Knurled Guides

[icanfixall]

Yes, thats right. The shop knurled my new heads exhaust guides to "tighten them up.... The shop owner and I talked in depth about what kind of guides they would be installing because we felt the new heads were just a little sloppy. When I was there today dropping off my crank and pistons for rebalancing they said I could take the heads. When I asked what kind of guides did they install the answer was "I think he just knurled the exhaust and the intake was ok". I almost messed myself but I kept my cool. I told the owner at no time did we ever talk about knurling and that I would never accept that. We had way too much dialog on using several differant types of guide material. So, here I am still waiting for the right thing to be done. Further talking with the owner revealed the worker acted on his own and thought knurling was the most cost effective way to go on this. Geez.... Can a guy get a break here. I also found out that they DO NOT have the correct freeze plug installation tool so they wont be doing that for me either. I may just go down there tomorrow and watch them. I sure hope they don't mill the heads or set the valves too deep. Something more to loose sleep over.

 

[typ4]

Knurling is not cool on a long life engine, or any other for that matter. Although we do it at work on the 300 heads, they usually run them out of oil or water before they wear out anything. They should have replaced them with solids then honed to fit. I feel your pain.
I can walk you through the freeze plug install if you want. pm me and ill give you my toll free work number.
Russ

 

[Exekiel69]

No one will do it as well as You would because is Your engine. After having all that work done the guy decided to do what was more cost effective? You spend the time and money to get all the special turbo parts so that when it's time for them to do the job they will take all the shortcuts

 

[h2odrx]

Knurling is not cool on a long life engine, or any other for that matter. Although we do it at work on the 300 heads, they usually run them out of oil or water before they wear out anything. They should have replaced them with solids then honed to fit. I feel your pain.
I can walk you through the freeze plug install if you want. pm me and ill give you my toll free work number.
Russ

Knurling? what does this do? i looked on Wikipedia and saw what it said but how can they do this to a guide?

 

[RLDSL]

Knurling? what does this do? i looked on Wikipedia and saw what it said but how can they do this to a guide?

Valve guide material is soft metal. To knurl it, they run a tool down the hole that looks similar to a drill, except it is not sharp, it is larger than the hole on the hig spots and the correct size for the valve stem on the low spots.
As you turn the tool down into the hole, it squeezes the metal into the grooves and leaves a series of thread looking things that half are the correct diameter of the hole and the rest larger. In theory, they are supposed to do a good job of keeping the valve straight and holding oil back. In reality, you now have half the original surface for the valve to wear on, so half the life expectancy ( there are some who theorize that the knurls hold more oil against thevalve stem and offset the less surface area, but experience shows they don't last as long.

When I got my heads back from a heavy diesel specialty shop, I was pretty torqued about finding that they had only replaced a few and knurled the rest, but after I saw the bill, I wasn't in a hurry to go any further

----------Robert

 

[icanfixall]

Knurling the valve guides is an older way of making the worn out guides in the head back to the standard size. What happens is a hardened tool is slowly rotated down thru the guide. It trys to smash the cast iron back out to the particial correct size. Then its honed to the fastory fit. Problem is cast iron does not smash very well. It chips away easier. If you ever machine it you would see very small chips of it flying off the cutting bit. No long cuttings at all. You need to have the mill turning slow or the lathe turning slow. Otherwise it burns up the end mill or the drill or the tool bit. Its really abraisive material. Next time you are in a brake shop look at the cast iron milling thats in the catch pan. It looks like dust or sand.

 

[sle2115]

Wow dude, you just have no luck!!! We would only knurl guides with that being the order of the owner, NEVER would we do it on our own. We did however use a guide that had a spiral cut in it. Unlike a knurl, the groove was very small and maybe made 10 revolutions the length of a standard guide. They were bronze compound lined and were the best damn guide I have ever seen. I NEVER saw a set of heads come back with guide wear that we put them in, they were however quite expensive and most people didn't want to pay the price.


To Knurl - Our machine simply threaded the inside of the guide. It was really no more than a tap that fit our valve seat machine and we ran it through threading the inside of the guide - just as if you wanted to thread a bolt in it. We then used the proper sized reamer to cut the peaks of the threads to the necessary size for the valve. Pretty simple process, but I agree, not what I would want on a motor that you are pouring this kind of money in!!! Make them change them...

 

[GenLightening]

What are the stock guides made of, cast iron (part of head) or bronze? Also, are the stock seats part of the head or are they inserts? I'll find out when I pull my heads, but I've never had much patience (Christmas kills me).

Thanks1

 

[icanfixall]

The exhaust valves have stellite seat incerts but the intakes are just the cast iron part of the block. The guides are cast iron part of the head and appear to be part of the head casting. I went into the shop today just to make sure they knew what I wanted. I had my 4 to 5 inch mic to check the head height and my depth gage to check how deep the intake and exhaust valves are to be set. The owner showed me the AERA "bible" with all the same information about these heads so I'm resting easy now. The worker that thought he could just knurl the exhaust guides WITHOUT asking me has been taken care of.... Yes, he's still alive. I dodn't hurt him. He knew what he was doing. He just didn't know I wouldn't accept that kind of workmanship. I feel the knulring would work for other applications but not mine. It's not the time or the amount of money invested but it's what I want and nothing more. It is funny how things seem to happen to me along the way. Maybe it's really time to move on and buy a Freightliner Sportschassie and just be done with it. Maybe thats the best idea. Then I could make my idi a trailer queen and just haul it around the country instead of the horses....

 

[h2odrx]

Maybe thats the best idea. Then I could make my idi a trailer queen and just haul it around the country instead of the horses....

Hey that is an idea???