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[Hoist!]

Howie,
Okay I will be the stupid one and ask, what kind of tubing from the breather bolts, how long, and exactly where do you vent to ? Any pix? thanks john

Hey John, I haven't modified it yet, but the Doherty PP already has tubing connected to the Power Vents, that bolt to the head breather, and the tubing connects to the DPP Backplate. These tubes can be run directly to the ground instead of the backplate. I believe that the tubing is 1/4" or 5/8". I plan on connecting both tubes from the Power Vents to a tee, and runnng a single line down to the ground. I'd route that line behind the throttle body, between the barrels, behind the horn, and down to the ground on the opposite side, between the engine case and inner primary. Not much of the tubing would be visible that way. I hope this is clear, but when I do it, I'll get some pics of it. Hoist!

[djkak]

......I do not like is the S&S reed valves. I have several here that i would be happy to send to some one if they want to try them. But what we have found is they will sump the engine due to the reed being too stiff. We have pulled them from the 124 crate engines and have sen 5-6 hp as a increase and puking is gone.....

In late ’05 I installed a set of gear drive cams in my ’02, 103” Road Glide. When planning the job, I looked at installing the S&S crankcase vent. I didn’t have a problem with air cleaner oil carryover, even with the old style back plate; sure the air cleaner would get oily over time, but I never had oil accumulating between the pushrod tubes below the air cleaner.

I installed the S&S crankcase vent along with the gear drive cams and afterwards my machine immediately started dripping oil from the air cleaner which accumulated between the pushrods below the air cleaner.

I removed the cam plate assembly, inspected the cam chest area and discovered something interesting; first a little background. In the Pre-Twin Cam engines a full-circle airflow had to be established in order to effectively return oil collecting in the pushrod tubes and rocker boxes, where it accumulates after lubricating the valve train. This full-circle airflow although necessary, did not exist prior to the mid 1982 production machines. It is worth mentioning at this point that this airflow concept is not necessary or even possible in the standard Twin Cam engine. 

A “breather gear” valve is used on pre Twin Cam machines to control the flow of air and oil from the crankcase (flywheel area) to the gear-case cavity (cam-chest). An oil pickup in the gear-case cavity returns oil back to the oil tank. The breather gear opens on the piston down-stroke transferring oil and air to the gear-case cavity and closes on the piston upstroke, creating a negative pressure in the crankcase which is intended to draw the returning top end oil into the crankcase.

It’s funny to think about it now, but prior to mid-1981 the rocker box/pushrod tube area was not vented to anything. The pistons go up; the breather gear closes, creating a negative pressure in the crankcase and top end return, but little oil flows. The un-vented rocker boxes cause the oil flow to stop just like the Coca-Cola you are trying to suck out of an upturned bottle; the pressure drawing the oil down the return passage is matched by the negative pressure in the rocker boxes.

By the middle of 1981 production, HD realized there was a big issue with oil accumulating in the push rod tubes and rocker boxes. Their fix was to connect the bottom of the pushrod tubes to the base of the cylinders with fittings and hose. The idea was to apply a negative pressure to the bottom of the pushrod tubes on the upstroke of the pistons in order to evacuate the oil. The problem with that approach is that on the upstroke of the pistons, the same negative pressure is applied at both ends, the oil return hole in the bottom of the cylinder as well at the bottom of the push rod tubes.

By the middle of the 1982 production, the answer became clear; connect the pushrod tubes to the gear-case (cam-chest) with a passage through the tappet blocks. This allows the positive gear-case pressure up the pushrod tubes, over the rocker boxes and down the top end oil return hole in each cylinder and finally into the negatively pressurized crankcase area; full-circle.

The result of this change was dramatic and the oil flowed freely. This concept can be best illustrated by comparing the EVO tappet blocks to the Shovel units. The modified Shovel tappet blocks each have two small holes, approximately 1/8” to accommodate the air flow up the pushrod tubes. The EVO tappet blocks both have large air chambers built into them to accommodate the moving air/oil.

Enter Twin Cam oiling system and the S&S reed style crankcase vent. The S&S vent performs a similar function to the old H-D breather gear. On the piston down-stroke air and some oil mist are transferred from the crankcase area to the cam-chest. On the piston upstroke the reeds close, creating a negative pressure in the crankcase. I can relate to this; kind of warms the heart. Well there is one small detail, the Twin Cam top end oil drain passages no longer run into the crankcase area. Twin Cam top end oil is routed down the cylinder and into the cam-chest area. The air movement that was essential for good oil control in the EVO and earlier machines is no longer necessary in the Twin Cam engine.

