• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Valve adjustment

Share this page

Marvin Gruber

Marvin Gruber

Yoda
Silver
Country flag
Offline
Its been years since I adjusted any valves on a XKE. A 68 XKE that I am working had what I thought was loose valves. Lots of clacking. Yesterday when I got the clearances. I find that most of them are too tight. One valve was .03. most were .08 or .09, couple were 11 & 12. I will be setting them to 12/14. Question is, would the valves being to tight make a clacking noise.

Marv
 
Are you sure?
I just checked my exhausts last fall, don't remember the clearance being as wide as .012" or .014".
Maybe on an "E".
But, that said, tappet guides.
The bigger engines can have issues with tappets being loose, there are guide plates to be installed to hold them firm.
You did check upper chain tension, correct?
 
I just re-checked my factory shop manual for my 2.4L, inlets .004", exhaust .006".
I'll see if I can find 3.4, 3.8 and 4.2L data.

.012 and .014 is what we use on Isky cams in Flathead Fords.
 
Chiltons, .004 and .006, all XK engines, except E type in racing use, exhaust to .010".
The .003", if intake, is probably close to the .004".
Double-check your readings AND your spec sheet.
Something is wrong.
 
.004" is .10MM
.006" is .15MM

What units of measurement are you using/reading?
 
Marvin:
The correct valve clearance is stamped on the data plate. For a 68 the valve clearances should be in the range of .004" to .006" . The .012-.014 range was used on the late 69 and 1970 engines, unless someone changed the cams to a later spec. I think the later cams have four holes on the front flange instead of two.
 
My Chilton's is 1969......only .004 and .006 listed, and his is a 68.
The .003, if in fact it's the wider setting (cam ramp would dictate) is either a piXX poor adjustment last time or valve recession.
Waiting to hear.......
 
Got the cams and pads out today. Four of the pads were homemade small dia. pads. Ditched them. Set everything to.012 but now you guys have me wondering. Chiltons and Haynes both say 04 & 06 for early cars and 012/014 for later cars. The Complete Offical workshop says 4/6 for 3.8 L cars but 4.2 supplement doesn't list valve clearances. This car is late 68 with ZS carbs so I figured go with 12/14. What say ye!

Marv

BTW - these cams only have two holes in the chain flange.
 
Andy got me thinking about the data plate so I pulled out a plate from a 69 XKE(1R81XX), it has 004 and 006 listed at the bottom. So I will look at the data plate on the 68 tomorrow and see what its lists (4/6 I'm sure). I forgot the data plate listed the valve clearance.

Thanks Andy!
 
Marv:
If it is truly a 68 then go with the "early" setting. Again, check the data plate on the car - it will give the correct setting. My S2 Parts Manual indicates that the cam change occurred at SWB Engine 7R.8687 and 7R.38854 2+2. The early S2 cars (like mine) use the same cam and valve clearance as the triple carb 4.2L. The larger valve clearance was for the tighter emissions standards required on the later cars (mostly 1970); another way to tell is the distributor. The early Series 2 distributor does not have a vacuum advance; the later engine has a vacuum retard.
 
WEell, at .008 and .009, they were obviously noisy, so better check your tag.
 
I'll say. All were loose except one that was tight. Bet it will run a little better and quieter tomorrow.

BTW Andy, no vacuum advance. All things point to 4/6 but I'll double check tomorrow.

Thanks ALL

Marv
 
I can't count the number of "home-made" shims I've found under those buckets... jack-leg mechanics had their hooks in these things for decades.

I figure the .004"/.006" will be correct.
 
Data plate said 4/6 so I got them set last night and ran it long enough to get oil everywhere but it sounds a lot quieter. I forgot what a pain it is to set them. Its clean up day today.
 
Back
Top