I'm confused, (almost my natural state)

Looking through Harley's 2018 accessory catalogue and noticed the specs for the M8 cams.

While I know there are many factors, the basic old school thinking was that for a Torque cam you'd have an early Intake closing to give higher compression and therefore more bang and for a Power cam a later closing which sometimes means adding higher compression pistons to keep the squish.  I know there are other factors, lift, duration, LSA, overlap etc but the Intake closing, (so I thought) was the biggest factor.

Harley says the stock M8 (and they don't specify which one, 107, 114 or 117) has an Intake closing of 1 degree ABDC, so wow that's almost a full compression stroke.

The old TC HO 103 I believe closed the Intake at 30 Degrees ABDC, so for more torque you might install the SE255 cam with .045 more lift but importantly an earlier intake closing of 25 degrees giving you an extra 5 degrees squish over stock.

With the new M8 cams, they've specified later Intake closing times over stock. 17 degrees ABDC for the Torque cam and from 24 to 45 for power versions.

Does anyone know why the old rules (ok guidelines) wouldn't apply to the four valve M8s?

Totally new and different engine 

Yeah China I see your point about Harley bending over for the EPA with these cams.
116 torques is ok but the 97 horses is probably being held back by the cams crummy 5 degrees overlap which must be suffocating the top end.
Even the top power SE M8 cam's only giving 9 degrees overlap whereas the old SE259e runs 31 and the 266e 41 degrees.

Thanks for posting the sheet from Fuel Moto, that's one sweet torque curve. Looks positively addictive, hope the issues get sorted soon.

Hi Chriso
Yeah, I hear some guys are getting 110hp but do you know what their torque rev band/numbers are?
All depends on your riding style, but I'm usually changing gear well before peak horsepower comes along, so it's the usable torque that does it for me.

Fuel moto curve is impressive but they're a big business and their dyno graphs are generally better than punters can achieve. Not to say we all wouldn't want something like that 

Hi China, am I reading that right: some ppl are onto their M8 engine? Bloody hell.

No drag bike hilly, I rode that softy 1000 ks and it was brilliant, TQ was excellent.

Not many here are going to achieve the same numbers because most look in the Harley's accessories catalog for their parts and shop at the the Dealer.
Quite a few looking for promised results from 'flavour of the month cams' but won't give up their shit exhaust because it looks good and sounds good.
FuelMoto get results because they look at the complete package of parts.

And ' I want to make my bike go, but I don't want to lose my warranty.'  ?????

Here are some more pics, testing from HDForums

The test mule was a 2017 Road Glide Special with a 107 ci. engine. The only mods were the stock exhaust was decatted and the left pipe was ground to the radius of the collector where it extended into main collector with Fullsac 2” cores in stock muffler cans and using an Arlen Ness Stage 1 Big Sucker air cleaner.

The cams that were tested were the SE8 462, CR460, RS468, WM8-22x, TTS 100, and the TTS 150.

Spoke to Harley in Ringwood and they said pretty much the only cam they have used so far is the 585 but interestingly no dyno results yet.  Could mean people are taking elsewhere to Dyno them ,which is what I'll be doing.  Also asked them about using aftermarket cams and they pretty much said no warranty on the cam and any damage it could do, so reading into that they will blame the cams for any failure and you will have to prove otherwise.

Oh dear that's no filling me with confidence in them, yes I did tell them. I guess it must be the 447 as that is the only torque cam.

The 447 is the only choice you have with the M8s really, if you need to keep your warranty.

Thanks for the info guys

I'm loving look of that cycle Rama 460 cam! Sounds good as well. ??

Fred got a great result with my 447......119 ft/lbs at 3400rpm.

Yeah it does. And with over 110 ft/lbs up to 4500 rpm would av thought perfect for style of bike.....But yeah, I ride at mid rpm’s.....seems to me that’s what Harley’s are more about. Maybe you guys don’t.

True that. And I love it! Looking at the dyno comparisons of the after market cams though, they drop through 100ft/lbs between about 5200-5600rpm with my 447 doing same at 5200rpm. Not many managed 119 ft/lbs either..... so I guess my point is Fred did well with an EPA Cam IMO.

Yeah just trying to get my message across, as I meant. Not having a go at anyone.....appreciate the discussion.