Cb450 performance camshaft
Performance camshafts can add different characteristics of power to your engine.
- Cams with high lift can add mid range punch, while cams with longer duration can add high rpm top end power.
- Cams with both can really add power but you need to make sure the head can flow properly.
It really depends on what you’re trying to do and making sure your parts and set up all match. Even if you have a completely stock motor, putting in a cam with a tiny bit more lift / duration can be a benefit. If you add an exhaust and pods, a very mild cam upgrade will yield a couple HP. And… if you have a high compression piston kit you’ll really get a benefit from cams. Especially if you have head porting done.
Megacycle is a cam company that’s been around for a long time. Ever since doing the high compression piston kit in my 450, I’ve been wanting to add a megacycle cam. Megacycle will take your existing camshaft, grind it down. Weld new metal on the lobes, then grind it down to their new beefier specs. This is called hard-welding. This winter I was gonna send my cams out to megacycle. Ironically on eBay popped up a set of used megacycle cams in the grind I wanted for $200 cheaper than new. I bought them.
I’m having a hard time accurately measuring the lift. It’s obvious to the naked eye the duration is way more gnarly. The lobe is much fatter. I’m going to send the cams back to megacycle to have them verified to ensure they’re still within spec and okay.
They’re stamped from 1992 which is when they were made. Pretty cool.
My 450 set up
- 500t motor bored to a 550cc with high compression Todd Henning pistons
- 32mm mikuni VM smoothbore carbs / pods (powerbarn.com kit)
- pamco ignition
- straight pipes with 8″ baffles
- head is not ported
- stock torsion bar valvetrain set up
So I think the megacycle 120-40 cam grind will work well.
My compression at the moment is just over 200psi per cylinder which is a little too high. These cams should lower the cranking compression to around 170 which will be more comfortable.
Intake and exhaust cams below.
Megacycle 120-40 grind
Grinded by Megacycle in 1992
Stock OEM cam profile below
Megacycle profile below. You can see the different color metal welded on and see how much lumpier the duration is. Holding the valve open longer. More top end high rpm power.
Straight pipes with 8″ emgo baffles … get the shit out as fast as possible. Don’t need much back pressure with the type of set up i’m going for.
Mikuni VM smoothbores
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Published - Aug 16, 2020
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