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Valve seat cutter: total waste of money?

Started by JW113, December 31, 2021, 02:07:35 PM

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JW113

I've got my heads apart, and valves and seats faces don't look so great. In fact, for as few miles has they have on them, I'm amazed they are as worn as they are. I'd like to dress them up a bit, and if they don't lap in, it's off to the shop for a valve job. However, I'd like to give a go at doing it myself. I saw this on ebay. Yes, I know. India. For a one or two time use only, ya think this is a waste of money?

https://www.ebay.com/itm/252632793701

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Ohio HD

I don't know JW, the sellers name is tulz_junky   :smile:

Before I spent that and doubting the quality, I'd just pay someone to lightly clean the seats with a proper cutter. May as well have the them touch up the valves too.

I wouldn't trust them, just my 2 cents. 

Don D

1st check existing protrusion. There may not be any valve jobs left.

JW113

Quote from: Ohio HD on December 31, 2021, 02:54:20 PMI don't know JW, the sellers name is tulz_junky   :smile:

Ha ha ha! Yeah, I saw that too. Was hoping that meant "tool junkie", but of course, probably the other translation. Yeah, I hear you guys. Just doing a reality check. Yes, I'll try to have a look at the protrusion. The valve seals are glued on, I didn't want to pry them off if I didn't have to, but...

...and this could turn out to be new seat as well. Ouch.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

FSG

but you guys over looked the PLASTIC SHOCKPROOF DEDICATED BOX   :SM:

JW113

Happy New Year!

OK, got that out of the way. Now to the happy part.

Valve protrusion on these heads is anywhere from 1.62 to 1.72. They already have 2.00 intake valves and 1.75 exhaust. The seats look like hell, as do the valve faces, probably due to unleaded fuel damage with incompatible metallurgy. So the options are few. 1) replace seats and valves, and get set up for .500" lift, and wait for who knows how long for my shop to get around to it (he hates doing shovelheads, his fixtures are all set up for TC & now M8). OR 2) just buy a set of S&S shovel heads and be done with it.

Hmm...
 :nix:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Don D

Done all the time but not with any ebay tools. All new parts and restored to OEM. The 2" intake will allow a little improving on the short turn. All the parts need to be matched so the spring seats fit the guides and allow seals while also allowing adequate spring pack to support added lift. All normal stuff but it usually takes all new parts to get there.

JW113

So here's what I'm looking at. The entire engine was rebuilt 6 years ago, including the heads. Between me having 5 bikes to ride, and no place to go the past 2 years due to Covid, suffice it to say this Shovel motor don't have that many miles on it. I give it 4,000 at most. When he did the heads, he converted to bronze guides and fitted valve stem seals, and set up travel to .450" + .030".

I am going to use an Andrews #2 cam, with .490" lift. So I got a set of those Andrews medium lift upper collars to add another .060" of travel, hence the reason I have the heads apart. However, I can now see the valve faces and seats look like crap.

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So how could these get this bad after so few miles? I'm sure the seats are original, so not compatible with unleaded gas. I believe the valves are Kibblewhite, so should be OK but they look pretty bad as well. Damage to the seat thus damage to the valve?

So here I am, with worn out seats that will need to be replaced, the valves could possible be cleaned up buy for $30/ea, why not just replace with new stuff that is known to be OK with unleaded and be done with it? Also, the tops of the valve stems where the rocker rides is worn/chipped on these valves as well. Junk!

My dilemma is how much money to I want to throw at fixing up a set of old heads that will probably still weep at the rocker box flanges, and will take (I'm guessing) 4-5 months to get back from the shop. Or just buy a new set of heads for ~$1200 and have them in a week.

Decisions, decisions...

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Ohio HD

Just my 2 cents. I'd probably buy the S&S heads.

Don D

The seats are original, unleaded + ethanol gas was not used back then. The upgraded valves are the hardened element, the seat sacrificial. It is microwelding.

kd

From what I can see in the pics a couple of things can cause that.  The valve and seat do not appear to have an thin contact interference angle and are making full seat contact. There should be evidence of a narrow seat contact and not full face.  That said, it may have occurred due to running hot and the seat damage is masking whether or not the valve job was in fact done right.  The harder valve has pounded the seat.

The valves should also be rotating but these do not appear to be. That can cause the pitting and loss of seat and valve face material as Don has mentioned.  Rotating valves will keep the seat contact best, transfer heat better and reduce what you see with material loss.

Are the custom seals interfering with the dampener spring coil in any of the range of movement? How is the fit of the valve stem in the guides?  Those bronze guides look like red brass (could be the pic) and that usually means soft.
KD

JW113

Quote from: Ohio HD on January 01, 2022, 11:45:56 AMJust my 2 cents. I'd probably buy the S&S heads.

