Thursday, January 19, 2012

Do motorcycle performance upgrades (exhaust, air cleaner, ect) increase CC's?

i just recently got some performance upgrades done to my HD iron 883. i got the Vance %26amp; Hines pipes, roland sands venturi air cleaner, screaming eagle super tuner and dyno tuned. still have the stock 883 engine. the stock HP was 46HP and now i'm pushing 58HP. does this increase how many CC's my bike has? thanks for reading.Do motorcycle performance upgrades (exhaust, air cleaner, ect) increase CC's?
NO. CC's is Cubic Centimeters, this is the engine displacement, how big the engine is. The only way to increase the displacement is to make the cylinder bore larger or increase the stroke of the crankshaft.



In your case, the most bang for the buck is a 1200 conversion. There are several different ways of doing this.



1. Bore your stock 3.000" bore cylinders out to 3.500". This will run about $250-300 depending on who does it.



2. Buy new 1200 cylinders. About $300.



Now it gets a little more complicated, depending on what you want the engine to do. Higher top end speed???...OR...More low end torque???....OR...BOTH.



To get more top end HP and speed, install stock 1200 heads and flat-top pistons. This basically turns your 883 into a stock 1200.



To get more low-end TQ with a LITTLE less top end speed (about 10mph) use your stock 883 heads with reverse-dome pistons, my preference is Keith Black Hypereutectic Pistons.



If you want a 1200 that HAULS ***, get the Screamin Eagle Sportster Heads and High Compression Pistons. The HC Pistons will give you 11.3:1 compression, stock flat-tops will give 10.5:1.



An 883-1200 conversion with 883 heads and reverse-dome pistons will out pull a stock 1200 due to the intake and exhaust ports being slightly smaller, creating higher intake and exhaust gas velocity which creates more torque. Also, the 883 comes with a 27 tooth front sprocket as opposed to the 29 tooth on the 1200, this gives the 883 a mechanical TQ increase due to it's smaller displacement. The 883 also uses cams that help produce more TQ as compared to the cams in the 1200 that are designed to give more higher rpm HP.



If you use the Screamin Eagle Heads, your engine builder can help you pick out cams that will compliment the rest of the engine and suited for the type of riding you do.



BTW....58 HP from an 883 is NOT bad at all.....sounds like you got a good tuner, stick with him and ask him for advice on further engine work.



If you have any more questions, email me here through my profile, I'll be glad to help.



Here is a XR1200 that I just did recently.........I had the heads ported with oversize valves, hi-flo guides, radius valve job, 10.5:1 compression, cnc ported throttle body, Screamin Eagle Air Cleaner, RedShift Cams, and modified STOCK exhaust, all with a Screamin Eagle Super Tuner modified ECM. This was actually one of the easiest bikes I ever tuned....it put out 112hp @ 6700rpm and 108 ft/lbs of torque @ 5900rpm..............these measurements are taken at the WHEEL...not the crank.....and are higher figures than a STOCK HD 103" Big Twin.............Do motorcycle performance upgrades (exhaust, air cleaner, ect) increase CC's?
All you upgrades did not change the engine displacement. Cubic Centimeters is a term for an engine's displacement.

Here is the formula.

Area of the bore (radius squared times pi) time the length of the stroke times the number of cylinders.

You have not alters the diameter of the bore or the length of the stroke or increased the number of cylinders.

Therefore your Harley-Davidson still displaces 883 cc's.

It is a shame that you the customer has to pay extra money for these needed performance modifications. This should be standard equipment from Harley-Davidson. To think in this day and age a nearly 900 cc engine only producing 46 horsepower.

Good Luck with your Harley-Davidson.Do motorcycle performance upgrades (exhaust, air cleaner, ect) increase CC's?
If you take a quart of milk and wrap it in fancy paper with a bow and ribbons you still have a quart of milk.The same is true with an engine all the fancy doodahs you add on the outside doesn't change the physical dimensions of the motor.
What Bob said...about the doodahs...LOL

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