I have the exact same set-up, minus the cams, on my Ultra Classic. If I'm understanding correctly, the "baseline" shows the 570-2s installed, but on a different tune. How would you rate them to the stock cams? Thanks!

 

I'd love to see a dyno chart if you find a PV2 tuner that can work out the combo for you.

 

 

 

Here's a 2016 with 222's tuned by J&B Performance with a PV, bike runs great.

 

Few years ago I was looking seriously at the Andrews 57's too. TFBB in Moncton would happily supply and install these but suggested that, if I simply wanted a drop in cam and would require no further modifications, the 204's would be worth considering. I went with the 204's and couldn't be happier. There's a nice lope at idle and torque is spread out far more evenly throughout the RPM range. My 6th gear was just overdrive, changing nothing but the RPM's, till I put the 204's in. Now, 6th pulls very convincingly. SE204's only come on at about 2800 RPM though so if you're a "lugger" they won't be the cam for you. A friend of mine went with 255's for the low RPM grunt and is happy with them.

Anyhow, I'm no cam expert but changing to 204's made a very marked improvement in my 2014 BO's performance and they don't require "any" further mods to optimize them. The SEST tuner has a map for the cam. TFBB techs had zero issues tuning for the 204's.

 

I know this thread is a little old and hasn't had any activity in a little over a year, but I started researching as many of the cams mention in this thread, mostly for my own purposes and thought I would share what I have come up with. Quite a bit of the technical terminology used here is taken from a couple of articles on Summit Racing's website, but an internal combustion engine is an internal combustion engine, it doesn't matter if it is in a muscle car, a sprint car, or a motorcycle (we are talking 4 strokes here, not 2 strokes)

Remember when selecting a cam

Wider lobe separation (less overlap) makes for a better idle than narrow lobe separation (more overlap).
Advancing the cam makes more low end torque. Retarding results is more on the top end.
Longer duration cams make more power up top, but suffer from a rough idle, and lack low-end.

Now to describe some of the specifics, where to look for things to happen based on the desired outcome.

Overlap (from the Intake Perspective)
When we open the intake before TDC, a few things are happening.
The Good: Opening the intake valve sooner won’t delay cylinder filling on the intake stroke. It’s least inhibited when we’re at WOT and running an open exhaust.

The Bad: Any residual exhaust pressure back flows into the intake manifold due to high vacuum at part throttle (blow back, or the chuffing some make at low RPM's with certain cams). Any burnt mixture from the cylinder goes back in the intake. Not only will it not burn again, but it’s taking up the space where the fresh incoming mixture should be going.
These are seen at lower RPM's and idle when vacuum is high causing the engine to run rough (that big cam sound and shake). Carbureted engines suffer more than injected engines because they rely on this pressure differential to flow fuel more air/fuel flows into the engine with less back pressure from the exhaust however some some back pressure is necessary to build power).

Overlap (from the Exhaust Perspective)
When we close the exhaust after TDC, there are a few things happening.
The Good: At WOT and higher rpm, a well-tuned intake runner and exhaust primary length (along with a free-flowing exhaust) will flush out burnt gases.

The Bad: If you are running a standard exhaust, you may have up to 8 lbs. of back pressure at WOT. Exhaust (that’s already past the exhaust valve) can reverse direction into the intake. Luckily, a free-flow exhaust often has less than 1 lb. of back pressure. Fresh air/fuel may be pulled out through the exhaust without being burned as a complete waste. This is what causes engines with a lot of cam overlap to smell of raw fuel.

Overlap (General Observations)
Overlap pulls in fresh mixture at high rpm, wide-open throttle (WOT) with a free-flowing exhaust, but hurts efficiency and driveability at low-rpm part throttle.
Engines with big cams show bigger gains with headers and a free-flowing exhaust than stock cams because the cams increase duration and/or lift allowing more air/fuel and exhaust to flow in and out of the engine. The same works in reverse, without sufficient intake and exhaust the bigger cam cannot pull the required amount of air/fuel into the engine or push the required amount of exhaust out of the engine to produce optimal horsepower. (as stated several times throughout this thread the ideal is to find the perfect combination for the owner/operators riding style, and the conditions they most often ride in). Free flowing intake and exhaust can only account for so much, beyond that head work is required to increase the flow in and out of the engine.

Intake Stroke
Taking Advantage of Intake Tuning and Inertia
Let’s talk about the period right after overlap. The intake valve is open and the piston is moving down the cylinder. Peak piston speed happens roughly 73 degrees after TDC and peak inlet airspeed is slightly behind that.

