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    #81
    Quote Originally Posted by MILD THUNDER View Post
    Wow, was Ken sent me that last dyno sheet. Den, if those AFR ratio numbers on the right are correct, that is WAY lean for it to survive in a boat. Those numbers need to be in the low 11's, in my opinion. It may fatten up in the boat, but I dont think two full points. I'd rather have to pull a jet size or two out when installed. Wednesdays pulls were showing we were going in the right direction jetting it up, when the dyno broke. What happened!! i would be concerned with those AFR numbers on a N/A 502, let alone a 15psi blown engine. 13.7? Thats getting a little too close to stoich. A 2012 Ford Escape V6 would probably have a full throttle AFR reading similar to that.

    Two things I would do. Make Joseph spend a few hundred and take his tails to the welder, and put 02 bungs in them. Then, borrow a wideband and check while running the boat. The 02 wont lie, and I wouldnt trust plug readings on a 1300HP marine engine. Second thing, drop the boost to 10-11 PEAK psi. It will still make 1100HP. Im not sure how much cylinder psi those MLS headgaskets can withstand?

    I agree with you that the O2 sensor doesn't lie, but it is giving you the average of that cylinder bank. Even on boosted engines its not umcommon for the A/F to vary from cyl to cyl as much as .5. This is why plug checks should be mandatory to verify what the O2 is saying on each cylinder not to mention timing and plug heat range checks. Now if the average O2 was 11.0 there would be more of a cushion to cover the potential lean cylinder. Imagine if the average is 13.5 and one cylinder (#7) is 14.0 under that boost / power level!! Too bad the dyno sheet doesn't have fuel flow or BSFC's listed. A lot of engine shops rely on the fuel being consumed more than the O2's to get the motor dialed in.
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    #82
    Registered OBNOXUS's Avatar
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    Quote Originally Posted by redhotsommer View Post
    Dear Dennis,

    Could you make sure we get the work done on my boat before you test drive Joeys? Thanks.

    Love,
    mike
    Actually think Im going to sneak you in by next weekend.

    I will have a small window of time and all that crap,,,,,er,,,, I mean your transom and drives are taking up alot pf space !!!!
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    #83
    Registered ICDEDPPL's Avatar
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    Quote Originally Posted by MILD THUNDER View Post
    I'd be worried about #6's at those power levels!
    One thing I learned from my drag racing days and forgot about with my first boat...the rat race for more power and speed just brings more headaches and an empty wallet.
    Damn I`m getting old
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    #84
    Founding Member / Super Moderator Ratickle's Avatar
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    Very interesting discussion....


    Does anyone have a set of headers he can borrow with sensors in every cylinder? On my Haltech engines, that was what we used so we could go cylinder by cylinder to balance.
    Getting bad advice is unfortunate, taking bad advice is a Serious matter!!
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    #85
    Registered MILD THUNDER's Avatar
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    Quote Originally Posted by WETTE VETTE View Post
    I agree with you that the O2 sensor doesn't lie, but it is giving you the average of that cylinder bank. Even on boosted engines its not umcommon for the A/F to vary from cyl to cyl as much as .5. This is why plug checks should be mandatory to verify what the O2 is saying on each cylinder not to mention timing and plug heat range checks. Now if the average O2 was 11.0 there would be more of a cushion to cover the potential lean cylinder. Imagine if the average is 13.5 and one cylinder (#7) is 14.0 under that boost / power level!! Too bad the dyno sheet doesn't have fuel flow or BSFC's listed. A lot of engine shops rely on the fuel being consumed more than the O2's to get the motor dialed in.
    Im with ya Craig. Thats why i was saying 13.8 AFR on that one bank at full pull, is living on the edge in my opinion! IDK why they dont use BSFC numbers there. I know they look at EGT's as being a tuning tool. If the EGT's are good, then the tune should be good. Im not sure if I totally agree with that?

    Meaning you can be borderline lean AFR, put some additional timing in it, and the EGT's come down. Or, be on the fat side, but not enough timing, and EGT's will show high.

    I am trying to learn new things everyday. My feeble mind tells me get the fuel right first, then add or remove timing to get EGT's to a safe level. However, thats what my brain tells me, and may not be what actually works.

    I actually was on the phone tonight with a buddy from Grand Rapids. He had some 460CI N/A engines in his Formula. The first shop dynoed the engine, doing some full pulls. The egt's and fuel numbers looked fine under full throttle load on the dyno. However, once he put them in the boat, it had a awful lean spot while cruising, that ended up burning some pistons and tuliping almost all the valves. Thats no good! This time around they rebuilt the engines, and put it on the dyno again, and did some cruising simulation, they found the lean spot, fixed it, and all good now. Kinda like those sled engines, Burning down while cruising at 55mph! This is why I think im gonna add 02 sensors in my tailpipes this year. I can then monitor whats going on at cruise, and wot.
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    #86
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    Sounds like Dan is ready to become Cruiser Dan! lol
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    #87
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    Give me a few more years then I`ll want some twin Diesels
    Cummins 450`s get like 28gal per hour.
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    #88
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    Quote Originally Posted by MILD THUNDER View Post
    This is why I think im gonna add 02 sensors in my tailpipes this year. I can then monitor whats going on at cruise, and wot.
    Funny you mention that I was just a soldering fool tonight extending the harnesses for my AFR gauges. Had em in last year mounted for passengers to see but what good does that do. They gonna be in the dash now.. You know I gotz to I gotta keep an eye on those big beast motors biotch! lol
    If I recall I was at 11.7 at idle to 13.0 at wot

    I have pictures.


    Last edited by ICDEDPPL; 02-22-2012 at 01:37 PM.
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    #89
    Registered MILD THUNDER's Avatar
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    Cool Dan!! I thought about adding those to my dash too. Only I heard that moisture kills the sensors fast. I'd like to look into this. I think having them on the dash would be great!
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    #90
    Founding Member / Super Moderator Ratickle's Avatar
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    Where do you pick up the A/G for those?


    And when you say moisture, in the fuel because of ethanol? Or when it is sitting?
    Getting bad advice is unfortunate, taking bad advice is a Serious matter!!
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    #91
    Registered MILD THUNDER's Avatar
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    I just remember hearing that any moisture contaminates the O2 senser itself. Maybe from condensation, reversion, etc. My exhaust is totally dry, so I think i'd be fine to run them. The cool thing about them, is say you plug up a needle and seat on a carb setup. A fuel PSI gauge would still show good fuel psi, but the engine is actually going lean. Having the 02, is really nice!
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