Hammer Perf Timing Suggestion

[theMelvster6]

So I'm reading about installing a big bore kit, and I come across this on the Hammer Performance tech tips

The stock timing on all HD models is too aggressive for the increased compression that typically come with a performance engine kit. Higher compression speeds the burn and timing advance must be reduced from the factory level when installing an engine kit.

One of the biggest tuning mistakes we run into is people who run their ignition timing up (i.e. more advanced), mistakenly believing this enhances power. Nothing could be further from the truth! We have dyno tuned thousands of bikes, and the typical street hot rod Harley with 10:1 or 10.5:1 compression makes maximum power at about 30 degrees total advance. Furthermore, they like the timing brought in slowly - not all in until 4500-5000rpm. More timing than this makes the motor run hotter, lose power, and puts the engine kit at risk, so please pay particular attention to this!

Stock our Buell XBs are right around 10:1 compression...the big bore kits bump it up to 10.5:1. Anyone installed a big bore kit and retarded the timing like suggested by Hammer Performance? or do most folks just leave it alone? Most tuning info out there is on fuel maps, not a whole lot about the timing tables.

 

[mrNICEGUY]

On my understanding stock Buells have 10.5:1 static compression ratios.

Heres some interresting **** going on with timings: http://xlforum.net/vbportal/forums/showthread.php?t=1471352

 

[theMelvster6]

Yeah, that's why I was wondering. Buells are already High(er) compression than their Sportster relatives which IIRC compression is 9.5-9.7:1. I on the Sportsters just want to be safe when I do the bore kit.

 

[jetlee]

On my understanding stock Buells have 10.5:1 static compression ratios.

XB's are 10:1 static, 8.97:1 dynamic.

 

[theMelvster6]

I'm aware Buell is 10.0:1 that's why I asked the question...Lol From what I've been reading, to tune the timing you really need a dyno and some know how. I'm wondering if anyone had any issues running stock or even the race timing with the little higher CR?

 

[jetlee]

That was for mrNICEGUY, who was under the impression that XB's were 10.5:1 stock; that's why I quoted him.

You also want a knock sensor so you're not relying on just your ears to listen for ping, especially on these noisy-ass engines.

 

[theMelvster6]

Yeah, I got what you were saying. I just wanted to be clear on what I was asking. You know these threads tend to get replies and never actually addressing the posted question.