Yes mine is the same way, but it would be nice to have that slack so I don't have to unclamp it from the frame.

 

I put 2" risers on mine; same story. It wasn't tight enough to break, but I didn't want to press my luck. I installed a longer line that goes into "that block below the horn" (ABS).

-WRM

 

Hello everyone hope you are all getting some good summer riding time in.

I have put quite a few miles on the new 57H cams, tuned it in very well with the PV TT system. All in all it runs great except it is a bit weaker down low than I would like and I notice it more now with 2-up riding. I would attribute this to the lower static and dynamic compression of thee cams- it is 181CCP with the 57H cams @ 38deg IVC and 9.04:1 dynamic comp.

Stock cams, compression ratio was higher at 187ccp (@ 30deg IVC) - dynamic comp was 9.30:1 - Although the 57H gives long duration and greater lift, the reduction in compression and later IVC event is taking more notice with my riding style (mostly town, a lot of stop / go).

So I have two choices to consider- Keep the 57h cams, pop the heads and run a thinner HG to raise comp - or - drop in a set of 48H cams (29deg IVC). Either will get me to 188CCP and 9.33:1 dynamic. Essentially back to stock comp levels but with better lift & duration. Actually with prices of the 48H cams so low, it looks like the cheapest option.

 

Hopefully one of the resident engine builders will chime in here...

You can try the Andrews 4 degree advance gear. From what I read it gives a bit of a compression bump, & moves the curve to the left a little.

Again, just what I've read.

__________________________________________________ ____
For ROCKOUT information & purchasing please click the LINKS below...

 

Thanks- Yes that is true - looked into it and it's a decent option- but it's not worth it for my case - I'd still be at 34deg IVC and a bit lower in the dynamic comp than I would like.

By getting to a 29 IVC I'll be on the cam at closer to 2k rpm and pulling up comps to a more optimal level. I'm also looking at the S&S 583 cams - IVC of 19 but supposed to have a usable range of 1500-5000 rpm and would give me about 9:53:1 dynamic comp. Interesting grind on them. I don't really need the ez-start gadgetry though.

 

Wow! Are we talking about the compression reading you get when you turn the engine over with the starter with the compression releases disabled? 181?

My Stage 4 Race kit (2014 version with the 259 cams) shows 210 on that test. Of course that kit I have included hi-compression pistons and CNC heads.

Jim G

 

Hi Jim- Yes that is pretty much it, I have compression test gauges here that I used before and after the 57H cam swap. Basically, a stock motor is going to be in the 185-187 CCP range and about 9.8:1 static comp with the 30 degree intake close cam event. By having a later intake valve close event, comps will be reduced. this is why most aftermarket cams benefit from raising compression a bit, unless of course, the cam is cut to have an earlier intake close than the stock cam- which will raise comps. This is just one aspect of it though, I am really only discussing cam selection in regards to my bike and motor so no one should take this as general advice. Some bikes will run a bit more compression out the factory door than others which is why some guys will get a bit better result from a drop in cam vs others- it depends on things like if the factory pistons were set .008 down the hole or say .003 down the hole. there are some mfr tolerance differences bike to bike / year to year from what I understand.

Your stage IV setup will have higher comp by nature of its design, and ideally, the shop that installed it made sure the pistons were zero-deck and quench was optimized with a 30 thou head gasket. those things would all help raise your CR and CCP to the good levels you have.

Just ordered a set of 48H cams $200 shipped. I'll get them installed in the next couple of weeks and post back. 57h will be up for sale if anyone wants a very low mileage set - maybe 500 miles on them max.

 

Dog, interested to see what you thing of the 48s. I'm somewhere in the middle with a 33 intake close.

 

Indeed- You have those nice MR103 cams. If you are pleased with the pull and all around power, it could be your 103 motor has a tad more compression out of the box than mine.

Of course there are other things to consider in the cam specs besides IVC that will affect where the power comes on, like the LSA, but in my case from what I'm seeing it is a case of less compression and later IVC not equaling the "in town" riding result I want- I'm still not ready yet to throw a 107 kit at her and deal with extended downtime during nice weather. A set of cams I can toss in and tune in half a day, and it is less costly / time consuming that even pulling the heads for thinner head gasket swap.

Maybe this winter though on the 107 kit. I might be putting the Big Dog up for sale and then I'd want that nice grunt on the Breakout. ;p

Here is the info on the 48H cams:

Andrews 48H cams Product information:

Manufacturer #: 216348
Drag Specialties #: 0925-0598
Biker's Choice #: 49-4093
Fitment: 06 Dyna, 07-14 Twin Cam

• Broad tip cams for baggers with stock motors
• Max torque at low and mid RPMs

Timing-Open---Timing-Closed---@.053---Duration---Lift
Intake----13°----------29°--------------------222°---.548
Exhaust--43°----------15°--------------------238°---.548

 

BTW I'm really not expecting a major diff with the 48H, just looking at recovering some slight but noticeable compression losses which I definitely feel when taking of from the light with a passenger. Nothing here is going to be a large difference until I move forward with further motor work. For example, the higher lift of the 48H is a tad bit of a waste with the restrictive stock heads, but hey it was a good deal on them and they have decent specs. It will be fun to see how the motor changes with the 48h cams installed and if my indications for improvement are correct.

Honestly the biggest and most significant performance difference to the bike (to date) has been the upgrade to 30/70 belt pulleys. I have yet to see any other mechanical mod give as much gain for the same (relatively) small $ of money spent