Su carbs

[johnj]

Hi all im sure this is covered somewere on here but cant find it anywere so if someone can direct would appreciate it
i am converting a USA E type series 1 1/2 1969 4.2 litre from stromburgs to triple SU , carbs are all rebuilt and ready to fit
Its a Very tight and i cant get manifold on to motor do i need to lift engine ?

Thanks John

[golfnut324]

Hi John,

I had no issue with clearance while installing my triple SU manifold/carb assembly on my 1968 series 1 1/2. However, I do have new motor mounts. If your mounts are old and/or sagging it might cause your clearance issues. Also, if your engine is sitting low and you don't have enough clearance around the throttle linkage, your throttle linkage might hang on the frame rail and leave you screaming (literally and figuratively) down the highway.

Let us know what you find out.

[christopher storey]

It is not widely known that with a 4.2 engine with SU carburetters , there should be a spacer inserted under the right hand ( carburetter side ) engine mount which lifts that side of the engine by about 1/4 inch or perhaps slightly more. This prevents the carburetter linkage chattering on the upper frames when the engine twists under torque , and besides the fact that it prevents damage, it also prevents the linkage getting jammed with potentially dangerous consequences. I would guess that this spacer is missing on your car and/or that collapsing mountings are contributing to the problem

[mgcjag]

Hi Christopher....there are packing spacers specified in the parts catalogue C18242 for "as required" but dont know of anything that says just on carb side.....is it documented anywhere that you know of.....seems odd that Jaguar would spec something like this as required.....Steve

[ralphr1780]

It is not widely known that with a 4.2 engine with SU carburetters , there should be a spacer inserted under the right hand ( carburetter side ) engine mount which lifts that side of the engine by about 1/4 inch or perhaps slightly more. This prevents the carburetter linkage chattering on the upper frames when the engine twists under torque , and besides the fact that it prevents damage, it also prevents the linkage getting jammed with potentially dangerous consequences. I would guess that this spacer is missing on your car and/or that collapsing mountings are contributing to the problem

Pleased to read this comment Chris , I was not at all aware of this important matter.
Recently I made the conversion for triple SU on my S2 and after quite some struggle decided to lift the engine and fit a spacer exactly as you state. The engine mounts are rather in good shape but this got me thinking could be thicker ones available on the market?

[christopher storey]

I think the answer to Ralph's question is catered for by the " as required" mentioned by Steve. If one spacer does not lift it enough, then add a second one - or even more I suppose in an extreme case.

I only learned of this need for spacers when I attended a JEC seminar some years ago, and David Marks gave a lecture which included this point in which he said that the spacers are often mislaid/forgotten if the engine is removed or the mountings replaced

In relation to an earlier query about why the spacer is only on the right, I imagine this is 1. to prevent the front of the engine being lifted too much and 2. to cause the engine to lean slightly to the left thus maximising the clearance under the linkages

[johnj]

Thank you all for your replys very much appreciated ,
After a bit of messing around and lifting the engine they are on and bolted in place
At present dont need to shim but will look at that when motor is running as this has been a nut and bolt resto
Also a conversion from LHD to RHD so few more bits to do then onto first start in many years

Cheers again john