Valve seat cutter: total waste of money?

[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

[Ohio HD]

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

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]

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

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

[FSG]

but you guys over looked the PLASTIC SHOCKPROOF DEDICATED BOX   

[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...
 

-JW

[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

[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.

[JW113]

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

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

 

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

[Ohio HD]

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

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

 

-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!     

[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.
 

[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

[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]

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

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

 

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. 

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.   
 
 

[Don D]

Buy the new heads

[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.
 

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

[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.

[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

[Don D]

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.

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.
 

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

[Don D]

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

[JW113]

My understanding of valve spring motion:

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If the springs twist as they are compressed, rotate the valve, and "something" grabs the valve and keeps it from rotating back in the opposite direction, why do they put valve rotators at the bottom of the spring in some/many engine designs? Obviously, not Harley-Davidson.

-JW

[Don D]

No comment on rotators, not used on a HD.
Consider that the valve locks are collets. Sometimes they fit tightly in the recess of the retainer and lock the stem to the retainer, and sometimes not.
https://youtu.be/6Vz4mjPKXJ0

[kd]

   I was looking for some of the spintron and laser camera video stuff.  There was one in na HTT thread about a year ago in a discussion over beehive, conical, double wound and springs with dampeners. The link you posted is as good as any of them if not even more exaggerated than most.  Some show the unbelievable harmonic vibration in the spring more and it becomes easy to see how the keepers could at points in the stroke of the valve lose traction and allow the spring coil rotation to drive the valve and release it.  You can't compress a coil spring without the ends moving.  There are plenty of IC engine engineering papers to be found that comment on the extended valve and seat life imparted to the rotating valve phenomena. Almost all of them state the benefits (up to 40% and more extended valve and seat life) is lost as the mean RPM is lowered and the valve begins to stall.

[Don D]

Off topic but positive rotators are beneficial for gas (or LP) engines running near full load for extended periods of operation. Other methods to cool the exhaust valves used was sodium filling. Gensets, some marine and industrial applications. There were a few big block Chevys that used them in trucks. The aftermarket even make eliminators for those LOL.

[JW113]

OK that's pretty interesting, and I still don't quite understand the mechanism that causes that to happen. In the text, it did say "at extreme RPM". Sure would like to see a video of the same thing but at 3000 RPM. As evident by my valve spring tips, that sure isn't happening in my case. Guess I need to take it up to 10,000 RPMs more often!

kd, I totally understand that a compressed coil spring twists. It's the same mechanical action as taking a long straight spring metal rod and twisting it radially, ala a torsion bar. But in both cases, when the force on the spring/bar is released, the spring twists the opposite direction back to the original position. That's the part I'm hung up on. Something has to "hold" the valve if the spring twists it in direction A, while the spring relaxes back in direction B. Ala valve rotators. If no rotators, what is providing the one way clutch effect?

I don't get it. And the other part I don't get, if valves do this naturally, why do automotive engineers add valve rotators?

-JW

[JW113]

OK, after giving this another think, I think I understand (at least in that Spintron video) why those valve springs were rotating and in only one direction.

As we all know, as RPMs go up, valve control goes down on the downhill side of the cam lobe. At some point, the spring can't push the valve train back down as fast as what the cam is dropping the tappet, hence "valve float". So think about that. On the uphill side of the cam lobe, the spring (and valve) get compressed, and the coil spring twists a little bit, rotating the valve. But if we're up near or past valve float, that spring is now also "floating" between the collars, not applying much, if any, pressure on the valve, and is free to twist back to it's home state without rotating the valve with it.

So yes, at those screamin' high RPMs, I can totally see how those springs and valves spin like whirling dervishes. But at "normal" RPMs, like most street bikes live in, I don't see it. And my data point of one says they don't.

That's my story and I'm sticking to it!
 

(unless you have a better explanation!)

For you guys that build heads, got any shop pics of what the valve tips look like on heads before you rebuild them? Would be interesting to see.

