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I also posted this question on my blog but I thought more people might see it here. I have a 1951 200 with a 288 engine that has a cracked valve guide that needs replaced. Is there anyone else who has done this that would care to share any tips or tricks to this job? I read through the service manual which of course lists some special tools which I don't have. The main thing I'm concerned with is how do I make sure I have the new guide driven into the right depth without the appropriate tool?

Owen_Dyneto has done more than his fair share of the replacements and thought he might have seen the first post to share his expertise and had the dimensions you need.

Here is an old post of his showing some of the tools he uses or has made. Am sure he will be along eventually but you can also do a search of the site and some of the old posts. Am fairly sure the subject has come up before.https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=144641#forumpost144641

The main thing I'm concerned with is how do I make sure I have the new guide driven into the right depth without the appropriate tool?

The simple drift (tool) to drive out the guide and drive in the new one DOES NOT determine the depth the guide is inserted to; you determine that by measuring the depth from the block surface of the old one or other ones first and drive the new one to the same depth. A 1/16 or so either way shouldn't make a difference but try to get it right. Packing the new guide in dry ice or at the least, a freezer overnight, will make installation easier. When done don't forget to check the stem clearance and ream if necessary though with replacement guides I've bought in the last 15 years from Egge or Kanter I've not found that necessary.

Thanks for the replies. I will definitely scour the old posts and see what I can find. Owen, I was looking at the service manual and they had a specific tool for pressing in the new guide that had a collar that bottoms out against either the head or valve seat, not sure which, that insured the new guide was driven to the right depth. I guess I'll just measure the old one and try the get it close and then check clearances as you suggested. Thanks!

That tool, valve guide driver and depth gauge, was made for Packard by Kent-Moore and was probably tool KM J-2577, it's listed in my 1950 Kent Moore catalog of Packard tools. I can't say I've ever seen one or seen anyone use it, everyone I know uses the KD-815 driver or equivalent (easy to make one) to remove and also install, just measuring the depth from an existing guide.

No reason to be apprehensive about the job, though it's not the most pleasant job it's easy enough. The only really annoying guide to do is #8 exhaust as the overhang of the cowl makes it difficult to get a good hammer blow on the drift pin. Remove the hydraulic plunger body if you have hydraulic lifters (which I don't think you do), drive the old guide down to within 1/4" or so of the cam follower/tappet body, go in thru the valve lifter chamber and snap it off with a cold chisel - they are very brittle and snap easily. Then the drive the remainder out the same way. All this of course assumes the cam and followers are still in the engine; if not, just drive them all the way out in one piece, they will drop right through the bores of the lifters.

PS - If you make a driver like the KD-815, the pilot that goes into the guide should be 11/32 and the first shoulder should be just a bit smaller than the ID of the guide bore.

So today we finally got around to working on getting the cracked valve guide out. My dad made a driver on his big metal lathe that worked really sweet. I ordered a new guide from Merritt's and have it sitting in the freezer. Hopefully it goes in tomorrow as easily as the old one came out!

I'm glad you got it out easily, sometimes they can really try your patience.

With a new guide and possibly a slightly different centerline for the valve, assuming the seat and valve face are in good shape I strongly suggest you hand-lap the valve face/seat lightly with some valve-grinding compound. A good technique to make sure you have full contact is, after lapping, use a soft pencil and make a series of radial lines across the valve face. Then rotate the valve under slight thumb pressure (without the spring installed) for a partial turn back and forth and make sure all the pencil lines have been broken by the seat. If the seat or valve face is questionable, have them refaced before reinstallation and that's a good time to ask yourself if, as long as you're into it this far, if it isn't time to examine and possibly reface/lap all the valves.

Yep. I've already done that. My dad has a really nice old valve grinder and everything needed to do a complete valve job so that's what I did. Ground the valves, cut and refaced the seats and started putting everything back together this afternoon. Reinstalling the valves has been a little trying. I don't think I have quite the right spring compressor, but am making due with what we have. We got half the valves in today before we quit. Hopefully we can have everything back together and ready to try firing up by the end of next weekend.

That was a good move attending to the other valves - in that era flathead engines normally had valve jobs every 40-50,000 miles.

Although there is a special tool for placing the valve keepers on the stem (picture enclosed) I really find it not worth the effort - if you're having problems with that just put a tiny dab of grease on the inside of each keeper half and press it into place - the surface tension of the grease will keep it place. And don't forget to use rags or corks to block of the oil return holes or you may end up with a keeper or two in the crankcase. Also enclosing pictures of the preferred valve spring compressor - you can with some difficultly use the big C-clamp type intended for OHV engines but normally you have to remove the manifolds to do that.

How about deleting your duplicate post?

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