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 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....

 

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

 

You'll like that 3010. Ruggs59 went to that and loves it.... Don't forget the new cam bearing b-138. Full compliment....

 

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

 

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

 

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..

 

You might want to check pushrods length if reusing stock ones, shorter cylinders and thinner head and base gaskets will add some to the stock length. Adjustables might be a better choice.

 

He has. 030" to play with before they become an issue.. although I personally like adjustables set to. 140"