Are valve guide umbrellas really needed?
 

I'm replacing the (O-ring on the valve stem) valve guide seals on my 1971 250 and wondering if umbrella (or perfect fit) seals are really needed (in addition to the standard o-ring). Let's assume the valve guides are in good shape........... at least the first one I checked is great.

Since umbrellas weren't fitted on these engines originally how do I ask for them at the local auto parts store. I've seen comments online that Ford small blocks used them. I would still need more specific info for a parts counter person.

The valve stem diameter measure 0.340" (probably 11/32" nominal) on this engine and the valve guide boss' measure 0.750" diameter.

How tight do the umbrellas have to be on the valve shaft? When looking at the specs on some aftermarket umbrellas they give the I.D. and most of them are 0.342 or thereabouts.

Re: Are valve guide umbrellas really needed?
 

I did orings and umbrellas on an older engine, by the time the valves where up into the seats needing a rebuild. The seals helped for a while.

If your considering having the head rebuilt with hardened seats consider viton stem seals, they work!

Re: Are valve guide umbrellas really needed?
 

I like to put umbrellas on for a little extra insurance. I told myself next time I change valve seals I am going to buy the tool to put the newer style Viton seals on. The tool is cheap, it looks like an easy process and the seals are sooo much better.

Re: Are valve guide umbrellas really needed?
 

https://www.rockauto.com/en/catalog/...stem+seal,5800

I used the orange ones 3rd from the top. I am hoping they will last longer than the old black rubber type that would end up at the bottom of the pan.

Re: Are valve guide umbrellas really needed?
 

Thanks for the link!

Re: Are valve guide umbrellas really needed?
 

So, I did most of the 'job' today. What a total PITA of a job it was. I only replaced the O-rings under the keeper. The old o-rings were hard as a rock and needed replacement. After doing as much research I cared too I don't think the umbrellas would have added much value. JMO.......................

This is the first time I've done this on a motor in a car and I almost wouldn't recommend it. It was VERY difficult getting the springs off on the rear cylinders. I even had to disassemble the spring compressor tool to install it on cyl #6. Did I mention it was a PITA job? :banghead:

I'm just happy I got it all done without dropping a valve keeper into the black hole of the engine or garage. :lol:

Re: Are valve guide umbrellas really needed?
 

That’s a hair puller job!
What did you use to hold up the valves?

Re: Are valve guide umbrellas really needed?
 

I have never done it in a vehicle. I do not have that much patience. Good job gitten 'er done

Re: Are valve guide umbrellas really needed?
 

I pressurized the cylinder to ~30PSIG with a spark plug adapter air fitting. That was enough to hold the valve 'closed'. I still had to be careful not bumping the valve from the seat and having it drop into the abyss of the cylinder. :mm:

Re: Are valve guide umbrellas really needed?
 

Next time get the piston at the bottom of the stroke and push a piece of rope into the plug hole until it's full. Roll the motor over until it compresses the rope. Now do your valve work. Just back the motor up a little to remove. This takes all the chance out of dropping the valve.

Re: Are valve guide umbrellas really needed?
 

I did it to a 6 cyl 280 Mercedes with full shop air on it and it cracked the aluminum head. I think they had the compressor cranked all the way up to 180 psi. After bolting on a head from a different engine and finding no compression because the heads were different, I had the first one welded and all was good. Lots of people have told me that would be impossible but I heard it pop and knew I had a problem. That was probably more than 35 years ago.

Re: Are valve guide umbrellas really needed?
 

Just a quick followup. All is GREAT with this near 50 YO (original) 250ci motor. No faint smell of burning oil after starting or while idling at stop lights now. In this youtube age of massive over-restoration I'm digging the 'old original' of this truck more than ever. :metal:

https://photos.smugmug.com/photos/i-.../i-CB8ZjTs.jpg

Re: Are valve guide umbrellas really needed?
 

To prolong its life I would recommend that you use the oil recommended for flat tappet engines.

Re: Are valve guide umbrellas really needed?
 

I'm currently using Delo 400XLE 15-40 diesel oil

API Service Categories CK-4, CJ-4, CI-4 PLUS, CI-4, CH-4, SN, SN PLUS

https://cglapps.chevron.com/sdspds/P...&docFormat=PDF

Re: Are valve guide umbrellas really needed?
 

I had an old beater 68 shortbox fleetside that was known to have carried 1.8 ton of sand over the airport bridge in Vancouver. Lucky the wheels didn't fall off it.

Yours looks really nice.

Re: Are valve guide umbrellas really needed?
 

WOW................. that's a big load!

I've only owned this truck for a bit over 5 years and have slowly worked through most of the standard mechanical maintenance items. Still need to replace the wood in the bed and tackle some rust in the inner rockers and cab supports. I use the truck fairly often so I've been putting off the rocker repair. I've been trying to figure out a 'trick' way of getting the two lower-front cab pillar support bolts off with removing the hood and fenders. :confused:

Re: Are valve guide umbrellas really needed?
 

YIKES! That is old school thinking that is not appropriate any more. They have changed the formulation of oils so much that this thinking is not good anymore.

Read this, in its entirety: https://540ratblog.wordpress.com/

That guy has done a ton of work with not getting paid to do it.

After a rebuild I was using Valvoline VR1 for over 90 k now. No cam or lifter issues. Look deeply with his wisdom and you will see why that is a superior motor oil for our old engines.

Cheers! Its a very long read.

Re: Are valve guide umbrellas really needed?
 

I will save you a bunch of time read this:https://sharena21.springcm.com/Publi...2-ac162d889bd1

Look specifically at this:

47. 10W30 Valvoline VR1 Conventional Racing Oil (silver bottle) = 103,505 psi
zinc = 1472 ppm
phosphorus = 1544 ppm
moly = 3 ppm
calcium = 2,707 ppm
TBN = 7.6

The main thing outside of the ZDDP is the high film strength. 103,505 PSI