Worrying noise

[cliff.b]

34 minutes ago, johny said:

Cant be the oil and unlikely to be anything you did changing the oil so its a coincidence. Could it be a carb affecting two cylinders? Spark plug wet of cylinder(s) thats not firing?

Aha, you have got me thinking straight now. The number 1 plug was dry and very white, so maybe fuel supply issues to front carb🤔

 

Also, regarding my question on vacuum advance, I checked the ignition timing by strobe, but forgot to disconnect the vacuum pipe and the mark was off the scale at about 26BTDC. When I pulled the pipe off at the dizzy end I could feel it was sucking and the strobe now showed 12BTDC which is what I was expecting.

So I actually wondered if this was connected with the original problem and took the car out to warm it up with the vac pipe disconnected to see if it made any difference to the noise. But I never got that far because a few miles down the road the misfiring started. And reconnecting the vac pipe made no difference.

 

[cliff.b]

6 minutes ago, Pete Lewis said:

think you need to stop ,  dont relate an oil change with any misfire 

rocker box off have you disturbed the breathers ?

and there is the dreaded rubber slivers from fuel hose meddling  jams the float needle  brings a good misfire to go with it 

Pete

 

Only had the rocker cover off after the misfire started. Fuel hoses not disturbed for over a year. But based on other comments I'm now thinking carb issues may make sense.

[cliff.b]

13 minutes ago, cliff.b said:

Aha, you have got me thinking straight now. The number 1 plug was dry and very white, so maybe fuel supply issues to front carb🤔

 

Also, regarding my question on vacuum advance, I checked the ignition timing by strobe, but forgot to disconnect the vacuum pipe and the mark was off the scale at about 26BTDC. When I pulled the pipe off at the dizzy end I could feel it was sucking and the strobe now showed 12BTDC which is what I was expecting.

So I actually wondered if this was connected with the original problem and took the car out to warm it up with the vac pipe disconnected to see if it made any difference to the noise. But I never got that far because a few miles down the road the misfiring started. And reconnecting the vac pipe made no difference.

 

Just thinking about this again, surely the vac unit can't physically give an extra 14deg of advance but maybe that was in part due to the increase in tickover speed adding centrifugal advance as well. 

Also, trying to understand if it is possible for a carb to generate excessive vacuum and then I wondered, if the front carb has a fault, could that increase tickover speed even though the butterfly on the rear carb was closed?

[Pete Lewis]

the vacuum is developed from air passing a small hole near the throttle plate  and is nothing to do with the vacuum in the manifold 

the vac unit has a start vac a end vac  and the max  amount of advance thats developed  need the manual to see the spec   

lucas are better  the vac unit has the figures stamped on    like 5 -11- 9  thats startat 5inhg  max +11 deg   end vac   9ins hg just as example

vac unit only advances at low throttle opening so it gets max advance when cruising  has no effect on any acceleration  its a economy devive of around +4mpg

if you dont have a balancer undo the clamp on the throttle  cross shaft   undo each idle screw , turn them in to just touch the casting , turn each 1.5 turns   nip up the cross shaft  and then both throttles are mechanically set the same   thats how they were supplied to the engine bench    on the assy line   .

pop the top off the float bowl  ...is the fuel level low when its misfiring    remove the float and needle  blow it clear backwards 

prime the pump to squirt some fuel into a jar  ....any tiddlers  ????

Pete

 

[cliff.b]

4 minutes ago, Pete Lewis said:

the vacuum is developed from air passing a small hole near the throttle plate  and is nothing to do with the vacuum in the manifold 

the vac unit has a start vac a end vac  and the max  amount of advance thats developed  need the manual to see the spec   

lucas are better  the vac unit has the figures stamped on    like 5 -11- 9  thats startat 5inhg  max +11 deg   end vac   9ins hg just as example

vac unit only advances at low throttle opening so it gets max advance when cruising  has no effect on any acceleration  its a economy devive of around +4mpg

if you dont have a balancer undo the clamp on the throttle  cross shaft   undo each idle screw , turn them in to just touch the casting , turn each 1.5 turns   nip up the cross shaft  and then both throttles are mechanically set the same   thats how they were supplied to the engine bench    on the assy line   .

pop the top off the float bowl  ...is the fuel level low when its misfiring    remove the float and needle  blow it clear backwards 

prime the pump to squirt some fuel into a jar  ....any tiddlers  ????

