Old jaguar engines has not seals on exhaust valves . What if will install all inlets guides with seals ? Both valves is sodium

Differens between valves
Sodium freely rotating in upper cap

Rob Beere sells bronze guides that have seals incorporated into the guides for both intake and exhaust.

Rob Beere-Camshafts

Yes, I read about about it.

Another option - my guides are all worn elliptical and I will be K-Line guide liners. My engine builder said he used these in the race V12's and they hold up well.

becareful ,sometimes sealing the guide to tight has increased stem to guide wear.

compounded by hi exhaust stem heat, metal to metal , NO oil lubricant.

OK for race engines that will never see the hiways, also to reduce chance of detonation from oil in fuel mixture that has caused a low octane issues.

personally for our toy cars, that rarely see continuos hiway driving, i dont use any seals on exhaust guide, and modern synthetic oil is a great hitemp lube.

i DO use on inlet where hi vacuum can suck oil down the guides.

but most what is said here will be OK for our paticular use,(to each his own).

of course factory clearance specs should be followed.

HEY xjzv12, what year is your engine, and what displacement, 5.3 or 6.0?

i notice valves look to be same length, but with different stem locks/keys?
like 5.3 preHE.

possibly heads have been rebuilt, with new but mis matched parts.

also i like that type exhaust valve shape, the inlet looks to be heavy weight may lead to early bounce/float!

helpful for a pic of chamber?

Hi Ron
Engine is 6.0 95 year


I am in progress of rounding ports and runners.
About valves. Different valves was depending of market, European was sodium and flat, US was dished. I like dished too. But I don't have those valves. I have two sets sodium.
I brought two sets guides. And thinking what to install. Oil in my engines is Castro 0w40.

Did I read correctly, the V12 engines have no valve stem seals?

ports look good, much better than stock!

i did not know that US engines were so much different than Euro/UK, small details important!

oil 0w40 , that should be fine, as long as you dont have the dreaded rope seal, by 1995 Ford had made many small important mods. for the better.

pay close attention with the rear crank seal and front seal when installing, i'm guessing Jag V12 had some crank whip especially when hot and the aluminum main bores expanding oversize.

more reason to run a cool engine temp, along with a large auxiallry oil cooler!
Praise FORD and there new Mustangs finally ,after 50 years , importing to Europe

Intake valves have seals but exhaust valves do not

Hmm, odd... Though on the other hand, it wohld probably have a reason (possibly temoeratures etc.) which wasn't solveable 'back in the day'

Thanks for the info!

Ron said it earlier, oiling for the exhaust valve stem,helps keep it cool

I bought Neway equipment for valves and valve seats.
On two angles valve spend 20 minutes. And as much to spend on each polishing

My God, I have this engine never finish

xjsv12,, you could also undercut/polish the stem,only in the no travel part of stem air flow area, like 1 mm smaller diameter!

i done that on a few engines ,never any problems, and a lighter weight!

also do you tulip the top of valve to reduce weight!

every little bit helps peak RPM float.

This is sodium exhaust valve and I am afraid to remove any metal.
l have a plan to do it with inlets.

Whew, this is way above my tech level. I date back to Valve grinding compound. coarse and fine. and, some quaint tools to spin the valves in situ.


But, my son is/was a master auto machinist. He closed his shop to venture into performance parts MFG and sales of other stuff. All auto related. But, runs the auto tools on special occasions. Does beautiful valve work. Just latched on to a high tech
Sunnen valve and seat machine. Did my last few valve jobs for me. He does not approve of my lapping!!!! Imprecise.


But, a thought occurred to me as to why have seals on exhaust valves. Leaking and
damaging catalyctic converters. If not present, a little oil vapor in the gasses, no issue.


Early stove bolt Chev. 6's tended to smoke. No real harm, but owners alarmed. Engine is an "oil burner". So, steel "umbrellas went on the valves. don't recall if on all or just one or the other, intake-exhaust.


Carl

The V12 did not come with exhaust seals, maybe the exh valves run too hot.

You could either use Rob Beere bronze guides with integral seals or use Teflon seals.