Factory heads... true quality
Club Member
Joined: Mar 2009
Posts: 66,125
Likes: 51,441
From: Niles Canyon Ca.
ok, for ***** and giggles (nothing to lose, right) I lapped the exhaust and intake valves. Both lapped in just fine, and the guides are concentric with the seats. any offset between the guide and seat is a parallax error from my shitty photography. Ill probably either feel out a full on valve job locally and have them address the step, or if I get feeling froggy, ill break out the die grinder and carbide burr and smooth the step into the rest of the port. Either is bound to be better than having that large assed step there.
Club Member
Joined: Mar 2009
Posts: 66,125
Likes: 51,441
From: Niles Canyon Ca.
I have run across that issues with old shovel heads a time or two in the past, while a pain in the *** it was a straightforward repair once you quit grumbling about it and got busy. Think I still have a set of late shovel heads in the attic needing that kind of work on a couple guide holes.
Thread Starter
|
Seasoned HDF Member
Joined: Apr 2017
Posts: 9,605
Likes: 20,741
From: Globe AZ
I have run across that issues with old shovel heads a time or two in the past, while a pain in the *** it was a straightforward repair once you quit grumbling about it and got busy. Think I still have a set of late shovel heads in the attic needing that kind of work on a couple guide holes.
not in a terrible hurry, still waiting on stem seals to arrive. Mostly tried to show how QC from the factory allows this **** through, and why good rework is worth it. as i said, nothing 10 min wiht a die grinder cant fix. Beware the Dremel.....
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,923
Likes: 8,027
From: poway
First off. Stock heads are not lapped at the factory. It looks like typical core shift. It's not so much the seat was installed in the wrong place than the port was cast in the wrong place. These heads are all CNC machined in locating fixtures.
Thread Starter
|
Seasoned HDF Member
Joined: Apr 2017
Posts: 9,605
Likes: 20,741
From: Globe AZ
I am aware that the heads from the factory are not lapped. I was pulling the valves to change the stem seals. I will (did) lap the valves while I had them out to both assess the true condition of the valves and seats, and improve the seat that is there as the heads are relatively low mileage. Aside from some oily gunk on the existing seat and on the back of the intake valve the condition isnt that bad (gunk probably from the breather sending the blowby into the intake... It all cleaned up with a light wire brushing and some brake clean). Stem seals are a no brainer at 21 years old, no sense in not changing them for cause when the heads are off, and I have the tools to do the job. I posted this to show that the factory really doesnt care about the lip that is in the head, and being there, it does rob what little power the engine has already. Not so much sure its a core shift, as its nearly all the way around the seat, with the exception of where the intake manifold feeds the head. It seems more like a slightly too small core and a "its good enough" mentality for mass production. Ill clean that up before reassembly. pretty hard to screw up that little bit of removal, and a full on port job WILL break the budget at the moment.
Seasoned HDF Member
Joined: Oct 2019
Posts: 10,804
Likes: 7,444
From: OH
[QUOTE=JustDave13;19103593That's mass production "close enough for government work" for you.
.[/QUOTE]
Cant disagree but the mass produced heads have propelled tens of thousands of bikes many millions of miles
.[/QUOTE]
Cant disagree but the mass produced heads have propelled tens of thousands of bikes many millions of miles
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,923
Likes: 8,027
From: poway
I am aware that the heads from the factory are not lapped. I was pulling the valves to change the stem seals. I will (did) lap the valves while I had them out to both assess the true condition of the valves and seats, and improve the seat that is there as the heads are relatively low mileage. Aside from some oily gunk on the existing seat and on the back of the intake valve the condition isnt that bad (gunk probably from the breather sending the blowby into the intake... It all cleaned up with a light wire brushing and some brake clean). Stem seals are a no brainer at 21 years old, no sense in not changing them for cause when the heads are off, and I have the tools to do the job. I posted this to show that the factory really doesnt care about the lip that is in the head, and being there, it does rob what little power the engine has already. Not so much sure its a core shift, as its nearly all the way around the seat, with the exception of where the intake manifold feeds the head. It seems more like a slightly too small core and a "its good enough" mentality for mass production. Ill clean that up before reassembly. pretty hard to screw up that little bit of removal, and a full on port job WILL break the budget at the moment.
