M 8 Head Breathers

[Jack Klarich]

After rerouting the breathers I still have a bit of oil in the throttle body, not much but IMO there should be none
Wonder if The MOCO is going to address this?

[vito]

After rerouting the breathers I still have a bit of oil in the throttle body, not much but IMO there should be none
Wonder if The MOCO is going to address this?

Not disagreeing but I don't understand the benefit or problem. Most manufacturers have been routing the breather into the intake since the 1960s, thanks to EPA. My 1990 Evo was the same and went nearly 200,00 miles with no problem traceable to this. Could even be that the MOCO engineers planned on this small amount of oil for top end lubrication.

[rhino 2]

I solved the problem if you want to call it one.... Just by not trying to keep the oil at the full mark.. 1/2 Quart low and no blow-by...Did that with my Spyder 'Sportster And now my Tri-Glide..

[DK Custom Products]

MoCo cannot do anything about it. It is the nature of an internal combustion engine, it has to expel the crankcase air somewhere.

The EPA has said it cannot be into the atmosphere, it has to be back into the engine.

The problems are many-

Builds up carbon on the pistons (see pics below)

Can gum up the sensors in the throttle body, eventually causing failure, or more likely, just a loss in efficacy, resulting in a poorer running engine.

Increases compression ratio, so the tune that used to be good no longer is. This is why you hear of guys saying their bike ran fine, then after xxxx miles it wasn't running so good, and then they pay to have it re-tuned.

The air is hot that is being fed back into the intake. Internal Combustion Engines 101- The cooler the intake air, the more power and economy you get.

The air is mostly oxygen depleted exhaust gasses that went past the rings and then out the breathers, into the intake. The main purpose of mixing gasoline with air is that there is oxygen to mix with the gas to create power. The oxygen depleted air is just taking up space, reducing power & reducing fuel economy.

Will an engine run, and for many miles, while feeding this hot, oily, oxygen depleted air into the intake. Absolutely. But it will not run anywhere near as strong or as economically as it would without it.

Charts, more photo's & information at this LINK.









Kevin

[gerald martin]

although I had no problems with blow by on my freewheeler I still took Kevin's advise and installed an external breathing system on my stock oil filter. After a sort amount of time I noticed an unbelievable increase in the way the trike ran. It idled smoother, ran much better and my gas mileage increased a small amount. Because I vented the breathers to the atmosphere I do have a yellowish drip of something on the floor after a ride so I am going to install one of th DK oil catch cans

[Jack Klarich]

The catch can is the best idea IMO
I have one on now

[bib/bob]

the pic's was enough to convince me, i sent DK a couple pics of my setup to get the right one, and beings I'm getting close to 8k, so i have got an order in.

[Jack Klarich]

although I had no problems with blow by on my freewheeler I still took Kevin's advise and installed an external breathing system on my stock oil filter. After a sort amount of time I noticed an unbelievable increase in the way the trike ran. It idled smoother, ran much better and my gas mileage increased a small amount. Because I vented the breathers to the atmosphere I do have a yellowish drip of something on the floor after a ride so I am going to install one of th DK oil catch cans

The yellow oily mist has water condensation in it 1 more reason to vent the heads IMO I have been doing this since the Evo days
and do belive after all the years of wrenching the EPA may have laws does not meen they are good laws JMO

[geezerglide11441]

MoCo cannot do anything about it. It is the nature of an internal combustion engine, it has to expel the crankcase air somewhere.

The EPA has said it cannot be into the atmosphere, it has to be back into the engine.

The problems are many-

Builds up carbon on the pistons (see pics below)

Can gum up the sensors in the throttle body, eventually causing failure, or more likely, just a loss in efficacy, resulting in a poorer running engine.

Increases compression ratio, so the tune that used to be good no longer is. This is why you hear of guys saying their bike ran fine, then after xxxx miles it wasn't running so good, and then they pay to have it re-tuned.

The air is hot that is being fed back into the intake. Internal Combustion Engines 101- The cooler the intake air, the more power and economy you get.

The air is mostly oxygen depleted exhaust gasses that went past the rings and then out the breathers, into the intake. The main purpose of mixing gasoline with air is that there is oxygen to mix with the gas to create power. The oxygen depleted air is just taking up space, reducing power & reducing fuel economy.

Will an engine run, and for many miles, while feeding this hot, oily, oxygen depleted air into the intake. Absolutely. But it will not run anywhere near as strong or as economically as it would without it.

Charts, more photo's & information at this LINK.









Kevin

Kevin, I am collecting the debris from my catch can in a plastic bottle (small pill bottle), and if everyone could see what I have collected that would have went into the TB I would say that they would be absolutely amazed. I carry it in my tour pack and show anyone at the local dealership that shows an interest and they are quite taken back by what is going into their TB.

