My engine project

[Lee83]

I have been in the garage this weekend working on a little project i am playing with and thought some of you would be interested in seeing what I’m up to.

I have a love for engines and the XK engine has been one i have been wanting to get stuck into for a wile. My past engine builds have all been small block chevys but also being a jaguar enthusiast it was a matter of time before i got myself a XK powered jag. Thats hasn’t happened yet! i have owned 3 X300 in the past so the XK engine is all new to me.

Anyway i first bought a cylinder head (B type head) and then a 4.2 block out of a XJC. My initial plan is to learn about these engines to rebuild it and then put it in to a engine frame and fire it up but if a jag comes up at some point during the engine build then i would put it in what ever car came up as I’m not a numbers matching kinda guy.

The block is cracked so i made that into a wine rack (photos of that coming soon)

The head is ok but needs some work witch i have started and i will post photos as the work goes on. I hope you will find my posts interesting as i am a very much a do it at home type of guy.

I also hope the project will spark up some hot topics as i love hearing peoples ideas and opinions. I chose to post my build in this forum as it seems to have the most posts and the cylinder head is of a MK2 3.8 engine.

[PPV]

I shall watch with great interest as I have the same engine in my car. Should be straightforward but interested to see if you change the rear cranshaft oil seal to a later version to stop the thing leaking!
Regards,

[Martec]

Hi,

Before you spend any decent money on the head, turn it over and look at the cooling slots at the head gasket area. If these are heavily corroded then it will need alloy welding to make a seal face (not cheap) and if it requires excessive welding then the head will become warped and is scrap unless you wish to go to the high cost of line boring the camshafts. I found this out the hard way!!

I have seen the efforts of others to improve the power output which has involved bigger valves and strange shaped special pistons in an attempt to get past 200bhp at the flywheel.

Jaguar 'CLAIMED' 220bhp from the 8-1 compression ratio twin HD6 engine, but in the real world it only made 170bhp at the flywheel, look how the bhp figure fell when it was DIN rated. The best production XK was the 4.2 EFI engine at 200 BHP.

I wish you all the luck in the world and it would be nice if you could blaze a trail for us mortals for a cheap and easy way of increasing efficiency to improve bhp/ltr and fuel consumption. Numerous expensive firms claim to have achieved it with big valves, throttlebodies and high compression engines.

I hope you don't see this as a dampner, just steering you away from the 1960s hype into the real world figures, it was a hell of a shock when I had mine rolling road checked on petrol and LPG. It is also nice to see you are using the early 'B' type head rather than the later straight port head.

Best wishes,

Brian
PS as has been said when looking for a block to fit it to make sure it has a rope type rear seal as the early scrowl type 'appear' not to be capable of being converted to a real lip seal.

[PPV]

A good book for the tuning the engine I found was 'How to Power Tune Jaguar XK .. Engines', part of the SPEEDPRO series by Des Hammill (ISBN 1-901295-63-X). Have seen copies at the various car shows.
Regards,

[oldtimer]

Hey Up Martec,
What ever the claims for power output , the 3.8 Mk2 went like, whats it off a shiny shovel.

Being just a youngster you won't remember what the competition was, but mostly pretty sluggish. No motorways or 70mph speed limit either.

Much more fun back then but took for ever to get anywhere

[Martec]

'Being just a Yougster', Thats the nicest thing anyone has said for a while.

The bar-room bragging rights on horse power are missing for the 3.8, but it was the huge torque from idle that makes it a brilliant engine. My then new distributor taylored to my car meant I could put it in 4th gear slow down to 500 revs and then stamp on the accelerator and it took off.

I haven't bothered tuning this engine due to 17 mpg, but other engines I've worked on I found that high duration cams just made them a pig to drive on the road as all the torque was above 2000 or 3000 revs. I'm too old to play that game anymore.

But I seem to remember you enjoyed being a hooligan in your diesel tea tray last year!!!!!

Best wishes

Brian

[Lee83]

Hi guys

PVV I will be upgrading the rear crank seal to a modern rubber lip seal. i still need to recerch and find a place the will do the machine work on the crank for the conversion kit. Do you know of shop where i can get it done?

Martec I am well aware of the BS HP numbers from back in the day. My past engine experience with american V8’s has taught me this. what make and type of distributor did you fit to your old engine? I will be putting new cams in the head and the duration will be mild but if you can remember your cam specs it would be a big help to me as i am after all the advice i can get.

Here are some photos of how i removed the valve guides from the cylinder head.

I first taped a M10 thread into the guide form the combustion chamber side of the head and screwed in bold finger tight. I thought by hitting the punch against the bolt would be a better and safer way of removing the guides form the head as using a punch on top of the guide could splay open the top of the guide or round it over witch will increase the diameter of the guide hole or even worse score a grove down the length of the guide hole. With the heat gun sitting in the tapped guide for a min or so they came out with minimum effort.

I would like to hear any feed back guys.

