much?

 

As to lateral movement; this is a problem that I first noticed on this engine and which I was convinced was causing the knock because there was a large amount of free play.  I took up the clearance on this bearing cap by tinning the edges with soft solder.  The melting point of solder is slightly below that of the babbitt metal and given there is not much loading in that area I considered it safe. I was frustrated that my efforts had come to nothing.

 

For the record, I have eliminated the possibility of a plug fouling a valve by fitting shorter reach plugs.  I have also eliminated the possibility of wear between the valve spring retainer and pin by renewing everything.  The camshaft looks like a replacement considering the negligible wear.  I wondered if I should be setting the timing as per standard if an improved camshaft has been fitted?  I read somewhere that a different cam profile was fitted to some Australian cars (which this is).   Perhaps I should play around with the timing to see if it helps...or am I just clutching at straws?

 

Ray.

 

      

[cahartley]

There is no point fiddling with the timing as you can do that from the steering column.

Did you happen to have the rods checked for straightness?

You can do that at home, with a helper to man the crank, by turning the engine over and watching to see if the rod walks back and forth on the piston pin between the up and down strokes.

I really wish you'd get a break!....... 

[R.White]

35 minutes ago, cahartley said:

There is no point fiddling with the timing as you can do that from the steering column.

Did you happen to have the rods checked for straightness?

You can do that at home, with a helper to man the crank, by turning the engine over and watching to see if the rod walks back and forth on the piston pin between the up and down strokes.

I really wish you'd get a break!....... 

 

I only wondered if the distributor could be a whole tooth out?  Yeah, I'm clutching at straws!

 

I checked the con rods for straightness when I had them out.  The engineer says he also checked.   They all look central to the  wrist pins when I look up at them! 

 

I was surprised to read that the Chevy 4 could knock at 0.0015" big end clearance.  

 

I have a theory that No.1 cylinder suffered a serious trauma sometime in the past and this noise may be related to that time, I wonder if the crank pin has been knocked about enough to cause the knock. During the rebore they found a small piece of piston ring embedded in the cylinder wall!  I couldn't feel anything but an indentation - which I believed the rings were just passing over.  It is of little consolation to be proved right.

 

It looks like I made a mistake by adjusting the bearing with the piston at the bottom rather than the top. I will have another go at it.

 

 

Edited August 13, 2017 by R.White (see edit history)

[Bloo]

I sort of doubt it has anything to do with the timing. Nearly all of my experience is with force fed engines, but as I understand it splash oilers need to run tighter than force fed engines. I think that rod tap-sideways test had more to do with checking the bearing clearance than the side clearance. I think their goal (on those Chevrolets anyway) is to run them as tight as they possibly can without binding, and they don't really quite believe what the plastigage is telling them. Any out of round would prevent getting the bearings very tight, as they would bind as you turned them. I don't know how much is too much.

 

If it were mine, I think I would shim that bearing as tight as I could get it without binding, and see if it still makes noise. Even if it still does, that is a huge clue.

 

It is so hard to tell about engine noises. All engines should behave about the same under the typical tests (cracking the throttle to listen for a rattle, disconnecting a spark plug and so on). In my experience they don't always. Usually, however, a small end (gudgeon pin) noise is a double knock. Usually it will change but not go away when you disconnect a spark plug. A rod knock should get quieter or go away. It is often hard to tell the difference between a small rod knock and some relatively harmless piston slap. What kind of pistons did you use and how much clearance?

 

I would also wonder about the closest main bearing. How tight is it?

 

I don't see how it could be anything to do with the camshaft. A noise there shouldn't change no matter what you do.

 

Edited August 13, 2017 by Bloo
oops (see edit history)

[ILIKECARS53]

Have you been in touch with Vern Barker at Romar here in the States. That is all he rebuilds is dodge engines, maybe he can shed some light.

[cahartley]

Having, within the last few days, got my 1932 Chevrolet Confederate engine running I can tell you da bois at the Vintage Chevrolet Collectors Association warn that .002" clearance on a  194 six banger which has 2" rod journals WILL knock!

My Dodge had more than that before I checked the shims and it didn't knock.

Both have nearly identical rod oiling systems.

Go figure........ 

[R.White]

Go figure indeed.  I was always under the impression that engines that relied on splash feed should have sufficient clearance for the oil to just flow in and out under gravity and that the introduction of pressure fed systems meant that closer tolerances could be achieved safely.  There is a certain logic  to it and that the reason we can go for closer tolerances now is that if synthetic oil is used it is not just better but thinner than the old straight oils.  I am always prepared to accept that I may have got it wrong but none of the other big end bearings are tighter than 0.002"... and they don't knock.  Why just this one?

