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Crankcase Venting 101

"An automotive air pump check valve serves the purpose nicely @ a fraction of the HD cost. One may purchase KEM part number 174-176 or cross reference said number to that of your local automotive vendors inventory (Kragen, etc.) . "

i don't know what a KEM number means? it's not a term i understand. i would like to get some check valves, can anyone put me onto one of those web sites that does this kind of thing?

regards

Taffy
 
cypher said:
Air Injection Check Valve (Jaguar # C34017) All XJS with V12
(Note: This is a GM part. It is used, for example on a 350 cu inch Chevrolet V8.
A1 Cardone A42-103
AC Delco 2332530
Automotive Electronics 17001
Big A 46-1005
Borg Warner CV8
Filko 45-105
GP Sorenson / Guaranteed Parts 779-2929
Kem 174-176
Motormite 55050
NAPA 2-2900
Niehoff FE-476
Sound Solution 15903
Standard / Carquest AV7
Tomco Ellis 17001
Walker 15903
Click to expand...

kem is just the make.

above are alternative part numbers for the same thing, thats already in this thread.
 
i think we already ordered thanks bob! we went for the jaguar parts. we need something classy on the outfit!

regards

Taffy
 
Very interessing subject and amzing how much theorie is behind a simple vavle.

Dale wrote:
"Hi Rancheroracer,
Crankshaft cavity scavenging operates via pressure differential between the main crankcase and said cavity. By installing a check valve in the engine vent line a vacuum is created in the entire engine assembly, however, the pressure differential between the crankshaft cavity and main crankcase remains the same.

Hope this helps. "

This partially answered the question I wanted to post: how about the function of the reed valve?
I'm not sure but doesn't the piston/reed-valve-combo acts as an oil pump to splash oil onto the distribution chain, wich in turn brings the oil up to the camshaft for lubrification purposes? Is this affected in any way?
Or perhaps I see it completely wrong, wouldn't be the first time :(

Cheers,
Adriaan
 
hello adriaan

the reed valve is simply there to get oil away from below the crankshaft once it has done it's job of oiling all the mains, big end and piston. as the piston comes down there is a massive increase in pressure below the crank and the reed valve is effectively blown open and air driven out taking oil with it each time.

the general whizzing of gears just touching the top of the oil in the left cover means that everything in the left cover is getting enough oil to lubricate it but it's from here that the increase in pressure goes up the chain tunnesl and out the engine breather.

all very clever!

regards

Taffy
 
there is also the effect of the big hole up near the intermediate shaft

without that big hole and with a sealed bearing on the intermidiate shaft there should be little performance to gain from a checkvalve perhaps?

as is like taffy said the reedvalve is just a scavanging pump not really a crankcase vacuum maker casue of all the oles
 
The lower the air pressure in the gearbox the slower the oil can get pressed through the wire gauze filter into the oil pump.
Also I don't think that you want vacuum in the rocker box because it takes some air to carry the oil mist to those hard to get to places. In vacuum there is nothing to carry the oil mist droplets and they just fall down immediately because of gravity.
 
vent

you guys need something to do,my 97 fc501 has been just fine the way it came from the factory,i have been racing motocross with it since new .change the oil,adjust the rocker arms and ride!i think the engineers at husaberg probably know more than me
 
RE: vent

"just fine" describes a great many things relating to the level of design and engineering found in most motorcycles

such is well below the level I am required to work at in my day job if I want to keep it longer than a week.

as a result I have plenty to do :D
 
Not one for the quantum mechanics of the internal volumetric co-efficient properties of the Husaberg, I have a heater hose on the vent from the front of the rocker cover with the carby side blocked off. My 06 FE550 was setup from factory for Adam Lees A4DE that year with the same pipe fitted. No check valve or even a filter. Only a slight discharge out the pipe after 5 hours of riding. That bike had done 220hrs when I sold it & was still going like a train. No vacuum or pressure buildup without having to induce the oily vapour through the carby. I'll stick with it for sure.
 
crankcase vent

last post was a good one,all you have to do is vent the rocker box cover,nothing fancy,as for me i will just ride my berg,you other guys can keep re-inventing the wheel,i had a friend that told me if he hadnt chosen to play music in clubs for a living he could have been a rocket scientist,think about it,no wait dont
 
Skully, could you not just go and ride it then...
Click to expand...

:D

perhaps reading the thread from the begining and brushing up on the background of the OP might be interesting.

no one is reinventing the wheel skully. there are plenty of engineers who with the benefit of hindsight after years of tinkering know enough to improve on OEM designs.

thanks to the OP and others you can buy better camshafts, better carb needles, better main bearings, better valve springs .... ...... all things that as OEM either break or don't work properly.

the primary function of a reed valve on the hole i mentioned is to encourage oil flow to the crank. such may be useful if you wanted to extend the life of the big end bearing in a 628 engine.

mine was just starting to go at 200hrs. if it hadn't then like yourself I would have no reason to modify anything.

the addition of a high speed air check valve to the breather doesn't alter the pressure differential between the crank and the gearbox.

I broke 2 gearboxes and 2 rear hubs in 2 years, hub problem fixed by running talon hubs, they don't break. I am working on the gearbox.

with your approach to the issue i'd still be running oem hubs and still breaking one every 5000km.
 
crankcase venting,duh

sounds like i just dont know anything about bikes,ill be damn must have spent the last 40 years as a certified cycle tech and factory suzuki and yamaha race mechanic for nothing.but i guess they do it different down under,good luck my friend maybe you should get a job for husaberg and help them out,and please post more smart *** remarks bushwacker
 
The wheel is one of the better inventions ever made. So no wonder that people find it worth to reinvent over and over again, it is that good. :wink:
 
Re: crankcase venting,duh

skully said:
sounds like i just dont know anything about bikes,ill be darn must have spent the last 40 years as a certified cycle tech and factory suzuki and yamaha race mechanic for nothing.but i guess they do it different down under,good luck my friend maybe you should get a job for husaberg and help them out,and please post more smart *** remarks bushwacker
Click to expand...
40 years as a bike tech and 3 posts on this forum.... Bushmechanic was amazingly reserved in his response, given you obvious ignorance of the information within this one thread, and Dale Lineweaver's and his own contributions to this site.

Lighten up, Francis.
 

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