[PPV]

Lee83, I had work done by VSE (http://www.vse-engines.com/) on my head but the rest of the engine seemed OK. It was really but the rear crankshaft seal leaks which I did not recognise when I bought the car as it had not been used for some time so was 'dry'. Still hind sight is a great thing. VSE seem to have a goodreputation but I am not sure if they do the crank/seal mod. Worth a call to compare with others though.
I was very pleased with the results of VSE's handiwork. However courier costs to mid-Wales for a complete engine may be a bit excessive. I lived in Gloucester at the time and if I recall it was not too bad ffrom there.
Best of luck with the work.
Regards,

[Martec]

Hi,

My distributor is a 25D6 with springs and bobweights to suit my car, the questions asked were, what engine, what axle ratio, what use was it for.

The job of setting up the weights and springs for advance curve was excellent, but the positioning of the magnetic pickup was C?AP, with the result that Another rolling road section was needed to find the fault, and when expected to rectify the fault they returned it with a broken rotor arm and I had to re-postion the magnetic pick up to stop it cross firing. So I won't recommend the well known firm.

Distributor doctor maybe able to supply and modify a distributor for you. I junked my old worn DMBZ6 dissy but have heard people say the 45D6 is better than the 25 as it has bigger bearing faces????!!!!

The cams were good second hand XK140 cams, apparently the same as original MkII cams.

The reason for recommending an engine with the later rope seal is that conversion kits are made for this but not for the old scrowl crank.

At the time of building my engine 1999 I used Ken Jenkins to supply my parts so naturally I had the benifit of his advise (I have never seen so many XK engines in one place as at his store). As you are relatively local he can probably recommend a good local machinist.

I see from the picture that the water galleries are good on your head. I can appreciate that you have removed the guides to open up and reshape the ports, but back then I was advised not to remove mine as the aluminium can get ragged and the new guide will move in the head?? my existing ones were sleeved with bronze., but they were bulleted and the seats and valves were 3 angled.

Due to the introduction of unleaded and the unknown I was advised to stay with 8 - 1 CR as after machining it would be close to 9 - 1 anyway, but fuel is better now!!

Best of luck, and Ken is worth a call just for advise.

Brian

[Lee83]

Hi guys

So here is the inlet i will be using on the head. I got this as cast manifold of eBay for £200 witch i think is bargain compared the price new plus this manifold has a separate water outlet witch i can’t seem to find as all the new ones have water outlets cast into to the manifolds. This inlet I’m using looks a lot like the ones used on the C-Type and D-Type engines using triple weber/dellorto carbs plus keeping the hot water away from the inlet runners has to be better than casting them in one.

I first marking blued the head side of the inlet. Using a inlet gasket and the stud pattern in the head to help me mark out the drilling it was a case of measure 10 times and drill once! :p

The inlet ports line up really well but i will port match these when i start the porting job.

I will be fabricating my own water outlet from stainless steel components I’m having laser cut.

hope you like the photos guys!

[Lee83]

Here are the before photos

[Martec]

Is this the arrangement you are copying?

[Lee83]

Is this the arrangement you are copying?

WOW.....EFI! i wish i had the skills Martec. That engine is stunning! Is it yours?

[Martec]

No, not mine, I photographed this engine in a MkII a few years ago. It is from a firm down south and I can't remember their name, but note the inner wing was reshaped to fit in the air filters and the battery and hydraulic master cylinders have all gone elseware. This is why fitting 3 carburettors or 6 throttlebodies is so difficult with out re-engineering the enginebay.

That firm claimed a sizable increase in power and of course 6 throttle bodies is the ultimate fitting (for me). I suspect that this is the later straight port head and it has a similar inlet manifold to that engine.

My engine has two independant fuel systems and two independant ignition systems for reliablity on continental hoildays.

Best of luck
Brian

[Tilleyjon]

Hi guys

PVV I will be upgrading the rear crank seal to a modern rubber lip seal. i still need to recerch and find a place the will do the machine work on the crank for the conversion kit. Do you know of shop where i can get it done?

Martec I am well aware of the BS HP numbers from back in the day. My past engine experience with american V8’s has taught me this. what make and type of distributor did you fit to your old engine? I will be putting new cams in the head and the duration will be mild but if you can remember your cam specs it would be a big help to me as i am after all the advice i can get.

Here are some photos of how i removed the valve guides from the cylinder head.

I first taped a M10 thread into the guide form the combustion chamber side of the head and screwed in bold finger tight. I thought by hitting the punch against the bolt would be a better and safer way of removing the guides form the head as using a punch on top of the guide could splay open the top of the guide or round it over witch will increase the diameter of the guide hole or even worse score a grove down the length of the guide hole. With the heat gun sitting in the tapped guide for a min or so they came out with minimum effort.

I would like to hear any feed back guys.

Hi Lee, I had all my machine work done by Frank Anderson (Anderson Race Engines), he supplied an external oil seal. not the usual conversion that sits inside the sump on a reduced Crank shoulder, the type he supplied goes on the larger diameter and can be changed without removing the sump. I will post pictures if you are interested.

Jon

Good luck with the rebuild Martec