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Thread: DrFishbone Engine Build Thread 2017

  1. #196
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    Good job all things considered. But I wonder why you think this will keep going till 7000, the cam will limit you and the blower aswell. But itís great to see great running M90s in the 400whp range.

  2. #197
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    Quote Originally Posted by ricardoa1 View Post
    Good job all things considered. But I wonder why you think this will keep going till 7000, the cam will limit you and the blower aswell. But itís great to see great running M90s in the 400whp range.
    Yes, I'll probably find the limit of the blower somewhere up there....I guess 7K just doesn't sound that far away. I need to brush up on MPXs limits though....it's been awhile since I read anyone else's finding on that subject. There aren't too many out there that are pushing the MPX to the max. It's more fun putting on an AR, Whipple, TVS or turbo, right!?

    I don't see the cam as a limit though...
    Matt Haub
    Shootouts: '09 SS 1st | '10 Mod1 2nd | '11 Bracket 3rd | '12 Bracket 1st | 2013 | '14 Bracket 3rd | 2015 | '16 Bracket 1st & Mod2 2nd | 2017 |
    Black '89 5spd - 281K miles, MPx, E85, Alky-Inj ¶ RWHP: ? RWTQ: ? ¶ Best 1/4mi:12.521, MPH:107.23mph
    35th Anniversary Auto 46k miles | Red '93 Auto 186k miles
    My Garage

  3. #198
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    Matt,

    Do you have MLS head gaskets ? Sounds like you may be adding combustion pressure into coolant causing the freeze plug failures. Asking because I once had one that would only leak under high boost and high rpm then reseal itself the rest of the time. Mine didn't pop any freeze plugs, but it would blow coolant out of the reservoir/overflow tank.

    David
    1991 SC AOD 4.2..2.3 Whipple..........10.910 @ 125.61
    2016 SRT Challenger Hellcat.............750 rwhp 720 rwtq

    My Garage

  4. #199
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    Jul 2003
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    Ottawa, Ohio
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    Do you have a dyno sheet with boost logged to see what the blower output is capable of? When I dyno'd last month the boost curve and the HP curve had a funny coincidence at 6200 rpm way below the 6800 rpm that I'm limited by to give me an idea what was going on. ie hp curved down as the boost went up 3 psi at the exact same point pointing at a restriction in the system.
    SCCoA Member#: 2515
    1990 SC AOD 2.1L Kenne Bell
    11.676 @ 121.35 mph
    506hp/478tq
    My Garage

  5. #200
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    Quote Originally Posted by rzimmerl View Post
    Do you have a dyno sheet with boost logged to see what the blower output is capable of? When I dyno'd last month the boost curve and the HP curve had a funny coincidence at 6200 rpm way below the 6800 rpm that I'm limited by to give me an idea what was going on. ie hp curved down as the boost went up 3 psi at the exact same point pointing at a restriction in the system.
    Correct, my recent Dyno to 6500 also revealed the limits of the cam and lifters. Boost creep is a phenomenon that happens to me, the blower is feeding the engine more than the the engine can digest past 6200-6300. At 7000 rpms it is just wreckless. I assume solid lifters can alleviate the problem but still if we are out of cam nothing we can do about it. This community has experience with llarge cams during the coy miller era, but we all know they become a tuning nightmare, we also start to lose the flat torque curve to trade for high rpm hp# simply based on revolutions and not because of torque. vTEC anyone?

    Twin scre blower have a specific operating rpm/efficiency range. The Mpx is not as much, but it is limited by inlet restrictions and cavitation. Then again have you pulled an mpx after heavy use at 25% od? You will likely see some scoring and rotor impact.

  6. #201
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    I don't have stock replacement lifters and even Dave was kinda confused whats going on. Thought is the crimp bent exhaust I have is causing restriction as some of the bends are fairly crunched, so full mandrel exhaust will be installed in the spring to see if this is the issue.
    SCCoA Member#: 2515
    1990 SC AOD 2.1L Kenne Bell
    11.676 @ 121.35 mph
    506hp/478tq
    My Garage

  7. #202
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    Quote Originally Posted by rzimmerl View Post
    I don't have stock replacement lifters and even Dave was kinda confused whats going on. Thought is the crimp bent exhaust I have is causing restriction as some of the bends are fairly crunched, so full mandrel exhaust will be installed in the spring to see if this is the issue.
    Maybe but donít chase your tail too much. I do have crimped exhaust aswel, But is it peeing in the ocean would be my next question? IDK sometimes
    We just need to settle and enjoy.