It is a muddy looking gooee mess with some water mixed in. The consistence is like a tan/brownish pudding. Discussting!! And believe it or not, I can feel the increased (seat of the pants) performance. It idles better, runs better and my mileage is pretty good giving that it is a high performance 120" motor. I really like the idea of having a drainable catch can on the system as well. Draws a lot of attention also since I have it mounted on my left side front down tube. This actually starts the conversation as most people want to know what that "can/filter" is for.

Ride safe, and still looking forward to your reviews/comments on the front suspension components you are testing.

Roger

[DK Custom Products]

Hey Roger!

Can you post some pics?

If it is ok with you, I would like to use 1 of them in a technical reference article I'm doing for the new website.

Yeah, suspension testing is coming along. The riding part is fun (did about an hour of it today), pulling the forks and swapping everything out time after time...not so much.


Kevin

Kevin, I am collecting the debris from my catch can in a plastic bottle (small pill bottle), and if everyone could see what I have collected that would have went into the TB I would say that they would be absolutely amazed. I carry it in my tour pack and show anyone at the local dealership that shows an interest and they are quite taken back by what is going into their TB.

It is a muddy looking gooee mess with some water mixed in. The consistence is like a tan/brownish pudding. Discussting!! And believe it or not, I can feel the increased (seat of the pants) performance. It idles better, runs better and my mileage is pretty good giving that it is a high performance 120" motor. I really like the idea of having a drainable catch can on the system as well. Draws a lot of attention also since I have it mounted on my left side front down tube. This actually starts the conversation as most people want to know what that "can/filter" is for.

Ride safe, and still looking forward to your reviews/comments on the front suspension components you are testing.

Roger

[Jack Klarich]

Hey Roger!

Can you post some pics?

If it is ok with you, I would like to use 1 of them in a technical reference article I'm doing for the new website.

Yeah, suspension testing is coming along. The riding part is fun (did about an hour of it today), pulling the forks and swapping everything out time after time...not so much.


Kevin

I would but mine does not collect the muddy mess for a while, in other words short trips cause the water vapors to mix with the oil, I mostly ride longer trips tho I have had the same muddy yellow drip a few times it is just nature of the beast, remember the old Chevys with the road draft tube before a PCV system same deal

[DK Custom Products]

Yes, riding habits (lots of low RPM heavy throttle, lots of high RPM) create more oil blow-by, type of oil, high heat, level of oil in tank...all these thing affect how much oil blow-by there is. Shorter trips, where the engine does not get fully heat soaked, will get more condensation mixed in with the oil.

But there is always a certain amount of oil coming out of the breather bolts (it is impossible for it not to be so), how much, and if water is mixed in, are the variables.

Here is a pic Roger sent me (thank you) of what he drained out of his EBS catch-can.




Kevin

[geezerglide11441]

Yes, riding habits (lots of low RPM heavy throttle, lots of high RPM) create more oil blow-by, type of oil, high heat, level of oil in tank...all these thing affect how much oil blow-by there is. Shorter trips, where the engine does not get fully heat soaked, will get more condensation mixed in with the oil.

But there is always a certain amount of oil coming out of the breather bolts (it is impossible for it not to be so), how much, and if water is mixed in, are the variables.

Here is a pic Roger sent me (thank you) of what he drained out of his EBS catch-can.




Kevin

Kevin, one other thing that I think contributes to MY blow-by is the fact that with this performance engine, my oil pressure at cruise is about 50 - 52 lbs and I also have the SE11/2 quart extra oil pan, but I keep the level about 1/2 quart down from the full mark. For anyone who is on the fence regarding the installation of one of the EBS systems, hopefully this will "push them off the fence"!! I can tell from the seat of the pants dyno that it is running smoother/stronger and cleaner!!

Roger

[Jack Klarich]

Kevin, one other thing that I think contributes to MY blow-by is the fact that with this performance engine, my oil pressure at cruise is about 50 - 52 lbs and I also have the SE11/2 quart extra oil pan, but I keep the level about 1/2 quart down from the full mark. For anyone who is on the fence regarding the installation of one of the EBS systems, hopefully this will "push them off the fence"!! I can tell from the seat of the pants dyno that it is running smoother/stronger and cleaner!!

Roger

I agree, I run mine the same way
The internal combustion engine is always going to produce the water vapor, bUT do you want this mess robbing you of power going thru your intake my answer after turning wrenches all my life is NO
Short trips cause more water vapor to build up faster, the oil does not reach a high enough steady temp to burn it all off, you can see this by running your car engine short trips and look @ the oil filler cap I bet if the rings are not worn you will have white frost on the bottom of the cap jMO

[vito]

I agree, I run mine the same way
The internal combustion engine is always going to produce the water vapor, bUT do you want this mess robbing you of power going thru your intake my answer after turning wrenches all my life is NO
Short trips cause more water vapor to build up faster, the oil does not reach a high enough steady temp to burn it all off, you can see this by running your car engine short trips and look @ the oil filler cap I bet if the rings are not worn you will have white frost on the bottom of the cap jMO

I'd only add a couple thoughts. First, on the pictures of pistons. having wrenched professionally for years, some before thee advent of EPA, I have seen both kinds of carbon on pistons B4 breathers got routed back into the intake. IMHO it is more a function of how the motor is used. Too little hard acceleration by little old ladies causes the soft carbon shown in picture 1 breather or not. Second, use a catch can if you change the factory system - it is very irresponsible to dump the mess onto the street.