And just my $1300 delivered, they will be here on Jan 10.

 :baby:

Bronze, red brass, not really sure to be honest. Next time I talk to him I'll ask what he was using. Far as rotation, it's news to me that HD valves rotate. Between the valve spring pressure, stationary collars, and locking keepers, how is it that they can rotate? Rotating valves requires "valve rotators", don't they? Like they used in Ford and Chevy trucks on the exhaust valves?

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Ohio HD

Quote from: JW113 on January 01, 2022, 01:04:02 PM
Quote from: Ohio HD on January 01, 2022, 11:45:56 AMJust my 2 cents. I'd probably buy the S&S heads.

And just my $1300 delivered, they will be here on Jan 10.

 :baby:

-JW

At least you know your starting with good castings and high quality components. I've had a lot of misery over the years with OEM Shovel head castings. I've had two sets that were so porous that when hot, they let oil seep from the oil return port into the intake port. Creating a constant light oil burner.

Someone has to keep the economy going, it may as well be you and I!     :teeth:

Hossamania

A friend had a shovelhead completely redone, blew a head gasket, head had many hairline cracks in it, decided to buy one S&S head, bolted it on with no clearance checks, nothing. Kept the other head stock. Yup, he's that kind of guy.
Ended up getting a second head when the other finally crapped out about 500 miles later.
Same guy that broke 3 clutch cables in a year but would keep riding it for the day. Blew his brand new transmission gears doing that. A beautiful bike he paid a LOT of money to restore and pretty much ruined it in one year and 4000 miles.
To fix it, he repainted it.
 :crook:
If the government gives you everything you want,
it can take away everything you have.

JW113

Yeah, if this were a Knucklehead or even Panhead, that was going to spend a lot of time just sitting in the garage and get a couple hundred miles of ride time a year on it, I'd just glue it back together as is and not worry about it. I mean, heck, it *ran*, and quite well, before I took it apart, totally unaware there was anything wrong with it other than it vibrated pretty bad. But of all my bikes, this one is my favorite to ride, and plan to do a lot of it once we get past this covid crap and have places to go. So yeah, worth going the extra mile on this go around.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Ohio HD

The only thing I'd want to verify that could make a difference is the size of the combustion chamber. I assume these are based on stock heads.

kd

January 01, 2022, 02:43:45 PM #16 Last Edit: January 01, 2022, 03:27:04 PM by kd
Quote from: JW113 on January 01, 2022, 01:04:02 PM
Quote from: Ohio HD on January 01, 2022, 11:45:56 AMJust my 2 cents. I'd probably buy the S&S heads.

And just my $1300 delivered, they will be here on Jan 10.

 :baby:

Bronze, red brass, not really sure to be honest. Next time I talk to him I'll ask what he was using. Far as rotation, it's news to me that HD valves rotate. Between the valve spring pressure, stationary collars, and locking keepers, how is it that they can rotate? Rotating valves requires "valve rotators", don't they? Like they used in Ford and Chevy trucks on the exhaust valves?

-JW

They don't spin but they do move.  They would scuff and wear pretty quickly if that were the case.  The spring coil will drive them slowly to keep the seats clean and provide even contact to dissipate heat better.  This is more efficient at an RPM above what we would consider lugging.  The engine is rotating so slowly the springs do not impart a turn to the stem.  Run your engine too slow and you can end up with exactly what you have going on.  I'm not saying that's what happened with you but it explains my comment.  Harleys that are treated like low RPM tractors (because the sound cool and are cammed to deliver enough torque in the low revs) are prime candidates.  Nothin like the sound of a slab-side pan or shovel chuffing down the lane.  :teeth:

Doing a search on "do cylinder head valves rotate?" will give up some good info.

This video is a flathead twin running on one cylinder with the other head off to view this phenomena.  It also occurs in OHV engines but would be somewhat impossible to demonstrate while running so an L head engine is used.   
 
 
KD

Don D


JW113

I took a look at that video. Although I do see the valve rotate, I don't think the reason why applies to OHV engines. In Flathead engines (and most flat tappet OHV engines in general) the tappet is slightly offset to the cam lobe, and the tappet rotates. Since the valve is riding on the tappet, it has rotating force at the valve tip, which would cause it to rotate as well.

