Diagnosing sumping
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Cruiser
Joined: Nov 2014
Posts: 182
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From: East Tennessee
I will repeat, I am not a tuner but concentrate on corrected CR and/or CCP when planning a build. The higher those numbers go, the more likely there will be tuning challenges but that's JMHO.
I also think going to a custom ground cam is a extreme approach to solving a problem that most likely has a less extreme cause that we just haven't figured out yet. I think before I paid for a custom ground cam, I would at least stick the 259 back in and see what happens with the catless head pipe. I expect the low end will still leave something to be desired but the information you get from trying the 259 at this point should be useful.
Was the CCP ever checked with another gauge? Doesn't happen often but I have see guys chase CCP issues and finally check with another gauge only to discover that the gauge the have been using was faulty. it would be important for me to know, for sure, what actual CCP was.
Has the tuner tried turning off the anti-knock feature during a tuning session? If CCP is actually 220 and that feature turned off, the motor should ping under load.
I also think going to a custom ground cam is a extreme approach to solving a problem that most likely has a less extreme cause that we just haven't figured out yet. I think before I paid for a custom ground cam, I would at least stick the 259 back in and see what happens with the catless head pipe. I expect the low end will still leave something to be desired but the information you get from trying the 259 at this point should be useful.
Was the CCP ever checked with another gauge? Doesn't happen often but I have see guys chase CCP issues and finally check with another gauge only to discover that the gauge the have been using was faulty. it would be important for me to know, for sure, what actual CCP was.
Has the tuner tried turning off the anti-knock feature during a tuning session? If CCP is actually 220 and that feature turned off, the motor should ping under load.
Here is my idea: Feuling 594 cam (56 closing). Valve springs to accommodate the lift, also lighter springs to ease up on the cams & lifters.
What do you think?
HDF Community Team
Joined: Jun 2006
Posts: 12,779
Likes: 2,609
From: san antonio
I cannot see all that head work just run a cam. And due to the ridiculous valve train noise I won't try the 259 again.
Here is my idea: Feuling 594 cam (56 closing). Valve springs to accommodate the lift, also lighter springs to ease up on the cams & lifters.
What do you think?
Here is my idea: Feuling 594 cam (56 closing). Valve springs to accommodate the lift, also lighter springs to ease up on the cams & lifters.
What do you think?
As to your comment about the head work. You are pulling the heads anyway to change valve springs so at least have the chamber volume measured. The work I am referring to isn't that costly and doesn't take much time and is not "just to run a cam" but to open up cam selection to many more cams.
Thread Starter
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Cruiser
Joined: Nov 2014
Posts: 182
Likes: 0
From: East Tennessee
Worth a try. You could even retard the cam by 4* for a 60* intake close. However, it the tuner can't get decent numbers and a respectable power curve; time to change tuners. JMHO.
As to your comment about the head work. You are pulling the heads anyway to change valve springs so at least have the chamber volume measured. The work I am referring to isn't that costly and doesn't take much time and is not "just to run a cam" but to open up cam selection to many more cams.
As to your comment about the head work. You are pulling the heads anyway to change valve springs so at least have the chamber volume measured. The work I am referring to isn't that costly and doesn't take much time and is not "just to run a cam" but to open up cam selection to many more cams.
HDF Community Team
Joined: Jun 2006
Posts: 12,779
Likes: 2,609
From: san antonio
Hard to say exactly without knowing chamber volume, deck height and head gasket thickness but with Woods 888 cams, stock pistons and .045" head gasket, about 185psi at sea level. Replace the .045" head gasket (which I would do in this case) and CCP increases to 191psi. Going that route accomplishes the same thing increasing chamber volume does with regard to cam choices; many more options.
Thread Starter
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Cruiser
Joined: Nov 2014
Posts: 182
Likes: 0
From: East Tennessee
Hard to say exactly without knowing chamber volume, deck height and head gasket thickness but with Woods 888 cams, stock pistons and .045" head gasket, about 185psi at sea level. Replace the .045" head gasket (which I would do in this case) and CCP increases to 191psi. Going that route accomplishes the same thing increasing chamber volume does with regard to cam choices; many more options.
Although cam overlap is a good thing where does it become a tuning issue passing unburned fuel to the sniffer providing false AFR? I also questioned the length of my tuner's sniffer and prefered other methods including using the upper bungs in my headpipes or tapping into the headpipes with universal bungs.
HDF Community Team
Joined: Jun 2006
Posts: 12,779
Likes: 2,609
From: san antonio
I am on board with the 9.6 compression target.
Although cam overlap is a good thing where does it become a tuning issue passing unburned fuel to the sniffer providing false AFR? I also questioned the length of my tuner's sniffer and prefered other methods including using the upper bungs in my headpipes or tapping into the headpipes with universal bungs.
Although cam overlap is a good thing where does it become a tuning issue passing unburned fuel to the sniffer providing false AFR? I also questioned the length of my tuner's sniffer and prefered other methods including using the upper bungs in my headpipes or tapping into the headpipes with universal bungs.
Thread Starter
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Cruiser
Joined: Nov 2014
Posts: 182
Likes: 0
From: East Tennessee
Bike runs different but not sure I'd say better. I only had time for around the block and going to hold off until I can ride it to check for its stall RPM issue and other quirks.
I'll report back when I can get in a good ride.
Thread Starter
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Cruiser
Joined: Nov 2014
Posts: 182
Likes: 0
From: East Tennessee
Before I take the bike in to be torn down I changed out the MAP sensor. I figured for 100.85 its better to know for sure its good.
Bike runs different but not sure I'd say better. I only had time for around the block and going to hold off until I can ride it to check for its stall RPM issue and other quirks.
I'll report back when I can get in a good ride.
Bike runs different but not sure I'd say better. I only had time for around the block and going to hold off until I can ride it to check for its stall RPM issue and other quirks.
I'll report back when I can get in a good ride.
Ran the tank down to E it took 5.5 gallons and rode home the lazy dog.
I would imagine the bike tuned to with a tank of 97 would be above my expectations.
Last edited by SleepyBagger; Jun 13, 2015 at 08:58 PM.
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Thread Starter
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Cruiser
Joined: Nov 2014
Posts: 182
Likes: 0
From: East Tennessee
Running 104 octane mixed down to + or - 97 octane. Got the bike out for a 250 mile ride and noticed its driveablity running at 97 octane is much improved, improved to the level I am very satisfied with the roll on, off idle and 3-6k walked away from my buddy time after time (his bike always pulled away prior to this hot tank of fuel). The glitches at 2250 and 2750 (I was having so much fun I didn't notice or they were gone IDK).
Ran the tank down to E it took 5.5 gallons and rode home the lazy dog.
I would imagine the bike tuned to with a tank of 97 would be above my expectations.
