Straight Port v B head

Correct and on the bumpers. My 340 had the large bumpers.

Interesting theme, the suggestion left over Mark 2 parts being used up for US market LHD cars, but canā€™t say I have ever heard of anything similar re original RHD cars in Australiaā€¦ I am aware of 240/340s being restored, substituting Mark 2 bumpers as a preference, and improved sales appeal (in Australia) given the 240/340 are less loved than Mark 2ā€¦ And there is a fully restored RHD 340 on SaloonData that has been given the Mark 2 bumper treatment

It would help if we understood basis/definition of what is it that makes a car be identified as a 340, rather than a Mark 2. (regardless of any build variations)

Is it simply a case of having a ā€˜340ā€™ badge on the boot lid, rather than a ā€˜Mk2ā€™ boot badgeā€¦
Or is it based on the Chassis/Car Noā€¦ now being in the new 340 series with 1J prefix, and LHD from 1J80001 onwards. I do note that of all the LHD 340s listed on Saloon Data, including the earliest 1J80030BW, none show as having Mark 2 bumpers

TimG - do you recall your Chassis/Car Numberā€¦

Roger, I agree that itā€™s an interesting topic. Thereā€™s the historical question of what constituted a 340 and the performance one of why they (or at least the ones sold in the UK) were so fast. The 1J prefix cars are definitely 340s and fit in with the spare parts manual (in as much as it can be relied on). Presumably a factory re-badged car will not have the 1J. There are also a lot of 240s and 340s that became Mk2ā€™s in the UK. The DVLA (car registration authority) didnā€™t help by grouping 3.4 Mk2 s and 340s together as Mk2
3.4/340 when they computerised their system.

Quite a few of the books add to the confusion. Paul Skilleter, who is usually accurate, wrote that the 340, unlike the 240, kept the B type head in his Jaguar Saloons book. Perhaps, he was thinking of the US cars? 340s Iā€™ve seen in the UK have the end most spark plugs at the outermost position making them straight port.

Perhaps this deserves a new thread?

It seems we have established beyond any doubt that not all 340s had a straight port head, as vouched for by jagman66E ; presumably the earlier ones still had the B Type. Next question is, were the B Type heads painted blue like the 3.4 Mk2, or silver like all later SPHs, gold being discontinued earlier (1967 ?) BTW, Skilleter, whilst stating the 340 retained the B Type head, also, in the Mk1 chapter states that the performance can be improved by fitting the SPH setup from either the 240 or 340, so a slight contradiction there.

Are we being hasty making conclusions on one example??? I always like to have preferably several confirmed examples before concluding anything at odds with the previously accepted wisdomā€¦
jagman66E said his 340 with B-type head was ā€˜numbers Matchingā€™ - can he confirm his cars Car/Chassis Number and also its Engine Numberā€¦


I know manuals arenā€™t infallible, but itā€™s another snippet.

Flogging a dead horse, but the S Types were subject to the same cheapening process as the 240\340, ie Ambla interior, loss of foglamps etc. In the interests of rationalization, why did they continue with the B Type head and not go SPH at the same time as 340; after all, the setup would be identical? Either they continued with B Type to use up existing stock, and if so why not also 340 until stocks depleted? Or, the SPH engined cars did not perform sufficiently well in the heavier S Type. I know the 420 was even heavier and SPH equipped, but it had more torque from the 4.2.
The 340 soldiered on after the demise of the S Type; did they run out of B Type heads at that point and thereafter use SPH on 340?
Just a thought.

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Kevin, I think it was mainly a matter of using up stock. The 340 got the SPH because it was planned to run on longer than the S type. Itā€™s interesting that some 340s were ordered with 3.8 engines. According to various authors, Jaguar used 3.8 engines from the S type line for these special order cars. As standard 3.8 engines with the B type head, they may well have been slower or at best no faster than the fastest 340s with the most upgraded 3.4 engines.

I believe the 340 3.8 actually had the sph of the 340 3.4, so not the same as the S Type.But if just using up old stock, why not use it all up on the S Type and 340 simultaneously until gone and then use the same setup with sph on both? Installation would have been identical with both and it would have simplified production and parts supply? Perhaps thatā€™s what did happen and 340s got the sph after B Type units were either all used , or at least accounted for in projected S Type production.

