2015 RGS Cam, oil pump etc. questions - Page 3 - Harley Davidson Forums

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2015 RGS Cam, oil pump etc. questions

Old 01-12-2019, 11:22 AM
Shadowbennie is offline
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Originally Posted by djl View Post
I owe SA66 an apology as I thought I was responding to the OP with my posts and just realized that we have hijacked his thread; SA66, apologies for that.

It's really not a conundrum. Pretty plain as rigidthumper has laid it out; you must have a preference for one or the other; you just need to choose between the two. If you are going to open the cam chest to check tensioners, pump, run out, etc. you have done 75% of the work; pretty straight forward all lMHO assuming funds are not an issue.

Dyno charts tell part of the story but you need to be sure you are looking at all the data, i.e., heads ported? (If heads were ported they were most likely decked as well) what exhaust? what T/B? tuner? etc. Dyno charts do not tell the viewer the CCP. The same build with a CCP of 185psi is going to present a different profile with a CCP of 200psi. Do no be afraid of compression. I think you meant intake close, not intake open as a criteria?? Your comment about the S&S M103 cam being soft on the bottom could be the result of just not providing enough compression to wake that cam up off idle; dunno.

What I like about the Cyclerama cams is that you don't see the typical difference between TQ and HP with Wes Brown's cams. With a good tune and the right exhaust, numbers will look like 115/115 and not 115/105.
Agreed, I also owe SA66 an apology as well, I guess Iím the hijacker. but hopefully our discussion has given some additional information to consider pertaining to the original question.

I also like that the CR cams seem to have less disparity between HP & TQ, and that the powerband seems to come on early, and is flat and long. Iíll just keep looking at Dyno charts
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SA66 (01-13-2019)
Old 01-12-2019, 11:26 AM
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Originally Posted by Steve Cole View Post
I have said this before but I will repeat it for some of you that may not of heard it before. I have to say what does a cam card tell you? If we break it down it tells you very little as to how the cam will really perform. Let's take a look at what you get on a TC cam card. It tells you when the cam lobe is @ 0.053" lift and when the cam is @ 0.053' lift on the closing side of the lobe. Neither of those points is valve opening or closing points! Then it goes on to tell you what your expected valve lift maybe based upon some rocker ratio. Problem, there is not any of the cam cards that I've seen tell you that the ratio being used may well not be what the TC engine has in it. Various suppliers use various different ratio values too. So its tough to use those values in anything but a general guess. If you put a solid lifter in a TC engine (just for checking) and adjust to zero lash then check real valve lift you will find it different from just about every cam versus what it says on the card. In speaking with the company's that make the cam grinding equipment they will tell you there is a normal tolerance for the grinding machines that runs about 3 degree's, so that means when the cams are being made it's common to see 3 degree's variation in measurement during a product run! Then let's look at just the crankshaft gear fitment in the TC. I have measure as much as 8 degree rattle in that gear alone! Typically there is about 4 degree in them. So for those of you that think the cam card is going to say this the one you need based on whats printed on them I am sorry but it isn't going to happen.

Let's give you all a simple thing to draw on a piece of paper for yourselves. Take a tablet and pencil and draw one horizontal line across the page, then another line 1/4" above the first line followed by a third line 1/2" above the first line. So you now have three lines across the page. Now right in the center of the third (top) line place a dot on it, then drop down to the second line and place a dot on it 1" to the left and another 1" to the right of the first dot on the third line, both on the second line. You now have what the cam card tells you for one lobe. The first or lowest line on your drawing is the zero line or you may refer to it as the base circle. There is nothing else on the cam card that defines anything else about that lobe! So now you have to draw a continues line from the 1st line that touches all three dots and returns to the 1st line. See how many various lines you can draw........................... hundreds if not thousands! Each and every line you draw as long as you hit those three points would have the exact same specifications on a cam card! Now some of those lines cannot be made but you get the idea here. Some will work much better than other yet they ALL get the exact same specifications.

There are things that will get you better performance but will also wear parts out faster, things that will make them quieter and yet others to hurt performance to some degree. So thinking a Camcard specification is a measurement of how a cam will perform in a given engine could not be further from the truth. You have to first know much more about the cam than the card will ever tell you and then you must install it and know where it is timed in the engine. In the HD world just bolting a camshaft in with never measuring anything is the normal way things are done. Very few spend the time to degree a camshaft in, let alone degree the front and rear cams in the engine and adjust them as needed. I am not talking about lining up the dots either. For a bolt in HD TC camshaft you will be better served to be honest with yourself and define what range do you really run the engine in 90 + % of the time you ride the bike, then pick components that work best in that RPM range. I see way to many people chasing numbers they will never use as they are not out racing the bikes. Some are and for them a different selection of parts would be better, than a person that rides there bike in town and out for a cruise. In the HD world I see 95% of the rides run there engine from idle to around 3500- 4000 RPM then shift. So a cam that makes big HP at 5800 RPM is going to do you little good. What would do you much better (if that's how you ride) is a camshaft designed to give you low RPM Torque from idle to 4000 RPM. The 110 + HP at 5800 isn't worth a damn thing to most bagger riders other than telling you buddies at the bar! Now a bike that makes 95 + Ft lbs @ 2000 RPM and climbing, will put a huge **** eating grin on there face once they get on it and ride it. It will not have the bigger HP bragging rights at the bar but you have to ask yourself what you really want.
Really good info Steve, certainly easy to get caught up in number chasing, but Iím trying my best to stick to components that are rideable day to day & match where I like to ride.
Old 01-13-2019, 06:56 PM
SA66 is offline
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No worries for hijacking guys, I am reading and getting informed

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