What he said.

 

I would suspect that the 4.38" stroke of the 96" motors would have more blow by than the 4.00" stroke of the earlier 88" and 95". My high milage 95" has no blow by whatsover. I also run a full 4 quarts.

It would bother me to run a bike lower on oil to prevent blowby given that these are oil AND air cooled motorcycles.

(There are companies out there selling oversize oil sumps to aid cooling and here we have people short-filling their stock bikes!)

 

i agree with what your saying, that's the main reason i went with the big sucker, after reading tons of threads on the matter, my oil level is on the full mark, i've ran the snot out of it, and so far so good.

 

My 2010 SG w/SE Intake and Rinehart True Duals gets a fair amount of blow by on hot days. I haven't noticed any blow by on my 2012 SG w/SE Heavy Breather & Jackpot Touring Mufflers, but I doubt that I would notice it due to the way that the Heavy Breather is mounted (horizontal).

 

When I installed the Big Sucker I noticed oil in the filter and the back half of the filter housing (black plastic backing of football cover) Installed the BS and ran with that for a few weeks and decided to switch back to the stock a/c. Whne I took the BS off the was a dark spot from oil ine there also......after running the stock a/c and looking through the opening I can see oil in there as well...nothing really coming out on bike, just that oil is coming into the a/c portion

Going to try the SE a/c next...doesn't look promising huh

 

part 2.) just kidding.

I do think the Ness is a better design than the S/E ( I have been told S/E changed their design, I dunno).
i had S/e's on the Evo's and they were fine- I used about 4 of their sets over the years- but back then they were less than $100 and included a K&N filter.
I use the Ness on the current bike for cost and filter media considerations.


Blow by schmutz in the air cleaners can also be complicated by reversion.

reversion is when air/fuel comes out of the intake and collects in the air cleaner housing, and possibly mix with some oil and make a mess- the smell test will let you know if gasoline is part of this.


when exhaust gasses leave the heads and head out the pipes, pressure waves build up and travel back and forth in the pipes, these pulses can cause fuel/air mixture to come back out the intake throat at certain rpms.

at which rpm is dependent mostly on cam duration and overlap
( overlap is the time in which both intake and exhaust valves are open-- this time period is expressed in degrees, and will be briefer ( in time) at higher rpms.

and on pipe design, pipes should be a "tuned length" where the pulses from one cylinder will help to pull air/fuel into the other cylinder ( scavenging- which can give a more than 100% cylinder fill which is the advantage of a good 2/1 pipe)
the pulses are tuned in such as way that they are biased to just exit the muffler at good velocity, and keep going--- you've seen mufflers appear to "suck" air in---

depending on cam/pipes and rpm, there may be times when reversion is at it's peak.

some pipes are made for performance, some are made for "looks" or "a sound"--- in this area marketing budgets sometimes exceed R&D.
Poor pipe design can show in ways other than blued chrome- sometimes it's hard to wrap your head around mufflers causing fuel to coat your right leg

it is very difficult to design a motor that can operate well from 1000 to 6000 rpms, much easier to design a motor to run in a narrow rpm range such as a stationary motor--- this is the idea behind the chevy volt motor which runs a generator to power the electric drive once batteries are run down.--- that motor runs in a narrow rpm range and can be designed to best efficiency for fuel economy and emissions

Mike