Just wandering whether we are not seeing the obvious hereā€¦
The introduction of the USA 1968 Federal Exhaust Emissions standards had a huge impact on all XK engines in all Jaguar models destined for the USA market, but equally had no impact at all of course on ongoing XK engined models sold in the UK home market and all RoW (Rest of World) markets, including Australia, Europe, Asia, Middle Esat etc etc

With profitable/in demand models such as the E-type, it was the USA markets 1968MY Emissions requirements that was reason for the total emasculation of the E-type engine, which amongst other things resulted in the fitment of twin Strombergs instead of retaining the triple 2in SUs as in all other markets - this aspect being the most obvious, but having been directly involved in Vehicle Certification, there was a huge amount extra involved, in having a model certified and legally allowed to be sold in a regulated market such as USA. There was not any similar effort I am aware of for any of the existing range of Jaguar Saloons to go through the incredibly expensive process of being re-engineered and then certified to comply with the USA 1968 MY Emissions legislation. Now most people will be aware that the last LHD 340 was built in August 1968 (last LHD 240 in March 1969), but if you go onto Saloon Data you will note that the majority of these last 240s (not ever sold in USA ? - correct me if I am wrong) and last 340s were sold to Europe and other LHD non-USA markets, as they would have been illegal after 1st Jan 1968ā€¦ Now again if I use the E-type analogy, the USA market also introduced 1967MY and then 1968MY Safety Regulations which amongst other things resulted in the so called ā€˜pop-eyeā€™ Series 1-1/2 E-type, but also other safety related modifications to door latches, switches, interior door handles etc etc, with similar modifications never made to the 240/340. That to my mind would suggest that that was the main reason for the Mark 2 being discontinued from the USA market with the last LHD Mark 2s being made in August 1967. So given the totally new Safety and Emissions compliant new model XJ6 was introduced in August 1968 (along with the also 1968MY complaint Series 2 E-type), you had a 12 month period where Jaguar introduced their run-out revised 240/340 for the Home and RoW market bridging the gap to the new XJ6 replacing all of the compact saloon rangeā€¦ So with no safety/emissions regulatory difficulties/costs Jaguar was free to run out all parts as it best suited them, very much the same way as they also did with the RHD and RoW LHD Series 1-1/2 E-typeā€¦
I have no doubt there are 340s in USA (and maybe now the rare 240), but I suspect they all came in via Canada, or home-delivery/military/diplomatic imports and were not 1968MY Safety and Emissions compliant. Forget the badging on these cars, whether Mk2 or 340, as before I would like to see whether these cars have 1J prefix chassis number or notā€¦

Jaguar would have built 240s/340s to their best guess marketing priorities of their home and export markets, so I would think could well have been build variations accordingly - so I would be looking at where a 240/340 was sold new as a start to explaining any build variationsā€¦ again look at SaloonsData - quite a diverse new market place for 240s/340s relative to Mark 2s

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Hi Peter

If I may shed a little more light on the SPH fitments
I am lucky enough to own one of the almost mythical 3.8 340,s
and back in 2001, I sat down with the JDHT archivist and discussed these rare models
There are 4 models known to exist from a total production of 13 being 12 RHD and one LHD
They were built between November 1967 and May 1968 and I have seen 3 of them and a photo of the fourth.
I have also seen late 3.4 models registered as 340,s with B-type heads and big bumpers
These must have been run-out models towards the end of production
To add to the mystery the engine numbers on the 3.8 340,s were either ā€œEEā€ prefixes or ā€œSEā€ prefixes
Jack White of the JDC magazine has published my findings in the club magazine in 2001
andFEB2016

Brian,

The EE prefix usually indicated experimental or special order. I think the lightweight E types had engines with the EE prefix. What you write also agrees with Bernard Viartā€™s Jag Lovers article on engine numbers. Iā€™d read of the use of the EE numbers in the 3.8 340 before, but forgot about it. Iā€™d also read of the use of S type engines. Unfortunately, the wrong info stuck in my head.

A while ago Historics auctioned a car that was supposed to be a 340 3.8, but the numbers (and the bumpers) seem all wrong.

Have you come across that car? As a matter of interest, is yours SPH or B type. Itā€™s easy to see if the spark plugs of number 1 and 6 cylinders are on the extreme ends of the block, outer side of the combustion chamber, (SPH) or not (B type).

It would be nice if the JDC articles could be put on an internet site or something to reach a wider audience.

ā€¦ forgot to say, yes, you are very lucky!

Hi Peter
The 3.8 340s have a straight port head with a pair of HD6s,s and one piece inlet manifold with a water jacket the same as a 420ā€¦


Painted silver
When I fitted 2-inch HD8s I was surprised to see that the inlet ports were 2inches already so a straight forward swop with only the airbox differing because of the different carb spacings Note the rad top hose is different
That was a very nice car in your link but as the text says modified from original
Brian

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Brian, Thatā€™s a very special car that you have. It must be impressively fast as well!

I suspect stock availability played a major factor in giving SPH to the 340 models. However, it might have made sense to reserve the B type head for 3.4 S types because the greater weight of the S type would have favoured the lower down torque of the 3.4 in terms of giving relaxed town driving.