Ponderings...

Thought I had the valves adjusted... put the covers on today and fired her up only to be met with noise, rough running and... smoke out the exhaust. Maybe my valve seal job just didn't do the trick. But in any case, seems I need to do some more work on adjusting valves. It shouldn't be this hard! The manual says to tighten till no lateral movement without collapsing the lifter's hydraulic range. Then turn one more full turn. Of course, I didn't do it that way because the crank has to be turned to set each pair of valves to be fully closed and turning the crank is a bitch with the limited room in front. (Is that a lame excuse or what?)

One thing that will help with turning the engine is to use a remote bump switch. And one thing that will make that easier to use is to get my "Start'M Up" kit fully installed. (Started this when I pulled the old voltage regulator as a part of upgrading the generator to an alternator.) I need to pull the positive battery cable and measure for a new one in order to finish that job, so I think I will stop with the valves and turn to that before I go back to valve adjusting.

MAD Electric and Painless both make these kits and you can come up with your own by using a Ford starter solenoid and some wiring supplies. Kit contents (MAD) and wiring concept (Painless) shown above. Car Craft has a good article that includes this kit. 

Long-term thoughts though... if the engine smoking is really not solved (meaning there isn't just residual oil burning off), then I think the next plan is to invest in a few bottles of Lucas to control the oil. Supposedly this is a low-mileage engine and I think I have seen enough evidence to believe it. So I do not want to invest in an overhaul! I can't see spending $4K on an engine that is supposed to be only 27K miles.

Which brings me to another thought... if I do need to invest in an engine, considering that these cars are meant to be drivers, not show cars, what I would really want to do is put a crate engine in instead of a rebuild of the original. Of course, that means dealing with the transmission too. Adapter kit or replace with whatever bolts up natively. And if it's "replace", then one has to deal with drive-shaft and third member. Ugh.

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I got a nice response from a Pontiac friend on the Pontiac '50 mailing list:

I put a 350/TH350 in my 1950 Pontiac.  I had never done an engine swap before.  I did a lot of reading and research before doing so to make sure I was doing it right.  I had heard of poor swaps if all was not well aligned. I don't think it was all that difficult, but there were several things to consider as far as proper alignment with the rear end etc.  It would also depend on how comfortable you are with doing the work yourself .....and...... how patient you are. After doing it myself on my 50 Pontiac I think it would go faster and easier the second time, because I was learning as I went.  I personally would recommend doing it.  It doesn't take much to make your own motor and transmission mounts if you have much mechanical sense and can take accurate measurements. The main things to keep in mind are: 1) keeping the rear end input shaft and the transmission tail shaft at the proper angle to each other. those angles/lines must be parallel  2) carburetor mounting surface level at ride height.  3) Also remember that most engines were offset to the passenger side about 1/2" from center.   Once I figured out how to do those,  the rest was pretty simple. ...just time consuming to get the parts and hook everything else up. But, I think it was worth the time and effort.
Good luck.
Bill

Nice!

Valve Cover Gaskets

So I cleaned off the (not so) old cork valve cover gaskets today and found that they had been attached via weatherstrip adhesive to the covers. At first I though this was an idiotic way to attach the gaskets, but the further I got in cleaning them off, the more I realized this was actually a pretty good way! I had purchased rubber gaskets so it seemed it might be even better with those. I used the Dremel to get the cover seal surface nice and clean, then smeared with my "elephant snot" 3M Weatherstrip Adhesive and presto! The gaskets are not going anywhere! Ran out of time so will have to finish next weekend.

Valve Adjustment

Put the plugs back in and wires on so I could start the engine and tighten up the valves. Lots of clattering when she first started! Had her quieted down pretty quickly but not I've got oil all over the place. I used some brake cleaner to get some of it but I'll have to go get some Gunk® tomorrow after I get the valve covers back on.

Valve Seal Progress

At last all 16 valves have new umbrella seals installed. It took about 6 hours but I had the valve covers off and everything ready to go from a few weeks ago. All of the intake valves with their factory shields were real buggers to get the springs off of because the shield interfered with the hooks on the spring compressor. I think one shield survived undamaged, but since I am not re-using them, it doesn't really matter. I was hoping to be able to save them and maybe offer them to someone who might want to use them. The only way to have gotten them off undamaged would have been to remove the heads and use a conventional valve spring compressor. Oh well!

The plan is to put the plugs back in their holes, reconnect the plug wires and start the engine to reset all the rockers. I tried to tighten them down to "best guess" but with the engine running I can adjust the lash down properly. If I remember rightly, you tighten down til the engine stumbles a bit due to the valve not closing all the way, then back it off. Better check the manual and see if there are any tips.

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.