 

Ray.

 

Bloo.  The main bearings have been a nightmare.  In a previous post I related how I couldn't get them closer than 0.003" without binding.  As I say, I think this crankshaft has suffered trauma at some time. 

 

That it runs at all is probably something of a miracle.

 

Ray.

Edited August 13, 2017 by R.White (see edit history)

[robert b]

Ray how much crush is there on the bearing shells, you need at least 00.4" on each shell or they will walk in the rod and sound like a bigend knock ,and disappear when shorted plug on that cylinder , just a thought bob, bearing clearance is 0.001 on a round crank ,that is a light drag on a dry journal .

Edited August 14, 2017 by robert b (see edit history)

[R.White]

Hi Bob.  On my engine the shells are trapped by the shims so cannot move around.  They are dead flush with the bearing cap and are quite a tight fit so need to be prised out.  There are also notches on the back which locate them.  As I see it, the shells cannot move in the rod when the bearings are bolted up.  I will look at it again, though, because thinking about it that might just be what is causing the knock if all the other bearings are quiet at 0.002".

 

Ray.

Edited August 14, 2017 by R.White (see edit history)

[Spinneyhill]

On 8/14/2017 at 9:55 AM, R.White said:

Bloo.  The main bearings have been a nightmare.  In a previous post I related how I couldn't get them closer than 0.003" without binding.  As I say, I think this crankshaft has suffered trauma at some time.

 

Is it possible the shaft is bent? I think we canvassed this before.

[cahartley]

Referring to my '29-'32 Chevrolet Service Manual which states "The dial indicator should not vary over .002"" when checking a  crankshaft.

This for a 294 straight 6, 3 main bearing, engine.

Interesting they use the word should.

The Dodge crankshaft is somewhat  more stout so I think it would have taken a catastrophic event to bend it....... 

[Bloo]

5 hours ago, Spinneyhill said:

On 8/13/2017 at 2:55 PM, R.White said:

Bloo.  The main bearings have been a nightmare.  In a previous post I related how I couldn't get them closer than 0.003" without binding.  As I say, I think this crankshaft has suffered trauma at some time.

 

Is it possible the shaft is bent? I think we canvassed this before.

 

I was wondering that too. .003 seems a bit loose.

 

7 hours ago, R.White said:

I will look at it again, though, because thinking about it that might just be what is causing the knock if all the other bearings are quiet at 0.002".

 

I brought up those Chevrolet threads because I was wondering if its possible #1 isn't really as tight as the others, even though it seems so.

 

On 8/13/2017 at 2:55 PM, R.White said:

Go figure indeed.  I was always under the impression that engines that relied on splash feed should have sufficient clearance for the oil to just flow in and out under gravity and that the introduction of pressure fed systems meant that closer tolerances could be achieved safely.

 

Actually I think that works the other way. The splash oiled engines needed to be tighter. I have heard many stories over the years about clearances in these old engines being set to the modern "rule of thumb" and winding up noisy. In pressure fed engines with a lot of miles it isn't uncommon for the bearings to talk a little before the oil pressure comes up. Splashers do need fairly thin oil to ensure flow, especially cold.

 

Edited August 15, 2017 by Bloo
.. (see edit history)

[cahartley]

There's a reason many new car manufacturers are using 0W20 oil.

Much the same reason I use 5W30 in my Model T and 10W30 in the two Chevs ('32 and '59).

[R.White]

7 hours ago, cahartley said:

Referring to my '29-'32 Chevrolet Service Manual which states "The dial indicator should not vary over .002"" when checking a  crankshaft.

This for a 294 straight 6, 3 main bearing, engine.

Interesting they use the word should.

The Dodge crankshaft is somewhat  more stout so I think it would have taken a catastrophic event to bend it....... 

 

I think this crank must have a slight bend in it because I found it impossible to fit the main bearings tighter than 0.003" without it binding.  I thought I was doing the right thing in taking up the slack because it had been running with 0.005" clearance. Previously, the engine ran fine with no mains problems but since adjusting them there is a noticeable increase in vibration.   It sometimes feels as if I am going backwards!

 

 

Edited August 15, 2017 by R.White (see edit history)

[MikeC5]

Hi Ray, I do know that for Model T engines, when new babbit is poured the bearings are set up very tight.  A friend of mine had his engine rebuilt by a long-time Model T specialist who was close enough that we could deliver the engine to him.  He showed us a completed short block he had on stand and let us try to turn it over with a long breaker bar.  It took considerable force to get it moving.  Instructions for starting it the first time required towing the car since it was too tight to crank by hand (our only other choice).  After running for several minutes it did loosen up enough to hand crank.  I think I would try tightening up the clearance on the offending rod big and and see if it changes things.  If it helps I might be tempted to tighten up the others too.  

