S&S Easy Start Cams for 124" w/10.5:1 Compression

[turboprop]

I am done screwing with electric compression releases. DONE. Going to replace the cams currently in Torque-A-Hoe (Blue/White FXR) with an easy start grind, preferably an off the shelf grind.

The engine is a TC 124" built on a TC88-A case with heads set up for .660" lift with god flow numbers.

The S&S catalog lists the 585ez, 625ez and 640ez cams and according to the description by S&S all three cams are recommended but the 585 seems to be the best of the three.

Pulling the heads and changing stuff is not an option right now. Just simply swiping cams. After searching the dyno section of this forum it seem that the 585 at 10.5 gets mixed reviews by the experts on this forum. I am sort of curious about maybe advancing or retarding the 625 or 640 cams by way of an offset key. 

I am curious to hear what the experts think but would like to limit this discussion to just these easy start cams by S&S (Is that even possible?)

And go!

[Ohio HD]

I'm running the 625's in a 124" at 11.3:1 compression. They feel really good there, and on the compression gauge gives about 190 ~ 192 lbs. cold. The cams are installed straight up, no advance.

I wouldn't think I'd be happy with these cams at 10.5:1 even if advanced 4°. Most 124" motors in the dyno section that run the 585's have decent low end power, and a little pull on top. If I was looking at the 585's or 625's for your situation, I'd take the 585's. I think the low end on the 625's even with the intake closing @ 51° would be a little soft. No experience doing it however.

[Deye76]

"even with the intake closing @ 51° would be a little soft."

In a heavy bagger, for sure, in a lighter bike a FXR, I'm not so sure. In my Evo 113" FXR the cam (S&S .600) has a 55° intake close, @ 10.2:1 CR it's surprised me more than once. Add 11 cubes and better heads like Turboprop's would be more than a handful for many riders.

[Ohio HD]

Yep, I get that John, he has a lighter bike as well as maybe lower gearing. I'm going by the bikes name of "Torque-A-Hoe" that this bike is intended for low end grunt. That's kind of why S&S puts the 585's in the LC 124" crate motors. I have no doubt the 625's will pull better on the upper end.

[Don D]

The story however is on the exhaust side. The 585 has 260° degrees duration and a 60 exhaust open. Advanced 4 now we are at 64° right in the neighborhood as the 640. Despite the 41° intake close the early exhaust open may cancel the cylinder pressure gains and make it a little snotty down low at light throttle, if that concerns you.

I would run the 585 straight up, theoretical 196 or 201ccp advanced, or the HP103, theoretical 191ccp or 196 advanced, and add a 1.7 ratio rocker on the intake side to either. The lower ccp will obviously allow more timing overhead and work better on a carbed bike, if it is. The HP103 has a LSA of 104, 50 exhaust open and if advanced the LC would move to 100 and 108, perfect. and still have a exhaust opening of 54° BBDC letting the work stay in a little longer.

[turboprop]

The 585s with 1.7 rockers is certainly worth considering. Thanks.


Also, for clarification, the bike is currently geared 25/36 in the primary and 32/65 on the final drive, but have plans to swap to 32/70 when I add the 6-speed gear set.

[Ohio HD]

1.7 rockers can't hurt. They get you to about 1.621" lift.

[wfolarry]

The 585s with 1.7 rockers is certainly worth considering. Thanks.


Also, for clarification, the bike is currently geared 25/36 in the primary and 32/65 on the final drive, but have plans to swap to 32/70 when I add the 6-speed gear set.

This is what Regie did at R&R. He liked the way it performed so he had cams made with it built in.

The 585 is my favorite cam from S&S. I've used it in everything from 95's to 124's with good results. Give it the compression it wants & it performs.   

[m1marty]

Another vote for the 585s here set straight up. I'm currently running them at a very sedate 10.4 in my 110. Very very responsive and near electric motor smooth going down the road.

[m1marty]

Still debating pulling heads and setting it at 10.8-11:1
My motor has been through several configurations over the years. The previous set up (DME598/HPi Elip 58mm) made 138/127. I can honestly say I like the 585/55mm the most so far.
I can only imagine what your 124 would put down.

[Arseclown]

The 585s with 1.7 rockers is certainly worth considering. Thanks.


Also, for clarification, the bike is currently geared 25/36 in the primary and 32/65 on the final drive, but have plans to swap to 32/70 when I add the 6-speed gear set.

This is what Regie did at R&R. He liked the way it performed so he had cams made with it built in.

The 585 is my favorite cam from S&S. I've used it in everything from 95's to 124's with good results. Give it the compression it wants & it performs.   

GMR also had a cam built to mimic the 585 with the longer intake rocker ratio.

Im also thinking of going to the no fuss ezy start cams when my acrs start playing up