Checking cylinder bore
Thread Starter
|
Grand HDF Member
Joined: Apr 2007
Posts: 3,714
Likes: 3,040
From: Brighton, MI
Checking cylinder bore
Just took the top end of my 94 dyna with 37,000 miles. Virgin engine as far as I can tell. Took apart due to base gasket leak on rear cylinder. Take down was "uneventful" except two cylinder studs came out with the funky socket cap stud/head nuts when removing them from front cylinder. The socket cap nuts were rusted to the threads of the stud and I'm thinking that's the reason they came out. The ones that came out with disassembly are not even on the cylinder that was leaking.
The threads on the studs and the block look fine, no aluminum came out with the studs. They are the studs with the collar pointing up at the head and the "friction" type threads go in the block. I plan on just cleaning those two block holes and studs with brake clean and using a little red loc-tite on the threads, then installing them exactly like the other six studs with the collars up and at the same length.
Cylinders and pistons look good (except for lots of carbon on the tops), rings only show about 25% "shine" on upper portion of each. Bores look pretty good but going to have them checked by the machine shop.
According to factory manual, the bores need to be checked using torque plates in order to accurate measurements. I am aware of the cylinders needing the torque plates for a re-bore, but just checking them with torque plates for wear is news to me, however it does make sense.
How critical is this? I have read many threads recently on top end rebuilds and I hear no mention of them being checked on torque plates. The shop I plan using comes highly recommended by multiple sources, but want to educate myself as well. I can check them myself also, but not if they need to be checked on torque plates.
Sorry for long post, just trying to look at all the details and do my homework. YD
The threads on the studs and the block look fine, no aluminum came out with the studs. They are the studs with the collar pointing up at the head and the "friction" type threads go in the block. I plan on just cleaning those two block holes and studs with brake clean and using a little red loc-tite on the threads, then installing them exactly like the other six studs with the collars up and at the same length.
Cylinders and pistons look good (except for lots of carbon on the tops), rings only show about 25% "shine" on upper portion of each. Bores look pretty good but going to have them checked by the machine shop.
According to factory manual, the bores need to be checked using torque plates in order to accurate measurements. I am aware of the cylinders needing the torque plates for a re-bore, but just checking them with torque plates for wear is news to me, however it does make sense.
How critical is this? I have read many threads recently on top end rebuilds and I hear no mention of them being checked on torque plates. The shop I plan using comes highly recommended by multiple sources, but want to educate myself as well. I can check them myself also, but not if they need to be checked on torque plates.
Sorry for long post, just trying to look at all the details and do my homework. YD
Seasoned HDF Member
Joined: Mar 2010
Posts: 21,026
Likes: 7,549
From: Poolville
The shop manual is correct. Torque plates are necessary to properly check for taper. While at the shop you should get the base of the cylinder trued. It's the reason for the base gasket leak.... Not only that it will bring your piston to cylinder deck clearance closer to zero. Are you planning on new Pistons etc? .030 head gasket is highly recommended as well.... Cometic....
Thread Starter
|
Grand HDF Member
Joined: Apr 2007
Posts: 3,714
Likes: 3,040
From: Brighton, MI
OK thanks, good advice. Yes to bases trued/shortened, MLS .030 head and SLS .020 base is the plan.
In addition, changing out cam to Vthunder 3010, new cam bearing (the good one), Johnson hylift lifters, and stock pushrods.
I pretty much putt around laid back, but like to check the tires on the turns from time to time. YD
In addition, changing out cam to Vthunder 3010, new cam bearing (the good one), Johnson hylift lifters, and stock pushrods.
I pretty much putt around laid back, but like to check the tires on the turns from time to time. YD
Thread Starter
|
Grand HDF Member
Joined: Apr 2007
Posts: 3,714
Likes: 3,040
From: Brighton, MI
Yep! B138 is what I have. One of the first things I picked up for the bike (actually two of them) when I first bought the bike used.
As far as the 3010, I will be using my stock gear. YD
Thread Starter
|
Grand HDF Member
Joined: Apr 2007
Posts: 3,714
Likes: 3,040
From: Brighton, MI
Dropped off parts to machine shop today.
Cylinders are getting .010 overbore and base milling. We talked about honing only and owner of machine shop advised to "go with the over bore and new pistons and be done with it all for a long time". Said the bore will actually be more true than when it rolled off the showroom floor.
He does all the machine work for the local HD dealers and indy's, and has been for a long time, so I am going to take his advice. Also going with wiseco k1641 piston set. I know there is more exotic stuff out there, but just want to keep it simple.
He is also giving the heads a once over. Lots of carbon, a little pitting, and stem seals are hard.
I do have a question regarding the cometic MLS .030 head gaskets if anyone has any input...is it better to go with the 3.500 inch head gasket or the next size up that is 3.625?? My new bore will be 3.508 and I'm thinking 3.500. Thanks, YD
Cylinders are getting .010 overbore and base milling. We talked about honing only and owner of machine shop advised to "go with the over bore and new pistons and be done with it all for a long time". Said the bore will actually be more true than when it rolled off the showroom floor.
He does all the machine work for the local HD dealers and indy's, and has been for a long time, so I am going to take his advice. Also going with wiseco k1641 piston set. I know there is more exotic stuff out there, but just want to keep it simple.
He is also giving the heads a once over. Lots of carbon, a little pitting, and stem seals are hard.
I do have a question regarding the cometic MLS .030 head gaskets if anyone has any input...is it better to go with the 3.500 inch head gasket or the next size up that is 3.625?? My new bore will be 3.508 and I'm thinking 3.500. Thanks, YD
Seasoned HDF Member
Joined: Mar 2010
Posts: 21,026
Likes: 7,549
From: Poolville
Stick with the 3.5
The one for the 3.625 actually has a diameter of 3.67.
With doin the bore n Pistons I would seriously look at Wiseco 10:1's.. you won't be disappointed..
The one for the 3.625 actually has a diameter of 3.67.
With doin the bore n Pistons I would seriously look at Wiseco 10:1's.. you won't be disappointed..
Trending Topics
Grand HDF Member
Joined: Nov 2012
Posts: 3,784
Likes: 100
From: Pasadena TX
Originally Posted by Yankee Dog
OK thanks, good advice. Yes to bases trued/shortened, MLS .030 head and SLS .020 base is the plan.
In addition, changing out cam to Vthunder 3010, new cam bearing (the good one), Johnson hylift lifters, and stock pushrods.
I pretty much putt around laid back, but like to check the tires on the turns from time to time. YD
In addition, changing out cam to Vthunder 3010, new cam bearing (the good one), Johnson hylift lifters, and stock pushrods.
I pretty much putt around laid back, but like to check the tires on the turns from time to time. YD
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
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
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
Thread
Thread Starter
Forum
Replies
Last Post