Fitting Valve Guide Boss in a 7.3 Head?

[Sorro71]

I just recieved 2 rebuilt bare heads from Diesel Cast West in Portland Oregon, one of the heads has cracked valve guide bosses.
Is it possible to bore out the existing cast valve guide boss and press in an insert?
The heads have a warranty but freighting back across the Pacific isn't really an option. I'll contact Diesel Cast and see what they can do, but just wanted to get some idea's.

I'll post pics when I get home tonight.

 

[Sorro71]

Pictures of the cracks. There's 3 that I can see by eye without Mag particle testing.

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[towcat]

that's sad how work like that is allowed out the door, let alone go halfway around the world.

 

[Sorro71]

It hurts I can't seem to have a win with these cylinder heads.
On the bright side I've got 2 cracked ones to practice on if need be.

 

[PwrSmoke]

That's how it's done. Drill 'em out to a specific size and drive in a new insert. The parts catalogs list the guides. The Sealed Power number is VG-804 (intakes and exhausts) and the FP Diesel number is FP-1805407. I watched them being installed in my head. No worries! Easy-peasy job with the correct size drill bit (based on the OD of the new guide + interference fit and all that). Order the guides and then mike them to select the right bit.

Thanks for sharing the name of the place that sold you the heads so we can avoid the same fate. Least they could foo is ship you a new set of guides for your trouble.

 

[icanfixall]

Well this is really a surprise. I have purchased several sets of NEW heads from them and never had any issues. What you have here in your post are used heads. If they sold you new bare heads then you got screwed big time. Might wonder how I can tell these have been reworked. I can see the knurling in 2 of the guide pics. Thats the threaded look inside the guide. Thats not a good way to repair guides. Its a cheap way to make it work for a short time. Now to break the guides and not care about it is not good workmanship or good seller practice. When a guide is knurled a tool is forced into the guide bore and pushes the cast iron out into the bore swelling the cast iron. Cast iron does not swell or cut well. It chips. So a knurled guide is fast, cheap and will not last. A new guide is the only way of repairing worn guides correctly. Sadly I do not think drilling out your guides with the cracks and pressing in new guides will hold up. Any chance Dieselcast milled the heads flat or did a valve seat repair or cut. The minimum head thickness measured from the top of the valve cover machined surface to the bottom of the head is 4.795 and can be as large as 4.805. The intake valve needs to be recessed into the seat 0.042 to 0.054 and the exhaust is 0.051 to 0.063. The precups can be above or below the deck of the head by -0.0025 to +0.0025. Really sorry to learn of this problem too. There is no good reason for this kind of work leaving any shop.

 

[PwrSmoke]

Sadly I do not think drilling out your guides with the cracks and pressing in new guides will hold up. Any chance Dieselcast milled the heads flat or did a valve seat repair or cut.

I just looked at a set of head done about 12 years and 100K miles ago at a machine shop, where the guides were drilled out an new ones pressed in... most suitable for reuse! All he had to do is use an air hammer to drive out the old and then pressed in the new. Commonly done on many types of heads and I don't know why you don't think it would hold up. Unless you were thinking of those sleeve inserts. The ones I am talking about you drill all the old guide out to a specific ID, and them press in new ones, which are big and thick. That's what went into my heads. Here are a couple of pics.

Here, Kevin at Kalvinator Engines, in Wapakoneta, Ohio, is using an inside mike to check the guides for size and concentricity.

Here Kevin is miking the guide.

Here you can see the exhaust guides have been drilled out and he is driving in the new ones with an air hammer. He measured the old guid protrusion but I think he also found the dimension in the AERA guide for the engine.

Here, the new guide is checked for the proper installed height.


Had some extra time so I redid the pix.

 

[IDIoit]

please enter this into the hall of shame!
any reputable shop would have made sure this was known to the seller before payment and shipping.