[DK Custom Products]

Those two photos are of the same engine, with the same rider, riding the same way. Difference is the EBS.

On a modern HD, I am not sure you could ever get that much build up, no matter how it was ridden, if it had an EBS.

Older cars, or even motorcycle engines, with different oiling systems, possibly bad valve seals, leaded gas, etc., yep, they could get carboned up like that...but methinks a modern EFI HD could not.

Kevin

I'd only add a couple thoughts. First, on the pictures of pistons. having wrenched professionally for years, some before thee advent of EPA, I have seen both kinds of carbon on pistons B4 breathers got routed back into the intake. IMHO it is more a function of how the motor is used. Too little hard acceleration by little old ladies causes the soft carbon shown in picture 1 breather or not. Second, use a catch can if you change the factory system - it is very irresponsible to dump the mess onto the street.

[Jack Klarich]

I'd only add a couple thoughts. First, on the pictures of pistons. having wrenched professionally for years, some before thee advent of EPA, I have seen both kinds of carbon on pistons B4 breathers got routed back into the intake. IMHO it is more a function of how the motor is used. Too little hard acceleration by little old ladies causes the soft carbon shown in picture 1 breather or not. Second, use a catch can if you change the factory system - it is very irresponsible to dump the mess onto the street.

I run mine initially open to make sure it is working correctly, then I use an air tool in line oiler

like this for my catch can, do not hook it up backwards

[vito]

Those two photos are of the same engine, with the same rider, riding the same way. Difference is the EBS.

On a modern HD, I am not sure you could ever get that much build up, no matter how it was ridden, if it had an EBS.

Older cars, or even motorcycle engines, with different oiling systems, possibly bad valve seals, leaded gas, etc., yep, they could get carboned up like that...but methinks a modern EFI HD could not.

Kevin

I'm surprised and don't necessarily disagree. EPA has mandated too many harmful bandaids trying to fix a problem caused by overpopulation - but that's a bigger issue. Venting the crankcase/heads to the air is surely better. The only question is "Is it worth the bother for the average rider?". There YMMV. The important thing in my mind is that those who do so use a catch can rather than dump the oil/water mix on the pavement. Suggest you include a catch can in your kit.

[DK Custom Products]

All of our kits use a catch-can or a filter. For most, the filter will hold the gunk in it for 3000-5000 miles, at which point it should be cleaned out to allow it to accumulate for another 3k-5k miles.

The benefits, even to a casual rider, are numerous, as listed above in post #4 and explained in more detail at this LINK, which also has charts showing the power benefit, for those interested in more power.

By using an EBS, just that, will result in a Stable tune, which most (even the average rider) will Not experience, sans an EBS.

The interesting thing we have discovered over the years is that there is usually no One modification that produces a Big result. It is usually a synergy of many smaller mods that result in significant improvement.

Almost without exception, our Performance Plus Stage I Upgrades will have a Harley producing more power than other Harley's that have had a typical Stage I AND Stage II upgrade. This is because we pay attention to all the little things...and those little things add up to a big benefit.

Nice Side Benefit: Our Performance Plus Stage I Kit usually cost less than a Typical Stage I kit, and Far Less than the typical Stage II upgrade.


Kevin

I'm surprised and don't necessarily disagree. EPA has mandated too many harmful bandaids trying to fix a problem caused by overpopulation - but that's a bigger issue. Venting the crankcase/heads to the air is surely better. The only question is "Is it worth the bother for the average rider?". There YMMV. The important thing in my mind is that those who do so use a catch can rather than dump the oil/water mix on the pavement. Suggest you include a catch can in your kit.

[bib/bob]

All of our kits use a catch-can or a filter. For most, the filter will hold the gunk in it for 3000-5000 miles, at which point it should be cleaned out to allow it to accumulate for another 3k-5k miles.

The benefits, even to a casual rider, are numerous, as listed above in post #4 and explained in more detail at this LINK, which also has charts showing the power benefit, for those interested in more power.

By using an EBS, just that, will result in a Stable tune, which most (even the average rider) will Not experience, sans an EBS.

The interesting thing we have discovered over the years is that there is usually no One modification that produces a Big result. It is usually a synergy of many smaller mods that result in significant improvement.

Almost without exception, our Performance Plus Stage I Upgrades will have a Harley producing more power than other Harley's that have had a typical Stage I AND Stage II upgrade. This is because we pay attention to all the little things...and those little things add up to a big benefit.

Nice Side Benefit: Our Performance Plus Stage I Kit usually cost less than a Typical Stage I kit, and Far Less than the typical Stage II upgrade.


Kevin

what do you suggest to use to clean the filter with