[Bloo]

I remember reading on some period publication, probably Dyke's Encyclopedia or maybe Audel's, about a machine used to "burn in" newly cast babbit bearings. The machine would spin the fresh engine with an electric motor until it spun freely. Sounds risky. I would want it to turn freely, if only barely.

 

 

 

 

Edited August 16, 2017 by Bloo
... (see edit history)

[R.White]

Hi Mike.  I haven't had the crank reground so no new babbitt metal.  I should have ignored the "professional" advice who said it was O.K.  and had the crank reground with new babbitt metal poured.

 

The way things are going I will have to get it done anyway.

 

Ray.

[R.White]

Today I confronted  (politely) the engineer who  worked on my engine.  I told him how it was still making a knocking noise.  He said he was sorry to learn that - but it would seem he is too busy to do anything about it for at least six months and then it would cost me the best part of $2000 (or the £ equivalent) to regrind the crank and re babbitt the bearings.  

 

There is about as much chance of this guy fixing my engine as a one legged man winning an ass kicking contest.

 

Ray.

[Spinneyhill]

It is a real bummer when (judgement) advice you take from "experts" turns out to be poor. Drip fed bad news seems to be worse than when it all comes at once. I feel for you.

 

I am going through something similar. My radiator was blocked. i took it to a local shop and he was confident could clear it without taking the top tank off. He could not. So he took the top tank off. But then it leaked when he put it back on. And his franchise couldn't supply a new tapered core but offered a short one for a huge amount of money, even though I told him it is the frontice-piece of the car. So I took if for a "second opinion" - he couldn't agree fast enough. I asked at car club and took it to the place recommended. This fellow has been doing radiators for 30 years, the other fellow for just a year! The second man may be able to fix it... we'll see. It depends on how much damage the first man has done trying to solder the top on.

[R.White]

OMG Spinneyhill!. 

 

If only our Dodge Brother Robert B wasn't so far away...

 

My engineer chap came highly recommended from other old car guys.  Yes, he is a skilled machinist and what he does is good work but that doesn't make him a good mechanic, does it?

 

Ray.

 

 

 

 

[cahartley]

Ray, did you ever mic the rod journal yourself?

Have you tried shimming the rod bearing the old school way?

Set the bearing tight enough that you can tap it back and forth with a light hammer.

Unless the rod journals are in bad shape it seems logical the mains wouldn't be either.

After all the work you have gone through and shorting #1 stops the ticking I'm as stumped as you are....... 

[TonyAus]

Hi Ray

 

I'm clutching at straws here.  Many posts ago you mentioned that you tinned the edges of the bearings to take up the sideways movement.  Was this only on the offending rod?  I was similarly concerned about the sideways movement in my rods.  However, consulting the Mechanics' Instruction Manual indicated that this movement should be .010" and they measured at that with a feeler gauge.  Seemed like a lot more on first impressions.  Perhaps a reduced clearance may result in the bearing banging against the journal cheeks due to a minute lack of straightness in the rod?? 

 

Tony

[R.White]

6 hours ago, cahartley said:

Ray, did you ever mic the rod journal yourself?

Have you tried shimming the rod bearing the old school way?

Set the bearing tight enough that you can tap it back and forth with a light hammer.

Unless the rod journals are in bad shape it seems logical the mains wouldn't be either.

After all the work you have gone through and shorting #1 stops the ticking I'm as stumped as you are....... 

 

As it happens, I have been doing just that this afternoon. I did it before and found no wear which to be fair is what the engineer said.  No matter what points across the journal I choose, I can find no difference.  It measures 1.670" in all directions.   Just to be sure I have lapped in the shells with a compound specially developed for white metal bearings called "time saver".  This particular "yellow" compound does not contain any emery, ground glass, silicon carbide, aluminium oxide and will not charge into any metal surface or continue to cut so I feel happy that a near perfect bearing surface can safely result.  I shall make sure there is no movement of the shells in the rod this time.

 

The latest results are promising with what appears to be just 0.0005" taper.  I hope to finish with an overall clearance of 0.001" after taking measurements from top as well as bottom of the stroke.

 

We are, it seems, back where we started if the knock is not the big end.  I keep wondering if it is somehow a serious pre ignition knock.  Where I am flummoxed is that it is only on the one cylinder.  Perhaps there is a fault with the distributor causing No.1 to spark early?  I keep thinking about the non standard camshaft design that may have been fitted.  This throws up issues with both valve  timing and ignition timing.  Firstly, is the ignition too far advanced?  Could it be a completely different setup if the camshaft is non standard?  I could experiment to see if the distributor is a tooth out for example.

