Exhaust valves domed?

[MBF]

Just pulled the valves out of the 52 to clean them up, and replace the burned one before starting the valve job. I notice that all of the exhausts are slightly domed, and not flat like the intakes. With the exception of #6 all have good looking faces, no knife edging and should be usable. Is this normal?

Also-is there a way to tell if the water dist tube is in good shape w/o pulling the pump? I was planning on knocking the freeze plugs out and giving her a good flushing, but only want to deal w the water tube replacement if I have to. Comments/suggestions? Thanks-Mike

[JBNeal]

When in doubt, pull it out...the dist.tube is fed directly from the water pump, so inspection requires removing the pump. Removing the freeze plugs is a good idea because they can corrode from the inside out and form pin holes. Removing the freeze plugs in the '49 revealed total blockage on the bottom row of plugs with sediment that creeped up to the upper row. With the head & pump off and the plugs removed, I jammed a water hose in the dist.tube and poked at the sludge with a screwdriver while flushing...WOW there was a lot of crud up in thar. The trick in installing the new freeze plugs is to put sealant in the engine block seats first, then driving the new plugs into place. This oughta keep them plugs from weeping.

[MBF]

Good news-new tube must have been installed during the previous rebuild-on with the flushing and valve job! One more question, can the pan be dropped w/o lifting the engine? I''d like to clean that out too. Mike

[JBNeal]

The pan can be removed; I recommend jacking up the frame & pulling off the front wheels so the front axle will drop to give ya more room to work. You can pull the pan out otherwise, but it requires a great deal of jockeyin', finaglin' & cussin' to get it removed. The '49 had enough sludge in it to form a softball-sized glob, so cleaning out the pan (and the valve spring area) is worth the effort.

[garbagestate 44]

On a 47 Chrysler, the steering arms can make removal tight. If thats the case on your car, turning the crank one way or another may give you more clearance when sliding the pan out past the steering gear.

[Frank Ollian]

I've recently taken apart a few engines, a 218 and three 230's. They had a mixture of domed and flat exhaust valves, mostly domed. I think the domed exhaust valves are probably the originals, I'm thinking more meat there will handle the heat better.

I also found a couple intake valves that where recessed or dished, is this what you get now if you order new valves?

Frank

[John-T-53]

The original valves and new ones in my 230 are all flat.

Perhaps the domed exhaust valve design helps the hot gas exit the combustion chamber better?

[Dodgeb4ya]

Domed exhaust valves were factory depending on year. I think they are better than flat headed exhaust valves- more mass-less warpage.

Bob

[grey beard]

Hi Mike,

Make sure to check your valve guides, whilst yer down that far. If they're worn, it will be impossible to redo your seats, since it is the guides that centerthe valves.

My own guides were very worn. I knurled them and they tightened right up - except for the frontmost exhaust guide, which I had to replace. If you want to knurl yours, let me know - I have all the stuff you'll need.

Whilst yer pan's off, stick a big honkin' old speaker magnet down on the bottom, behind the drain plug. It'll keep any nasties outa' the oil galleys.

Good Luck

[MBF]

Thanks GB-the only guide that is warn is the #6 exhaust valve-I think my machinist is either going to ream in and put in a sleeve, or if he can get jost one-just replace the bad one. Probably going to need a new seat too. It looks like all the guides were all replaced during the last rebuild, even the water tube is new. Hope I can get a domed exhaust valve-if not I have a parts engine in my shop that I'll pop the head off to see if I can harvest one from. Mike

[Don Coatney]

Can you post a picture of this domed valve?

[Dodgeb4ya]

Can you post a picture of this domed valve?

Here is a picture of a factory flathead 8 Chrysler crowned head exhaust valve, Part # on underside. The little Ply/Dodge 6's look just the same-Pt.# is on the underside. They-exhaust valve's have a very slight crown or "Domed" head.

Bob

[Don Coatney]

Here is a picture of a factory flathead 8 Chrysler crowned head exhaust valve, Part # on underside. The little Ply/Dodge 6's look just the same-Pt.# is on the underside. They-exhaust valve's have a very slight crown or "Domed" head.

Bob

Are these valves sodium filled?

[Dodgeb4ya]

Are these valves sodium filled?

They are not sodium filled. In some of my Dodge trucks they have sodium filled .437" stemmed exhaust valves and are flat headed.

Bob