Question cylinder head elements

[Adeleandre]

Hello,

I looked at Rockauto and they sell valve guides for the 223. When I look at the Fordification technical drawings, I don't see any?? is this an improvement that can be made or am I not understanding everything ?

I also found the valve seats but they sell them in standard and repair sizes only for exhaust, can you confirm the standard sizes for exhaust 1 3/8 and inlet 1 5/8?

They also sell seats for cast iron cylinder heads? I didn't know the 223 had cast iron heads ?

Thanks !

 

[manglass]

They would be replacement valve guides, available in iron or bronze. A machine shop would bore out the head and press the new guide in.

The seats are also repair parts. Originally the valve seats were just ground into the cast iron head. When the original seats are worn and begin to sink, the head is cut out and new hardened seats are pressed in. Actually valve seats are often cooled in dry ice then allowed to expand in place.

I'm not certain about the valve sizes but I'll look them up and if no one else chimes in, I'll let you know.

Lou Manglass

 

[Adeleandre]

Merci Lou ! donc les guides sont bien une modification et non un équipement d'origine. OK pour les sièges, le mieux sera pour moi de démonter la culasse et de regarder les dimensions de ceux en place. Merci beaucoup pour ta réponse

 

[Adriatic Machine]

I would think the machine shop would have a better idea of what valve seats to use. Might be best to let them use their supplier. If I remember correctly these heads were not made with replaceable valve guides. My buddy reamed them out and used copper beryllium valve guides that were a bit longer than the original length.

 

[Adeleandre]

Ok I understand, the best would be if I brought the cylinder head and they checked what is best

 

[philford]

I had a shop install stainless steel seats in my old volvo with a cast iron head. I installed new guides, he knurled them ( to hold oil) and then reamed them to fit my new stems.

I spent a few days prior with a dremil polishing up the intakes and he said they looked great, it did really seemed to do a lot for it's performance.

also made a better fit of the ports, the manifolds don't always align perfectly so a little work and you can remove any "step" , which affects flow.

I believe the reason I changed was because leaded fuel was no longer available and the lead helped the valve seats, or so the theory was. now there is still no leaded fuel of course..

cast iron is a bit brittle but bronze or non ferrous guides may be able to distort a little..
Id check with the experts, but I believe that you can simply knurl the guides ( reducin gthe ID) and then ream them, making the ID correct.. Id check with an expert. maybe you do not need new guides. I remember an engine shop guy said . 004" was the threshold for clearance. in a Volvo with cast iron head.. he said he wouldn't fix it if it was not any more worn than that.
Id ask that question of an old ford guy or the machine shop, to get a more trustworthy confirmation . if reaming does it, then why replace them.

I knew that that reaming was a way to reduce the ID. I was surprised that the engine shop would ream my new guides, it wasn't done for sizing, but for oil retention. i felt that the particular guy knew his stuff , he had race engines and nice equipment all around there.

Some of the jobber shops I've seen were real mass production quick and dirty places, I didn't feel they paid a lot of attention to detail , where you go, matters.

I thik if you go to remove the valves, take the keepers off etc, but before you go yanking the valve out of the head make sure to remove any burr from the slots near the keeper, otherwise pulling that end through will enlarge the guide. if they slip through easy, fine, but I would not get rough with that.. you can first remove any "lip " off the stem..


The vintage racers will know more on all that than I do..

 

[Adeleandre]

Thank you, I will check with the rectification company what they think, they have already worked on another cylinder head of an engine that I rebuilt and they are rather good in their field

 

[philford]

I made some typos, but my point was that if the ID of the guides can be decreased by knurling and then sized accordingly by reaming it may be a logical way to repair the guides and have them fit perfectly as opposed to replacement.. Having a shop you trust the advice of is really important.

 

[Adriatic Machine]

Knurling a used engine part for re-use is not really a thing anymore, as far as I know. The exception would be knurling the OD of a piston to fit in an over-honed cylinder and even that is something you would only do in a Mad Max movie after the factories shut down.

As a tool & instrument maker, the thought of knurling the ID of a valve guide makes my head hurt.

New valve guides are not expensive to buy but can be expensive to install and machine to spec. Regardless, I have never heard of anyone re-using a valve guide, but I am willing to learn.

 

[Frank]

Knurling a used engine part for re-use is not really a thing anymore, as far as I know.

It still exists here in the deep south. My machinist with 50 years of experience knurled the intake valve guides on a 240 head. They weren't far out of spec, and in his opinion this was the most effective solution.

