Long stud straight port head....or short?

[Wilder]

Hi all, I am best described as technically incompetent, and so am asking a question i am sure a few will be able to answer.
I have a S2 in need of a long stud straight port cylinder head to match my original block.
I have this one (pictured) available to be refurbished, but no one I know can tell me which it is.
( I believe this may be from a 240 which I also believe used the same head as the S2 E type, along with the 420g - but that may be BS for all I know)....
I am sure mine is a long stud block as I checked the engine number with SNG, so the question is...is this the right one?
many thanks all for taking a look.

[christopher storey]

That looks to me from the top picture to be a later long stud type head, as it has the slight rearwards extension at the back of the head

Your block , whichever it is, will be unmistakable.Short stud blocks have the studs solid within the block face. Long stud blocks in contrast have the stud coming up through an untapped hole in the top face, and you can waggle them very sightly from side to side

[PeterCrespin]

I can see what Chris means but the head is a straight port Series 2-compatible version without the extra two cooling holes at the back. Your block should have the same two oil drain holes at the back and no pair of extra coolant holes.

[Wilder]

Thanks that is interesting.
Does the fact that this head does not have the extra cooling holes mean this should not be used, or does it have any negative effects if it is used?
I do not want to use anything that could possibly be detrimental, or compromise the longevity of the engine .
Further to that , can be extra cooling holes Be drilled into this head? or do I need to obtain a long stud head with the extra cooling holes for the long block ( which I believe my engine is)?

[PeterCrespin]

If your block has the extra holes you’d have to blank them off. Usually it’s the other way round. If I was you I’d look for a Series 3 XJ4.2 big valve head which would drop on without the hassle of plugging its extra holes first.

[Wilder]

Sadly I have all this hassle because that is exactly what is fitted, and on a nut and bolt restoration (being sold as a matching numbers car) a 20 year newer head is the last thing I needed. I have to go with the right head whatever that may be...I just do not know exactly what to hunt around for.

[Tom W]

How about this one? https://rover.ebay.com/rover/0/0/0?mpre ... 2973326856

I don’t know anything about the seller, just spotted it on eBay.

Incidentally, does this mean you have an S3 xj6 big valve head you’re looking to sell?

[Wilder]

Hi Tom, yes I will be selling as I need to recoup money towards getting and restoring the correct head..
Here is a couple of pictures. I believe it is a S3 head on an original and correct 4.2 long block, but I am sure you guys will be able to confirm or deny this.
Unfortunately all i know is the valves on the S3 big valve head should be 1 -7/8" instead of the normal 1-3/4" valves...
I hope to get the company to take the head off this week so we can wrap it up for sale, and also confirm (with pictures), as well as measuring the vales etc, so anybody who is interested can satisfy themselves as to what head this is..
If you have any questions, then please ask...
The MD of the engineering company did all the work himself, and it is simply stunning with everything you would expect from (what I thought) was a top quality restoration on anE type S2 head....... All new parts fitted... I will post more detailed photos once we take the head off. I also have all the gaskets seals etc as we found out before the engine was run.

[Tom W]

That does look smart, pity it’s not the correct spec for you. I don’t know how you identify a big valve head from the outside. Measuring the valves when it’s removed would confirm. It does look like a later head though. You have the later style cam cover on the RHS, with the half moon bung filling the aperture where the head was line bored. Earlier heads have an extended cam bearing cap and metal bung which fills this hole, a legacy from the tachometer drive. My S2 E-type has this style.

If it is a big valve head, I would be interested, depending on price and how far away you are. If it has standard size valves, it won’t be any change from what I have.

Thanks, Tom

[Wilder]

One more picture I found of the valve side... Perhaps someone might be able to tell more from this photo.
I believe from Carl at Rob Beere racing that there are discernable differences...I cannot remember exactly what he said, but I think the S3 has a double chamfer where the gearbox slots into the block, where as the non big valve head only has a single chamfer (?)..

[mgcjag]

Hi Wilder....whats your name...please try to put it with your car model details in the signature area......why not post in the wanted section for a head.....you never know what members have tucked away and you may also be able to do a swap.....Steve

[johnetype]

I'm sorry if I've misunderstood but this seems very strange to me. You have an already assembled engine with the most desirable head already fitted and you are looking to take it off to replace it with one you don't yet have when at the same time you are past the point where there's a matching engine number on the cylinder head and from an external view there's no difference

[politeperson]

Is this whole thread some kind of strange windup? On so many different levels?I dont know where to start?

[Wilder]

First of all there are significant differences which you can spot from a mile once you know what to look for
I will give you just a couple of examples.
1/ The logo on the cam cover is a vinyl sticker on the inlet side where the E type had an embossed or raised Jaguar motif (as in the picture)
2/ there should be three bolts in the top of the head which are missing from the S3 head as they are just plugs
3/ The rear of the inlet cam cover is squared off and not semicircular as the E-type heads were.

The matching numbers question was resolved and I posted that elsewhere .
Nobody provided an answer as to when the series 2 heads ceased to be stamped with the engine number, but I did get the answer from Jaguar heritage . The head ceased to be stamped with the engine number when they moved it from the block to the flange on the Bell housing, engine number7R 6306 .
I would have thought the reason I want to return it to the same state as it left the factory would’ve been obvious. On a matching numbers car undergoing full nut and bolt restoration , the values are hugely disproportionate, as one is all matching as it left the factory and the other has a head on it from a car that wasn’t even built for another decade or so.
By all means if I’m missing something , please let me know

[Tom W]

Makes sense to me.

[mgcjag]

The cam covers are easily swapped(note black ribbed covers with or without cutouts on the top depends on engine No)...and the caps could be replaced with hex plugs..it will still be a matching numbers car as only the engine block and gearbox are numbered......It is debatable but i have yet to see a nut and bolt restoration that look the same as when the car left the factor...they look far better....Paint and plated items are just two things far different from factory....Steve

[Wilder]

The cam covers are easily swapped(note black ribbed covers with or without cutouts on the top depends on engine No)...and the caps could be replaced with hex plugs..it will still be a matching numbers car as only the engine block and gearbox are numbered......It is debatable but i have yet to see a nut and bolt restoration that look the same as when the car left the factor...they look far better....Paint and plated items are just two things far different from factory....Steve

I take the point Steve, but its a question of honesty and integrity.
I cannot offer a fully restored car for sale if it is not "original" in terms of the major "period components".
If you do this, then where do you draw the line?
It is interesting to note, that non original specs on an E type (gearbox/engine etc), regardless as to how well it is done, can affect the value of a fully restored car by between £20 -£30K ( source Hegertys jaguar specialist who sets the values on their website).

[Tom W]

Cam covers might be easily swapped, but a later head designed for a cover without the cutout won’t have the extended bearing cap for the rear of the RH camshaft. Bearing caps are matched to the head, so they shouldn’t be swapped between heads. That leaves the options of fitting a later cover, or manufacturing a semi-circular part to take the place of the extended bearing cap section.

[mgcjag]

Hi Tom...the cutouts i refered to above are the rectangular cutouts on the top of the cam covers not the rear round ones.......Steve

[johnetype]

With an October '69 car you're on the cusp of the camshaft and potential clearances changes so if you're so keen to get everything right and your engine number is lower than 7R8688 you need a head with the original camshafts and 4/6thou valve clearances.