Pete

 

Thanks Pete 👍. I've not been too well and got very cold outside all afternoon. Think it's fuddled my brain 🤯

[Pete Lewis]

its looking a cold spell for a few days      stay warm 

Pete

[johny]

Surprisingly the Lucas vac advance on a Vitesse (presumably similar for four cylinders) can advance up to 26º so some advance at idle is to be expected👍 

[cliff.b]

1 hour ago, johny said:

Surprisingly the Lucas vac advance on a Vitesse (presumably similar for four cylinders) can advance up to 26º so some advance at idle is to be expected👍 

Ok, that's interesting to know. Thanks 👍

[cliff.b]

Well an interesting day.

The bad running is now cured. There was very little fuel in the front carb float chamber and I suspect the amount getting past the valve was not enough to meet demand. Valve cleaned and all running fine so clearly, as suggested, it was just a co-incidence. While there I balanced the carbs, which were way out and reset the mixtures as the rear carb was running weak.

 

On my test run I found the new oil seems to be giving almost twice the hot pressure for any given engine speed with hot tickover pressure of 15 to 20psi now.

[johny]

Come on then what about the noise! The only trouble is that youve done other things as well as change the oil so any difference in the noise could be due to any one of them😩

Have you got a paper fuel filter in the line?

[cliff.b]

Yes, well, regarding the noise.

I think I said near the start of this that I had a similar noise when my crank pulley nut fell off and I wanted to remove the pulley again just to confirm it wasn't causing it this time. But I couldn't shift the nut so decided to check other things out first, assuming as it was so tight it probably wouldn't be the cause.

Anyway, when I got fixated on valve gear yesterday I was turning the engine with a socket on this nut but forgot it was there and started the engine. A bang and a clatter and on the floor was the socket, my ratchet drive and the nut lol

Today, I ran the engine briefly without the pulley and couldn't hear the noise, but had to stop as the engine was getting rather warm (no water pump)

 

Once I sorted the carbs out I went for a test drive with the pulley on and no nut, and it did clatter a lot but the noise was not that different to before. 

So the next step is to put the pulley back on with the nut torqued up properly and listen carefully. The thing is, I will have inadvertently changed 2 things at once, so if the noise has gone I won't know if it was the pulley or the oil masking a bearing issue 🤔

[cliff.b]

26 minutes ago, johny said:

Come on then what about the noise! The only trouble is that youve done other things as well as change the oil so any difference in the noise could be due to any one of them😩

Have you got a paper fuel filter in the line?

And no, I don't have a paper filter. I do have one of those glass ones before the fuel pump.

I didn't find any sign of debris in the carb, but the float valve felt like it was sticking. After I dismantled and cleaned it moved easily. 

[johny]

I wouldnt drive it anymore with the pulley on and no nut as thats asking for problems.

A paper filter will stop smaller particles line tank rust than the gauze type but as your carb was clean that doesnt seem to be an issue. Its sounds more like the sticky float valve was down to residue from fuel drying out so maybe use the car more or at least refill the carb with fuel more often...

 

[cliff.b]

44 minutes ago, johny said:

I wouldnt drive it anymore with the pulley on and no nut as thats asking for problems.

A paper filter will stop smaller particles line tank rust than the gauze type but as your carb was clean that doesnt seem to be an issue. Its sounds more like the sticky float valve was down to residue from fuel drying out so maybe use the car more or at least refill the carb with fuel more often...

 

No, I'm not planning to drive it anymore without the pulley nut, although I may start it again tomorrow without the pulley to see if I can hear anything. (Or more strictly speaking, not hear anything)

 

Regarding refitting it, I was wondering if some loctite around the woodruff key might help eliminate any potential movement in that area. No idea if that is a good or bad idea as outside my experience. 

I'm guessing someone wiser than me will comment shortly, explaining why it's definitely not a good idea 😊

[johny]

I really cant see why just torquing the nut up to the correct setting shouldnt be enough - is it really floppy on the key? If it is wheres the wear and I suppose if a lot it could conceivably loosen the nut over time but surely it'll be held tightly to start with so cant be the source of any noise?

[cliff.b]

10 minutes ago, johny said:

I really cant see why just torquing the nut up to the correct setting shouldnt be enough - is it really floppy on the key? If it is wheres the wear and I suppose if a lot it could conceivably loosen the nut over time but surely it'll be held tightly to start with so cant be the source of any noise?

