Lump issue, fuel rail

Does anyone have a photo of

a XK150 RHD showing carbs and fuel rail orientation? I blew it and did not take photos of the engine bay prior to disassembly. My RHD 120 has HD6 carbs from an XK150 or Mark whatever. The rear float bowl is touching the steering column, could these have been installed without the insulator? Nor can I figure out how to reinstall the fuel rail. There is not enough room for it to be routed between the carbs and the column, and if I try to fit it between the carbs and the manifold the rear banjo fitting would need to be rotated 180 degrees or so.

I might be able to move the column 1/4 inch, but that is still tight to the rear float.

Randy, it may be impossible to use XK150 carbs in a RHD XK120. The H6 XK120 carbs were set-up with the float chamber for the rear carb forward of the piston chamber. That was necessary to obtain “just enough” clearance with the steering column.

The RHD 120 also had a spacer under the RH engine mount to raise up the right side, something like 1/2 inch or more I think, to give it clearance over the steering column. Some RHD owner will be able to provide details.

I see Viart indicates two spacers, I do not see any dimension or indication from any of the parts providers. I do not find any spacers in saved parts even though they did save the old motor mounts. Go figure.

FYI the carb and fuel rail parts are what came off the car after I drove it for 10 years.

Should I go for 2 each 1/4 inch spacers and see what that does?

Looks like it depends on whether you have the rectangular mount or the round one.

I checked the archives and this subject of the packing pieces has come up 3 times, but no definite thickness was given. One posting thought it was more like an inch.

Awesome info, thank you Rob. My car is s/n 660753 with the rectangular mount. An inch seems like it would compress the torque mount a bit much?

Randy Brand

There were different distance pieces under the torque arms for different configurations. Also the torque arm could be bent to fit. And with HD carbs you may have to just try what works.
As I said, our information on this subject is sketchy.

Thanks again Rob!

Still trying to figure out how I went through one engine rebuild and drove it for 10 years now it won’t fit!

While Viart shows two pieces on the RH side, the XK catalog, and an old SNG catalog show one one each side, about the same thickness as the base plate of the rubber mount, maybe 1/8 inch thick.

I loosened the RH mount and jacked the engine until I barely had enough room to position the fuel rail in place, which appeared that would fit. I had to go up maybe 5/8 of an inch which generated a space of about 3/8”. So to make this work I would need a 1/2” spacer. However I think the bolt holes were too far out of alignment to to refasten (if I had the appropriate spacer). I am thinking that putting a 1/8” spacer under one or both sides is possible, but do not think that will do the job……

I am wondering if the stock carbs are shorter? I posed that question to Mr. Curto.

Do not assume that restoration books and vendor catalogues are right.
The XK120 factory Spare Parts Catalogue shows one packing piece on each side in Plate A. It’s a drafting mistake. Everybody else copies the SPC and repeats the mistake.

The stock H6 carb might be shorter, I can’t tell.

Here is a pair of H6 carbs.

Here is an HD6

You may have to bend the fuel rail with a tubing bender.

I think I see the problem. To Moana washers under the torque arm?

Too many washers

Well I took out 3 of 4 washers (about 1/2”), but only gained about 1/8” at the rear float. Might try removing the last washer tomorrow.

I don’t have a RHD car so some of this might not be pertinent, but here’s some data. The original carbs on an XK120 were H6’s and they were 5.5" long, and they did not have insulators. The HD6’s that you have are shorter at 5" long but you have insulators between them and the manifold which makes up most of that difference.

However, you will notice in Rob Reilly’s photograph of the original H6’s that both float bowls are positioned towards the front of the car. Yours, however, are not, with your rear float bowl protruding towards the rear and interfering with your steering column. I’ll bet that if you assemble your carbs with both float bowls towards the front your problem will disappear.

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Thanks Mike, been thinking about that but measurements indicate 0 or a little negative clearance to the starting carb. And there wouldn’t be any greater clearance to the steering column. Plus trying to figure how I rebuilt it once and then drove for 10 years before this exercise started.

With the front bowl as is, and the rear bowl facing right (like 3:30) the rail fits perfect when the engine is raised enough to make room. Next exercise will be to make a couple shims and see if that helps, but not sure how that will work as the mounts line up perfectly now, but won’t after any spacers are inserted.

I’m thinking Mike Eck is right, you have to put the rear float bowl in front of its carb.
I scrolled through RHD cars on XKdata and the first 4 I found were that way.

Even my LHD car is that way.

When you switch that you will probably find your fuel supply pipe is wrong. It may have come from a 150 which has a totally different steering column.

I think you can forget those washers under the torque arm. Start with getting shims under the RF motor mount. The #1350 Packing Piece shims are probably the same shape as the rectangular mount base plate. We just don’t know the thickness.
You can use washers to experiment and get the right height. Use a pointy tool to line up the bolt holes.
Do the torque arm last.

Its unfortunate that no RHD owners are responding. Perhaps they are not reading this thread. I suspect it is your topic title. Lump usually means a Chevy V8 is installed. Not a lot of interest here.
You can change the title to something like RHD 120 engine mount shims.
That’s the missing piece of the puzzle. What is the thickness of those two #1350 Packing Pieces?

I’ve never discovered the correct thickness for engine mount shims on an early RHD 120 with the mounting plate across the front of the engine. I used two base plates from old sandwich type engine mounts, so I suppose the thickness of the two would be around 1/4". It made a slight difference, but with the heat spacers fitted to the H6 carbs the rear carb’s jet assembly is still extremely close to the steering column.

Finally got it together with 2 1/8” shims. Not much clearance between fuel rail and steering column, but it is there!