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

[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,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.

Use the rings that come with the pistons. They'll be sized right for the overbore.

[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.

Use the rings that come with the pistons. They'll be sized right for the overbore.

That was my thoughts as well. Just checking.

[Racepres]

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.

Nobody gonna do my Rebore and Hone that don't already got the pistons in Hand!!!!!

[MikeL]

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.

Nobody gonna do my Rebore and Hone that don't already got the pistons in Hand!!!!!

                                                                                                     MIKE

[Pete_Vit]

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.

Nobody gonna do my Rebore and Hone that don't already got the pistons in Hand!!!!!

that's what I always experienced, the place I take my cyls to does the bore with the pistons already in hand. 

[SixShooter14]

Alright, machinist is going to order the pistons +0.010 or 20 depending on what's available. Then he'll bore the cylinders.

Also going to work on the heads to get me up to 9.5-10:1 comp and clean them up some and the valves. Shouldn't hurt anything with the stock cam, but should help with whatever cam I decide on later. (narrowed it down to EV23, 27, or W6)

Meanwhile I'll install those Rockout lockers and new cyl. studs and check to see what my carbs jetted for (though in reading, I think the enrichener was not set right)

[Pete_Vit]

Alright, machinist is going to order the pistons +0.010 or 20 depending on what's available. Then he'll bore the cylinders.

Also going to work on the heads to get me up to 9.5-10:1 comp and clean them up some and the valves. Shouldn't hurt anything with the stock cam, but should help with whatever cam I decide on later. (narrowed it down to EV23, 27, or W6)

Meanwhile I'll install those Rockout lockers and new cyl. studs and check to see what my carbs jetted for (though in reading, I think the enrichener was not set right)

[SixShooter14]

Alright, machinist is going to order the pistons +0.010 or 20 depending on what's available. Then he'll bore the cylinders.

Also going to work on the heads to get me up to 9.5-10:1 comp and clean them up some and the valves. Shouldn't hurt anything with the stock cam, but should help with whatever cam I decide on later. (narrowed it down to EV23, 27, or W6)

Meanwhile I'll install those Rockout lockers and new cyl. studs and check to see what my carbs jetted for (though in reading, I think the enrichener was not set right)

Just off memory, I think my knob doesn't have any slack as is in the Mik instructions. So I'll be adjusting that. Hopefully that brings my mpg up a little. Still gonna check the jetting.

[JW113]

Uh, 10:1 with stock cam? Maybe, if you live in Denver. I think I'd be looking for one with a bit more duration though.

-JW

[SixShooter14]

Uh, 10:1 with stock cam? Maybe, if you live in Denver. I think I'd be looking for one with a bit more duration though.

-JW

new cam is coming soon...Thinking 27 or W6 

[Ohio HD]

Uh, 10:1 with stock cam? Maybe, if you live in Denver. I think I'd be looking for one with a bit more duration though.

-JW

new cam is coming soon...Thinking 27 or W6 

Your bike is a later model, so geared pretty high. I would do an EV27 or an EV13 if you want more lower end. Both a big improvement over stock. FYI, I'd not go 10:1, you need to mill a lot off the heads or use different pistons. See Rigidthumper's recipe above.

[kd]

IIRC .060 is what Harley takes off the SE evo heads to get 10:1.  I have them on both my evo's with SE-3 cams and the CC is fine.

[SixShooter14]

So, a couple questions... What problems will come from the 10:1 and stock cam (detonation?)

Should we split the difference with somewhere around 9.5:1 less risk with stock cam but still an improvement when the new cam goes in?

Thanks

[Hossamania]

You know, for as much time and effort you are putting in to this, not to mention the bucks, a new cam is not a lot of money, and then you can just be done with trying to figure out how to build for now and later at the same time. Are you going to miss the extra few hundred dollars in three months, or sit and wonder why you didn't just do it in the first place?
You seem to be getting caught up in the incremental build process that happens too often, "I want to just get it freshened up, but I want to set it up for future improvements, but not hurt the performance I have now, but build it for later, but keep it the same for now......."
The part that kills is trying to set it up for two different goals with one action. It's tough to get that right. You have the opportunity right now to do it right.
Remember, I'm here to help spend your money! I'm just trying to keep you from going down two different roads at the same time but trying to make them work together, and drop be yourself nuts. Set your end goal, and go to that point.
Remember, stock sucks!

[SixShooter14]

haha, you're not wrong.