The S&S vent increases the cam-chest pressure as well as the pressure differential between the cam-chest and air cleaner. This is significant because Twin Cam top end oil no longer drains into the crankcase flywheel area. The pressure differential that worked so well in the pre Twin Cam engines now works to promote air movement from the cam-chest area up through both the pushrod tubes and top end return passages, out to the air cleaner. Enough air/oil movement in this direction can exceed capacity of the air/oil separators resulting in oil carryover.

I removed the S&S crankcase vent, put my machine, now 113” back together and the old girl runs clean and dry.

djkak

It is my sense that the wet-sump condition in a Twin Cam equipped with an S&S vent, results from reduced return pump efficiency. The lowered efficiency is caused by the substantial increase in the pressure differential (negative crankcase pressure) between the oil return pickup in the crankcase and the cam-chest / oil reservoir. I believe that a certain amount of positive crankcase pressure would improve the return pump’s efficiency rather than reduce it; JMHO.

djkak

[Bagger]

GMR

I've read about others experiencing sumping issues too with the S&S Reed Valves and they are not compatible with the Feuling oil pump. 

Particularly with the newer bikes, most guys won't know just how much oil is being sucked into the throttle body due to MOCO's direct routing from the crankcase breathers off the head to the throttle body.  As was mentioned in a previous post, routing the breather hose into the throttle body allows an oily mist into the combustion mix of your engine.  The engine is designed to ignite a mixture of gas and air in the combustion cycle, adding a heavy oil mist to this mixture serves to greatly contribute to excess carbon formation in the combustion chambers, on piston tops and glaze cylinders as the oil burns along with the gas and air.  Obviously, this leads to an eventual decline in the performance and reliability of the motor in the long term through this and other related factors (such as fouled plugs).

Here's another tip I just picked up from Latus Harley Davidson forum.

Oil out of one cylinder would indicate it's the breather assembly in the rocker housing. Could be the O ring under the rocker support is missing, the umbrella valve is warped or unseated, blockage of the drain back holes in the rocker support, bad breather assembly gaskets or warped breather assembly.

It can also be a drain back problem from the head down through the cylinder to the cam chest. This can be checked by pulling the top rocker cover and cam cover. Then blowing compressed air either up the return channel in the cam chest or doing the same from the hole next to the exhaust valve spring (blowing down into the cam chest) to see if it is clear.

[HWYMAN1]

Hey John, I haven't modified it yet, but the Doherty PP already has tubing connected to the Power Vents, that bolt to the head breather, and the tubing connects to the DPP Backplate. These tubes can be run directly to the ground instead of the backplate. I believe that the tubing is 1/4" or 5/8". I plan on connecting both tubes from the Power Vents to a tee, and runnng a single line down to the ground. I'd route that line behind the throttle body, between the barrels, behind the horn, and down to the ground on the opposite side, between the engine case and inner primary. Not much of the tubing would be visible that way. I hope this is clear, but when I do it, I'll get some pics of it. Hoist!

Howie,
Got most of it. will print out direction and walk out to bike. I'll wait until you "engineer" the size and length of tubing before I try it though. I just was not sure which way you were going to take  it to "gravity". John

[HWYMAN1]

GMR

I've read about others experiencing sumping issues too with the S&S Reed Valves and they are not compatible with the Feuling oil pump. 

Particularly with the newer bikes, most guys won't know just how much oil is being sucked into the throttle body due to MOCO's direct routing from the crankcase breathers off the head to the throttle body.  As was mentioned in a previous post, routing the breather hose into the throttle body allows an oily mist into the combustion mix of your engine.  The engine is designed to ignite a mixture of gas and air in the combustion cycle, adding a heavy oil mist to this mixture serves to greatly contribute to excess carbon formation in the combustion chambers, on piston tops and glaze cylinders as the oil burns along with the gas and air.  Obviously, this leads to an eventual decline in the performance and reliability of the motor in the long term through this and other related factors (such as fouled plugs).

Here's another tip I just picked up from Latus Harley Davidson forum.

Oil out of one cylinder would indicate it's the breather assembly in the rocker housing. Could be the O ring under the rocker support is missing, the umbrella valve is warped or unseated, blockage of the drain back holes in the rocker support, bad breather assembly gaskets or warped breather assembly.

It can also be a drain back problem from the head down through the cylinder to the cam chest. This can be checked by pulling the top rocker cover and cam cover. Then blowing compressed air either up the return channel in the cam chest or doing the same from the hole next to the exhaust valve spring (blowing down into the cam chest) to see if it is clear.

