Mk7 daydreams and nightmares

Just having a lie down . Been quoted £6500 + vat for a cylinder head rebuild . Maybe I still live in the past ,got to get the cost down . If I take it off and remove valves etc maybe I can afford it . It’s sods law , my mk7 is rust free , solid as a rock , a rarity , but all but one cylinder is low on compression . Anyone want a job ?

That price seems way too high. Contact Dick Maury at Coventry West in Atlanta, GA.

When I saw Coventry West , I thought I was in luck , but I am in the UK , and my Coventry is only a hundred miles away ! Thanks anyway Pat . Yes , I thought it was a bit much !

Hi,

Coventry West is excellent in the US but I don’t think he would need to ship it from UK to US. There are plenty of good shops in the UK.

From what I have heard, Guy Broad is among the best regarding that vintage of cylinder heads. It probably would not cost that much unless there is something seriously wrong with that head. In which case I am sure you could find a suitable replacement.

Cheers!

Hi Ptelivuo , it was just a phone quote , the head is sound ,

There’s some decent ones kicking around on eBay. There not exactly scarce here in UK.
All XK type B heads are basically interchangeable from the mk7s through to the MK2 and Stype. (Not Etype, Mk10 or 420)
I fitted an Stype head to my Mk9 last year. If the valve guides are shot you can have sleeves fitted instead having the complete guide replaced. Park engineering in Malton near York did mine.
Ken Jenkins supplied the parts.

Kenneth, that quote is way too high. Join the local Jaguar club, and you will learn the best places to service your MK. VII. If you haven’t done so, purchase the shop manual which will give you step by step instructions for removing the head and doing a valve job. I’ve found that members of the local club enjoy the opportunity to help other club members with mechanical tasks.

Back in the day, Jaguar published Rapair Labour Schedules for dealers to provide time estimates for almost every type of repair. Below are some of the hourly estimates for engine repairs for the Mk. VII. If you take the car to a shop to have the work done, it would be interesting to compare its hourly estimate to Jaguar’s hourly estimate from the 1950s.

The head is aluminum and therefore really not that heavy. Shipping cost would be slight compared to the repair cost.

Greetings All,

I had a WHOLE Standard 20HP Flathead engine with starter and generator along with intake and carbs…AIRSHIPPED, from the U.K. to the US!

650 Lbs for about $850 USD.

Head…no problem.

Was there anything cracked or needing special attention? That price you were quoted was waaaaaaaaaaaaay high!

walk away from that place immediately, unless you mean a complete engine rebuild for that price

Is the head off the engine yet ?

It is quite likely the head will be corroded internally, in which case it will either need expensive weld & machining, or be completely unserviceable, needing a replacement

You cant tell till the head is off the engine

Excessive price. There are several places in GB. You need to shop around. An example is Headshop (UK) Ltd in Warrington. No experience of this company myself so it’s not a recommendation but it might be useful to get a figure from them.

How low ?

does it drive ok ?

it would be entirely possible the rings are somewhat “sticky” if the vehicle not been used

Once apart, it would be expected to need a total rebuild on such an old engine, (unless it has been done before)

On your previous quote, I can only assume the company has quoted for a 100% head rebuild, and added a large contingency for welding, or purchase of another head.
Even so, the price is double what I would expect for that

I suspect a similar but satisfactory head could be obtained in the UK for about 1/10th the price you are quoted.

I know someone here who is offering a complete MK1 for $A450 = 250GBP

As mentioned by someone else, join the Jag Club

I second Tony, here. Is the oil dirty? Why did they check compression? Did they do it with the engine warmed up and with the throttle open? Did they put oil in the cylinders and recheck to differentiate between ring and valve problems? The rings and valves can be sticky and significantly improve with running on clean oil. I recently recommissioned a 4.2 Mk10 that had been put back in service by someone else. Oil was filthy and the engine had very low oil pressure, smoked like crazy. With fresh oil, tuning,and time it is one of the smoothest running engines that I have - minimal smoke only on startup, good power. If you can, run it and recheck after you get some miles. If you have to rebuild it, it will cost the same then.

Let me explain , I checked compression , no 1 was 110 perfect , 2&3 were 105 , 4&6 were 100 and 5 was 90 but I didn’t do it with the throttle open . Will do it again. I then rang the shop for a quote . Yes , it runs , it’s a bit putt putty and when the choke cuts out and the revs drop it’s hard to keep going . When it stopped , I took the plugs out and all were dry , except for no 1. So this could be carburetion . Oil looks clean on the dipstick

Try that test again with open throttles and with a full battery. Cylinder 6 is at the front for the XK in case there might be confusion. £6500 is way high, probably even if the head was warped and had to be flattened. Get a few quotes and just in case, heads are not terrible expensive. You could have one done up while driving and keep the other since your problem, if it even is the head, doesn’t seem bad. I‘d first look at other possible causes.

Hi David , yes I did understand the position of the cylinders , when I get the lift installed I will change the oil and filter . It’s probably not in the best shape .

They should all be around 140/150 psi for an 8 to 1 engine.
The fact that your results are within sort of 10 percent of each other may, (hopefully), suggest a problem with the way the readings were taken rather than an actual fault.
So don’t despair. (Yet).
The back plug is often a bit oily because the engine slopes towards the firewall, oil collects at the back of the camboxes and gradually trickles down the valve guides into no1 cylinder when it’s been stood for a while.

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Decided to pull the head after all . Not happy . The way it phut phuts on tickover suggests a valve not seating properly , and the cylinder with the low reading might be the culprit . Its7 to one compression and the book says 110 pounds . The car is rust free so it would be a shame to ignore this . Oil pressure is good , so the bottom end should be ok

For a 7:1 compression ratio 65 year old engine, those numbers don’t sound all that bad to me. Run it awhile with good fuel at speed and see if it improves.
Otherwise it may just need the valves decarbonized, which is not that difficult a job.
This forum encourages people to do their own work up to their abilities. We can help you through this.

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You might like to check the valve clearances before you start any stripdown. Any tight valves , particularly on that suspect cylinder, might give you an indication.

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