-JW

[Don D]

They either look like yours or are uniformly polished. Simple as that. Some rotate and others don't. A loose fitting lock in the retainer is not a good thing and can result in failures. The lock is meant to be a collet as I stated before. This is so easy to test during assembly and I reject them if they do not lock properly. I also do not use aluminum retainers. TI, Tool Steel, or Steel.

There are many qualified shops that can fix these heads, this is not a do it yourself proposition with hand tools or gizmos from ebay. Or your mention of new heads is also a possibility and the bike is back on the road. It will be much better than new either way. All the theory in the world does not solve this, it just takes parts and machine work. If you want to learn more about valve train dynamics carry on, I suggest speed-talk.com

[JW113]

Yes, I agree, I could throw money (and time) at these stock heads, and the result would probably be just fine for what I intend to do with it. But at the end of the day, they will still be AMF era heads, with less than high quality materials and workmanship. If this bike was a 99 point AMCA show bike, indeed that would be the way to go. At the same time, I could take the same money, and with just a wee bit more, have some nice high quality S&S heads, better materials, better ports, and perfectly flat gasket surfaces that (hopefully) won't weep. And this is exactly what I am doing, they will be here in a week.

Regarding valve rotation or not, I'm not trying to solve anything, just trying to make sense of it. In fact, in my case, I'm not worried about it one iota.

cheers,
-JW

[Don D]

The shovel like you said is a low rpm torque producer. Never the greatest of valve oil sealing or ring seal and fat mixtures all reminiscent of even much more coveted foreign exotic cars of the era. The valves don't need to turn. In fact turning the valve on the exhaust may even hasten recession with those old cast seats In a higher rpm clean burning similar era Mercedes engine they used rotators because they burned exhaust valves without them. The rotators help with the release of heat and not allowing local hot spots. Never seen a burned valve on a shovel but I have not seen many thousands either like the later models.

[capn]

I just put new heads and KB 8.3 pistons in my 76 and the way it runs is like night and day difference.

[turboprop]

Yes, I agree, I could throw money (and time) at these stock heads, and the result would probably be just fine for what I intend to do with it. But at the end of the day, they will still be AMF era heads, with less than high quality materials and workmanship. If this bike was a 99 point AMCA show bike, indeed that would be the way to go. At the same time, I could take the same money, and with just a wee bit more, have some nice high quality S&S heads, better materials, better ports, and perfectly flat gasket surfaces that (hopefully) won't weep. And this is exactly what I am doing, they will be here in a week.

Regarding valve rotation or not, I'm not trying to solve anything, just trying to make sense of it. In fact, in my case, I'm not worried about it one iota.

cheers,
-JW

Those trouble heads from S&S are a no brainer. I have used a few sets of them. Perfect right out of the box. Enjoy.

[JW113]

Yes, am really looking forward to getting all the parts back, and put this ancient beast back together. What started out as a flywheel rebuild/balance by Dark Horse has turned into new S&S heads, and now S&S cases as well. Like Capn, will be using KB 8.5:1 forged pistons, and an Andrews #2 cam with Jims Powerglide tappets. I think this is going to be a completely different animal than what I took apart!

-JW

[76shuvlinoff]

You're a better man than I JW. I pulled my leaking vibrating numbers matching factory mill of questionable care and handling in 2004 then installed a full S&S "shovel" repop and never looked back. However I think I have changed the cam in it 4-5 times now and there's been 3 different carbs on it. The 76 mill still sits on the same milk crate where I put it. Once in a while I put oil in the spark plug holes and roll it over. It's a problem for the next guy now.

 Good luck with your overhaul. I am sure you'll come out the other end in love all over again. 

 

[JW113]

Well Mark, we'll see who's the better man. I mean, after all is said and done, about the only thing left of it that is "stock" will be the flywheels (not the shafts), the rods, and the cylinders. About every thing else is aftermarket, and non-matching frame/engine. I'm sure that 93" would run circles around my dinky 74", and for the money I'm throwing at it, maybe should have just bought a whole engine! But I figure a 74" is easier to tame the vibes than a stroker/big bore, and smooth running is more important to me than big power. At least for this old FLH. I think you're right, probably going to really dig this mill once it's all back together and broken in.