Did not mean to internally jack your thread. but this is great info on a common problem and I may have found the cheapest answer to a problem  yet! john

[Midnight Rider]

John, agree that it might be a good solution to the problem.  With the Doherty PP, we see what is really coming out of the engine, as it is piped into the bottom portion of the backplate, and not directly into the vortex of the TB throat.  So pure liquid won't get in there (the TB) because the heavier oil tends to collect in the clear tubes until enough is there to be pushed beyond the backplate, which ultimately shows up by dripping out the bottom of the A/C.  Mine is very slight since I've allowed the oil level in the crankcase to reach it's happy point (about 1/2 quart from full), but it still pukes a bit at high running speeds.

If Howie can come up with some plumbing that doesn't look like a Monkey's A$$ sewn up with a Grapevine, I might be interested in following his lead...

[Hoist!]

If you check the left side of the bike, there's a small gap between the inner primary and the case. The only exposed line will be at the bottom of the barrels after it comes down past the bottom of the horn. I unfortunately found no good location on the right side on the '07. Maybe a SS Braided line would look better. If anyone comes up with a better "hiding spot" for this line, let me know. That was the least conspicuous way I found to route the line. You need a line size tee, or maybe increase the "bull" of the tee one size to tie the 2 breather lines from the PV's into 1 outlet. I thought that was better than running both lines directly down. Then we either find plugs for the backplate holes or put a screws into a short piece of hose left in the 2 backplate openings, and fasten with hose clamps. This is Hoist Redneck Engineering hard at work here guys! Hoist!

[dejavo]

Connect the tee behind the A C cover then run down the right front. go along lifter covers and then forward. use clear tubing. It will be almost invisable. Note- use hose clamps on all nipples if not a few heat cycles later they will leak around the tubeing.

[Hoist!]

Connect the tee behind the A C cover then run down the right front. go along lifter covers and then forward. use clear tubing. It will be almost invisable. Note- use hose clamps on all nipples if not a few heat cycles later they will leak around the tubeing.

Thanks mr. I looked at that and felt less tubing will be exposed by taking it to the left side, since you can drop between the inner primary and the case. Have you done this already? If so, do you have any pics of it? Thanks for your input. Hoist!

[HWYMAN1]

Thanks mr. I looked at that and felt less tubing will be exposed by taking it to the left side, since you can drop between the inner primary and the case. Have you done this already? If so, do you have any pics of it? Thanks for your input. Hoist!

Howie,
I would like to see this too. After your posts yesterday, i talked to doherty (josh) and of course if you check this out: http://www.dohertymachine.com/product_info.php?cPath=2_23&products_id=156&osCsid=eb672872ad26b34a26d80d49fa0cb985
they feel that you don't need to have long run off as the filter will collect any residual OIL/MIST. john

[Hoist!]

Howie,
I would like to see this too. After your posts yesterday, i talked to doherty (josh) and of course if you check this out: http://www.dohertymachine.com/product_info.php?cPath=2_23&products_id=156&osCsid=eb672872ad26b34a26d80d49fa0cb985
they feel that you don't need to have long run off as the filter will collect any residual OIL/MIST. john

John, I'm reluctant to try that, as I've used them on Evo applications and wasn't thrilled with the results. It's fine for awhile, but then the filter eventually gets saturated and it starts dripping from that filter. Air Filter or Auxillary Filter, they get wet and drip, then spray the bike at speed. That's what I'm looking to eliminate. But that filter would at least keep your Air Filter cleaner than it is now. That thing is a black mess!

Hoist!

[HWYMAN1]

John, I'm reluctant to try that, as I've used them on Evo applications and wasn't thrilled with the results. It's fine for awhile, but then the filter eventually gets saturated and it starts dripping from that filter. Air Filter or Auxillary Filter, they get wet and drip, then spray the bike at speed. That's what I'm looking to eliminate. But that filter would at least keep your Air Filter cleaner than it is now. That thing is a black mess!

Hoist!

i asked about the saturation rate and got a vague answer "it depends....", but this is their attempt at keeping any oil from air filter element. john

[Hoist!]

i asked about the saturation rate and got a vague answer "it depends....", but this is their attempt at keeping any oil from air filter element. john

Key word being "attempt". Attempts don't always work though, do they? My idea will work for sure. That's the way it's been done for years, before emmissions requirements. Hoist!

[HWYMAN1]

Key word being "attempt". Attempts don't always work though, do they? My idea will work for sure. That's the way it's been done for years, before emmissions requirements. Hoist!

your right Howie!  so now you need to retro engineer this thing and get us PIX!!! john

[Hoist!]

your right Howie!  so now you need to retro engineer this thing and get us PIX!!! john

I'm bringing the bike in Tues for some work. I'm doing it after I get it back. I'll come up with something John. Hoist!