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Worn valve guides in-car fix... R&R or sleeve?


bamfordsgarage

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I need to address the worn valve guides in my 1947 D25 (25" Canadian block). This is a job I am inclined to do in car. The existing guides were knurled back to size in 2011 are once again worn out of tolerance — I assume they are the original guides, and that a re-knurl is not feasible.

 

The factory service manual recommends a Mopar factory tool "DD-849" for removal and replacement of worn guides. A google search turned up nothing, as did a site search here. Can anyone shed light on what this tool looks like and/or how it works, and if it was intended for in-car use.?

 

Another option is to ream and sleeve the existing guides in situ. From what I read, bronze liners offer 3-5 times the wear of cast iron, and an 11/32" ID is very close to what we need for Mopar valves of 0.341 stem diameter.

 

I welcome your comments, experience and suggestions on how to proceed from here.

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i did this job on my 48 DeSoto and a couple of other MoPars flatheads some 40 years ago.  It's an easy job, just press the old ones out and new ones in.  I remember the exhaust valve guides were put in opposite or upside down to the intake ones.  All you need is a valve guide driver, common tool.  I just used the common tool in my auto shop class.  Of course you will need to remove the valve springs and valves first.  

 

https://www.amazon.com/V-twin-Manufacturing-Valve-Driver-16-0132/dp/B002BCW3F0/ref=sr_1_7_mod_primary_new?crid=AYNCHPNH1WF6&keywords=auto+valve+guide+press&qid=1676349008&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sprefix=auto+valve+guide+press%2Caps%2C137&sr=8-7

Edited by MarcDeSoto
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Thank you Marc. I expect installing the new ones from the top down to be straightforward, as you suggest. 
 

Pulling the old ones up out of the block where the have been for 75 years… that is the challenge!

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I had to do the exhaust guides on my 29U Plymouth which is essentially same as the later sixes. The engine rebuilder sleeved the guides in brass but when it started to run rough and lose compression I took the head off and found the cast iron exhaust guides had split at the top, causing the valves to no longer seat. I pulled the guides using a high tensile bolt for traction, and an assortment of washers and pipe offcuts, similar to how you change a spring bush.  Three came out easily but the one next to the firewall was a struggle as it was hard to get access. I used second hand guides as I live in Western Australia but new ones are readily available in USA. I didn't take an action photo unfortunately.

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Both air and manual professional quality guide drivers are available.

A slight angle relief is cut into the driver to prevent mushrooming of the guide when driving it.

I have replaced the MoPar guides and Packard guides using a manual driver..(better control)  and heavy weight hammer.

I Line the tappet chamber with a towel after all the springs and valves are out.

This to keep the broken off guide ends from falling into the tappet chamber pockets etc.

Pount them down, break the lower part of the guide off as the guide gets close to the tappet. I use a heavy steel drift. They snap right off.

Drive the new guides in orientated properly...exh/intake and to the exact depth.

You need to hold the driver firmly and accurate, be able to use a heavy 2 lb hammer and swing it straight and solid to hit the guide driver.  

That's how they did it all the time back in the old days doing flathead valve job work..right in the car.

I prefer the machine shop to do that job always with the engine out.

 

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43 minutes ago, Dave72dt said:

The new guides may still require reaming after install and the valve seating needs to be checked.

 

I did the exhaust guides in my 230.  Luckily no reaming required.  I think that's because the current production guides for intake and exhaust have different part numbers, and the only difference is the ID.   Cast guides don't shrink when installed like steel or bronze.  But, if one had some real old stock, they where the same ID and required reaming for sure.

 

Seats need to be remachined when guides are replaced.  Some just lap, but I don't trust that to get the valve face and seat concentric.

Edited by kencombs
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I too have not had to ream the guides...I use a dial indicator and the .341" thru .344" guide pilots when checking driven or old guides.

Would never cut it on modern day valve job work...very critical tolerances and practices.

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14 hours ago, keithb7 said:

This won't work with the cam and tappets in, but gives you an idea how they can move in a 75 year old engine...

