going crazy over cams

[Hellion]

I just purchased an 08 fxstsse and am looking at the 251 cams, perfect fit push rods, sert, and D-rings instead of the factory baffels. My dealer is running a big sale this month on H-D products and service so I am going crazy trying to figure out what to do. Now, I like to ride hard and fast along with being able to take a cross country ride this coming year. What do you suggest?

[Mike]

The 251's will give up some low end tq (2-3k rpm) but yield better numbers from 3k on. Since you "ride hard" this should not be a problem. I would look closer at the 257's or even 258's (in the SE cams), for your riding style, since this is a 110ci motor in a Softail. Downshifting to get into the power will be required.

[COVSpringer08]

I also have an 08 FXSTSSE an thinking about cams these are what i have looked at

T-man. TR-590G or TR-625G
Yuill Bros. YB14sec-07
Woods. TW-7H the only cam with same duration on intake & exhaust?? does the heads like this??
Andrews 32H
Zippers 575
Crane 1-3003

What to also add compression later and port heads

[COVSpringer08]

Crane 1-6003 HTC-290-2
240/248 .570 lift int 18/42 ex. 46/22

Mike how would this work in the 110?

[Mike]

Most of the cams selected will produce similar results with the possible exception of the Andrews 32. All will work well with lower compression but better with 10.-10.3 in a 110. The TM625 has a little more lift and this may help cylinder fill and tq along with the earlier timing. The low overlap of the And 32 will also promote tq but may not be best for a large displacement motor, better in an 88/95 , also has a wide LSA and fairly late intake event. I do not have the specs for the Yuill Brothers cams and cannot compare (they are supposed to be sending).

All of the cams should give good low to midrange performance with 10+ but will be a little soft with the stock 9.2. All will show a tq dip around 2.5, especially when compared to your stock 255.

Depending on what your after, the TM 625 would be my choice when used with 10.2 commpression. Since you've mentioned you like to run "hard", I would be looking at a little more cam and compression similar to the Wood TW9B or TM 650 with 10.5-10.8 compression. But only after the ported heads are added.

[COVSpringer08]

Yuill YB14SEC-07
intake 0.546 242 duration 20/42 101 tdc lift 0.187
exhaust 0.546 253 duration 53/20 106.5 tdc lift 0.175

11 deg more duration on exhaust.. Most of the cam i see only have a 2-6 deg split?

[Mike]

That's to get the duration, it's more about the overlap. Still at 40, similar to the others. You may be overstressing the differences. Many of those differences are put in the cams so that they are not exact copies of others, thus enabling them to be branded. Again, with the possible exception of the Andrews' short overlap, vs the others, they'll all perform essentially the same.

[COVSpringer08]

The andrew 32H intake timing opening at 10*BTDC is this the problem? My se-255 starts at 6* BTDC and most of the cams i have looked start at 18-25* BTDC..

My SE-255 only has 13 overlap?
And the andrews 18

Mike my SE-255 olny has .079 lift at TDC all the cams i have looked at have at least .100 more.. I'm learning now Thanks

[Mike]

13 overlap, 211 duration, intake closing off 25 AND .550 lift. Hard to find anything in the aftermarket even close to these specs.

[COVSpringer08]

Mike
I know i'm over stressing the cams, it's 4 months later i'm finally going to do it.
I have talked to you (bugging you) over and over about cams. At the end Zipper's RS575 seems to be the one for me. Now if more lift would be better what about the T-man 625? Baisley will have the head work, i'm going to keep my stock valves.

[Mike]

Since both cams are very similar, timing wise, I would go for the lift. The trend seems to be that most motors using stock head castings respond to lifts up to around .630 (even when ported). After that, adding more lift does not seem to make much difference, when using stock head castings (based on results using .650 and .680 cams in builds similar to those using .590-.630). Aftermarket heads, or Baisley Hybrids can respond to higher lifts due to valve angles, raised ports and seat location.

Another experiment we've not tried to a large extent is to run the lower lift cams but change the intake rocker ratio (leaving the exh stock). This will give the higher desired lift on the intake side while maintaning lower lift on the exh which helps with TDC's and valve to valve clearance, which in turn can help flow. This could be a question for Baisley with respect to your head work.

[COVSpringer08]

Thanks

So i could run the rs575 with a higher intake rocker?

[Mike]

Yes. As stated, we've not done this a lot and so do not have a great deal of data to confirm. Best to get Baisley's take before doing.