Twin SU rebuild question

[paul staines]

Finished cleaning/rebuilding carbs. Noticed when removing from manifold that no washers were fitted,feel sure they should be there. Are they anything special or will any washer do. I have all new manifold nuts. The carbs cleaned up great just using solvent cleaner a toothbrush/soft wire brush and WD40.Sprayed the heatshield with BQ paint. Intend to wire brush and spray the manifold silver tonight. Just got to keep myself from going too far and pollishing the carb tops. regards Paul.

[Quarterless]

There should be some large thick slightly domed washers which hold the inlet/exhaust manifolds on the head. They could be replace with other similarly large washers. There are two top ones that have mounts for the carb return springs also.

[Bladerider]

Paul, do you mean washers on the studs that mount the carbs to the manifold or the studs which mount the manifold to the head?

If the former, I put washers on (didn't exist before), but then I'm an engineer.

If the latter, see above.

[paul staines]

HI its the studs that mount the carbs to the manifold/heatshield. I do have 2 new washers with spring mounts on them. Thanks Paul

[Ron Kwas]

Paul;

There should be washers, but there is a detail which you need to answer first.

What manifold(s) do you have?

If you have a one-piece intake/exhaust manifold, typical, thinner washers would do fine...but when you have the separate alu intake and cast iron exhaust manifolds, a gap exists between the two manifolds, right at the stud, which the thick oe washers are much better suited to bridge.

...and when installing a header, its flange is typically much thinner than the height of the bolting surface of the alu manifold...this step must also be bridged by fastening hardware, which requires other measures, but I don't think you have that situation to worry about...unless you advise otherwise.

Cheers from Connecticut!

[paul staines]

Hi Ron. Its cast iron,and is a one piece inlet/exhaust manifold. When removed no washers on anything !. Although it ran fine like this i would like to put it back correctly. Regards Paul

[simonvolvo]

Confusion.

Paul is, I think, talking about the nuts that fasten the carbs to the manifold and Ron is talking about the nuts that fasten the manifold to the cylinder head.

I have a 122S made in 1970, with the twin SU’s, and I’ve had it since new. There are no (and never have been) washers under the nuts that fasten the carbs to the manifold.

[paul staines]

Yep thats spot on Thanks. Will rebuild without washers.

[PenR]

Simonvolvo is 100% right - installed my rebuilt carbs and exhaust manifold today (single exit downpipe into Simonz frontpipe)
All was easy peasy except for the throttle linkeage - bit of a sod to get running smoothly through its action (twin su 122s)
Cheers
PenR