Y2KZX12R
Needs a job
CompetitionCNC.com
Posts: 3762
|
posted April 05, 2006 05:16 AM
Clean air system, things to watch for....
I wanted to point out a few things that I noticed with the kawi clean air system when I pulled the engine apart for the 1375 build.
For those that have blocked off the cleanair systems on the 12r by bolting on the blockoff plates, watch for exhaust valve fouling from oil being sucked past the seals around the sparkplug/air tube. The back of the valves were very goobed up with burnt caked on oil that was entering thru the tubes.
I cleaned the tubes at the topside and shot silicone into the tubes along with new gaskets.
Grodies on the back of the exhaust valve reduces the flow bigtime.
____________
Y2KZX12R
CompetitionCNC.com
   
|
psycho1122
Pro
Posts: 1608
|
posted April 05, 2006 06:47 AM
If I my add an observation....
If you are using this system to evacuate your crankcase. I recommend using a reinforced tube. I observed my original choice of tube collapse at high RPM on the dyno.
As Y2K stated, this system can realy suck if in good working condition.
____________
You say PSYCHO like it's a BAD thing!!
|
Y2KZX12R
Needs a job
CompetitionCNC.com
Posts: 3762
|
posted April 05, 2006 07:06 AM
I'd be concerned about using the system to evacuate the crankcase. Its going to suck oil in and burn and crust up the back of the exhaust valves. Any buildup on the valves will seriously reduce exhaust flow. The loss of exhaust flow will reduce engine power way more that the bennifits of reducing crankcase pressure.
On a 350 SB chevy, a very powerfull crankcase evacuator will show between 2-4 hp increase. On smaller engines its even less. On turbo engines its slightly more. and thats pulling big vacuum!!! The slight amount of evacuation that the exhaust can provide on this small of an engine would be almost unmeasureable. and it will reduce the ability of the exhaust system to scavenge the exhaust from the cylinder because its getting a supply of crankcase air instead. Then you add the grodie chunks and buildup on the back of the exhaust valves and you are most likely loosing power vs. blocking off the air injection alltogether.
Crankcase evacuation is MUCH more important on engines that are at extremely high mean piston speeds and need ported pistons. Between the ported pistons and the VERY strong crankcase evacuation the sealing of the rings can be much improved at very high mean piston speeds.
Just somthing to think about.
____________
Y2KZX12R
CompetitionCNC.com
|
VincentHill
Needs a life
Posts: 6520
|
posted April 05, 2006 09:48 AM
On doing Dyno Runs I put a clamp on the inlet to stop the vent from the case because the readings are not correct when hooked to the Crank case. I also have to take that into consideration when reading the Information after a run and must make the readings adjusted for the almost 1 point higher reading. If I see 13.5 I know it is closer toe 12.5
____________
Made History @ Daytona and still one fast old man!!
|
Y2KZX12R
Needs a job
CompetitionCNC.com
Posts: 3762
|
posted April 05, 2006 10:35 AM
Wow. A full point. Thats with the crankcase going to the clean air system?
____________
Y2KZX12R
CompetitionCNC.com
|
VincentHill
Needs a life
Posts: 6520
|
posted April 05, 2006 11:28 AM
quote:
Wow. A full point. Thats with the crankcase going to the clean air system?
From 12.5 to 13.3 Not a full point but close enough to make you change the fuel map if not watching out!
____________
Made History @ Daytona and still one fast old man!!
|
Megabyte
Pro
Posts: 1047
|
posted April 05, 2006 03:34 PM
What about using a PCV or other type of filter to prevent oil getting sucked up?
quote:
I'd be concerned about using the system to evacuate the crankcase. Its going to suck oil in and burn and crust up the back of the exhaust valves. Any buildup on the valves will seriously reduce exhaust flow. The loss of exhaust flow will reduce engine power way more that the bennifits of reducing crankcase pressure.
On a 350 SB chevy, a very powerfull crankcase evacuator will show between 2-4 hp increase. On smaller engines its even less. On turbo engines its slightly more. and thats pulling big vacuum!!! The slight amount of evacuation that the exhaust can provide on this small of an engine would be almost unmeasureable. and it will reduce the ability of the exhaust system to scavenge the exhaust from the cylinder because its getting a supply of crankcase air instead. Then you add the grodie chunks and buildup on the back of the exhaust valves and you are most likely loosing power vs. blocking off the air injection alltogether.
Crankcase evacuation is MUCH more important on engines that are at extremely high mean piston speeds and need ported pistons. Between the ported pistons and the VERY strong crankcase evacuation the sealing of the rings can be much improved at very high mean piston speeds.
Just somthing to think about.
____________
We First make our habits and then our habits make us.
|
Y2KZX12R
Needs a job
CompetitionCNC.com
Posts: 3762
|
posted April 05, 2006 05:47 PM
An oil seperator of some type would be ideal. Would eliminate the problem.
Drag cars use the header pulses at the collector. That would be an ideal place to run the crankcase hose. then the oil wouldnt matter.
|
psycho1122
Pro
Posts: 1608
|
posted April 07, 2006 05:45 AM
I currently use the factory Rubber Tube before the Vacuume Valve. It is packed with foam and catches oil. I frequently service this and clean the reed valves. I do not find too much "crap" on the reed valves other than carbon deposits.
Would you feel that using 100% synthetic oil would reduce this "Build up" possibility?
____________
You say PSYCHO like it's a BAD thing!!
|
Y2KZX12R
Needs a job
CompetitionCNC.com
Posts: 3762
|
posted April 07, 2006 01:37 PM
The buildup of crap is on the back of the exhaust valves. When the oil vapor hits the valve it instantly cokes up and then when you shut the engine off it drips and cokes up.
Even synthetic oils will burn at some point. It might be higher but how high?
I run spectro full synthettic. And it coked up bad and i have the blockoff plates. I was getting what it sucked around the gasket in the cam cover.
|
psycho1122
Pro
Posts: 1608
|
posted April 07, 2006 02:37 PM
 Edited By: psycho1122 on 7 Apr 2006 15:38
Y2K; I hear you on where the build up occurs. I was kicking around the possibility that due to my set up and servicing that I may not be suceptible to the build up.
____________
You say PSYCHO like it's a BAD thing!!
|
Y2KZX12R
Needs a job
CompetitionCNC.com
Posts: 3762
|
posted April 07, 2006 05:23 PM
maybe.... the only way to really know is to take the pipe off and look. you may be shocked at whjat you see. maybe not.
|
psycho1122
Pro
Posts: 1608
|
posted April 08, 2006 08:20 AM
I will definately take be takeing a peak next time I drop the pan for a cleaning.
____________
You say PSYCHO like it's a BAD thing!!
|
|
|
HOME
NEW TOPIC