 

 What if the valve timing is wrong for this camshaft?  There were no timing marks on the crankshaft and camshaft gears to assist so I had to set it up using the method described in the book of information.  There are two methods depending on which camshaft is used.  The after market ones fitted to a number of cars in Australia to prevent premature exhaust valve failure  is a third and I have no information on that.

 

Hi Tony.  I went to considerable lengths to ensure that this rod is as straight as it can be. Interestingly,  all the other rods have masses of lateral movement and they don't make a whisper.  I am still not 100% sure where the knock is coming from.  As I said once before it seems to be coming from the head but as you know sound travels.

 

To say I am out of my depth is an understatement.  Several old car guys listened to the engine at a show I went to last year and they were also puzzled.

 

My Dad would have been able to sort it but I expect he is busy working on The Lord's car these days.

 

Ray.

Edited August 17, 2017 by R.White (see edit history)

[cahartley]

If, indeed, the knock was ignition induced it ought to knock on all four.

The fact it has been #1 cylinder all along is puzzling.

If you want to verify the timing is equal across all four cylinders you could change the firing order by R&R the distributor to place #1 a quarter off and move the wires accordingly.

If there is something wrong that would move the knock to another cylinder.

Edited August 17, 2017 by cahartley (see edit history)

[R.White]

Yes.  I will reposition the distributor and see if it changes anything.

 

Thanks.

 

Ray.

[TonyAus]

Hi Ray

 

My point was that the rods need lateral movement.  Has your tinning exercise reduced the specified 10 thou?  Perhaps this is the minimum?  Check the other rods with a feeler gauge and if equal to or over 10 thou this may be your problem.

 

Tony 

Edited August 18, 2017 by TonyAus (see edit history)

[R.White]

Yes tony.  I reduced the lateral clearance from 0.030" to the specified 0.10".  The noise has remained the same regardless so I felt it probably wasn't coming from there after all.  The other three rods are unchanged 0.025" - 0.030".   If tinning had made a difference I would have done them too. 

 

Ray.

[Taylormade]

Ray,

You mentioned in your first post that the knock goes away if you short the plug on number one cylinder.  Is it completely gone or just greatly reduced?  If it's completely gone, then the only thing producing the knock is the detonation in the cylinder and the downward force produced on the piston when the plug is firing.  Have you ever taken the number one plug out and turned the motor over to see if any unusual noise is coming out of the plug hole?  Like you, I'm grasping at straws here.  You've done everything I would have thought of if this were my problem.  At this point could you take the crank out and test it for straightness, or has that already been done?  A depressing suggestion, but it may be the only way to see if the crank is the problem.

[R.White]

The knock disappears completely when I short out the spark plug.  No, I haven't run the engine with just 3 plugs,  I don't know how I would learn anything from that but I am prepared to try anything.

 

As To the crank.  I left the crank with the engineer who rebored the block for me.  He didn't check it for straightness so it was only when reassembling the engine back in my garage that I found a problem.  As I mentioned in another thread, I was unable to get closer than 0.003" clearance on the main bearings without it binding.  This I assume points to a bent crank - but what do I know?

 

 I managed to improve things a bit by carefully lapping in the shells but i didn't want to remove too much white metal!   The mains had been running with 0.005" clearance previously and  had not shown symptoms of rumbling or vibration but now there is a noticeable  increase in vibration.  I don't know if this is down to that or just because the new pistons need bedding in.

 

I am trying to visualise how this might cause a knock in one big end?

 

I am also having to pacify my long suffering wife who hit the roof when I told her the engine might need to come out again and cost upwards of £1000!

 

Ray.  

[Taylormade]

This has to be every restorer's worst nightmare - just when you think you have everything sorted out, you're suddenly back to square one.  I hope a solution finally arrives.  As to the wife situation - been there, done that. ?

[TonyAus]

Hi again Ray

After a little digging I think you may be able to  eliminate a bent crankshaft.  The Mechanics' Instruction Manual states that a sprung (ie bent) crankshaft can be detected using a dial gauge on the centre main jounal.  The upper and lower bearings should be removed in this process and up to .005'"  variation at the journal is permissible.  You previously mentioned being able to fit the main bearings to less than this figure  so I'd take the  crankshaft to be OK.  Not much help with the noise but something else to eliminate!

 

The manual also mentions a loose piston being the cause of a light tap at low speed (piston slap?) which can be eliminated by shorting out the appropriate plug.  Did you fit split skirt  pistons?  If so, are the splits all opposite the thrust side of the bores?  Like you, I'm running out of ideas.