 

[icanfixall]

I just looked at a set of head done about 12 years and 100K miles ago at a machine shop, where the guides were drilled out an new ones pressed in... most suitable for reuse! All he had to do is use an air hammer to drive out the old and then pressed in the new. Commonly done on many types of heads and I don't know why you don't think it would hold up. Unless you were thinking of those sleeve inserts. The ones I am talking about you drill all the old guide out to a specific ID, and them press in new ones, which are big and thick. That's what went into my heads. Here are a couple of pics.

Here he is miking the guide. He then drilled the old guide out for an interference fit

Here you can see the exhaust guides have been drilled out and he is driving in the new ones with an air hammer. He measure the old guid protrusion but I think he also found the dimension in the AERA guide for the engine.

Sorry I resized these pics from the originals but they show up fuzzy here, but not on my computer.

Can't see any of your pics but.. My comment pertains to the drilling out the cracked guide and pressing in the sleeve type guides. Thats what I meant about the cracked guides would not hold up with the cracks and guides in them. Now if the complete guide was removed as you posted was done in yours.. Then of course they will be fine and preferable to a sleeve type guide. The knurling of the guides was a cheap thing of yesteryear. I really thought it was no longer used by front line companies but I guess some still employee the cheaper methods. I know it is tuff to Monday morning thing about all the questions that "should be asked" when buying anything. When we trust.. We get screwed. I'm no ****** to getting screwed and not one kiss on the neck too. These heads should never have left the shop without telling the buyer what he was getting. A rebuild set of heads is just that. Although I'm still wondering how a head is "rebuilt" and comes bare. How does a buyer know what the seat angles are or the valve depth in the seats is...

 

[typ4]

having installed thousands of iron guides in heads , the whole boss does not get removed, this is not uncommon, but it looks like crap, I hope they are iron guides, the question is why are they all not spiral ID or all smooth. I have used thes guys before and never got this kind of work.
Contact them , let them know you have an agent local to help. Im in there 3 times a week usually, and if they offer to send more heads ill go inspect them before. I should have gathered up a set and done them up for you

 

[PwrSmoke]

I redid my pix so go back and look at the guide installation process. I have misplaced a shot of him drilling out the head, which he did on a big drill press.

 

[icanfixall]

Thanks. Those are great pics of the work done to the heads.

 

[Sorro71]

Thanks guys for all the feed back and kind offers. PwrSmoke those pictures are gold. I've been in contact with DCW and they've been nothing but positive and professional in their approach to the problem so far. According to DCW they were in a batch of heads they purchased from another shop. My guess is there's probably more of them like that around. I hope no one else gets caught.
The reason I purchased refurbished heads is they don't have any new heads left in stock and there was no plan of having another batch cast. I would of bought new if they were available.
The reason I didn't buy them with valves fitted is I have 2 other sets of 7.3 valves already and set of new springs to fit to heads.
Why did I ask about whether the repair was possible?
These engines were never sold in a production vehicle over here so there's very little experience in repairing them. Ive already learnt the hard way that to try fitting valve seats to the exhaust is not a good idea, so I'm a little nervous about drilling or cutting into them. I'll keep you updated as things progress. Thanks again this forum's such a great help.

 

[icanfixall]

Exhaust valve seats are pressed in and pulled out. The easy way of installing the stellite exhaust seats is to soak them in liquid nitrogen till they stop boiling. Then they will actually fall into the heads. DO NOT TOUCH the cold seats. They are about 280 degrees below zero. That cold will burn your hands badly. If no liquid nitrogen is available then use dry ice. Its not as cold but it will shrink the seats so they fit better. When the temps normalize nothing will move. The intake seats are really not replaceable because of the close water passages in the heads. Very few if any have been lucky to replace the intakes and not have a leaker.

 

[Sorro71]

My apologies Gary I meant to say intakes. It's been a hell of week, I just worked out it was friday this morning.
I,ve posted this picture before somewhere here it is again its proof that messing with the intakes is risky business.

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