  8. #203
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    Quote Originally Posted by David Neibert View Post
    Matt,

    Do you have MLS head gaskets ? Sounds like you may be adding combustion pressure into coolant causing the freeze plug failures. Asking because I once had one that would only leak under high boost and high rpm then reseal itself the rest of the time. Mine didn't pop any freeze plugs, but it would blow coolant out of the reservoir/overflow tank.

    David
    Yes, MLS gaskets. I worried about that, but thinking back, the first two freeze plugs blew at moderate RPM and less than 5psi boost. The first blew with no boost applied at all.

    I'm pretty confident that's not the issue....or at least pretty hopeful!
    Matt Haub
    Shootouts: '09 SS 1st | '10 Mod1 2nd | '11 Bracket 3rd | '12 Bracket 1st | 2013 | '14 Bracket 3rd | 2015 | '16 Bracket 1st & Mod2 2nd | 2017 |
    Black '89 5spd - 281K miles, MPx, E85, Alky-Inj ¶ RWHP: ? RWTQ: ? ¶ Best 1/4mi:12.521, MPH:107.23mph
    35th Anniversary Auto 46k miles | Red '93 Auto 186k miles
    My Garage

  9. #204
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    Apr 2002
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    Greenville, IN
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    Quote Originally Posted by rzimmerl View Post
    Do you have a dyno sheet with boost logged to see what the blower output is capable of? When I dyno'd last month the boost curve and the HP curve had a funny coincidence at 6200 rpm way below the 6800 rpm that I'm limited by to give me an idea what was going on. ie hp curved down as the boost went up 3 psi at the exact same point pointing at a restriction in the system.
    I do have the dyno sheet (in front of me) and the log of the dyno pull (at home). From memory, the boost held constant throughout the pull. On the dyno sheet, the pull ended at 6k rpm....power peaked at 387 @ 5400rpm and dropped to about 330 @ 6000rpm.

    I don't think this dyno sheet and log are representative of a well-tuned car yet. It runs well, but the MAF curve needs work up high, plus it was pegged at 5500rpm anyway. Common sense says any air through the intake beyond the max a MAF sensor can output is going to have mixed and unreliable results. The way I see it, I had an "OK" dyno pull to 5500rpm...what happened beyond that can't be evaluated accurately until the hardware and subsequently, the tune, is fixed.
    Matt Haub
    Shootouts: '09 SS 1st | '10 Mod1 2nd | '11 Bracket 3rd | '12 Bracket 1st | 2013 | '14 Bracket 3rd | 2015 | '16 Bracket 1st & Mod2 2nd | 2017 |
    Black '89 5spd - 281K miles, MPx, E85, Alky-Inj ¶ RWHP: ? RWTQ: ? ¶ Best 1/4mi:12.521, MPH:107.23mph
    35th Anniversary Auto 46k miles | Red '93 Auto 186k miles
    My Garage

  10. #205
    Join Date
    Apr 2002
    Location
    Greenville, IN
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    I think I've said it already, but compared to previous Shootouts, that car felt slapped together....I didn't get to spend the time I wanted/needed getting it ready. I hope to get caught up and get it sorted out for next spring though.

    I do suspect that the limit of the MPx and inlet tract will show up somewhere up in the 6000's....if that means that power starts starts nosediving, that's okay. I'm hoping the solid rollers extend that range a little bit.

    Jacob asked me if I wanted to buy his Whipple this morning.....lol.
    Matt Haub
    Shootouts: '09 SS 1st | '10 Mod1 2nd | '11 Bracket 3rd | '12 Bracket 1st | 2013 | '14 Bracket 3rd | 2015 | '16 Bracket 1st & Mod2 2nd | 2017 |
    Black '89 5spd - 281K miles, MPx, E85, Alky-Inj ¶ RWHP: ? RWTQ: ? ¶ Best 1/4mi:12.521, MPH:107.23mph
    35th Anniversary Auto 46k miles | Red '93 Auto 186k miles
    My Garage

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