WLDR cam set, performance increase?

Have run my 45 stock for a year now and am looking for a little more from the engine.Was looking at these WLDR cam sets on the 45 parts depot web site,it also recommends number 6 heads and a carb upgrade.
Does anyone have experience as to what sort of performance boost this will give? Is there anything else anyone would add to this setup? or is it even strictly necessary to upgrade all 3 items at once?
Hope someone can give the benefit of their experience, if not I'm sure someone will have an opinion. :-)

[kiwidave]

this is w-a-a-a-a-a-y outta my league, but if you have no luck among the knowledgeable here, try the Flatheadpower forum, I guarantee you will get a result.

http://www.flatheadpower.com/BB/view...54595d52d8ff60

[the_french_owl]

Hi Jadman,

Where to start??? Tuning side valves's not that easy and just a cam change won't do much in way of increased performance. #6 heads are a start, but you'll need bigger carb, bigger manifold, bigger inlet track cylinders as WR had, improved sparks as in Fairbanks-Morse or Wico magneto and a lot of work to gain more flow. Have a look on my site:

www.harleykrxlrtt.com

where you can have a look in the KR XLR gallery (2 of them) at the amount of relieving needed in the cylinder and the head. You should also consider getting your valves and seats to 30 degrees from 45 degrees.

As a warning, NO ONE today can make the proper convex cam lobes that the factory used to do on KR to get maximum valve opening durations. On the older WRs, the factory trick was to use flat tappets, no rollers, but each was unique and they're hard to come by. If you were to have loads of cash, go onto the Beauty of Speed site (another Frenchman site, entirely dedicated to WR...) where you can upload the drawings for these special tappets...and get more feel for what is required to get a fast side valve.

I guess the ultimate the factory got was just shy of 120mph for a Daytona trim WRTT...

All the best from Patrick

Thanks for the replies, not looking for drastic speed increases, but would like to comfortably cruise a little faster (+10mph) to keep up with modern A road speeds.
Fantastic web site Patrick, some excellent old pictures.

Regards, John.