 

Very clever, and I have a lathe and some old air-hammer chisels. Excellent video as always.

 

13 hours ago, westaus29 said:

...I pulled the guides using a high tensile bolt for traction, and an assortment of washers and pipe offcuts, similar to how you change a spring bush.  Three came out easily but the one next to the firewall was a struggle as it was hard to get access...

 

All I had on hand last night that would fit down the guide hole was 5/16" standard steel all-thread. Obviously and as fully expected, the guides just laughed and snapped the rod in two.  Our local nut & bolt house has 8 mm all-thread (largest that will fit down the hole) in stock in an "8.8" higher-strength alloy (this is, apparently, the metric thread equivalent to SAE Grade 8). I was planning to make a more durable puller from this, until reading the comments below.

 

2 hours ago, kencombs said:

 

I did the exhaust guides in my 230.  Luckily no reaming required.  I think that's because the current production guides for intake and exhaust have different part numbers, and the only difference is the ID.   Cast guides don't shrink when installed like steel or bronze.  But, if one had some real old stock, they where the same ID and required reaming for sure...

 

Not clear here Ken... current production for newer engines I can see different IDs and part #s, but since you mention the 230, were you able to source different intake and exhaust guides for that vintage Mopar?  What I found online from BernBaum was one guide only intake and/or exhaust.

 

3 hours ago, Dodgeb4ya said:

...Pound them down, break the lower part of the guide off as the guide gets close to the tappet. I use a heavy steel drift. They snap right off... ...That's how they did it all the time back in the old days doing flathead valve job work...right in the car...

 

 

You had me at "back in the old days"... my late father—gone 23 years now—earned his mechanics license about 1948 and I've been imagining us doing this job together, with the tools and techniques from when my heap was new.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _

 

I have a stuck parts engine for practice. It's from a '40s D25 and carries a 1957 rebuild tag. The donor car had a 1972 plate, so the various parts have been together for 50+ years.

 

Plan A is to combine Keith's custom driver with b4ya's controlled clobbering and see if that does the trick on a couple guides in my parts engine. If it works, I'll order up a set of 12 guides and go from there.

 

Plan B would be guide liners.

 

Plan C would involve engine removal. Or maybe dynamite.

 

Thanks to all for your comments and suggestions. Very helpful and very much appreciated!

 

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24 minutes ago, bamfordsgarage said:

 

 

 

 

Not clear here Ken... current production for newer engines I can see different IDs and part #s, but since you mention the 230, were you able to source different intake and exhaust guides for that vintage Mopar?  What I found online from BernBaum was one guide only intake and/or exhaust.

 

 

 

 

Sealed Power, VG-419 AND VG-420.  Fits all 218/230 I believe.   I much prefer to buy from known brands when possible.

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I replaced the valve guides in our '37 Terraplane with the engine still in the car.  Virtually the same procedure as with our flat sixes, except the exhaust guides are not reversed in the Hudson 212 engine.  All the manifolds were removed, which on the Terraplane made it much easier, the exhaust ports and manifold are on top of the block, not the side.  Used a manual valve guide driver with no issues, and although prepared to, I did not need to ream the guides after they were installed.  Removal of the guides was relatively easy (other than appropriate application of muscle) if I remember correctly, three came out the top with the valves when I removed them, the others I drove out through the bottom.  Just enough room in the Hudson engine to do that.  Patience and attention to detail are very helpful.

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Well, the valve guide removal test on my parts engine went just fine.  My spare air-hammer bits were all too short to push the guide out fully but no matter — my little air hammer wouldn't budge them anyway. Fortunately, a few well-placed blows with a sturdy hammer did the trick, and as b4ya predicted, the protruding guide broke off with little effort. I would expect the guides in my runner engine will move at least as easily.

 

Ken, knowing what to look for led me to crossover charts for both intake and exhaust valves, the latter with 0.002 greater ID. Charts below. I'm sourcing them now.

 

Thanks again to all who posted and Sniper, I'll put that snazzy tool on the list for when I do enjoy "...money for tools is no object..." Don't hold your breath.

 

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