Hi everyone, been of for a while. I now own a 1971 xj6 swb . my question is the car is in decent shape inside and out. But not with original engine, a series 3engine came with in pieces. in boxes. now in order to use old parts like intake manifold, and all other parts it came with the bw12 trans. can I use Hs carbs? and the kick down cable bracket that mounts on rear of head I assume its ok to drill and tap but how abount distances etc where it mounts, will I need a template? what other things should I be aware of in doing this ETC would appreciate any input on guys who have had experience with this. I have two hs carbs and also the original ZS carbs.
hello frank hope all is well on your side! the engine bay is empty all clean and in nice shape a new steering rack an oil cooler mount, and stainless steel exhaust system. just an update frank I have installed crankshaft which has been machined and hardened .10 over along with connecting rods the con rods and pistons have been trimmed to all the same weight…I have installed dizzy drive shaft bushing and shimed it according to book I believe it was .004 with new brass gear and lock washer…pointing to number six cylinder. installed timing unit with all new chain and pads and tensioner . and installed new hex bolt for brass bush for dizzy. I’m now into the head…
one question I was reading about the oil pressure relief valve I assume it is different from EFI to carbs has I was noticing in xks unlimited parts book. and a whooping 344 dolllars. is there a reason for this can you explain.
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As to the last, Daniel - the price is the price, I have not the faintest idea of how it is set…
As far as I know; the oil pressure valve is the same for all versions of the xk engine - there is certainly no difference between the carb and the injection versions. However, being related to the filter housing, it may vary with the type of filter housing fitted…
There should be little reason to change the valve - it is fairly reliable, and is adjustable. The sole function is to open the passage from the valve to the sump at the preset pressure. This divert oil, going to the filter, back to the sump - reducing overall oil pressure in the engine to the set pressure, some 65 psi…
You have done the right thing so far with the bottom end - ensuring the integrity of the crankshaft, which is the prime source of bottom end longevity. Only question being if the blind plugs were removed and the internal channels in the crankshaft flushed? Of some interest; did you observe any damage to the crankshaft, scratches/abrasions or any damage to the bearing shells…?
Can’t fault you on the rest of the work either - as for the head; the minimum action is a valve job - and checking the head for straightness, changing the inlet valve seals as natter of course…
Frank the crankshaft plugs were removed and it was cleaned with new plugs.frank the crank was turned to .10 I have installed new main bearings. Also the piston rings are of a high grade. The head was working on last run I have torn it apart cleaning and checking guides valves so on my last head cost nearly 1000 dollars I’m going to attempt leaping valve in myself besides I want to learn how to do valve shims and learn the proses I’m hearing to go bigger on the clearance for a smother idle I believe .014 is the sweet spot not unless you have any suggestions.im assuming you do one cam at a time meaning leave one out torque down and shim then do other one removing already adjusted cam shaft. Have to read up on this process it doesn’t sound to difficult…
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You are a paragon, Daniel - working above and beyond necessity…
The valve clearance, .0012 - .0014, are set by Jaguar based on years of development - there is no reason to deviate. Bear in mind that the total valve lift is .375", as bound by the cam lift - adding a couple of thousandth is neither here nor there, with no observable effects. Increasing the lash will only reduce valve openings - and going lower than .012 risks valve burning.
However, valve timing has been mentioned for some effects - to be handled with some care. Jaguar specified valve timing for overall on road performance, and the clearances between the valve and piston is critical - any contact will inevitably bend a valve. Stay to specs…
With the head off, it is indeed necessary to do one cam side at a time - with the other cam removed, otherwise there is a risk of valve entanglement, and valve bending. The shims used should be verified with a micrometer - both when the shims are removed after initial measurements (to get the correct numbers for calculating new shim) and the replacement shim. As an aside - it is not unusual to find different readings the second time around…
Frank I will take your advice on the clearances to keep it safe. I have leaped all valves. Had to make a add on tool to my spring compressor. I used a piece of 1 inch PVC pipe grinder out the sides and beveled the under side to keep on the valve collar. It’s a time consuming job but all done until I had realized I had six valve stem seals sitting in my parts pile. So went at it again for second time on the intake side. Experience at its best… After finishing up I turn the head upside down last night be for I left for home and filled up with mineral spirits I came this morning to find them still full no leaks! Obviously I passed my leaping test. I used course the fine. Trying to find the paste at auto stores was a challenge. I guess no body laps valves anymore. So I’m waiting for my cam bearings. And now I’m in search of a dowel on the rear seal retainer. I’m missing one go figure every other part except that searched high and low have another block that came with car none to find apparently no one carries this part in USA. Got my oil pump butt no seals with it there extra. So anyways talk soon and thanks for all the help ps I found a 74 xj6 same color has mine with engine broken perfect body and interior only thousand US dollars I’m vey tempted. I don’t know if you recall my 1986 xj6 is still running great after the rebuild. 2 years ago driving over 20,000 miles. No oil leaks from front seal or rear and I used original rope seal and regular front seal. The only problem I have is once in a while when starting cold I get a little white smoke out tail pipe. Must be the choke injector sparing to much fuel.
Hi Daniel, expect you know this - for long stud engines make up a plug tap on a long rod and clean out the head stud threads at the bottom of the block. Studs must bottom or you can get trouble tensioning the head. Have seen engines with “extra” washers under the domed nuts. Paul
Hi Paul thanks for the info it was suppose to be done at machine shop but will check that. Thanks for the information on this problem it is well appreciated.
Cheers mate
