I have a question about my planned upgrade for my 2012 Street Glide. My dealer is installing the SE Pro 103 Performance Uprade kit which includes the 10.5:1 compression forged pistons, 259E cams, EFI Super Tuner, and perfect fit push rods, performance clutch spring, and high lift valve springs. I am adding the SE heavy breather element and Vance and Hines Power Duals with High Output slip-ons.

I have read several posts regarding the advantages of improving the heads and am considering having the SE Pro Factory CNC Ported heads put on the bike also. With a head exchange program, I can get them for $649.00 install labor included in the above.

My question is...will this be worth the expense in terms of additional performance gains. I don't want to see marginal gains at the expense of reliability.

I know from reading here that there are probably some better head options, but as long as I'm using HD parts and having them installed before the bike is delivered, the upgrades will be covered by the dealership under warranty.

Thanks for the help!

 

Why valve springs? Aren't the beehive springs that you already have more than adequate for those cams?

 

I have same build with the old cam se 251. Running vh 2 into 1 with SERT
and tuning. I looked at stage 4 with heads and just seemed to add to top end HP.

 

Don't know really...they come with the kit and I asume they will be spare parts if I get the upgraded heads.

 

Also, you better like riding higher in the band with your cam. I like the cam
when riding by myself but two up loaded down you have to shift down alot.

 

If you look at the specs, the stock springs can handle the cam but is cheap insurance because of increase lift and rpms. I may be wrong, just what I learned when I did mine.

 

Don't know really. They come with the kit and I assume will be spare parts if I get the upgraded heads.

 

Me thinks that you'd have much more enjoyment from a ported head, and either a Wood 6, or a Wood 555 cam, in that touring bike, but that would break the warranty rules. And we all know that "rules, is rules"
Scott

 

That set will make about 105/108 hp and 105/108 tq.
We have down that set with tman 555 and our stage1 cnc port heads with are 2:1 exhaust and have seen 114/116 hp and 124tq
And Red Rock Harley has seen the same numbers we have.
Good luck..

 

I assume the PN for the Stage III upgrade kit is PN 27513-08B? And the PN for the CNC head is PN 16500013A? If you will note, those heads have bathtub chambers and stock chamber volume. According to my calcs, if you install those heads, your static CR will be 11.6, corrected CR 10.3 and CCR 221psi; way too much.

If you look at the Stage IV kit, PN 92500010, although the heads are described as CNC Ported Factory cylinder heads, you can see that the chambers are oval, not bathtub. This would indicate a larger chamber volume, like 95cc which brings compression in line; 10.4 static, 9.3 corrected and 193CCR.

Before you pull the trigger on the Stage III deal and exchanging your heads, verify the PNs of the two different sets of heads and chamber volume. If going with H-D parts, I would take a hard look at the Stage IV package; more money but the heads are matched to the pistons and the larger TB is included. JMHO, but the Stage IV 103 upgrade is the way to go.