What part of the cams specs give ya that nice soundin idle.lift,duration,intake open,close.overlap etc.etc.

 

A twin cam idles between 950-1050 revs; You want a nice idle,get a shovelhead...........

 

LOL know come on I had a shovel head I dont expect that I would just like a little bit of a lope.didnt know if certain cams sounded better than others and what made them sound better than others.Actually I wish I had never sold it should've just kept it.IT was worth to much to sit in the corner of the garage so I thought at the time.You can't blame me for tryin.

 

The po-ta-to po-ta-to sound left the building about the same time as Elvis, when the the single fire ignition was introduced. The first beat of the three beat sound was caused by unburned gases firing in the exhaust pipe from the wasted spark, because an exhaust valve is open.

Run a jumper wire across the posts on your coils so they both fire at the same time, and richen up your mix so there's lots of unburned gases in your exhaust.

 

Generally speaking, a cams duration/overlap gives the sound I think you're talking about. Unfortunately, those cams with higher durations/overlaps also require other engine mods to perform to their full potential and will move the power curve towards higher rpm's, while sacrificing the bottom end. It's actually the cams inefficiency at lower rpm's that give it that nice sound.

 

The 254E has very high center line with 111 degrees on intake and 113 on exhaust and cam centerline of 112 degrees. You need to be below 104 centerline on the cam center line to get much of a lope. The over lap is very low on this cam which is due to the high centerline. It only has .094 lift on the intake and .102 on the exhaust during the split overlap. The cams that lope have nearly twice this much. The SE 204 for instance has .208 intake and .129 exhaust overlap and a 104 center line. The 204 will lope some on a fuel injected engine. The engines that will lope the best are actually the ones with carburetors. I think the "E" designation is for emissions. The lopey idle is actually the engine miss firing due to not getting a good mixture at low rpm. It has low vacuum at idle with the longer duration low center line cams. Carburetors work off vacuum signal at idle to draw fuel. The injectors need no vacuum to work. Hope this helps. I didn't say injected bikes won't lope, they just don't lope the same as a carb engine.

 

Thanks for that info, It now makes some sense to me. I always wondered why the FI bike are missing the bad a$$ idle sound.

 

it such a different motor the TC.
remember that shovels and pans are hemi heads, run super rich and make much less power per cubic inch.

I'll start making cd's of my panhead and selling them--- just pop it into the CD player.

mike

 

I hated everything about my Evo but the idle. With the CFR's on the twin cam it's a toss up. When actually riding the Evo doesn't compare.

 

Thanks Guys.I can tear em apart and put them back together but I don't understand the technical part of the numbers.I am doing a 107 this winter and was gonna get rid of he 254's just have'nt decided on which direction I'm goin with cams,that popped into my head last night just thought I'd ask.Was lookin at Woods and got to lookin at the specs on andrews 54 got thinkin bought that.