XK6 Engine Education

When I did the test, I pulled one spark plug at a time and then put it back before doing the next one. A family friend just told me to remove them all before doing the test. Will either method work or do I need to redo the dry test before doing the wet?

Remove all spark plugs and fully open carb butterflies plus raise or remove the carb pistons

Still, the values are relatively even, besides #2: try again without plugs and everything open, and do the wet test (with a shot of oil) to see if it’s rings or above. Expect some improvement, the question is: are the values even? I don’t think they are too bad as tested.
Put the plugs in and empty a can of brake cleaner to get everything nice and clean.
Nice plugs.

Are you saying a straight port 4.2 inlet manifold with strombergs will fit a 150 S head. Or is the inl. man from a 420 with twin SU’s the only way to go.

If a 150S is a straight port head (I don’t know) it will fit.

The cylinder head in the photo is from an early 420. The H8 C-type carbs are manual choke. The 420 manifolds have plumbing for an auxiliary starter carb, like a XK120, which I did not need.

Most E-Type manifolds, even those buried under layers of emission control band-aides, have much better cosmetics than the equivalent saloon item.

I don’t know anything about the Stromberg carbs, but I’ve never seen anyone describe them as desirable. I needed a straight port, twin carb manifold.

Because large numbers of Series 2 E-Types have been converted to the 3-carb HD8 spec, these manifolds are dirt cheap.

Yes a 150 S is a straight port, and like you I would like to assemble and install a SP head with twin HD8.
420 manifolds are non existent.
Thanks for info.

Interesting because I think that’s the type of simplicity I’m seeking. My question is… Is it crucial to have coolant flowing through the intake manifold? I would imagine that the answer is yes, but I found this example and it’s interesting. I’m assuming it works…

Certainly looks like a custom job. Seems like if one is wanting a 2 carb intake manifold, it might be reasonably easy (relative term, I realize) to have one fabricated. The templates are there already … use a manifold gasket for the engine and a gasket for the carburetor you want (making sure they fit perfectly). Have those gaskets scanned into a computer and the metal pieces cut with a CNC machine and then have a sober and competent professional weld it all together.

If I’m off in my thinking, let me know.

Round two for the compression test. This time I removed all of the spark plugs and did a wet test with each cylinder. Results are as follows…

(1). 175
(2). Several tests… 115, then 150, then 125
(3). 165
(4). 175
(5). 165
(6). 170

So looks like the #2 cylinder might be a problem. If I had to pop the top and replace the piston rings, I guess I may as well do them all. Not in a hurry to do that… just musing aloud.

Did you do a leak-down test as well? That should tell you if valves or rings.

Is this setup for a 1/4 mile car, with a sealed cooling system?
Surely for a road car coolant through the head is required as per photos, or
perhaps the Webers are combined with a air cooled conversion. :laughing:

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Those Volvo Carbs will supply almost all the parts to convert SU HS8 carbs into full manual choke.

The choke parts are hard to obtain and quite expensive, some are NLA and have to be fabbed, good find.

unless you obtain correct E-type HD8, which have manual choke inbuilt, the Saloon HD8 cannot be converted without a lot of work

So long as ambient temps are above 70F (16C) and humidity is low, you can get by w/o intake heated by hot water.

Yes Paul but you need water to flow from the head to the rad,
Peter B.

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True dat, and I do not see any path for that in that one pic. Thanks for making that point.

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Well, perhapts work in progess.

What Peter and Paul said. There is no coolant path to the radiator/water pump. You can get away with that on a drag race car. You fill the block with grout and put an atmospheric coolant reservoir on the cylinder head. Run for 30 seconds then shut off.

Or pipe it through a core plug in the head valley or the block.
Whatever, seems like an intake idea not well thought out. Don’t you usually want intake air heated for better vaporization?

I’m picking a burnt valve on this one if these were with oil. I agree the next test needs to be a leak down.

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T’would be an interesting dyno stand project: like many old engines, which used the head plugs in a manifold, I wonder if the flow paths that Jaguar carefully designed to work with the stock manifold would work properly.

You would not care about that for racecar. Squirt a little fuel down the velocity stack and hit the button.

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