Packard Forum Index » Post-War (1946-54)

Thanks Tom! Another useable tip.

By now I have the complete choke reinstalled, that is the housing which I've secured well on the carburetor housing with a little silicone sealant around the vacuum passage. Then the internals and the cover with plate and gasket. It all looks very promising. This week I'll take the throttle body to a local machine shop to see if they can rebush it. When that is done, it's time for final adjustments and a try out.

I'll keep you on the running with the first results.

I just came back from a friendly machine shop where I left the throttle body. The shaft itself is allright, just a little wear but nothing serious. So the housing is a candidate for receiving new self-lubricating bronze bushes. They need to be rather thin walled but nothing the shop can't handle. Very wallet-friendly too which is also important to keep the Mrs. satisfied

By the way, does anyone have any good tips or tricks when it comes to adjusting the valves? Is it good practice to adjust both inlet and exhaust valves in TDC on compression stroke?

I'm thinking of adjusting the valves cold, don't like fiddling around with a running and hot engine. Shutting the engine down at normal runnig temperature leaves too little time to do the job in a relaxed way I guess.
I read somewhere that in case of adjusting cold (=shorter valve stem) I should add a little clearance to meet the right clearance when hot (=longer valve stem). But how much more and is there a difference between intake and exhaust?

Who has experience and can give me good advice before I tackle this job for the first time?

Hans,

I agree, setting the valves on a Packard with the engine running is one of the least favorable jobs to do; especially for the center cylinders which requires working around the exhaust manifold.

Others here have adjusted the valves cold and add about .002" to allow for stem growth when warmed. They can comment on their method and the extra clearance.

I prefer to set them at operating temperature, but with the engine not running. After doing all the prep work for a valve adjustment (RF tire removed, fender splash shield off, and tappet covers removed) I thoroughly warm up the engine then shut it off and set the valves for No. 1 cylinder; then, restart the engine let it run for a minute or so and set the valves for No. 2 cylinder; and repeat this procedure for the rest of the cylinders. This will maintain operating temperature with the benefit of the engine not running.

There is a method for setting all the valves with just two revolutions of the engine. I don't have this procedure memorized, but others may know it or where it can be found.

Once adjusted, the valves will not need this job done again for many miles.

(o{}o)

JW, thanks for sharing your MO. Sounds like a good compromise between cold and running. I will seriously consider doing it that way.

The method of adjusting all valves within two revs sounds a good idea too. Maybe someone who knows the finesses can fill in the details? The less revs the better, I think.

Hans,

Actually, thinking about it, adjusting the valves in firing order will get you only two rotations of the crankshaft. The other method requires less, but I forget how it is done. Adjusting the valves in cylinder order will require more rotations of the crankshaft. Since I run the engine between adjustments I follow the cylinder order.

(o{}o)

Hans, read Peter's post in the above thread: Firing order and any cylinder layout.

(o{}o)

Sory about that, I put the info into the incorrect thread

G'day all, I posted this 2007 but it is still relevant and the method which I use

G'day all, I also used to half burn myself to death trying to set those tappets with the engine running. I thought that there has to be a better way. Well a lot of years ago I read of a method of adjustment, for straight eights of firing order 1-6-2-5-8-3-7-4 and have been using it successfully for over 40 years. The engine should be nicely warmed up to operating temperature and you only have to rotate the engine one turn from No1 firing position to set all of the tappets. Try it and see what you think. N.B.There is plenty of hot water in the engine so it is not going to cool down enough to make a difference within an hour.
STAGE A - NO 1 AND NO 8 PISTONS AT TOP CENTRE, WITH NO 1 PISTON IN FIRING POSITION ( BOTH LIFTERS DOWN)- ADJUST STAGE A
ROTATE ENGINE 360 DEGREES TO STAGE B, IF YOU OVER ROTATE BRING IT BACK 60 DEGREES THEN RE-ROTATE TO STAGE A. or B. ( TO TAKE UP BACKLASH IN TIMING CHAIN ETC.)
STAGE B - NO 1 AND NO 8 PISTONS AT TOP CENTRE , WITH NO 8 PISTON IN FIRING POSITION ( BOTH LIFTERS DOWN) - ADJUST STAGE B.

STAGE A - ADJUST
NO 1 - BOTH VALVES
NO 2 - EXHAUST VALVE
NO 3 - INLET VALVE
NO 4 - INLET VALVE
NO 5 - EXHAUST VALVE
NO 6 - EXHAUST VALVE
NO 7 - INLET VALVE

STAGE B - ADJUST
NO 2 - INLET VALVE
NO 3 - EXHAUST VALVE
NO 4 - EXHAUST VALVE
NO 5 - INLET VALVE
NO 6 - INLET VALVE
NO 7 - EXHAUST VALVE
NO 8 - BOTH VALVES

There is a margin of overlap in the above method, so it is not necessary to have the piston exactly at top centre. I also use the GO - NO GO feeler adjustment method. I also adjust valve stem clearance to 7 thou ( inlet) and 10 thou (exhaust) instead of 4 and 7 thou to keep the valves on the seat a micro-second longer, to run them cooler, as we tend to run the engines a bit harder than in the old days. There is also a similar method for 6 cylinder engines of 1-5-3-6-2-4 firing order Best regards Peter Toet
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Posted on: Today 11:54:42
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Good information guys! The less revolutions the better and one rev is the absolute minimum. The one rev method makes sense, as in theory stage A mirrors stage B, if you look at what tappet to adjust.

My engine had a complete rebuild and probably the valves have been adjusted to the right tolerances but I think I will see into it myself to make sure. With the engine run in and settled now it is also a good idea to check the clearances again. That should do the trick for many miles to come. In the past I had two WW2 Dodges 3/4 ton (Command Car and Carryall) and I remember I never had to readjust the valve clearances when the cars were in my possesion.

BTW Peter, do you have Dutch origins somewhere? Toet is a Dutch name from the province Zeeland, which is more or less where I live. A lot of families in the fishing trade in Zeeland have that name.

I forgot to ask. Although I can figure it out by looking at the manifold layout, does anyone have a diagram on the valve layout?

I mean from cylinder 1 to 8 the order of inlet and exhaust valves. Should come in handy when adjusting the valve tappets.

Thanks in advance.

Hans, you can probably determine the exhaust and intake valves by their proximity to their respective manifolds. You may also get this information from the Shop Manual that is available for downloading on this site. Go to the Packard Literature and Manuals section (on the LH side of the page here) to find it.

(o{}o)

Also, now would be a good time to re-torque the cylinder head nuts.