In an OHV engine, the end of the rocker arm is pushing directly down on the valve tip. Where is the rotational force? What I see on all four of the valves on this Shovelhead is a line across the valve tip where the rocker arm was contacting it. If the valve was rotating, that would not be. As mentioned before, certain truck (and car as well) engines had mechanisms to cause the valves to rotate. HDs have no such thing. Except (as I just found in searching) 1952 to 1960 Panhead engines, and only on the exhaust valve. This was discontinued in 1961. (ref "Classic Harley-Davidson Big Twins: Knucklehead Panhead Shovelhead" on page 191)

One back at ya kd: Google on "do Harley-Davidson valves rotate". Lots of links to guys finding that they don't.
 :SM:

Regarding RPM, I tend to operate this bike (and my Evo and TC) between 1500 and 4000) most of the time. In general, above 2400, but on the Shovelhead, with it's 4 speed trans gearing, around town more like 1800 in 3rd gear (35mph). There is hardly any load on it at a slow steady speed, and 2nd gear is screaming it along at 3000 at that speed. I don't think that is lugging. And at highway speed, it's turning higher RPMs than any of my other big twins due to gearing.

Honestly, I don't think the way I ride it is related to the issues that I'm seeing right now. I'm going with pre-unleaded gas valve seats, and perhaps a questionable way the last valve job was done.

Interesting discussion!

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

kd

January 01, 2022, 07:46:12 PM #19 Last Edit: January 01, 2022, 08:02:32 PM by kd
Well JW, I don't see anything convincing from an engineering standpoint supporting valves don't rotate when searching that way. I did try.  Harleys are pushrod engines and I guess you can find anything you want to agree with anything you ask a computer provided you don't look at it all.  Keep looking and stop on a few articles that are not driven by a forum of unknown levels of expertise.  Absorb the reasons and I think you will see why it is important for some uses. In fact it is important enough that some designs have devices that boost the rotation as you have mentioned.

I will ask you why you lap valves to the seat?  I don't mean grind them in with the grit.  That's hillbilly back yard stuff.  I mean to confirm you have contact all of the way around and in the right place.  The valve contact to the seat should never be full face.  It should be a small percentage of the valve face out near the lip to increase seal pressure and reduce carbon trapping.  The seat and valve faces should not have full width contact.  Light lapping is done because the valves rotate and they can run without full radial contact when they rotate to a new position. This loses compression and ultimately takes the valves and seat out with the hot gasses blowing through. Valves rotate and maintain the seat from carbon buildup by changing position. That's engineering fact.  Just like rings rotate (or should). Lapping should only be used to confirm the seat contact

I understand how cam lobe grinds contribute to valve rotation in non pushrod IC engines.  The same thing applies to not roller lifters to rotate them and even up wear.  Clearly, I stated the flathead video was not overhead valve but the valves do rotate in them too just different drivers.  I just never stated cam driven.  The valve spring coil when compressed and released provides the rotational force as the spring changes length..

To be clear my friend, I thought I was very careful to not accuse you of running your engine too low and causing the damage.  I merely stated it can be a contributing factor to valves not rotating and shortening their life or the seat's.  The damage that occurs looks just like your pics when left to deteriorate.

You are right.  It is an interesting conversation.  One that is not usually discussed in any depth.  If the heads need a valve job, they get one.  No one looks at cause much.  I would love to hear from some of the head porters on this.
KD

guppymech

January 01, 2022, 08:05:25 PM #20 Last Edit: January 01, 2022, 08:24:39 PM by guppymech
A couple years ago I posted similar pics of my engines valves and seats 5k after a valve job.  The consensus was that the pitting was caused by carbon particles and that my jetting was too rich or the engine was using oil.  I leaned my Super E out which made the engine run better but I haven't had the heads off since then to see if it helped. On your heads it's disappointing to hear about the rocker wear on the tip of the valve stems on what should be quality valves. Are you using solid lifters?
*Edit*  Just for reference, here is a link to my thread with pics of what my heads had going on. No thread hijack intended.
https://harleytechtalk.com/htt/index.php/topic,111171.msg1327211.html#msg1327211
'84 FXE, '02 883R

Don D

Quote from: kd on January 01, 2022, 07:46:12 PMWell JW, I don't see anything convincing from an engineering standpoint supporting valves don't rotate when searching that way. I did try.  Harleys are pushrod engines and I guess you can find anything you want to agree with anything you ask a computer provided you don't look at it all.  Keep looking and stop on a few articles that are not driven by a forum of unknown levels of expertise.  Absorb the reasons and I think you will see why it is important for some uses. In fact it is important enough that some designs have devices that boost the rotation as you have mentioned.

The valves do turn in operation, even with opposed helix springs.

I will ask you why you lap valves to the seat?  I don't mean grind them in with the grit.  That's hillbilly back yard stuff.  I mean to confirm you have contact all of the way around and in the right place.  The valve contact to the seat should never be full face.  It should be a small percentage of the valve face out near the lip to increase seal pressure and reduce carbon trapping.  The seat and valve faces should not have full width contact.  Light lapping is done because the valves rotate and they can run without full radial contact when they rotate to a new position. This loses compression and ultimately takes the valves and seat out with the hot gasses blowing through. Valves rotate and maintain the seat from carbon buildup by changing position. That's engineering fact.  Just like rings rotate (or should). Lapping should only be used to confirm the seat contact

There is no need to lap when you use the same seat and valve angle plus as you stated KD leave a small amount of margin on the valves' seat above and below the contact patch. I am not hugely opposed to lapping with fine compound just don't see the need. A seat wider than the valves' seat width is a no no and the contact area can be determined with Dykem and turning the valve. Only one element of a high quality valve job, concentricity and valve to guide fit are in the party too. Interference valve angles, "breaking in the valve job", are passé in my opinion. A good valve job seals full pull on my Serdi vacuum tester and shows full contact with Dykem from the inception regardless of the bikes engine type or intended use.