 

[philford]

when I took me head in with brand new guides freshly installed by me . there was enough meat to ream to size, the engine machinist I worked with recommended knurling them because the recessed areas hold oil so the intent was to keep oil in the guides, to make then last longer. It was not done in my case, because decreasing the ID was necessary. the shop did race engines and they had plenty of very expensive equipment, it wasn't a "farmer overhaul" type idea.. I trusted his word and went ahead but of course this is just one man's opinion.

i have seen the technique of using the jaws of a vice and rotating a piston to make serrations, or putting tin foil behind bearing shells, that's farmer overhaul stuff and it has it's place.. I do have a respect for that and the mechanics in cuba, India etc, , some of those guys can adapt to a situation where parts are not available to them and still win.. I think of it as a special skill. I've met a number of farmers who also had related skills and could think outside the box under similar circumstances. parts changers that follow manuals and can't think for themselves are a dime a dozen.

had my van in for a tire change an extra hundred and they do a wheel alignment so I said go ahead, the "licenced mechanic" turned to me after pulling the tires off and without even trying asked if I could break the rusty tie rod adjustment loose for him and then bring it in.. Some mechanic that is, I thought..

same place I go in with a belt, "can you find me a match to this"
"what car is it for? "

"Its for a 66 volvo with a GM alternator and that's a metric belt you are holding.. it fits but I want a spare."

"sorry it isn't listed"
my spark plugs are obsolete there too , evidently.. ;-)

 

[Adriatic Machine]

Well I guess a late-mid life dog actually can learn new tricks. To satisfy my curiosity, I’ll have to do a search to see what tooling is used to knurling the inside diameter of a small hole.

 

[philford]

Well I guess a late-mid life dog actually can learn new tricks. To satisfy my curiosity, I’ll have to do a search to see what tooling is used to knurling the inside diameter of a small hole.

yea it must be special and not something the average guy needs to own..
also cast iron is brittle , not very "plastic" so it may not work on that.

 

[Bronctopia]

This "knurling" is more like rifling, or threading.
It can be done with hand tools (I think Goodson had kits).
Since you can thread cast iron, you can also "knurl" it.

But you probably shouldn't.

It is best used on minimal wear guides that haven't tapered the bore, with overall clearance to be taken up less than a thou.

In other words, frequently removed heads with not a whole lot of running engine hours on them. Like is usually the case in racing.

100k plus rebuilds would usually be better with bronze replacement guides.

 

[Frank]

Well I guess a late-mid life dog actually can learn new tricks. To satisfy my curiosity, I’ll have to do a search to see what tooling is used to knurling the inside diameter of a small hole.

If I get a minute I'll swing by Garry's and ask him. Known him since high school. After graduation he went straight to work at the local machine shop. When they shut down he bought it out, relocated and has done nothing else since 1977. Guys bring engines from a long distance, all the racers in a hundred mile radius use him. . When I brought him the 240 engine the first thing he did was mic the front cylinder for out-of-round, knowing that was the weak spot on these engines. Not too many like him left these days.

 

[philford]

This "knurling" is more like rifling, or threading.
It can be done with hand tools (I think Goodson had kits).
Since you can thread cast iron, you can also "knurl" it.

threading or drilling cast is easy but those are cutting operations.
I believe the knurling is done with a tool that is distorting the metal so the metal needs to be somewhat malleable and not so brittle.

cast iron is not very malleable or plastic.. in that context I don't mean plastic as a material description but as the meaning, which is similar to malleable. ( it can be deformed without fracturing)

I can knurl the outside of things on my home lathe, using a rotating knurling tool which is set in contact width some force creating cross hatch patterns.

to do a valve guide maybe you'd use a mandrel press or similar and a tool designed and sized for that one operation. I think its being forced in and moving the metal but not removing any.. I have never done that. an engine builder or commercial machine shop would know more.

I imagine actually two being used and they turn when inserted , one for the left turning another for the right hand turning resulting in a diamond shaped pattern.. I may stand corrected on the detail.

reamers may be fixed or adjustable, they are cutting tools designed for specific hole sizes. I have some adjustable reamers but maybe a precision sized one or a set of them of varying size would be preferred as this is exacting work. reamers are cutting tools.

a little OT but I have a set of tapered pin reamers, they are made to work with tapered pins, for holding gears etc.. if they are metric they are 1:50 Standard is 1:48 the two are so close they are quite easily mixed up,, but to be right metric is a different taper and the wrong one wont be correct.

many mechanics won't consider the difference and go right ahead and bash it in there,,, and in some instanced get away with it,, . it matters if it's precision work.. if it is a larger size then you'll see the gap at one end.

