| Author | Message | ||
     V74 |
Went to my local HD dealer the other day,while there i had a look at the bikes and noticed an oil drain system on the XR1200 coming from the rear of the cylinder heads,draining into the top of the cam box,the system looked ugly to me but got me thinking, on my m2 i have put the XB breather valves into the rocker covers,the standard head breathers where left in place linked by one piece of tube,a aluminum feeler gauge cap from an old triumph is the correct thread to fit the crank sighting hole,replacing the alen bolt,i drilled one in the centre to see if it would be viable to put a connection in it to feed the cylinder head breathers from to aid oil drainage,but looking at the XR1200 made me think about draining to the cam box??? i saw an oil drain system in an issue of battle2win where oil drainage was taken from the front of the cylinder heads,do,s anyone have any measurements as i have been thinking of this system for some time and need to know exactly where to drill. Just weighing up my options at the moment,anyone have any ideas/comments??? | ||
| Buellistic |
This oil drain from the heads to the crank case is OLD RACING TECHNOLOGY that has made it to the SHOW ROOM FLOOR !!! You want to get the oil out of the heads fast, especially around the intake valves ... | ||
| Natexlh1000 |
So the XR1200 engine doesn't use the pushrod tubes as a drain? I'm confused. | ||
| V74 |
Hi buellistic,i have your 101 e.mails,have learned a lot from them,yes,i want to drain the oil out of the cylinder heads asap which is why i posted this thread,i know the oil can act as a heat dump also even though i have the XB breather valves in the top of my rocker covers i still get some oil blown out of them and would like to minimize this,i read an article in MCN that harley are going to make sportster heads semi oil cooled around the exhaust valve?an oil drain from the front of the cylinder head would be a good and similar up grade. | ||
| Buellistic |
The reason for the SEMI-OIL COOLED HEADS is 14.7 to 1 fuel air ratio for air cooled engines is TOO LEAN !!! Back in the day, the RACERS realized how hot the heads got on the race engines and came up with getting the oil out of the heads "ASAP !!! The exhaust valve spring pocket can be improved, "BUT" a drain back needs to be added to the intake valve spring pocket ... Not only does the oil lubricate, IT ALSO COOLS an air cooled engine ... Since the BUELL EVO SPORTSTER engine cam cavity oil drains into the top of the oil pump for return to the oil tank it helps keep that oil away from the flywheels and IMHO the best place to run the drain back fittings ... | ||
| V74 |
Thanks,there's three things there that i did not know,i think for now i will use the standard breathers as oil drains and route them into the top of the cam box not to the crank sighting hole as previously planned. | ||
| Essmjay |
If you try to use the breathers as oil drains you will mostly get splooge, which is why most of us run that crap onto the ground or a catch-can, not back into the engine. | ||
| Buellistic |
DO NOT TRY TO CONNECT YOUR HEAD BREATHERS INTO CAM CAVITY AS THE MUST BE RUN TO A CATCH CONTAINER !!! For "SAFETY" you should run the transmission breather hose to a catch container because if you ever get oil from it on your rear tire you will understand ... | ||
| 46champ |
When you drill the heads for drain back tubes you are draining the left side of the rocker box area. The pushrod tubes still drain the right side of the rocker boxes. The other thing you are getting rid of is oil draining on the flywheels causing increased drag, all Evo Sportsters drain the left side (valve) side of the head thru ports in the head and cylinder onto the left flywheel. | ||
| Buellistic |
From 1998 on the oil was removed from the cam cavity byway of the 26204-98 BUELL part number oil pump which was the 26204-91A Harley-Davidson part number when the H-D SPORTSTER engines started using this same design oil pump from 2000 on until the oil pump was up-dated to the XBRR style oil pump as on the 2008 BUELL Models ... | ||
| V74 |
Very interesting. First the transmission breather,I had the crank seal go a few years ago(dealer told me it was not the seal but i had over filled the primary)I replaced the seal and rerouted the breather hose to the right side of the bike. Second after reading about changing the oil drain system in Battle2win i was intrigued and seeing a racing s1 at cadwel park in 2000 at a buell meet with the same system i wondered if i could do something similar.having put XB breathers in the top rocker covers(i am planning a catch can for these) and still getting some oil blown out rather than blocking up the standard breather holes with solid bolts i thought i could put them to use as oil drainage,my first thought was to drain to the crank sighting bolt hole but now the cam box is more likely,now i am being told not improve the cylinder oil drain system?i just thought it was a good idea to get the oil out after it had done its job asap as to not let it become a heat dump where high heat is not wanted,particularly the rear cylinder where it causes problems???and oil drag on the flywheels would be reduced,i have seen on S1 dragrace only(NOT street)the cylinder head breathers are connected to the exhaust for maximum drainage,so is better oil drainage than standard viable(not the extreme of the drag bike)????????? | ||
| Natexlh1000 |
I've seen the breather in the exhaust thing too. I would be concerned with putting a positive pressure (exhaust) on the breather. Of course, the racer you saw probably put his breather near the end of the open pipe where there was more of a scavenging vacuum type of thing going on, right? The one I saw was on a chopper and it was about 1/3 of the way to the end of drag pipes. Didn't seem smart to me at the time. | ||
| V74 |
The drag bike was in battle2win it had the breathers connected half way down the front exhaust tube and had a forcewinder without the filter and a bar where the shock should be,i think if i remember right it was a US bike racing in Oz.will have to re read my battle2win mags sometime. |
