madkaw

L28+(maxima)47 build

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    5 minutes ago, rcb280z said:

    QC doesn't seem to exist much anymore. Good thing you checked.

    There was a QC sticker provided on a separate piece of paper with an explanation of why it wasn’t on the damper,  because the damper needed a protective coating, BUT be assured it was inspected. I will say they were very apologetic and sent a return label immediately. Customer service was good. Full review when I get another one

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    Awesome! What kind of gas are you going to use with that CR?

    And BTW, when I run the CR on your combo, I get a slightly higher number than you do. I get 11.42:1, but I've not reached the point where I'm completely confident in my numbers, What number are you using for head gasket thickness after it's been crushed into place?

    I get 11.42:1 with a .120 thick head gasket on an F54 and a 39cc chamber.

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    37 minutes ago, Captain Obvious said:

    Awesome! What kind of gas are you going to use with that CR?

    And BTW, when I run the CR on your combo, I get a slightly higher number than you do. I get 11.42:1, but I've not reached the point where I'm completely confident in my numbers, What number are you using for head gasket thickness after it's been crushed into place?

    I get 11.42:1 with a .120 thick head gasket on an F54 and a 39cc chamber.

    Rut roh - maybe more than I thought ? 

    And I shaved .005 off the block -eek

    Should be .049 or 1.25mm thick. 

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    Rut roh!   LOL

    Well as I said, I've not proven my calculations to be correct, but with a .049 (1.244mm) thick head gasket and .005 off the block I get 11.54:1

    I get 502.45 cc uncompressed volume and 43,55 cc compressed for a result of 11.54. Remember, I'm just a guy with a spreadsheet.

    You got any airports near you?  LOL!!

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    What cylinder pressure do you get?  CR is the calculation but cylinder pressure is the detonation cause.  As I understand things high CR needs to be matched with "big" cams.  I think that some people think of the whole package in terms of "dynamic" CR.

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    A YouTube link would be better.  Microsoft's trying to get my credit card number...

    image.png

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    2 hours ago, 240z70 said:

    1982 280zx F54 block (i think that it has dish pistons but not sure.  The engine has a rebuilt sticker: NISSAN JAPAN

    Fuel delivery=1970 round SU rebuilt by ZTherapy.

    Head:  MN47 (i think, since it has the temp plug below the 5th spark plug).

    The P79 and P90 heads have the temperature sensor in the head also.  What is cast in to the head up by the 1 and 2 spark plugs?  It's probably a P79.  Nissan would not put the L24 head on an L28.

    You can use the various calculators to estimate CR.  Plus there's another thread by CO discussing the topic.  

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    Somebody must have modified the Nissan rebuild then.  Not arguing, just pointing out that the "M"N47 head is designed for the Maxima L24E engine, Nissan did not put them on L28's.  .  You have a rebuilt short block with a different head on it.  Or, you actually have a Maxima L24E engine, not a 280ZX engine. Does it have L28 stamped by the 5 and 6 plugs, on the block.

    It would also be nice to start your own thread instead of filling up madkaw's build thread.

    Here's the thread where CO talks about CR's. 

     

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    Couldn't hear any sound on the embed or on You Tube. Is that just me?

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    4 minutes ago, Patcon said:

    Couldn't hear any sound on the embed or on You Tube. Is that just me?

    I just tried it and it worked fine . 

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    4 minutes ago, Captain Obvious said:

    Nice!! How's it feel on the road?

    Lovely ! The cam makes for a very exotic sputter at idle. Trying to be patient before thumping on it too hard. Hasn’t seen more than 4500 rpm yet. Much more torque than the 2.4 for sure . 

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    Just love breaking this engine in! The torque is very strong. I’ve limited myself to 5500 at this point, but still pulling very strong. Have to be careful not to hit it too hard in lower gears or I just break the tires loose. 

    Able to run 35 degrees timing so far, but probably close to the limit. Need to break this bad boy in and and get to the dyno to dial it in. Running very similar tune I did with my 2.4, just more fuel. Seems to be doing rather well on the MPG- beauty of EFI. On the dyno I will probably advance the cam a bit too if I can get away with it. I’ll see where the power curve comes in. 

    Took a peek at the cam and everything looks peachy.

    Just finishing up the install of my old motor in to the customers car. After it’s gone I can devote more time to tuning. Right now just driving around and letting Megasquirt do it’s thing.

    0303B5A3-152C-464C-96CA-FB5650DB0A25.jpeg

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    Not sure I will do ITB’s. I have a custom plenum I’m building for NA or turbo. One TB to mess with and tune . I do like the look and maybe I’ll go that route some day . I have a diesel manifold that I would love to run also - just something different . 

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    On 9/15/2019 at 10:18 PM, Zed Head said:

    What cylinder pressure do you get?  CR is the calculation but cylinder pressure is the detonation cause.  As I understand things high CR needs to be matched with "big" cams.  I think that some people think of the whole package in terms of "dynamic" CR.

    210 average by the gauge 

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    Well I’ve developed a noise down below. Not sure what’s going on, but more than likely it’s time to pull the pan . Runs good, but maybe a rod didn’t like the initial abuse. It sucks , but this was a budget build so I can’t expect miracles . Might get lucky and find something came a little loose, but nothing wrong on top. The head is what I’m worried about - too much time invested there. The short block is stock . 

    My helper is available by the end of the week to give me a hand for whatever I decide . I was planning on swapping transmissions anyway, but now it looks I’ll be pulling everything . This kid is good and we will have it on a stand in less than 3 hours . Takes a little pain out of the sting when you have a sidekick that can throw down a Snap on wrench faster than you can. 

    I really want dyno numbers on the stock flat top so I and going to continue this mission before dropping in the 3.2- besides that short block is not finished. I’m determined to see 200 rwhp with his combo. 

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