I am putting a 120 driver back on the road that has a ’62 EType engine with a three carb set up. I would like to remove one of the carbs due to body interference. Does anyone know how the engine will operate with two carbs? Or any suggestions?
You will need to find a duplex manifold. The E manifold requires three carbs.
First be sure it is really from an E and not a Mark X. You will get more for the 3 carbs and manifold than you will have to spend on a two carb manifold and carbs. Look for a '51-54 Mark VII manifold and two H6 carbs, which are exactly the same as the 120 had originally. But I don’t actually know if that manifold will fit on an E-type head. Might have to use one from a Mark 2.
Richard,
A number of options.
Its not just the triple 2inch HD8 carburetters but also the straight-port head fitted.
XK120 originally had an A-type head that uses a different matching inlet manifold to then mount its two 1-3/4in carburetters.
You can retain your straight-port head, but will need to find an Inlet Manifold of a 420 saloon that does match, and takes two only of the 2in HD8 Carburetters. If you try and use an XJ6 Series 1 manifold, there are complications with connecting to your radiator, and efforts I have seen are ‘not nice’
But a straight-port head, 420 Inlet manifold and 2off 2in HD8 carburetters does work well, indeed have done it a couple times including a long term ownership 3.8 mod Mark 2 with no adverse issues having been done properly.
Otherwise, your best option is to return to an authentic A-type head, authentic XK120/Mark VII Inlet manifold and two authentic H6 1-3/4in carburetters. You can never go wrong returning an XK120 to original - Jaguar made 120000 that way, and they all worked fine.
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Roger,
Thanks for the info. Yes, it is an original ’62 XKE engine. I pulled the
engine, trans and instruments from a wrecked XKE back in ’66. Is there any
reason I can’t just remove the third carb and cap off the port?
It wont run properly.
Each of the three carburetters feeds their own two cylinders, so if you retain that inlet manifold with one carburetter not used, you will be running on four cylinders only. Not nice!
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If you really have an original 3 carb E-Type setup then there should be no problem at all getting a two carb manifold with the carbs included, since that is a swap that many E-Type owners love to make. This is what you have:
https://www.ebay.com/i/382344800580?chn=ps
and this is what you want:
From the looks of things you should make about $3000 on the deal.
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The LAST thing you want to fit to your XK120, are these troublesome, emissions detuned Stromberg carburetors, and on a manifold that requires a hot air box connection to your exhausts (can be blanked off) and major difficulties connecting into your cooling system.
But Mikes point is valid, the value of your E-type Inlet Manifold and Carbs, would easily pay for you to retrofit a more authentic XK120 set up - you just need to decide what you want to do.
If my car I would source and fit an authentic A-type head, inlet manifold, and twin H6 carburetters, as per authentic XK120 fitment. All will still fit OK onto your 3.8 E-type block.
I am just speculating here but looking at the stromberg manifold it looks to me like the hot air box part of the manifold could be unbolted and then 2 su carbs bolted directly to the branched portion. A couple of coolant ports would probably have to be plugged since the head is 3.8 and the manifold is 4.2. I seem to remember some discussion of this a few years ago but my memory is somewhat fuzzy. This would solve the problem of the straight port head as well as the clearance issue plus you would have the bling factor of 2 inch carbs. Perhaps someone knows if this is a possibility?
Found a bit of a discussion on the etype uk site. Sounds like it is possible to bolt carbs directly to the primary manifold with a bit of reworking the attachment holes. Filling and redrilling. I am thinking that a short adapter might be a possibility if there is enough clearance.
I have a complete twin SU intake from a 420 that would bolt up for you. I’m sure we can work out some sort of swap.
You have a lot of options and plenty of advice here for going in different directions.
Tell us your chassis number and we may be able to give better advice.
For myself I favor original spec, like if you got hold of this guy’s engine you would be 70-80 percent back to original.
Drook,
Will the SU/420 manifold you have accept the 2 inch HD8 carbs? I’m looking
for an easy set up. I saw a set up on an XK6 that looked good.
If you mean XJ6 and not XK6, then the XJ6 has connection problems with manifold to radiator, which is straight forward with 420 Manifold, but can be done, although not all that nice and may well have some impact on cooling. Not sure, but not nice.
Also XJ6 has HS8 carburetters and a troublesome AED, albeit I cant be sure off hand what was on USA XJ6 as US cars now wearing emissions regulations affect on Carburetter choice.
A 420 has HD8 carburetters, but with auto-choke as per Mark 10 HD8, with E-type having manual choke HD8.
The better you source your parts, the less problems and compromises you need to resolve.
For my money grab the 420 Manifold on offer, and then worry about finding a pair of HD8 and linkages to suit.
Roger
Roger,
This is the type of set up I’m trying to copy. Can you tell me what it is?
I thought it was an XJ6 with HD8 carbs.
Richard
If you provide a picture it would be easier to respond - otherwise a struggle to get up to twenty word requirement.
Looks like a pre-emissions control Series 1 XJ6, so the HD8 carbs should be OK.
Bit notice the front end of the Inlet Manifold with in-line thermostat housing and difficult/close connection for top radiator hose. 420 Inlet manifold has more space at the front end, and thus much better connection to radiator.
But make sure you do get these same components, cant see the pictured car giving up its inlet manifold and carburetters.
I still say getting the best parts up front is always the best solution, as you want to minimise the compromises and problems when you try to mix and match components from different models and ages of Jaguars
that is an “early” S1 XJ6 (with HD8)…note the Thermostat HOUSING is variant in different Saloons and XJ, and can be “transplanted”, affecting water hose situations