Which Cams

[To The Max]

I am thinking of changing the Andrews 55g cams I'm running, would like to get the torque happening
a little bit sooner. I have a 08 softail with  103 cylinders sc, compressor heads set at 10.2, sc 50mm throttle body and bassani 2-1 exhaust. and of course would like a bit more horse power without getting bumped around on partial throttle opening. yes I want it all can any body help.

[Jaycee1964]

A 54 would work

[1FSTRK]

Advance the 55 cams 4 degrees.

[joe_lyons]

First try the advance, and see how you like it. 

[Jaycee1964]

Don't think he will be happy with the 55 with +4.  With the 55's much longer overlap and longer duration; Especially on the exhaust the + 4 will help but not that much and the TDC lift will be getting up there in the .220's with the +4 as well.

[metaliser]

I would throw a set of 57's in there and be done with it.

[dsvracer]

If you are looking for more power do something with those compressor heads.  they do not flow all that well and could use some TLC.  dsv

[Bigbluff]

I would throw a set of 57's in there and be done with it.

10.2:1 compression is too much for Andrews 57 cam...if reliability is desired. I'm running Andrews 54 with 10.3:1 compression on my 103 and 50mm TB. Very happy making 113 ft/lbs TQ and 112 HP. A T-man 590 or 625 would be good choices also.

[Barrett]

Don't think he will be happy with the 55 with +4.  With the 55's much longer overlap and longer duration; Especially on the exhaust the + 4 will help but not that much and the TDC lift will be getting up there in the .220's with the +4 as well.

Some cams have more TDC lift than that.. The +4* sprocket should move the R's 3-400 sooner.. A 30T pulley will help also.. I have 55's on the way and mine are going in advanced.. I hate the thought of giving up too much on the bottom from my 37's but I wanted to try bigger cams when I add some cubes..

[Hossamania]

I like my 55's, but I did change to 3:37 gearing. It helps, but they are still a top end can, not stump pullers. Downshifting to the power band is quite easily done.

[metaliser]

I would throw a set of 57's in there and be done with it.

10.2:1 compression is too much for Andrews 57 cam...if reliability is desired. I'm running Andrews 54 with 10.3:1 compression on my 103 and 50mm TB. Very happy making 113 ft/lbs TQ and 112 HP. A T-man 590 or 625 would be good choices also.

Bigbluff I respectively have to disagree with you on this one, the 10.2 on a 57 cam would be perfect with a good tune. I have it in my 2014 Limited at 10.1 and it wouldn't hurt at all to be bumped just a little on the compression, it would really bring it alive. I also looked at the 54 and 57 on BigBoyz site to compare the 2 and again see no problem with the 10.2 compression. There are so many different combo's that will work though the end result I hope will feel the bill for the OP.

[autoworker]

I would have the heads ported first.Then you can have them milled to add compression to your existing cam (55).It will work very well with more compression.

The 54 would work as well as the 57.You will need a good tune for the 57 at the compression ratio you will end up  with.

[To The Max]

Well so much to think about. 54 s I have looked at but worried that I may loose a little horse power through the top end. I wondered if stilting the inlet might help the top end a little. the 57s looked a little better and tuning wont be a problem but they don't show them as gear drive ? advancing the timing 4 deg might be worth a try but what I don't like about the 55s is the partial throttle low rpm surge they have ,I tried tuning it out and it helped but it still gives me the s--ts a bit. and thank you all for your input so far. Max

[Matt C]

Generally, when you "want it all", cubic inches (or boost) become the only options.
There's no free lunch, but if you can narrow down where your preferences are, you
can optimize and tailor your curve to the riding style. Give and take, so to speak...

You may be able to make the heads work better and pick some cams that are more
suited to your riding goals.

[sfmichael]

Generally, when you "want it all", cubic inches (or boost) become the only options.
There's no free lunch, but if you can narrow down where your preferences are, you
can optimize and tailor your curve to the riding style. Give and take, so to speak...

You may be able to make the heads work better and pick some cams that are more
suited to your riding goals.

+1   there it is ttMax

[To The Max]

I just got back from my mates work shop , he has worked on Harley's all his working life he told me the same thing that you guys have said (flow the heads and get 54 cams) . so thank you guys you have helped me decide. Max

[joe_lyons]

Some of your low rpm surge could be attributed to the tune. 

[autoworker]

Some of your low rpm surge could be attributed to the tune.

There is no reason the 55's would cause any low rpm  surge issues. I have them in a 107in. Road Glide and they work very well with the right compression and tune.

[joe_lyons]

Some of your low rpm surge could be attributed to the tune.

There is no reason the 55's would cause any low rpm  surge issues. I have them in a 107in. Road Glide and they work very well with the right compression and tune.

Key word is right compression.  I have tuned bikes with cams that would like more compression and a lot of the low end was a PITA to get sorted out.

[Barrett]

What compression is the happy spot for the 55's?

[joe_lyons]

I know stock 103 is too low for sure as I have had to retune a few.

[sfmichael]

What compression is the happy spot for the 55's?

Andrews says 9.8-10.2 but that seems a bit low to me for a cam with 248/252* of duration and a 46* close. I think they're about a half a point low give or take a bit.

[To The Max]

Its funny that you mention comp. When I fitted the 103 barrels I dropped the comp from 10.5 to 10.2,
that's when it seamed to get worse and I have tuned it out a lot. the other day I tuned my mates 96 softail its std with V and H large radius 2-2 and  a filter sc 211 cams ,well Ive got to say it supprised me it pulled really well sounded like a comp bike and rode as nice as grandmas electric gofer that's when maybe thers something better.

[autoworker]

10.7-10.8

If the tune is correct and the heads are able to be milled enough to achieve the compression ratio.The manifold fitment may be an issue if the heads need too much milled to gain the needed compression.

[Barrett]

10.7-10.8

If the tune is correct and the heads are able to be milled enough to achieve the compression ratio.The manifold fitment may be an issue if the heads need too much milled to gain the needed compression.

S&S 79cc heads come in at 10.76:1/9.82:1/207ccc.. That's 3.885 bore, +4* sprocket and a .030HG..
The .040HG puts it at 10.54:1/9.62:1/201.8.. I can get 93 octane with no problem and it is a barhopper Fatbob, But I think I'll be safer with the .040HG.. I already have the .030's so I will be tempted to use them..