E type 4.2 engine head studs

Edited on 2010-05-11 21:53:51

Patrick, yes I did seal the threads with red thread lock, let it sit for 24 hours. But, I
also noticed the center studs, which are about 12.5 inches, go through the head
and into the lower block, are not sealed. There was minor rust arround the head
gasket spacing. Did not think this was the best idea, but did not attempt to remove
then center four studs to correct this problem. I dought they could be removed
anyway, due to being there for for 39 years. I believe George and William answered
your question about 71 -6 - cylinders E-Types. There knowledge is so far superior
to mine relative to E-Types, I feel like a spring chicken.

Yes they did--they also cataloged a 6 cyl in the series 3 body and sold at least 3. Sort of like the 4cyl XK120 except they actually had a taker or two. But yes series 2 cars were sold in 71 to use up stock as the V 12 cars were sold the year after production ended.

George as you probably know the test cars were not series 2's either, some early e bodies were used as experiments with the then secret E Type with the XJ13 5.0 DOHC engine and once modified, the eventual 5.3 SOHC with lots of fun in between. Series two bodies were used as test beds for the 5.3 making them prototypes or factory chassis, there was still one at Browns Lane when I was there. There was also one with a prototype V8 and a number of V8 engines in the Dyno shop. They did of course continue to sell S2 4.2's into 71 to use up the in stock chassis.

Patrick I would seal with something even better--FYI all series 3 E types were not V 12S.

Dale....I hope you SEALED the threads with a thread sealant like copper coat before you installed them, otherwise coolant water will travel up the threads.

I thought all '71's were V-12 E-Types.?

Patrick

Final solution. The 71 XKE has three different size head studs. The middle
studs are about 12 1/2 inches, the ones holding the lifting bars about one
inch longer, and the two at the rear of the engine are 6 1/2 inches (165mm)
and are tapped into the head. I ordered one of the 6 1/2 inch studs, and
used drill/tap and helicoil. These short studs also have a slight shoulder
above the threads and will jam when screwed down into the block.

Tom, Thanks for your response. I will call you tomorrow.
Dale

Dale, give me a call at (407) 298 1358 during working hours. I can give you a better idea. Been doing these cars for 32 years. Cheers Tom

Yes Bill, I thought about Helicoil, and will use that procedure if I cannot find
proper stud. I will check with ARP to see if they have a useable stud. I would
rather drill and tap if possible. Thanks - dale

One more small point, use a helecoil insert to bring it back to the original 7/16th, Bill

OK William, I will order an early type stud. The hole size in my head and block
is 7/16, stud is 3/8, so I will need a stud with 1/2 thread on the bottom, installed
flush with top of block. You are correct about welding hazard, even if a large area
in the vicinty of the weld is heated with a torch prior to Tig welding. Always the
danger of creating a hairline crack. Thanks for your help.

I'm not exactly sure when the change was made but I would think any series 1 would have the short studs, any way just order one from a regular supplier. ps, welding the block could be difficult and catastrophic!

William, Thanks for the response. I was thinking this type of problem was common
due to the number of years these the E-types have been on the road. Your suggestion
ws one of my choices, since the head has 1/2 of metal on top. My other thought was
to use a 60 degree rasp and make a cone type depression about 1/4 inch deep in
the stud hole at the top of the block in order to have enough metal space to form a
proper weld bead, and then weld the stud to the top of the head. Your suggestion is
better. What type of studs from what type of engine have you used?
Thanks a lot. Dale

Dale, there is no access from the sump, the only way to get there is to remove a freeze plug, it is possible to install a modified stud and add lock nuts on the bottom, my usual recourse is to tap the block and use the short studs used on earlier engines.