 

[Bronctopia]

---

threading or drilling cast is easy but those are cutting operations.
I believe the knurling is done with a tool that is distorting the metal so the metal needs to be somewhat malleable and not so brittle.

cast iron is not very malleable or plastic.. in that context I don't mean plastic as a material description but as the meaning, which is similar to malleable. ( it can be deformed without fracturing)

I can knurl the outside of things on my home lathe, using a rotating knurling tool which is set in contact width some force creating cross hatch patterns.

to do a valve guide maybe you'd use a mandrel press or similar and a tool designed and sized for that one operation. I think its being forced in and moving the metal but not removing any.. I have never done that. an engine builder or commercial machine shop would know more.

I imagine actually two being used and they turn when inserted , one for the left turning another for the right hand turning resulting in a diamond shaped pattern.. I may stand corrected on the detail.

reamers may be fixed or adjustable, they are cutting tools designed for specific hole sizes. I have some adjustable reamers but maybe a precision sized one or a set of them of varying size would be preferred as this is exacting work. reamers are cutting tools.

a little OT but I have a set of tapered pin reamers, they are made to work with tapered pins, for holding gears etc.. if they are metric they are 1:50 Standard is 1:48 the two are so close they are quite easily mixed up,, but to be right metric is a different taper and the wrong one wont be correct.

many mechanics won't consider the difference and go right ahead and bash it in there,,, and in some instanced get away with it,, . it matters if it's precision work.. if it is a larger size then you'll see the gap at one end.

If you ever get to, watch some microscopic video of actual metal cutting tools in action.
What looks like clean cutting to us giants looks a whole lot more like plowing heavy clay when your field of view is just a few thou.
Even the cast irons deform like that, and automotive cast irons are usually Ni containing alloys akin to "ductile".

The "knurling" here is not really bi-directional like on handles (including cast iron ones).
I think it is more in reference to the tool cutting surface profile, optimized to deform rather than remove.

It basically "knurl-cuts" a valley and ridge spiral through the bore, where the valley is now wider than the bore was, and material deformed into the "tooth" ridges has now less clearance than the bore.

A reamer is then used to flatten the ridges into a new, smaller, spiral bore.

This is what the valve stem now will ride on, and it has LESS bearing surface area than a smooth bore.

Oil can occupy the valleys, but compared to porous bronze, there isn't a lot of capillary force holding it there, so expect more than stock amounts to migrate out down the valve, and lead to smokier starts.

Racers don't care about that, but your plugs and/or cat might after a year of starts.

 

[Motneal]

I’m going out on a limb here but thinking your working on a ford six that’s not too much more than a tractor engine… knurling guy was just being honest and as long as not excessive wear on guides is a fine fix. He was probably nice guy and said to machine for positive seals. He sized you up likely knows what your bottom end is (fresh or just doing head) has nice recommendations for you. Turn around you would have seen a guide and seat machine and maybe he told you to surface a chunk off that head to up your compression if you have adjustable rockers. He would have sold you guides and seats if he thought you needed them Nice guy not try to sell what you may not need. Lots people that do not have guide and seat machine no knurling tools no head resurfacing machine do not bore blocks . Can’t turn a crank or even draw me a picture of how cam grinder really works. They haven’t done 10000 engines no nascar no Indy car. No NHRA, Do not pay much attention to them. You may want to go look at the race cars on trailers at that shop every weekend. And listen to his advice… Grumpy

 

[Adriatic Machine]

Ok just in case anyone else is/was puzzeld like I was, I have a picture of a regular threading tap and a ‘forming tap’. The forming tap doesn’t cut any material. It uses the major diameter to push into the material and lifts up the surface in between each thread. These work absolutely wonderfully except we never use them on cast iron. I suppose this is a similar technique as the knurling action.

IIRC when my buddy reworked the head on my 223, he said the valve guide thru hole cracked when he tried to run the tool through it. I guess this is what he was talking about because we wound up using beryllium copper guides. Unfortunately he is no longer with us so I can’t ask him.

 

[Motneal]

Ok just in case anyone else is/was puzzeld like I was, I have a picture of a regular threading tap and a ‘forming tap’. The forming tap doesn’t cut any material. It uses the major diameter to push into the material and lifts up the surface in between each thread. These work absolutely wonderfully except we never use them on cast iron. I suppose this is a similar technique as the knurling action.

IIRC when my buddy reworked the head on my 223, he said the valve guide thru hole cracked when he tried to run the tool through it. I guess this is what he was talking about because we wound up using beryllium copper guides. Unfortunately he is no longer with us so I can’t ask him.

Take to machine shop… forming tap used for knurling inside of used valve guide billions done in cast iron then reamed to tolerance size. ! Cast guides at parts store machine shop runs guided core drill thru head then ream to press fit new guide mostly .500 OD. Copper Berylium guide liners lowest fix on my list. Shop owner.