Lets Talk Cams

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Scott you sure Lushy didn't fit pistons along with the cams ? Thought they came as a package , higher compression pistons that is.
Nev has what he calls drop in street cams (which are the ones Maly has I think) that don't need the hi comp pistons as well as the higher performance ones that require hi comp pistons
 
Scott you sure Lushy didn't fit pistons along with the cams ? Thought they came as a package , higher compression pistons that is.
no no pistons just drop In cams and i retune By friend at procycle dyno
 
Hi Tomcat, I have Nevs cams and pistons, that combo gives just over 200hp
 
With stock 25mm shims you can go up to about 9,5mm/3.74" lift and 260° opening (at 1mm/0,4").
That is already quite an improvement to stock. But you have to watch valve/piston clearing.
I love big overlaps, that will give you good performance at mid revs. And that won´t work with stock pistons. You can modify them. But if you do all that work, it is not that much difference to putting in high compression pistons.

Prost
Ulf
 
Many newer vehicles use a combination of timing, fuel delivery (timing and qty,) throttle control by TBW (throttle by wire means that even though you have the throttle wide open doesn't mean the computer does) and secondary butterflies to tailor the torque curve. Take all that away and the 1075 dyno chart would look very different. Also, by comparison to the R3, the 1075 has huge intake runners, large valves, much higher compression ratio, and aggressive cam profiles. And most importantly, it is not designed to live beyond 30,000 miles. Most don't make it that far before hitting the salvage yard. Most R3 owners would be less than impressed if their cruiser consumed itself by 30,000 miles.

You give the cam specs for the R3 but those numbers reveal very little about the lobe design. Cams partially control air flow into the cylinders. They directly control what is called "Valve Lift Area," or the distance the valve is open at any given crankshaft position. Imagine a bell curve on a graph. The height is total valve lift, width is from initial valve opening to valve closing. The shape of the curve can be peaked or it can be rounded or "fat." A cam with fast ramps will have more valve open area than a cam with slow ramps. So the numbers of just open, close and total lift while meaningful to a mechanic installing a cam, are not well suited for comparing one cam with another.

Opening a valve sooner and/or closing later (changes duration, centerline and overlap) will have an impact; so will more lift with the same open and close timing; so will more valve lift area with both the same total lift and the same open and close timing. There are limits to how fast you can open the valve such as bucket diameter, valve and bucket weight, spring rate, rpm, durability concerns, etc. Generally, more lift area with less duration builds mid-range, longer duration extends the rpm range and moves torque peak up, more total lift allows more lift area but is constrained by duration limits. More duration increases overlap with a given centerline, as does greater lobe separation at the same duration, both can decrease idle quality, low speed power and efficiency (lots of emissions) but provide more top end power.

So cam design really is a big compromise. Some aftermarket cam builders have made fortunes selling cams by using "impressive" numbers that once understood are actually quite meaningless. My suggestion would be to use what works based on the experience of those who have used a product and less so from advertized numbers.
 
True, True. Nothing like pressure to move more air! No coincidence that auto OEM are moving to forced induction, small displacement engines. By comparison, we could have 300 hp blown Rockets that run on 87 octane, unleaded fuel.

Warp, how are you liking the global warming? Colder than a witch's tit here. May have to make a mid-winter trip to south Texas to warm up.
 
IDK, I think Carpenter does pretty good, a little higher in the rpm band, but continues up past 8000 rpm. Have odd problem here of sometimes being able to load pics, sometimes not.
WE can give you a choice of cams , pistons , big valves for any powerband you like SO its not just one set of cams and thats it we can give 170+ HP to 270+ HP as an everyday rider streetbike OR if you want more we can give you more than you can handle
 
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