-JW

[Ohio HD]

You still have time for 3-5/8" bore on standard stroke, 82"........

Just give the piston weights to Darkhorse and have the cases bored.     

[JW113]

74 cubes is plenty for an old geez like me.

Then again...

 

-JW

[Ohio HD]

I took a look at the catalog, they're only showing 3-5/8" bore for 4-1/4" stroke and longer. They used to make them for 3-31/32" bore. You probably would just need to call them.

[76shuvlinoff]

74 cubes is plenty for an old geez like me.

Then again...

 

-JW

Then again..... It's a sickness. 

[72fl]

You're a better man than I JW. I pulled my leaking vibrating numbers matching factory mill of questionable care and handling in 2004 then installed a full S&S "shovel" repop and never looked back. However I think I have changed the cam in it 4-5 times now and there's been 3 different carbs on it. The 76 mill still sits on the same milk crate where I put it. Once in a while I put oil in the spark plug holes and roll it over. It's a problem for the next guy now.

 Good luck with your overhaul. I am sure you'll come out the other end in love all over again. 

 

Heck Mark put me in line for that Milk Crate      

[capn]

Mine is 80 inch but have owned 3 74 inch and I agree with JW about the 74 seeming smoother.

[JW113]

Then again..... It's a sickness. 

Not to worry about that, Mark. I've been vaccinated.
 

My understanding (jump on me and kick an education into me if this is wrong) is that the 74's feel smoother than the 80's because they use that thick heavy left side flywheel. More flywheel mass makes kick starting more effective. The Electra Glide didn't really need a kick starter, since they were all electric start, even though many (mine included) either came with, or had one, added. Many of FX models, especially the early ones, were kick only. But after 1978-1/2, when they rolled out the 80" motor, I don't believe any of the big twins came kick only.

Vibration is all about rotating mass and reciprocating mass. The more rotating mass (assuming it's "balanced"), and less reciprocating mass, yields less vibration. So yes, heavy flywheels can help mitigate the HD's inherent out of balance 45 degree design.

I'm all in for a 74" motor for this bike. The only reason to go bigger is for more power, which in my case, the bike does not need. It's an old man cruiser, not a drag bike.

cheers,
JW

[Ohio HD]

I ride my 124" TC like a little old lady headed to bingo!     

[Hossamania]

Ridden to church on Sundays...

[JSD]

I just purchased S&S shovel Heads and was disappointed with port finish from there casting so had to Disassemble and have them cleaned up. One valve seal was not fitted correct and also they have steel guides. As far as valve rotation on my TC with Roller rockers .619 lift Crane Cams, 180 seat pressure i have lifted rocker covers to fit Vulcan billet supports after 2000 k i noticed the roller to valve contact witness marks to be dead centered ( A bit of Luck for me ) so it told me the valves have not been rotating 
   

[JW113]

I too was a little surprised by the rough sand cast appearance of the ports in the S&S heads I bought for mine. However, it's been established through flow bench testing that polished ports actually flow less than ports with a textured finish. Why? Air sticks to the smooth metal finish and creates drag, whereas the air that is in all the "cracks" in the textured finish act like bearings for the air moving past it.

At least that's what I read on the interweb somewhere.

 

Mine's not a competition bike, so I don't really have much concern about it.

-JW

[kd]

  It's been discussed here on our interweb and CFM tested. The most important part is with a carb. The fuel comes out of suspension and sticks (pools) to the port walls.  As far as better flow, the common description that is compared to is golf ball dimples.  Aerodynamically, they make the golf ball fly further due to reduced friction.  Some porters will intentionally dimple or rough the ports where it matters most. Exhaust ports, not so much.

[Buglet]

  The last set of Shovelheads I received from S&S one guild was installed half way down the hole, I guess it was break time. So much for QC.