Eureka!

Valve stem seals are easy to swap out when you have proper parts at your disposal. The 1955 Pontiac engine is a little hard to find all the right parts for.

So I had ordered a whole bunch of different valve seals to see if I could find one I could work with here. And today, 112.3° ambient temperatures notwithstanding, I determined which one of the ones I ordered I can use. The valve stem mics out at .337 and the guide at .632. The Sealed Power ST2125 seal is very close, with the valve hole being exactly .337 but the guide opening is a tad tight... too tight to go on. But, the metal bell had a very thick rubber insert and with a little work using a sanding drum on the Dremel tool, it was easy to make it fit over the guide. Rock Auto had a great deal on these seals so what the heck.

SEALED POWER

ST2125

Valve Stem Seal

$ 1.32

Keeping fingers crossed that they will work. I only had ordered one so I have 15 more to go. I ordered the rest from Rock and asked for 3 day shipping so hopefully next weekend I can put them on.

[I heard back from Comp Cams about an inquiry I made with them last week. They said I could use Their part number 502-16, Valve Seals: Umbrella, Stock Guide, 11/32 and I would not need to machine the guides. The part looks cheesy in the photos, but the seals are only $10 for the set, so I ordered them from Summit as a backup for the ones I ordered earlier. The part has now arrived and I can confirm, it looks like it won't hold up very long. plain rubber, no reinforcement, a bit flimsy. It may work really well... but I think I'll wait til the others arrive and then decide which to use.]

More Education

Trying to figure out what to do, I found that there is a positive type seal for my engine but it will not work without pulling the heads and machining down the guide. I'd prefer not to! But, using that seal part number on a Google search lead me to a great article on valve seals: http://mgaguru.com/mgtech/engine/ch202.htm.

I can't use the same parts he references since my guides measured .632 with the mic so roughly 5/8" and my valve stems measured .337 so roughly 5/16"? I only measured once so might be a bit off.

Graeme Bridge, a Pontiac 1950's friend, suggested that Comp Cams sells a cutter to machine down the valve guide and that was what he had done to his 55 heads. He says he looked every where for umbrella seals and they were all the wrong size so this was his solution. The tool fits a standard electric drill and is apparently fairly easy to use. I can't do that this time since I am not pulling the heads, but maybe next time. He sent me the picture below to illustrate.

More to come...

Valve Stem Seal Education

I bought the seals for the valves awhile back and threw them in the trunk for doing sometime later. Today I pulled the valve covers off and started in. I did three valves before my misgivings got me to stop. I began with the front on the passenger side. The first valve had *nothing* on it to keep oil out of the guide. Turns out this is an exhaust valve. The second valve, an intake, had a steel bell (shield) that made getting the spring compressor to stay on quite a booger. (Not to mention that I deformed it with the same tool.)

The section in the manual (page 6-11) on replacing the seals is really stinky. It has no pictures and doesn't say much about these shields or which valves are which, etc. But in the section on cylinder head and valve overhaul I found a heading for assembling valves into the heads (page 6-28) which has a bit more detail. It specifically says the shields are for the intake valve stems. Thanks to some quick advice from the Pontiac 1950's Yahoo Group, I got educated.

Valve order from one end of the head to the other is E-I-I-E-E-I-I-E, where E is exhaust and I is intake. Each intake should have the o-ring seal and the shield umbrella that goes under the retainer. So put the seal on the stem in it's notch - there are two and the upper one is for the keepers while the lower one is for the seal - then the shield/umbrella on top of the seal.

Hoses Done

Got the hose clamps today and finished off the hose change job. The upper radiator hose looks pretty new so I opted not to change it out at this time. I have plenty of spare hose for the two side hoses, extra clamps, a fresh lower, good upper with fresh spare, and I also got a new fanbelt to pop on, though I didn't do that tonight. Once I do I'll order a spare for the trunk. This girl is thirsty! She took over 3 gallons of anti-freeze.

Get Hosed

Busy replacing radiator hoses today, or I was until I found out that the 2-1/4" hose clamps I use on everything are a tad too small on the upper and lower hoses of The Chief. The little side hoses that move water to the heads are skinnier and was able to use four of the smaller clamps there. Larger clamps are on their way so, to be continued...

Alternator Upgrade - Wrapup

Finished off the details of the cover plates in the engine bay and cabin. Ordered an LED 1156 bulb to put in the underhood emergency light. Alternator is working great! Have a little noise in the radio when the engine is running. Will need to see about adding a noise filter. [Found one on eBay and ordered it.]

Alternator Upgrade - Electrical

More alternator work. I have the ballast resistor (25 ohm, 25 watt) in parallel with the alt light now, the light is mounted under the lip of the dash near the ignition switch. I also wired up the under-hood emergency light and moved the wiring of the power window circuit to the back of the ammeter like the factory did it. There are a few items to button up. I have to put the two metal plates back on the firewall, inside and out. Otherwise that about does it. I ordered a spare alternator because this one came out of the '49 Cadillac and it has been acting a little flaky until it warms up. Better to have one on hand.

Alternator Upgrade - Electrical

Wires are run, test fired with an added panel light as exciter and it works but I need to rev the engine a bit to get it to start charging and turn the light out. Not sure why.

Addendum: Two issues. One, not enough ballast from the miniature bulb. Need a resistor. Two, alt may not be in top shape since it was run on the '49er for some time. Added bonus, maybe testing with the trickler charger on is a bad idea? D'oh!

Alternator Upgrade - Mechanical

Fabricated the mounting bracket from a universal one and have the alternator physically mounted on the engine. Nothing is wired up yet but I used the original belt and it looks like it lines up perfectly.

I did an small extention to the factory bracket without any cutting or welding so it's reversible.

Alternator Upgrade

I had begun to investigate converting to an alternator some weeks back and gathered some brackets, wiring and diode setup for when the time came. I started working on it seriously today. The universal bracket looks like it will work the best, with some modification. It seems it will bolt onto the intake manifold in the same location as the original generator bracket. However I will need to raise it up a bit using some spacers. I had been planning on it needing a longer belt if I were to bolt the universal bracket to the old bracket instead of directly to the manifold, but now it looks like the same or a slightly shorter belt will be needed.