That was my assumption. If the noise has gone then I suppose the only way of proving if it was the oil is to put the old oil back in again lol

 

I don't see myself doing that so is anyone running their car on a tight budget and interested in some barely used Castrol Classic 😊

[johny]

Is the nut going to come undone again though? Sounds like youve been lucky a couple of times but it needs a reliable solution...

[cliff.b]

49 minutes ago, johny said:

Is the nut going to come undone again though? Sounds like youve been lucky a couple of times but it needs a reliable solution...

The manual says that nut should be done up to a massive 150 lbf ft and I doubt I achieved that when I previously replaced the lost one. But I have a decent torque wrench now and the plan is to make sure it definitely is that tight this time.

 

Maybe some loctite as well, just to be on the safe side lol

[johny]

I believe its designed to be self tightening as well, thats to say the rotation of the engine keeps it done up. Certainly I never achieve that torque setting (no way to properly lock crank) but its not come undone and is always well tight the next time Ive undone it....

[NonMember]

1 hour ago, johny said:

I believe its designed to be self tightening as well,

I don't think so. It's a standard RH thread on an engine that runs clockwise (viewed from front). This is necessary because early engines had a crank handle fitting on the nut, so the act of hand cranking would tighten it, not loosen.

[johny]

True, maybe it comes down to play in the pulley then - as mines a pretty good fit theres minimal movement that could apply force to undo the nut?

[Pete Lewis]

back to basics  the keyway takes the drive and must be a good fit  any slack and the pulley can pant/shuffle    the nut does some work but holds the pulley in place 

150 lbft is not very high ( wheel nuts on a truck can be over 300 and there 10 of them)  

you must lock the flywheel  do not put in gear  as 150lbft is far in excess of the engine torque/power the clutch hub is designed to cope with 

an  decent  impact gun will work quite well without having to block the flywheel 

use of one of the loctite products is ok remember it can make romoval difficult and depends just which loctite you use ( there are many for specific uses)

Pete

[cliff.b]

5 hours ago, johny said:

I believe its designed to be self tightening as well, thats to say the rotation of the engine keeps it done up. Certainly I never achieve that torque setting (no way to properly lock crank) but its not come undone and is always well tight the next time Ive undone it....

Mine was showing no sign of coming loose and I couldn't shift it with my longest bar. I had previously wedged a bar against the chassis and used the starter motor but it just stalled it.

On Thursday though, I accidentally did something I would not have intentionally done, leaving the socket & ratchet in place with enough space to gain momentum and the engine to catch. 

 

There is no doubt the nut was on pretty tight, but still possibly not as tight as it should be. Can't know if that was causing the noise and all I can do is put it back on properly and listen 🙉

[cliff.b]

1 hour ago, Pete Lewis said:

back to basics  the keyway takes the drive and must be a good fit  any slack and the pulley can pant/shuffle    the nut does some work but holds the pulley in place 

150 lbft is not very high ( wheel nuts on a truck can be over 300 and there 10 of them)  

you must lock the flywheel  do not put in gear  as 150lbft is far in excess of the engine torque/power the clutch hub is designed to cope with 

an  decent  impact gun will work quite well without having to block the flywheel 

use of one of the loctite products is ok remember it can make romoval difficult and depends just which loctite you use ( there are many for specific uses)

Pete

Maybe I will buy that impact wrench I was going to buy to get the nut off 🤔

[cliff.b]

Crank pulley refitted while leaky radiator out. Small amount of loctite around key, keyway and nut threads then up to specified torque.

 

Rad refitted and run up to temp, then rad out again (see cooling thread 😒). All back together and up to temp again and can't hear engine noise so far. Need to bolt rad in properly and then out for a proper run, but out of time today. Maybe tomorrow if not raining.

 

Interestingly, this Millers 20w/60 certainly gives a higher pressure but it takes longer before I see pressure on the gauge when starting from cold. The oil light goes out pretty much right away though. I remember someone else who had a start up rattle said it went on for longer with this oil. No noises from mine on start up with either oil but shouldn't a 20w60 oil have similar viscosity to a 20w50 oil when cold?

Not that bothered and will just crank for a bit before pulling the choke out, but just curious.

 

Anyway, will report back after I have had a chance to get things properly warmed up.