[SixShooter14]

You know, for as much time and effort you are putting in to this, not to mention the bucks, a new cam is not a lot of money, and then you can just be done with trying to figure out how to build for now and later at the same time. Are you going to miss the extra few hundred dollars in three months, or sit and wonder why you didn't just do it in the first place?
You seem to be getting caught up in the incremental build process that happens too often, "I want to just get it freshened up, but I want to set it up for future improvements, but not hurt the performance I have now, but build it for later, but keep it the same for now......."
The part that kills is trying to set it up for two different goals with one action. It's tough to get that right. You have the opportunity right now to do it right.
Remember, I'm here to help spend your money! I'm just trying to keep you from going down two different roads at the same time but trying to make them work together, and drop be yourself nuts. Set your end goal, and go to that point.
Remember, stock sucks!

ya know......... The machine work is expected to be done next week. I could probably go ahead and do the cam while I wait... I think I'll pull the timing cover off and confirm the stock cam tonight. If stock, I'll go ahead with the cam change. Probably a bit easier with the top off anyway.

[Ohio HD]

Well, so the heads are already off right..........                     

[SixShooter14]

Well, so the heads are already off right..........                     

heads and jugs are at the machine shop. Waiting on pistons to show up next week.

[Ohio HD]

Port work?

[Pete_Vit]

Port work?

oh boy 

[JW113]

I've been more of a Crane Cams fan than Andrews, but it's gotten pretty hard to find them now. When I did a top end, basically the same as what you're doing, with 9.5:1 c/r, I initially installed a Crane FB-310, very similar profile to an EV-27. After a month or so, I pulled the 310 and installed a FB-300, which is similar to a EV-13. Am much happier with it, very strong in the 1500-4500 range. I don't rev the motor that high, and have the whole set up tuned for cruise and highway. The FB-300 is easy on the valve train, quiet, and I'm getting 50+ mpg at 75mpm/3100rpm.

It all depends on what you want for the final product. Since you have a Road King, am assuming not building a drag bike. Or maybe you are. If so, don't use a EV-13.


This is just a very basic rule of thumb:

High RPM Power = High Duration Cam + High Compression (i.e. race motor)
Low RPM Power = Low Duration Cam + Low Compression (i.e. stock motor)

And everything in between. RPM range, Duration, and C/R all kind of scale together.

-JW

[SixShooter14]

I've been more of a Crane Cams fan than Andrews, but it's gotten pretty hard to find them now. When I did a top end, basically the same as what you're doing, with 9.5:1 c/r, I initially installed a Crane FB-310, very similar profile to an EV-27. After a month or so, I pulled the 310 and installed a FB-300, which is similar to a EV-13. Am much happier with it, very strong in the 1500-4500 range. I don't rev the motor that high, and have the whole set up tuned for cruise and highway. The FB-300 is easy on the valve train, quiet, and I'm getting 50+ mpg at 75mpm/3100rpm.

It all depends on what you want for the final product. Since you have a Road King, am assuming not building a drag bike. Or maybe you are. If so, don't use a EV-13.


This is just a very basic rule of thumb:

High RPM Power = High Duration Cam + High Compression (i.e. race motor)
Low RPM Power = Low Duration Cam + Low Compression (i.e. stock motor)

And everything in between. RPM range, Duration, and C/R all kind of scale together.

-JW

It is a RK, but it's also likely to never have a passenger. So, not likely to be pushing much more than the bike, 180# of me and 30# of gear. I am also not afraid of downshifting to get into the power, I actually rather enjoy it. Definitely not a drag bike, but I also don't waste time getting up to that 55-70mph speed limit. And of course my home is in the Ozarks with lots of turns and hills that can require a lot of shifting anyway. So I figure the 27 would be a good, mild mannered (better than stock) choice. I seriously doubt I'll be disappointed, and if so...I'll just change it again,


I'm hoping to ID the current cam tonight or this weekend. The bike already had adjustable pushrods, a carlini torque arm, and there was a bracket for an external breather filter (which this engine doesn't have). So someone has either worked on the engine before (possibly had a larger crate in it and put stock back before selling) or they just thought it looked nice, Either way, it's past due to get a look at the innards.



I'll keep you fellers posted on what I find and how I proceed. I'll almost certainly be doing the cam and bearing change over the next few weeks. Since I've already got torn down.

[jsachs1]

I did a set of Evo heads 2 weeks ago for a shop in Jacksonville. Heads came in injured because of a broken exhaust guide, and customer wanted port work. Stock size valves, new guides, viton seals, new stock springs, and fluffed ports.They are using an EV27 cam, and .010" over 1340  flat pistons. I sent the heads out with 78 cc chambers. ( I had to take . 058" off to reach 78cc chambers).
John

[rigidthumper]

My memory must be bad- I thought EVO chambers were 76CC stock?

[pwmorris]

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.

Nobody gonna do my Rebore and Hone that don't already got the pistons in Hand!!!!!

Yup-milk and cookies....also, any non off the shelf head design must have pistons to match.
Everything works as one unit-Not individual pieces!