 

Tony

[Bloo]

The dial indicator would be a good place to start. I suppose it could also be that the bores are out of line. If the crank proves to be straight, and will spin freely laying in the block, but tightens at too loose of clearance when you put the caps on this could be the case. Assuming that these are poured babbitt bearings, it might be fixable by old fashioned bearing scraping, if there is enough babbitt left.

 

What about piston slap? Was the piston clearance looser on that bore? At least if it is piston slap it is relatively harmless. This block was just bored, right?

[R.White]

Thanks for keeping with this, guys.  I will try and answer all your points.  Firstly, Tony; I also have the mechanic's Instruction manual and wondered about that 0.005" figure.  I sounds far to big too me.  I wondered if it was a mis print and should have read 0.0005"?  My Dad was a precision engineer and he worked to 100th of a millimetre so I know what he would have thought.  

 

This knocking has been a problem with this engine of a long time.    In older posts I mentioned that a previous owner had fitted new standard size pistons to a block which had been rebored  oversize and the general consensus was that the noise was piston slap - but this appears not to have been the cause.  Piston slap has been eliminated.   Also, there was damage to  bore  No.1 in the form of a hole gouged out.  The engineer found a small piece of piston ring embedded in the cylinder wall and was convinced that a rebore would sort it.  Subsequently, a hairline crack was found in the bore so a liner was fitted... but the noise persists.   Everything was looking positive on assembly as the new + 0.040" pistons were a nice fit in the new bores which had been properly honed.  I correctly gapped the rings allowing 0.014" end gap but the knock from No.1 cylinder on the firing stroke is still there but now it is more noticeable on tick over whereas before I it tended to be louder under load.  The new pistons (like the previous ones) have modern fully floating gudgeon pins that are retained by cir clips.  The fit is perfect.

 

 Yesterday I persuaded my wife to turn the handle while I looked up at the underside of the pistons to see what was going on.  The rods are all central to the pistons and there is no "wandering".  I didn't think there was a bent con rod having gone to great lengths to ensure straightness (see photo) but have now eliminated it in practice.  

 

At present I am checking the big end on No1 rod.  I have more or less given up on the Plastiguage and gone back to the traditional method.   I have established an overall even bearing surface to the shells and  reduced the shims to the point of pinching. I could lap the bearing to provide 0.001" clearance or add some wafer thin brass shim stock which I have shaped to match. The only problem with lapping is that it reduces the thickness of the white metal. 

 

I don't hold out much hope of stopping the knock if this doesn't work but I still have a few tricks up my sleeve before I throw in the towel

 

Ray.

 

 

Edited August 21, 2017 by R.White (see edit history)

[Spinneyhill]

Just a long shot.... A school colleague had an 1100 or 1300. It had a tap at idle. It turned out to be end float on something unexpected, such as crankshaft or cam shaft or a timing gear on one of the shafts. It is 45 years ago so memory is hazy.

 

Is there any possibility the tap could be spark leakage from no. 1 plug or lead or attachment to plug?

[26Willys]

I was just getting ready to suggest slack in the timing gears or endplay on the water pump shaft. I had both problems on my '21 but it was more of a random knock than one that was in time with a cylinder.

[R.White]

Yes, Spinneyhill, I agree;  comparison with the BMC A series is a very long shot.  I have worked on many such engines for more years than I care to remember.  My father was an authority on these  Alec Issigonis designed cars and I recall him giving a well received lecture to a group of engineers- but that is another matter. 

 

At present I am having a game getting the babbitt to show contact evenly across the surface of the shells but once that is sorted I can refit the pan and try running it again.  I too have been wondering  if there could be a spark leakage from No 1 plug or perhaps  an ignition sequence fault.  The trouble is that every example I can think of; cracked distributor cap, faulty lead or resistance in the plugs etc. all point to a delay in the spark rather than an advance of it.  The way I am thinking, any pre ignition would need to be as a resuly of an advance rather than a retard of the spark.  Perhaps I am over thinking this because I have already replaced the plugs (tried two different reaches) renewed the leads and brass connectors and examined the cap for arching in dark conditions.  Please correct me if I am not thinking straight about this.

 

The noise is definitely not coming from the timing gears; besides, the camshaft gear is fibre and quiet.  There is a little backlash between the water pump drive gears but I have improved that and reduced the excessive end float on the shaft next to the pulley,  The water pump shaft and bushes are also brand new but I doubt they are related to the knock which only occurs on the firing stroke as witnessed by shorting out the plug on No.1 cylinder. 

 

Ray.

 

 

 

 

Edited August 21, 2017 by R.White (see edit history)