air cleaner blowby

[dutch]

I have a TC88 to which I have added S&S 510g cams, gear drive, S&S breather valve, and Fueling standard lifters. Problem?oil breather carryover into air cleaner. Will the LMR 2 oil bypass spring cure the problem? What does the spring do?

[dutch]

Forgot to include that I also have a stock oil pump and support plate.

[Mike]

The LMR-002 spring increases oil pressure by 15% to provide for a more solid lifter with heavier valve springs used with high lift cams. This is to reduce the potential for lifter noise with these combo's. The spring itself would not address a carryover problem. I hate to say it, but the first thing I would do is remove the S&S breather valve (assuming it is the crankcase reed valve). This valve can cause serious wetsumping which in turn can result in increased carryover (we have a number of examples in our dyno library under tests and compare). Wet sumpping can also be caused by and incorrectly aligned oil pump (earlier models with the "A" pump). We have yet to see any benefit from running the S&S valve, including decreased carryover. To date we have not found a 100% guarunteed fix for bikes with chronic carryover. The aftermarket "fix's" have yet to prove successful. Sometimes it can be a function of the combination cam overlap, exhaust backpressure and riding style (spending a lot of time at a specific rpm/throttle position/load vs. another rider who may run typically at higher or lower rpms) which causes reversion in the intake track, pushing fuel and breather oil back into the air cleaner (worse on carbureted bikes). At times, these can conspire to cause carryover, typically when on long trips (extended cruising at a set rpm that co-insides with the reversion). This all assumes that the motor itself is in good mechanical condition. Other causes can be warped cylinders, loss of ring seal or overfillling the oil tank. If you have an earlier TC with the plastic breathers in the heads (or if they were installed with the cams) these need to came out and replaced with the metal breathers. The plastics are famous for warping from heat, age or overtightening. When warped, oil can get under them, bypassing the seperator and end up in the air cleaner. Last, missing o-rings under the rocker supports or the rocker cover/head gaskets oriented incorrectly (flipped over so that they do not correctly cover the breather channel) will also cause carryover problems. Knowing the year of your bike would help narrow some of these down.
Thanks, Mike

[dutch]

Mike, Thank you very, very much for your time and expertise RE: air cleaner blowby 66.213.254.242. The reed valve would have been my very last suspect. Removing the S&S breather “Reed” valve has virtually eliminated the gross oil blowby into the air cleaner. The blowby is now slightly more than a stock engine, but no longer inundates the filter media, causing a rich condition and sluggish performance. I also had an issue with engine idle, and severe altitude sickness. The copious supply of blowby oil had also mucked up the M.A.P. sensor. That changed, the air/fuel ratio cleaned up and the engine now runs clean, sober, and strong. FYI, it is a 2004 FLHTCi, 27K miles, and the metal breather valves in rocker boxes were clean and perfect. I hope to take a ride up to Oregon, Washington, Idaho and Montana in the near future. When I do, I’ll stop in to shake your hand, buy lunch, brews or whatever. You are a fine gentleman, thanks for your help! Dutch, Durango, CO

[Mike]

Thanks for the kind words! It's nice when things work out.
Regards, Mike

[dnewman]

Hi Mike, On this subject.... I recently did a Screamin Eagle Stage 11 (203 cams) upgrade to my 2005 Ultra with stock heads. I ran the bike about 600 miles and did not notice any problems. I had it dyno tuned and while riding home I could smell oil like an oil leak. I could not find any leaks so I opened up the air cleaner (big sucker) and noticed oil running down the face onto the filter. I checked the oil level and actually lowered it 1/2 quart just to be sure it was not overfull causing this problem. The problem still exists. It looks like oil running down the back plate onto the filter media, but could it be a combination of oil and gas? It just seems funny that I did not notice this until after it was dynoed. (I've had gas run out of the carb. (re jetted) onto the filter in my 2002 Heritage under certain conditions. It also seemed to be worse with the Big Sucker so I changed to the stock system air box with a K&N filter which seems to almost eliminate the problem.) I have a power commander on the bike and the guy who dyno tuned it said it was a little lean on the low and top end so he richened it up some. I am just trying to figure out how to fix this problem if possible. Please enlighten me on this if you can.

[Mike]

It's a common complaint and we have not found a 100% cure. I would not think the dyno could cause the problem unless just bringing it forward sooner than street running. But, it could be with added fuel there is now more in the stand off to contaminate the filter sooner (it can sometimes look like oil once evaporated). It's also a big function of how the bike is ridden. Wide throttle openings with heavy loads (running 80mph against a head wind) will tend to be worse than the opposit condition (cruising easy flat and level at 60). You could try leaning out the PC using the midrange faceplate button. If your fuel milage is below 40, this may be the cause. Other possibles are one of the umbrella valves has become unseated, pick-up port in the sump partially blocked, etc. oiling problems. Again, the dyno doesn't neccessarily cause these a problems but can cause them to show sooner than on their own.
Mike

[dnewman]

Thanks Mike, I did change the Map and the problem still presists. I get oil into the breather at all speeds. Rode it about 50 miles today and there was some oil dripping/running down the faceplate onto the filter media. I am going to open up the valve covers and take a look at the umbrella valves. I hope they are the problem

[Mike]

Keep us posted!
Mike

[dnewman]

Hi Mike, I changed the umbrella valves to Doherty mist frees with no luck. I also realigned the oil pump, again no luck. The spark plugs look great. I guess it is something I will have to lean to live with. It is just a nuisance.

[Mike]

You may just have to route the hoses down below the frame to manage the problem (sucks not have a guarunteed cure).
Mike

[dnewman]

Mike, The guy who did the work on it said that it may stop as it gets more miles on it. He claims that he did the same build on his own bike and had blowby for about 4000 miles and it stopped. He said to run standard harley oil for awhile before changing to synthetic to let it break in completely. I now have about 1800 miles on it and have changed the oil twice. I am running standard Harley oil and figure I will change to Amsoil next time. What do you think about what he is saying? Also, Could it be a timing issue? I read somewhere that it might be. I appreciate your input. Thanks

[Mike]

I do not see it as a timing issue. Your mechanic is likely talking about ring seal. It is possible that as the rings fully seat the carryover will diminish.
Mike

[Talon]

Haven't had this problem first hand, but saw a post on one of the sites, can't find it again, It said when you take the cam plate off there are two small O rings, if they don't seat properly it can cause this problem. I looked at the exploded view of the cam plate assembly in my shop manual, I think it's the O rings on the blind hole, and or the scavenge port stub. It sounds like you problem didn't start until you made your upgrades, and since you had this plate off, could be an issue. Supposedly it won't affect you oil pressure much, so oiling might not be an issue it this was the problem. Maybe Mike could give his thoughts on this, I'm not sure what these passages do.

[Mike]

Those two o-rings or the oil pump to engine case oring out of place can cause or contribute to carryover. It's easy for the small ones to fall out of position when installing the web plate and not be realized. A new possibility (at least for 07's/06 Dyna's) is overtightening the oil pump/web plate screws, possibly warping the plate or pump causing an open between the two. These new models do not use an oring to seal the two together so being true to each other is critical (this can also show as low oil pressure).
Mike