SuzukiHayabusa.org
TECHNICAL => ALL MOTOR TALK => Topic started by: Daveeed on July 31, 2018, 06:08:45 PM
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I finally completed setting the cams on my 1397, JE 12.5, Ward headed, stock rod, lightened crank, N/A bike. I set cams so seldom, I always need to re-educate myself during the process.
I’m setting the bike up to run at Bonneville, 1/2, 1, and 1 1/2 mile events.
Anyhow, the cam card calls out 106 and 108. Guidance on this forum identified 109 / 110 or 110 / 111.
I am at 109 / 112.
I am seeking guidance on these lobe centers, should I take another swing? Or button this thing up?
Thank you in advance!
Daveeed
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Last time around I did mine at 110-112 and the bike made a tiny bit more power over 10,000 than when they were at 108-110 but my speeds were slower. When I eventually get this thing back together I'm going to roll the cams back closer to that 106-108 range that Web wants.
I think I don't have the flow in my head to support that wide of cam timing so that may have something to do with the slower speed.
Going with the Web recommendations should give me some more compression and some more torque. Of course that is going to depend on my PTV clearance.
What is your PTV clearance now?
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My all motor bike (1340 cc), has a set of BIG webcams that call for 108/108. I've moved them around a few times during different builds based on PTV clearances, it's got crazy high CR. The bike has literally hundreds of pulls and I've found a couple of degrees in the cam timing makes little difference other than where peak occurs by a couple hundred RPM. I settled on 110/112, makes the same peak HP and TQ as 108/108, but at 200 RPM higher. Pushing them higher to 112/114, peak HP remains the same at the same RPM but peak TQ drops just a bit. Bike peaks at 11,400-ish. More power differences happens with the deck height than slight changes in the cam timing.
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Thank you guys! This dialogue is exactly what I need!
So I had kind of a setback, or I will call it lucky. I Found the clearance between the cam lobes and the cam covers to be a bit tight, like maybe 2 or 3 hairs. I ground the crap out of them, now I got .040”
And I also found my intake had slipped a tooth, giving me the opportunity to set my frickn cams one more frickn time. I have not checked the ptv yet, I gotta get the cams timed first.
Are you checking ptv with a tool from Brock, or a screwdriver, or clay?
Generally is it safer to run higher or lower centers?
Thank you in advance!
Daveeed
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Brock's tool and dial indicator, I think CNC has one too. Higher is generally safer. I'm sure somehow you can get stupid and screw something up.
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Maybe set the lobes a bit lower when you dont have so much compression, i dont know what fuel you are using
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Thanks guys! I ended up at a perfect 110/112.
Thank you! I can’ Wait to run it!
Smokey Burnout!
Dave
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Hey MJ, what head are you running?
Dave
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It is one that I bought used from Shane San Miguel. I don't who did it for him, its not a CNC machined head it was ported by hand.
The machine shop that I use, https://www.facebook.com/Lyons-Technical-Machining-245908875427009/ does a lot of CR450F heads and road race heads says it is very good overall. Frank says there may be more airflow left in it but I would have to start making trade offs at lower rpms.
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What did you end up with for PTV clearance at those lobe centers?
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I was not able to measure PTV easily so yea, it looked good.
Cams set at 110/110. Engine runs great. I’m going to do a test and tune at Sacramento tomorrow to get some base line maps. Yup, the bike is ready to haul ass. I’m running 1650-M-AG. Running on Warner’s 196mph record. God willing and the wind at my back.
Smokey Burnout!
Dave
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:tu:
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Test and tune went well, Dave and I did about 6 runs ,starting slow and ramping up the rpm in later runs. Got good data from the Daytona logger. Dave was running 10.50's at 145 in third gear----Bonneville gearing-- :D
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Good speed for a nekkid bike.
Last time I was at the strip with B'ville gearing I went 12.10 at 147 with a stock fairing.
My 2 second+ 60 ft. time and 12.10 ET indicates skill level issues with the rider opposed to performance problems with the bike
Good luck to both of you at BMST.
Had to act like a grown up this and have to sit out this year. :toilet:
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great stuff, please keep us posted.
More please on the Daytona logger you mentioned.... WegoIII ?? Wego IV ?? ?????
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The engine: 1397, Ward head, +1mm intakes, JE 13?;1 pistons, Web .445" / .415" lift cams, Marine lightened crank, stock rods. It should have hauled ass.
Bonneville results: Running 1650-M-AG. I freakn suck. I made 15 runs, with the best runs at 192mph... actually slower than previous events, and I chased my tail all week. And yea I mapped and edited every run, and changed gearing about twice a day.
Please don't think I'm complaining, I'm not. Running on this years salt was epic, hanging with my friends Greg, Kim, and Jim, of Black Art Racing, drinking at Carmon's Black and White... This is what I live for, it makes my soul smile like nothing else.
Anyhow...
I have finally made progress to diagnose and resolve my lack of HP while running at Bonneville a month ago. Fireman Jim and I performed a leak down and compression test and immediately tore the bike down. The dry compression was 160 on all 4, and then with a squirt of oil, compression jumped to 210 on all 4. The leak down was loud and clear through the case, pointing to rings. All the valves were good, with no contact damage what so ever. As expected my ring gap was .005" oversize on the top, and .003" on the 2nd ring.
My cam settings were higher than I had set them, we found 113 / 113 however they were checked at .030" rather than .050" that I used to set them, so wtf.
Something that surprised me was ALL the intake cams lost ~.004" clearance in about 70 miles while running WFO at Bonneville. All the intake valves and seats were bran spankn new... I know the gas I was using (ERC A19C) was incorrect, my dynamic compression was low, the octane was to high (117 I found out later), and I installed a set of fugged up injectors by mistake. So yea.
The corrections we are making are:
1= Reseting cams to 108 / 108 as per Ward. However, piston to valve clearance will determine timing.
2= Purchased a beautiful new set of Wossner 14.25:1 pistons to bump my dynamic compression. The JE's were as flat as a 7th grade skinny chick. The Wossner's on the other hand are perkey as hell.
3= Ring gap will be reset to .004" per inch of bore on the tops, and >.004" on the 2nd's.
4= Clean injectors...
Gonna put her back together, and get ready to run the Shift Sector, Coalinga 1/2 mile drags.
Smokey Burnout!
Dave
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hey Dave dosent matter where you read your cams from .030" or .050" the end calculation will still be the same,,
Curious,, at that cam setting, at what rpm are you seeing peak hp? and, what dose the "torque" curve look like after peak "rpm", dose it drop away like falling off a cliff, or dose it just slowly slide down the hill ??
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hey Dave dosent matter where you read your cams from .030" or .050" the end calculation will still be the same,,
In the same reference, over the years I figured out a down and dirty and fast way to check cam timing ... uses a wheel and dial indicator, and I move the cams only .010 +/- the peak of the lobe. Always within 0.5 of a degree.