Preparing to refresh my first top-end, pics and questions

[rigidthumper]

What does the bottom of the piston look like?

[SixShooter14]

What does the bottom of the piston look like?

hope this helps

[rigidthumper]

It's been warm, but no significant issues I can see from here. What's the plan? Measure/clean everything and re-ring?

[SixShooter14]

It's been warm, but no significant issues I can see from here. What's the plan? Measure/clean everything and re-ring?

Pretty much. Just making sure no one sees anything out of the ordinary. Thanks

[rigidthumper]

Bore gauge and calipers will tell you what's next.

[SixShooter14]

Alright, folks I'm back from Canada and it's time to resurrect the thread and the refresh project.

I finally got to visit the machinist and he mentioned the scoring in the cylinder (something I had noticed but hadn't really looked at closely) The gouges feel pretty rough to my novice fingertips.

Attached are the Front cylinder marks...Rear is pretty much the same. If it matters, the grooves are on the front and rear surfaces of the bore(which I would think is expected?)

[SixShooter14]

Additional info......
You see those little O-rings on the oil passage nipples? There's one missing on the rear cylinder. It may have stuck to the head then fell off, I haven't looked around the shop floor. I just noticed it was gone yesterday.


Anyway.... The machinist suggested boring +0.010" and wiseco pistons.

Before I say yes, I figured I'd run it by yall. If I'm going to rebore, should I go a little more than +10 and give it a comp. bump as well. I do plan on a new cam at some point, probably next winter.

Again, I'll say it. My goal isn't big power, just a healthy reliable engine.

Thanks for the help

[Ohio HD]

Nothing wrong with 0.010" over to clean up the bore. But if you want to just make a healthy reliable, long life motor, use the OEM HD cast pistons as they "should" be fit tighter than the Wisco forged pistons. My 1-1/2 cents. 

[kd]

Then again, re bore to 95 or 98,  7 - 10 more cubes for the same cost.  Maybe find a low cost cam on HTT?  Let me see .... hmmmm.   

[SixShooter14]

Nothing wrong with 0.010" over to clean up the bore. But if you want to just make a healthy reliable, long life motor, use the OEM HD cast pistons as they "should" be fit tighter than the Wisco forged pistons. My 1-1/2 cents.

Even after the +10?

[SixShooter14]

Then again, re bore to 95 or 98,  7 - 10 more cubes for the same cost.  Maybe find a low cost cam on HTT?  Let me see .... hmmmm.   

Haha, I was kinda thinking more along rebore and bump comp to 10ish...An EV27 or W6 isn't that expensive.

[Ohio HD]

Nothing wrong with 0.010" over to clean up the bore. But if you want to just make a healthy reliable, long life motor, use the OEM HD cast pistons as they "should" be fit tighter than the Wisco forged pistons. My 1-1/2 cents.

Even after the +10?

Cast pistons (top of my head) would be about 0.0015"-0.0025" fit. Wisco forged about 0.0025" fit. Regardless of overbore size.

Cast pistons expend expand less than forged, so need less clearance.

[SixShooter14]

Nothing wrong with 0.010" over to clean up the bore. But if you want to just make a healthy reliable, long life motor, use the OEM HD cast pistons as they "should" be fit tighter than the Wisco forged pistons. My 1-1/2 cents.

Even after the +10?

Cast pistons (top of my head) would be about 0.0015"-0.0025" fit. Wisco forged about 0.0025" fit. Regardless of overbore size.

Cast pistons expend expand less than forged, so need less clearance.

so at only +10, you think new pistons aren't needed?

ALSO what're the options to up the comp. to say, 9.5-10:1? Domed pistons or head machining? Just trying to get things lined out. Thanks

[rigidthumper]

No he's is saying cast in general expand less under heat than forged.
I'd use HD cast pistons, they are quieter, and cheaper. Flat tops with cometic .030" head gaskets, and an EV27, deck the heads to 72 CCs, (9.6:1 cr- pump gas friendly wherever you may roam) adjustable pushrods, new lifters and inner cam bearing, and Bobs your uncle.

[SixShooter14]

No he's is saying cast in general expand less under heat than forged.
I'd use HD cast pistons, they are quieter, and cheaper. Flat tops with cometic .030" head gaskets, and an EV27, deck the heads to 72 CCs, (9.6:1 cr- pump gas friendly wherever you may roam) adjustable pushrods, new lifters and inner cam bearing, and Bobs your uncle.

ahh, thanks

[SixShooter14]

Can yall give any recommendations on where to get the cast flat-top pistons for 10 over? I assume HD doesn't stock these?

Thanks

[hbkeith]

anytime ive ever had a cylinder bored , I give them the piston first

[hbkeith]

No he's is saying cast in general expand less under heat than forged.
I'd use HD cast pistons, they are quieter, and cheaper. Flat tops with cometic .030" head gaskets, and an EV27, deck the heads to 72 CCs, (9.6:1 cr- pump gas friendly wherever you may roam) adjustable pushrods, new lifters and inner cam bearing, and Bobs your uncle.

ahh, thanks       

send them heads to Larry and let him cut them, bigger valves and port , it will be what I did to my 97 , you would be VERY happy

[Ohio HD]

What Mr. rigidthumper said.   

21942-83 is the 0.010" oversize piston, rings, and piston pin kit, you need two. About $100 a set. I doubt anyone would have them in stock, but you never know. A friendly HD dealer will do a national search and let you know who if anyone has them on the shelf. I wouldn't think it would take them long to get them into the store from HD.


https://shop.newcastlehd.com/part/21942-83

[SixShooter14]

What Mr. rigidthumper said.   

21942-83 is the 0.010" oversize piston, rings, and piston pin kit, you need two. About $100 a set. I doubt anyone would have them in stock, but you never know. A friendly HD dealer will do a national search and let you know who if anyone has them on the shelf. I wouldn't think it would take them long to get them into the store from HD.


https://shop.newcastlehd.com/part/21942-83

Thanks for confirmation, I had actually just found them on the Ronnie's partfinder. Should I hold off on the cylinder machining until I can get the pistons?

[Ohio HD]

In theory, if they bore +0.010" all is good. Never hurts to have the piston first. Especially if they can't get 0.010" for some reason, and you have to get 0.020". Then you have to bore twice.

[SixShooter14]

In theory, if they bore +0.010" all is good. Never hurts to have the piston first. Especially if they can't get 0.010" for some reason, and you have to get 0.020". Then you have to bore twice.

10-4

Thanks for the help.

[Ohio HD]

Double check your service manual, this is from my 1997 FXST manual. Pistons are a tighter fit than I recalled from my memory.

Nominal over bore target is 3.511".  Slowwww easy break in after some heat cycles.


[attach=0]

[SixShooter14]

Double check your service manual, this is from my 1997 FXST manual. Pistons are a tighter fit than I recalled from my memory.

Nominal over bore target is 3.511".  Slowwww easy break in after some heat cycles.


[attach=0,msg1335607]

Thanks, I'll check my SM.

Last question...for tonight...
Are there different ring sizes for being overbored? I've got a set of NIB standard Hastings rings that I got a few months ago.

[SixShooter14]

Double check your service manual, this is from my 1997 FXST manual. Pistons are a tighter fit than I recalled from my memory.

Nominal over bore target is 3.511".  Slowwww easy break in after some heat cycles.


[attach=0,msg1335607]

Mostly the same....except that 2nd comp ring lists a different max clear (in inches) mm is the same