MF 35, Continental Z134 Valve Stem Seals

All,

I find conflicting information on this all over the web. I see that seals are available, but also read that machine shops need to mill the head to accept them?

I've got an issue on #4 cylinder since I bought the machine in 2015, since it doesn't get used all the time I've just dealt with cleaning the plug and rotating it to a different cylinder to prevent oil fouling it. I'd like to put some new valve stem seals in it. I get a lot of oil in #4, enough that it'll coke up the plug and misfire badly.

I've narrowed it down to valve stem seals, compression is good across all cylinders.

Is there a drop-in set that I can just pump the cylinder full of air, or a rope, or whatever to keep the valves in place- compress the spring, pull the keeper, slap it in there and reverse the process for install?

I also see two different kinds, one with the little metal spring in it (the style I'm used to) and another set that appears to just be a rubber bushing of sorts, thoughts on that? Thanks.

This post was edited by shaeff on 08/17/2022 at 05:47 am.

unless that intake valve guide is worn out. even with no seals plugs will not foul. .003 thou. max for guide clearance. with valve cover off
and each cyl on tdc on compression you can wiggle the top of the valve spring and see how much play you have. if one you can feel or see the
wiggle you need more than seals. meaning a head job.

Good compression and good oil control do
not necessarily go together. Unless
valves are very loose in their guides
that's probably not where the oil is
coming from. Likely there are oil control
ring issues. One thing you could check,
is excess oil from the rocker oiling
system for some reason drizzling on those
valves?

Ive also found when having the same problem that the ring gap was in line on that cylinder.
Fouled plug tormented my neighbor many years after a dealer overhaul until I decided to get to the bottom of it.

Take care
Pointrow

They do have a intake valve seal, part number 1750062M1 (number 4 in the picture).




They do make what is called a umbrella type oil seal (FEL-PRO SS72616) that fits without machining but I do not know if they will fit inside the valve spring.

This post was edited by ptfarmer on 08/17/2022 at 11:13 pm.

(quoted from post at 15:59:45 08/17/22) unless that intake valve guide is worn out. even with no seals plugs will not foul. .003 thou. max for guide clearance. with valve cover off
and each cyl on tdc on compression you can wiggle the top of the valve spring and see how much play you have. if one you can feel or see the
wiggle you need more than seals. meaning a head job.

Click to expand...

I'll give that a try when I get some time. Was hoping to avoid a full on head rebuild, but if if it needs it I'll get it done.

(quoted from post at 21:33:41 08/17/22) Good compression and good oil control do
not necessarily go together. Unless
valves are very loose in their guides
that's probably not where the oil is
coming from. Likely there are oil control
ring issues. One thing you could check,
is excess oil from the rocker oiling
system for some reason drizzling on those
valves?

Click to expand...

True, I'll take that into consideration as well when I crack it open.

(quoted from post at 23:35:40 08/17/22) Ive also found when having the same problem that the ring gap was in line on that cylinder.
Fouled plug tormented my neighbor many years after a dealer overhaul until I decided to get to the bottom of it.

Take care
Pointrow

Click to expand...

I don't think this machine has ever been rebuilt, but anything is possible. I'd be very surprised if the ring gaps were aligned.

(quoted from post at 05:32:40 08/18/22) They do have a intake valve seal, part number 1750062M1 (number 4 in the picture).

They do make what is called a umbrella type oil seal (FEL-PRO SS72616) that fits without machining but I do not know if they will fit inside the valve spring.

This post was edited by ptfarmer on 08/17/2022 at 11:13 pm.

Click to expand...

Gotcha, I'm interested to see what's in there when I open it. Thanks for all the wisdom guys, I really appreciate it. I'll follow up whenever I get to dig into it. Hoping before winter.

I used to use ford umbrella seals on Chevy small blocks along with the stock Chevy square cut o ring seals when I had one with badly worn guides.
Can't remember which ford seals maybe a 170 six. Take your valve spring to a parts store and check the seal will fit inside the spring without
interference. I used air to hold the valves closed while I installed the seals.

Also the ones with the little spring are the ones that require the top of the guide to be machined. They press on the guides and the valve stem moves inside them. The umbrella type move with the valve and have the lower part comes down over the top of the guide like a shroud.