I drilled the oil return holes to 1/8" and used Cyco umbrella seals and foam. I also added a couple of hoses and an external breather filter. Seems to work great even at higher rpms it doesn't really spit oil. The biggest thing that helped my problem was going back and aligning the oil pump because I forgot to align it when I put it back together last spring 😂 Breather is above the air filter.
Wait til.the nasty crap draining back down the hoses and into the passages sets up and causes a blockage while its parked. Seen it happen. The pressure will build and find a way a way out eventually... Question is where?
I had a filter at the end of my hose running DOWN that got clogged from the nasty **** setting up in it. Blew 3 sets of rocker cover gaskets in 2000 miles on my sporty and started weeping from a head gasket on the dyno before I realized it was crankcase pressure building from the clogged filter. No more filters at the end of my hose. They aren't necessary anyway. What are you filtering? Breather valves are one way...out. Suppose to be anyway.
The guy I know that tested didn't test for power/performance increase but crankcase pressure or lack of it. These particular reed valves maintained a constant crankcase vacuum. The stock umbrella valves were up and down pressure when new. Presumably because they allow air back in briefly before closing. What happens to them after being exposed to the high heat of one of the hottest places in the engine? Its a dumb design . There's a reason every other big twin with 2 cylinders going up and down at the same time or nearly the same time use reed valves. Feel free to use the stock umbrellas if you think they're all that. They are obviously considered a maintenance item. That's why replacements come in gasket kits.
Do you know how much crankcase pressure you have? Would you agree or disagree no positive pressure is best? There's a reason race engines run vacuum pumps and it's not cuz they look cool.
I don't have to run my oil a half quart low either. In fact ATM it's slightly over the full mark. Not a drop hits the pavement where I park.
Running low on oil isn't a fix for poor crankcase breathers or oil pump scavenging for that matter.
A read valve will not create a constant vacuum.. There has to be some positive pressure to push out the excess volume from ring leakage.. Both valves close as the pressure drops. Does the reed close faster? Prove it.. The HD valve has to be made from Viton to work due to temps. Buna is only good to 250F and any time at that temp and they harden. If not viton, it needs to be mounted externally. Buy the cheap stuff and they'll get hard.
No positive pressure is best but you need a vacuum pump to achieve it.. One way valve don't cut it. Things like total seal ring might reduce the need.
I've not measured crankcase pressure.. Have you?
Before you get into your experimentation on one a sporty, there are things to note.. The top covers on evos sucked and always leaked. HD actually use a hole between atmospheric and crankcase next to the valve so the valve never stops all the backflow.. I believe it is for sucking the oil that makes it past the valve. TCs don't have it..
Do you have a bagger? Thought it was a softail. Softails run fine full up.. Try a bagger factory bore at say 80 for 50 miles. I really don't have any issues running full on a dyna at high speed either.. Ring seal is important. Pushing a bagger with big fairing and lower takes more HP.
Wait til.the nasty crap draining back down the hoses and into the passages sets up and causes a blockage while its parked. Seen it happen. The pressure will build and find a way a way out eventually... Question is where?
I had a filter at the end of my hose running DOWN that got clogged from the nasty **** setting up in it. Blew 3 sets of rocker cover gaskets in 2000 miles on my sporty and started weeping from a head gasket on the dyno before I realized it was crankcase pressure building from the clogged filter. No more filters at the end of my hose. They aren't necessary anyway. What are you filtering? Breather valves are one way...out. Suppose to be anyway.
While I don't care for the mounting either. I've had no problem running the hoses up on a TC.. Need to remember, Evos have the extra hole to allow for suck back..
They don't show the actual hole here but it's under the umbrella assembly and through the rocker arm support plate.
It's a small hole and I just used an 1/8" bit. I don't really like the breather above the air filter either but I was experimenting with the location and realized I cut the hoses too short to put it back under the air filter 🤔
[QUOTE=Road Slug;21338662]Anyone have any pics of this oil drain hole mod?[/QUOTE]
Last edited by Mi-Infidel; 08-12-2023 at 11:39 AM.
Reason: Clarity
A read valve will not create a constant vacuum.. There has to be some positive pressure to push out the excess volume from ring leakage.. Both valves close as the pressure drops. Does the reed close faster? Prove it.. The HD valve has to be made from Viton to work due to temps. Buna is only good to 250F and any time at that temp and they harden. If not viton, it needs to be mounted externally. Buy the cheap stuff and they'll get hard.
No positive pressure is best but you need a vacuum pump to achieve it.. One way valve don't cut it. Things like total seal ring might reduce the need.
I've not measured crankcase pressure.. Have you?
Before you get into your experimentation on one a sporty, there are things to note.. The top covers on evos sucked and always leaked. HD actually use a hole between atmospheric and crankcase next to the valve so the valve never stops all the backflow.. I believe it is for sucking the oil that makes it past the valve. TCs don't have it..
Do you have a bagger? Thought it was a softail. Softails run fine full up.. Try a bagger factory bore at say 80 for 50 miles. I really don't have any issues running full on a dyna at high speed either.. Ring seal is important. Pushing a bagger with big fairing and lower takes more HP.
Yes I have measured crankcase pressure. It's up and down like a yo yo with the stock breather valves. Not the case with this reed valve. Don't use it. I could give a ****. Its a far better one way than the umbrella valve. I don't have to run my oil a half quart low to keep from puking out the breathers. I won't go back to the umbrellas that's for sure.
Don't tell me about vacuum pumps. I ran an e!ectric pump on my jag. It kicked on and off at certain inHg. At idle it wouldn't run. Full throttle it would.
Oh and my Evo top covers never leaked again. Crankcase pressure is the number one cause of oil leaks.
Yes I have measured crankcase pressure. It's up and down like a yo yo with the stock breather valves. Not the case with this reed valve. Don't use it. I could give a ****. Its a far better one way than the umbrella valve. I don't have to run my oil a half quart low to keep from puking out the breathers. I won't go back to the umbrellas that's for sure.
Don't tell me about vacuum pumps. I ran an e!ectric pump on my jag. It kicked on and off at certain inHg. At idle it wouldn't run. Full throttle it would.
Oh and my Evo top covers never leaked again. Crankcase pressure is the number one cause of oil leaks.
If it didn't go up and down with the reed valves, the gauge was broke..
Add:
On a bagger?
You ran the test on your Heritage?
Last edited by Max Headflow; 08-12-2023 at 05:23 PM.
Rocker plate hole.. I do only the rear hole on the rear and front hole on the front.. As the are the lower holes. HD does 2 doe the rocker supports are the same front to back.. Don't need to be.
Well, I’m knuckle deep into this, and I cannot locate TDC/ overlap on either cylinder.
Rear tire lifted, trans in 6th gear.
I can rotate the tire, but neither set of rockers or valves moves.
I even tried to slip a 0.0015” feeler gauge between the rocker and the valve end while rotating the tire; no dice.
I think I’m going to have to remove the primary cover and rotate the crank itself.
Jeezus, NOTHING on this project has been easy-peasy.
I’m especially glad that I’m not paying myself a shop rate! 😂
08-12-2023, 06:44 AM
