117 in. case breathing

[norton74]

Mike,
What can OR should be done to improve crankcase
breathing? Engine is still apart on bench. 08 Dyna series.
117in Axtell cyl & 20 degree pistons 10.7 cr
Baisley Hybrid with 2.05 intake valve heads
Wood TW9BG cam
HPI 55 Max Flow T-body
S&S Darkhorse crank with timkens
Billet cam suport .
Also what tappets would be recommended ?
Thanks, Tony

[Mike]

Sounds like a nice build. We machine the cases for a reed valve to be installed and can do so if cases are sent here. How much it helps has not been determined because of the inablity to do true A/B testing. We install them in all of our aggressive/big ci motors. It's proprietory but similar to what's done in Buell/XL motors. It is NOT the S&S valve. Cost to machine for the valve only is 175.00 (mostly setup). We normally do some other cases mods for oil control at the same time and the total typically is 225.00 for all (including case cam clearancing).

We recommend STOCK "B" tappets. Far less failures (based on numbers installed) than anything else used.

[norton74]

Mike, How long would the reed machining take after its
in your shop. I have most if not all the other machining you
mentioned. I have the crank already installed in Left case half.
If im picturing this correctly, you would only need the right case.
Is this correct ? I have reinstalled the piston jets and thats the
stage im at now.
With out the reed valve mod, what kind of side effects could
I experience if any. I was really looking for a mod I could make
as I am located 3 time zones away, but still considering it.
The "B" tappets ? Does that mean the B engine ? If so what
is the part # so I get the correct ones.
Thanks,Tony

[Mike]

Right case half only if not knife edging the scrapers. Expect 1 week in shop. The "B" refers to the lifter revision, part number 18538-99B. Stock for all big twin TC's.

We feel the mod helps make more hp since the pistons should have less resistance on the down stroke. The air under the pistons can more easily escape or the cases can handle the increased volume of air from the motor size increase. Measurements of the square inch open area of the right side roller bearing indicated a need for this added capacity (the rocker cover oil returns were not added as these may be full of oil).

[norton74]

Mike,
Would the B tappets be stock in 08 models ?
If so then I should be OK on them.
Thanks alot for the info and Im trying to decide
on the reed
Tony

[Mike]

Yes, they are stock on an 08. You can use them if you have less than 7000 miles on them. If more, we recommend replacing with a cam change so parts start life new together.