I understand how cam lobe grinds contribute to valve rotation in non pushrod IC engines.  The same thing applies to not roller lifters to rotate them and even up wear.  Clearly, I stated the flathead video was not overhead valve but the valves do rotate in them too just different drivers.  I just never stated cam driven.  The valve spring coil when compressed and released provides the rotational force as the spring changes length..

Bingo there

To be clear my friend, I thought I was very careful to not accuse you of running your engine too low and causing the damage.  I merely stated it can be a contributing factor to valves not rotating and shortening their life or the seat's.  The damage that occurs looks just like your pics when left to deteriorate.

Cast iron seats, simple as that. Even when flame hardened, as the OEM car manufacturers did, there was valve recession, especially on the exhaust side, when lead was removed in the late 70s. The addition of hardened seat inserts is another argument against interference angles, they won't "pound in"

You are right.  It is an interesting conversation.  One that is not usually discussed in any depth.  If the heads need a valve job, they get one.  No one looks at cause much.  I would love to hear from some of the head porters on this.

JW113

This is all probably seems argumentative, but I'm really just trying to understand the mechanisms behind all this. I agree, when you compress a coil spring, it rotates. But when you let it relax, it un-rotates back to it's original position, does it not? In the case of a valve spring, the valve is locked to the upper collar by the keepers (you have to tap the collar to knock it loose, yes?), and there is a lot of friction between the ends of the spring, the keepers, and the head. So yes, when the valve is opened, the valve will rotate a little bit with the spring while it's being compressed, but why would it not rotate back to it's original position when the valve closes? Unless you have one of these under the bottom of the spring:

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Which is simply a sprag clutch, and would allow the spring to rotate at bottom, but not let rotate (against the head) when the spring is released, but rotating the valve instead.

Guys, this is the part I don't understand. If you don't have these under the valves, what is holding the valve from simply rotating back to it's original position? You need some sort of one way clutch. Right? Not right? Please explain.

Admittedly, I am not a head builder, so have not seen lots and lots of valve tips and the wear patterns on them. If the valve are rotating, the wear pattern on the tip would not look like this:

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All four of my valves look exactly like this. If they were rotating, the wear pattern would be round. Yes? No?

kd, I wasn't trying to imply anything about your comment about lugging, I get all that. Just trying to convey how I ride, that's all.

guppy, indeed my heads looked quite similar to those pics in your other post. And yes, I had a fair amount of carbon on the piston crowns and head chambers. But I also took a close look with a hand microscope at the valve faces/seats. The black spots are not on the surface, they are holes. Like Swiss cheese.
 :crook:

I can see how bits of carbon chipping off the pistons, and getting chomped in the valve seat, could possible chip away at the surfaces. Especially if the material is pre-unleaded metal. The bike didn't smoke, or really use much oil, and I don't think it was jetted overly rich (CV40 carb), it was getting 50mpg. But, all the crap in the cylinders was clearly coming from somewhere. When I put it back together, going to weld a O2 bung in the pipe and tune it with a WEGO AFR. With new pistons, rings, S&S heads, hopefully any oil issues will be under control.

I can't speak to how the last valve job was done, I didn't disassemble the heads and look until now. Clearly not a 3 angle job. No idea how S&S does it, does anyone?

cheers,
JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Don D

January 02, 2022, 11:47:12 AM #23 Last Edit: January 02, 2022, 11:57:24 AM by HD Street Performance
Those valves were not rotating correct, now tell me your theory for why?
Now when you figure that out you still have the same solution to face. New seats and a full reconditioning of those heads or new heads. All the theories in the world and discussions for pages of bandwidth are not going to change the outcome to fix the issue.

guppymech

JW, My valve stems had the exact pattern yours do showing no valve rotation, I was the first person to pull the heads since it left the factory.  As to jetting, I was on the verge of getting a WEGO but didn't, currently my Super E is jetted 28/66. After my thread I went from a 72 to a 68, then discovered a vacuum leak from a split intake band.  After I fixed that it wasn't carbureting as crisp as the intake leak/68 combo, so I went to a 66 and it was back to normal.  Probably the first time a intake leak helped with jetting. lol
'84 FXE, '02 883R