Did some number crunching- If you have your wrench raise the static compression (CR) to 10.5:1 and go with Woods TW-555 cams, you'll be an extremely happy camper. This cam would not do anything spectacular with stock compression of under 10:1, but will be a TQ beast with the 103 and 10.5:1 - TQ will come on hard in the 2200-up range. Plus you can further build out your motor later on and still make use of these cams.

I don't like the SS 510 cams for a higher compression motor (over 10:1) since it has an early intake close of 38 degrees. that is optimal for a stock compression motor but not good for a high compression motor. It also only has 510 of lift, vs the Woods 555 of lift.

The SE 204/205/255 cams are mostly for use with lower stock compression and also have an early intake close event. At least that's what the numbers tell me.

I'd stand firm on advising against the 510 cam considering you are going to raise static compression, and you must be able to know what the planned static compression is going to be *before* deciding on the cam - again that is simple math your wrench should know. My math says 510 = poor choice vs other cam options for a higher compression motor. If you have a high compression motor and choose a cam with too early of an intake close, that will push your DCR over 9.6:1, and that means hard starting and detonation issues. For a street bike on pump gas, you must always keep the DCR under 9.6:1- For example my Evo build is at 9.68:1 DCR and I had to cryo-treat my heads, pistons, as well as optimize the quench to reduce chance of ping. I run fine now with 91 octane. But it took some doing and I'm right on the edge.

This is why static compression and dynamic compression must both be equally considered with cam selection - Your operating compression (DCR) is what matters- too low and bike is a dog, too high and bike is a ping master. If the cam intake close event is early (say 38 degrees) it raises the DCR. If the intake close event is late (say 48 degrees), it lowers the DCR. the air/fuel does not start compressing until the intake closes, so a later intake close = less compressed chamber volume = less "bang". I like my intake close event to be around 40-41, in general, for a decent performance street bike running about 10.5:1 static CR.

I hope this helps, and I hope I have not confused you with all the info.

 

So I gave S&S a call this morning and they didn't recommend the 510 either. I got the sense they were trying to push me to try their newest and greatest. Went back to the shop and had a long talk with the guys and they went into more detail with what they are doing. So when they said they are raising compression, they are bringing the levels back up to the normal stock levels. They said due to the elevation it causes issues. They are going to port and polish the heads, adjustable rods (S&S recommended doing this as well), and I decided on Andrews 57H for the cams. Should be done next week sometime so I'll let you know how it goes.

 

You won't be disappointed! I have the Andrews 57H in my Breakout, and they are the BOMB!!! I'll have dyno numbers in a couple of weeks with them.

 

Ok- so it sounds to me like they are giving you normal stock compression levels, somewhere in the 9.5-ish:1 range (this really should not be guesswork, it's all based on fixed numbers and a formula). The Andrews 57 will work fine with that, it has an earlier intake close event (38) so there will not be much drop in DRC vs the static compression. it has way more lift and other more optimal parameters so that's good too. New pushrods, sure that's an acceptable safe recommendation.

Good luck and I hope they get this baby buttoned up for you soon and back on the road. The only thing you could have done better, at slightly more expense, is go with higher compression and different cam, but I think you'll still be happy and you won't really have to worry about anything. But keep in mind if you do raise compression later on (10:1 or higher), you'll need a different cam. But let's hope that is many happy miles down the road

 

BTW- Did they talk about flashing / tuning your ECU to optimize the changes? That is going to be equally important- more than likely they will put on a safe tune, it won't be optimal but you've got to break it in. After break in, go get it properly dyno tuned. That is when you'll be getting the most out of your upgrade. We would love to see your dyno numbers.

 

Important tip- Request your mech use a .027 (preferred) or .030 head gasket (second preferred) instead of the factory .040 gasket- you'll get a good bump in compression and payback from the 57 cams.

(whoops not allowed to post the outside link, but here is the gist of the thread):

"The 57h cam does great with a 103 and .030 head gasket. The factory pistons are already .010 down in cylinders, so you effectively end up with .040 quench if you use a .030 head gasket. The 57h intake valve closes at 38 degrees and the factory closes at 30 degrees. The extra bump in compression with the .030 head gaskets helps with the later closing of the intake valve with the 57h. I put one in a roadking with .030 head gaskets and the results were great. It actually had some descent torque in 6th gear. Don't think you will regret it."

Asking for the thinner head gasket is a safe, no-cost change that will give you noticeable benefit. .027 is the best choice, .030 is second best. The reason you want this is because the factory pistons are not "zero deck", meaning, they do not come up to the zero line at the top of the cylinders. they remain slightly down fro mthe top of the cylinder anywhere from .005 to .010, and that "gap" adds to the overall quench of the combustion chamber. So if you go factory .040 gasket, you'll send up with a .045 to .050 quench, which is not optimal for burn or HP/TQ. I know it's a small detail but does make a good difference.

 

Yeah, I already have a SE super tuner on it and it had been on the dyno after the pipes and air cleaner were installed. The quote they gave me included another 3 hours on the dyno. Plus its the same guy doing all of it instead of someone not knowing what their doing. Everyone in the shop comes and asks him for advice including the service managers who were former techs so im pretty comfortable with his work. The warranty parts should be in today and they ordered the cams out of Texas today. Told it should be ready in about a week depending on how long it takes for the cams to come in. I'll have to post the results when I get them. Hopefully I get some good results with a dependable motor (unlike brand new)

 

By the way, what is the deal with not being able to open attachments? Is that something with this site right after you sign up or something? I haven't been able to check out any of the charts etc because either says I don't have access.

 

yes you have to get your post count up.

 

you have 10 posts now so you should be good? I think it's 10 or more.