Engine makes noise after overhaul

[Gerke123]

To me it sounds like something simply not set up right have you tried moving the distributor whilst it is running to see if it gets smoother?   

Yes, I tried this but there was no immediate change

[Gerke123]

I agree that valve clearances are likely not correctly set and frankly if your mechanic can not do that job I would worry about the rest of the work. Set stone cold spark plugs out by using the tappet depression tool one at a time after using a syringe to remove the excess oil. You obviously measure first with feeler gauges looking for 0.40mm inlet and 0.45mm exhaust clearances. The Haynes Beta Manual tells you how, but you need a decent stock of shims to replace those note the right size. Avoid shims smaller than 3.50mm to prevent cam damage. If you have saved shims from previous engines you probably have lots of 4.20mm! Note always measure the shim thickness with a decent digital vernier or micrometer. to check the actual size and never use shims with heat bluing or surface scuffing.

Good luck.

Eric 

I took some measurements on the exhaust side. the first cylinder is at 0.50, 2, 3 and 4 have difficulty reaching 0.30........

I will see if I can obtain the special tool somewhere in the Netherlands.
It's a shame about the three hours of work the technician put into this.

-Gerke

[peteracs]

Hi

It is not a shame, I would tell him where to get off and not bother using him, never mind asking for my money back…….

Hopefully it has not caused any long term damage. Time to check the inlet side.

You should be able to find the tool easily, here is one advertised for Fiat 124 in Germany (same twin cam engine) but should be widely available at around 50 Euros.

https://shop.wum-autoteile.de/Valve-adjustment-tool-Fiat-124

Peter

[Gerke123]

Hi

It is not a shame, I would tell him where to get off and no bother using him, never mind asking for my money back…….

Hopefully it has not caused any long term damage. Time to check the inlet side.

You should be able to find the tool easily, here is one advertised for Fiat 124 in Germany (same twin cam engine) but should be widely available at around 50 Euros.

https://shop.wum-autoteile.de/Valve-adjustment-tool-Fiat-124

Peter

Hi,
The man from the garage comes to check the valve clearance in around 1-2 weeks time. He wants a chance to correct his mistake and I think I should give him that chance.

Thank you so far and I will keep you informed.

-Gerke

[Gerke123]

Hi,

Today I spoke with the man who overhauled the rotating part of the engine, so not the guy who did the valves. He advised to check the oil for aluminum particles in the bearings. The oil was clean and clear so this is not the case. He said that if the valves are too tight you should not hear a ticking sound, only if they are too wide......anyone have experience with this?

Gerke-

[peteracs]

Hi

In theory, yes, too wide gap will result in a noise, which is the cam hitting the shim on the steep part of the cam, ie instead of ‘gently’ reducing the gap. However if too small a gap maybe it is falling foul of something else?

Also you only posted the exhaust side, not the inlet side values?

I recently visited a fellow Spider owner who has a long knowledge of these engines and he had a chat many years ago with a Lancia factory mechanic whose comment was that the engines work best if you can hear the tappets, ie gap them on the loose side of the spec. This is purely anecdotal, so make of it what you will…..

Peter

[Gerke123]

Hi,

I took some more time and now come to the following measurements.

E1 0.20 E2 0.15 E3 0.20 E4 0.20 now the inlet.
I1 0.15 I2 0.25 I3 0.20 I4 0.25

What it should be E 0.45 - 0.51 and the inlet 0.39 - 0.45

there is a difference......

[peteracs]

Hi

Yes, not good. Hope you can get it sorted out correctly.

Peter

[HFStuart]

It seems unlikley that the clearances being 0.2mm too small would produce so much noise but I hope it turns out to be something simple.

[Gerke123]

Hi,

The mechanic at the garage has now adjusted the valves correctly and unfortunately the noise is still there.
I'm going to take the engine, subframe and all, out again. I don't know anything else either.
According to the mechanic, the noise is louder at the bottom of the engine than at the top.


Gerke-

[WestonE]

Hi Gerke,

When you have the sump off check if number 2 conrod is hitting the fuel pump lobe on the Auxillary shaft. The Aux Shaft has to be precisely positioned at TDC or it will hit eventually breaking the conrod and punching a hole in the block. If you no longer use a manual fuel pump it is common to cut off the fuel pump drive lobe and insert a plug into the oilway after careful cleaning. With this done there is no need for precise timing of the Aux Shaft. How to do this is explained in Guy Crofts workshop manuals.

Of course if your mechanic sets the shaft in the right place it does not hit the con rod.
Otherwise look for a loose oil pump or oil drain pipe hitting the crank. After that it becomes poor assembly or incorrect bearing sizes.

Unfortunately I have now seen these things too often from engine builders who should find other work!

Eric
PS with a bore scope you can inspect each cylinder through the spark plug hole looking for strike marks on the pistons from the valves. If standard pistons have been re-used which is rarely a good idea then the wrong size class in the wrong bore will create piston slap which is noisy. OE Size classes are stamped on the crank case sump join for each bore at the factory and detailed in GCs books.   

[peteracs]

Hi Eric

Good call on the aux shaft, that may very well explain it.

Peter

[rossocorsa]

Hi Eric

Good call on the aux shaft, that may very well explain it.

Peter

Easy to check visually if the pulley is in the right position without taking anything apart

[Gerke123]

Hi Eric,

This is a photo of the setting before installation. Visually it seems to be going well. I did use a different axle than the one that came out, but visually there was no difference.

[stableblock]

Its hard to see from the pic but looks like you could be a tooth out on the aux shaft.  Certainly worth a closer look, dont adjust and run the engine unless you are sure.  It should turn over by hand cleanly with the correct timing of the aux shaft but it might be hard to detect if there is only marginal contact.

[squiglyzigly]

The belt is not fitted correctly.
The teeth are not located on the left side of the aux pulley.
If this was run like this then is quite likely the timing moved.
The belt would be also be under tensioned as soon as the teeth slip into place and unlikely to stay correctly timed.

I hope this was adjusted before installation.

Ian

[HFStuart]

Hi Eric

Good call on the aux shaft, that may very well explain it.

Peter

It's also what I suggested two weeks ago

[WestonE]

What Ian (Squiggly Wiggly) Said I agree with.

Eric

[stableblock]

Good spot from the pic. Might need a new tensioner spring too.

[Gerke123]

hi to all,

This photo is taken before i turned the engine by hand, and all teeth were neatly in place after turning. I'm going to dismantle the engine in the coming weeks and will check the aux shaft first.

I'll keep you informed.

Gerke-