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XK8 engine stripdown.
2 questions from a guy having trouble. (Not me by the way):D
Can the heabolts be reused when reassembling or should they be replaced, and What is the easiest way remove the crank pulley. Car is a 96MY Many thanks in advance. |
Over 200 views and no one knows the answer.:icon_cry:
The reason I asked is because I didn’t know whether the bolts would stretch overtime or not and whether they should be changed as a matter of course so I didn’t want to pass on duff info. Thanks anyway. |
When I first read your post yesterday, I looked in the engine overhaul manual but found nothing on re-use of the bolts. As there have been no replies, I've dug a bit deeper.
JTIS does include this advice in the cylinder head removal/refit section for the 4.0 litre engine: https://cimg3.ibsrv.net/gimg/www.jag...7381f48972.jpg If the image is not clear, the highlighted section is "Clean and inspect the cylinder head bolts. They may be re-used on two occasions. When re- used, each bolt head should be marked with one dot from an automatic centre punch." The tightening procedure is in a specified pattern, using the following procedure: Stage 1 - tighten all M10 bolts in sequence, to 20 Nm. Stage 2 - tighten all M10 bolts in sequence, to 35 Nm. Stage 3 - tighten all M10 bolts in sequence by 90°. Stage 4 - tighten all M10 bolts in sequence by 90°. Stage 5 - tighten the two M8 bolts at the front of the cylinder head to 23-27 Nm. The equivalent JTIS section for the 4.2 engine makes no mention of bolt re-use but follows an identical tightening procedure. Graham |
Thanks Graham, that info is much appreciated and I shall pass it on.:)
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If they were my 20+ year old bolts I'd give serious thoughts to changing them anyway.
I believe it is usually advised to use the later 4.2 gaskets rather than the original 4.0 ones. |
If someone is determined to go that deep into tearing out an engine, best is to spend the time going through the Jaguar engine course. It is generously available on jagrepair.com. Nothing like getting a sense of the design, special tools and procedures involved because some of it is less than obvious (timing, VVT, etc.).
Just my thoughts. |
Fmertz is right- read read read before jumping in- not because of your ability, but because there are some "pitfalls" you can EASILY avoid by following steps instead of intuition (ask me how I know this)
There is a crank pulley procedure and tools- it CAN be done other ways, but the procedure works every time with less cussing. (HINT: move the pulley slightly out, then tap it back in to pop it off the cone washer) You CAN reuse the head bolts, but for not much $$ you can get LS bolts and not have to worry about one of them SNAPPING while you are getting that last 45 degrees of torque on the very last of a bazillion bolts. REMEMBER: Bolts stretch......until they don't. Also, I second the later gaskets |
some pics of my rebuild
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