Even when the piston passes BDC, the downward rush of air/fuel coming in is still stronger than the upward push of the piston. On a typical street/strip cam, we take advantage of this velocity by closing the intake valve 40 to 50 degrees after bottom dead center. This packs and traps in more mixture.

Fun Fact: The volume of air/fuel mixture trapped in the cylinder is always the same whether the engine is at idle or 9,000 rpm WOT. At part throttle, it’s less dense. At WOT, it’s more.
This is where we start looking at VE (Volumetric Efficiency) on tuners to determine where in the RPM Range the fuel and ignition need to be adjusted/corrected to achieve the most efficient burn and produce the most torque and horse power obtainable from the physical/mechanical conditions/limitations.

Compression Stroke
Effects of Closing the Intake Valve Earlier or Later on the Powerband
At lower engine speed and part throttle, the density of the mixture is low.

To build compression, we must close the intake valve earlier. This traps as much mixture as possible, begins to compress it earlier and builds torque lower in the power band.
At high engine speed and WOT, we can advantage of the intake duration and cylinder head velocity.

With more velocity, we trap the air a little later—which raises the powerband (RPM Range where the power is produced). This is when we see horsepower going up, but the overall peak-torque going down. It also allows a high compression ratio engine to run on lower octane fuel.

The valves are closed for most of the compression stroke and power stroke—until the exhaust valve begins to open again and being a degree off here or there is of little consequence.

All internal combustion engines are vacuum pumps. They pull air and fuel into the engine, then push exhaust out of the engine. Increasing compression also increases the vacuum pressure and the engine can pull and push the air/fuel and exhaust more efficiently as well as compress the same volume of air into a smaller area, thereby increasing the power produced during the power stoke, but this also increases the amount of strain placed on the crank and rod, the valve springs, the valve seats, the push rods, and valve train. The simple fact that, due to emission regulations, most manufacturers of road going vehicles in the United States have de-tuned their engines to the point of starving them for both air and fuel, and the availability of aftermarket parts to consumers allowing us to open the exhaust and intake to flow more freely and reclaim that power is an incredible benefit to us, however there are still physical limitations we will meet that will prevent us from reclaiming any more without considerable expense to increase cylinder volume (engine size), head work to flow more efficiently, valve size to flow more volume, valve spring rates to handle closing the valves faster, cam bearings, crank bearings, balancing the crank to reduce vibration due to increased RPM's, etc etc etc.

I have sorted, to the best of my ability based on specs, the cams from stock (on the 103HO, I did not check specs on stock 103 Non HO) to most aggressive. Of course some are a little hard to sort due to Intake or Exhaust Timing and Duration differences, as well as Overlap and Lobe Separation. It is also very difficult to determine volume differences based on Lift vs Duration. I may be a bit of a geek but I am not that smart. hahaha

 

Remember that everything you read does not means it works like that in real life. Most of the above information gets you a good general understanding but skips pretty much all the important things that can make or break a camshaft. A cam card give some specifications but they are not all done the same nor are they equal. Let's look at intake open as an example from any of the card numbers, there is not one of them that tells you where the intake valve opens at all! If you read close on the cards it is a measurement point taken after the valve is already open and everyone does not use the same point of measurement. So some will say open at 20 deg @ 0.050" and another may say open at 20 deg @ 0.053" and yet another open at 20 deg @ 0.20". So while they all declare open at 20 deg they are completely different from one another. Same goes for the close points.

Now once you move on to the understanding that the measurement points may well be different, no where does it say where the valve really opens or closes or how it gets from the base circle to the open point they put on the card. There is just so much that goes into how the cam works that will never show up onto a cam card its no funny. Then there are also plenty of cards that are flatout wrong when you really check things too. With that said take it all in and understand that camcards and information are just a general idea of what you might be getting.

 

Agreed, I put this sheet together for myself, for informational purposes. I find the SE204 very interesting, as well as the Fueling 574, CR570II, and CR575.

Looking at these specs and seeing the similarities between quite a few of them, it's no wonder why so many owners swear by the cam they chose for their bike.

I am a little surprised how similar the CR570II and CR575 are to one another.

The SE204 looks like it would be a great cam for torque improvements, good advance, as much as some of the pretty aggressive cams, but less lift, with good duration. The lobe separation and overlap look like it will idle well, but chunky like a built big block.

And of course matching everything up to the correct intake and exhaust, and having a proper tune/remap done will be equally important to making sure it all works together.