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240Z resurrection

Discussion in 'Rebuilds and restorations' started by tyroguru, Jun 15, 2019.

  1. Makesy

    Makesy
    Z Club Member

    Great work mate!

    Out of interest, what have you got planned for the rest of the EFI setup?

    I've gone for the FAST-EFI setup from Z Car Depot, currently with stock injectors and stock rail. I hit a few stumbling blocks and, in short, I haven't had the time to work on my car to rectify them!
     
  2. franky

    franky Well-Known Forum User

    how straight forward!

    you can long rod/short piston/offset crank it for 100cc less!
     
  3. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    I'm sure there are many ways to spend more money for no more performance. :)
    But I wouldn't want to put anyone off, I'm sure doing that kind of a build would be very enjoyable.
     
  4. tyroguru

    tyroguru
    Z Club Member

    It does appear that there are numerous ways to "optimize" an L24 but I figure that if I start with an L28 then this one will go up to 11 (just for the Spinal Tap fans out there :) ). Yes, I'll definitely in time look more seriously into getting more out of this engine but it's one battlefield at a time and I'm going to leave the engine until after I've sorted the EFI.

    All input welcome on this choice! (Not the EFI - that's a certainty but more if you think I should get anything done to the block/head at least to start with as I have absolutely no idea what state it is in).
     
  5. tyroguru

    tyroguru
    Z Club Member

    Thanks! I'm taking my time to make sure I don't make too many stupid choices that may cost me a lot of money in the mid/long term. As with everything there is such a lot to learn in this space for me so I really am trying hard to learn about the space to make informed choices. I got some courses from the High Performance Academy (https://www.hpacademy.com) and for someone such as myself they are absolutely fantastic - highly recommended. Pricey though.

    At the minute I'm thinking along the lines of sequential injection as it doesn't seem too much extra effort than what's needed for batch firing. Coil on plug in the ignition department although I also recognize you can do just as well with coil near plug setups for cheaper. Definitely ITB's which may be Jenvey if I can stomach the price and most likely a Harada Manifold. Not sure on the ECU front yet: I like the Haltech stuff but maybe that's purely because they do nice videos!
     
  6. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    If you did later go from 2.4 to 2.8 you'd have to get it remapped, and some of physical choices might have to revisited too such as port sizes, injectors and perhaps more.
    My understanding is that sequential doesn't get you anything performance wise over batch, but since there's many ems out there with enough channels for it, can't hurt to play with it.
     
  7. tyroguru

    tyroguru
    Z Club Member

    Yeah, that's exactly my thoughts Jon - if the ECU has enough channels then why not? Of course, it means I'd need a sync sensor for cylinder position info but that's just another thing so may as well do it. Your points about port sizes, injectors etc. are good ones and I have got an eye on that to some extent at least and that's one of the reasons why I'm taking my time a bit: as you know, these items aren't cheap so I'd hate to buy twice just because I didn't do my homework properly!
     
  8. Rob Gaskin

    Rob Gaskin Treasurer Staff Member Moderator

    Yep a 2.4 is still a big engine.

    My 2.4 was knackered - rebore/pistons, regrind, valve seats/valves etc were needed so going 2.8 was an easy decision. To do that with a decent engine is ott really unless you really need the torque and power given by increased capacity. Getting a good 2.4 running nicely is probably money better spent.
     
  9. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    I think there's a couple of reasonably straightforward options to look at for cylinder cycle sync - there's the dizzy drive (use an old distributor body and make a trigger wheel for it?) or you could use a MAP sensor on the runner for ITB 1. (JohnP did this on his silver rat car when on injection)
     
  10. tyroguru

    tyroguru
    Z Club Member

    I think I'm going to go for a variation on a single trigger input via the distributor. I'm not sure how the MAP sensor would help me out here though Jon as it's specifically for cylinder position.

    On the whole thing of MAP sensors and ITB's - I've been reading that you shouldn't really use a single MAP sensor with ITB's owing to the different pressures across the different intake runners and, obviously, having no plenum. An alternative approach is to use Alpha-N which I believe is using the TPS as your load axis input for you fuel and ignition tables. More reading to do though. I wonder if you could have a MAP sensor per ITB? That's a lot of holes in the intake runners :) .
     
  11. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    Yes, I read speed density algorithm doesn't work well with ITBs. I'll be using alpha-N on my Speeduino, but it does have secondary fuel tables that can use map at higher rpm or something. (Haven't got into it yet).
    But John used MAP reduction off pressure on his Life EMS to indicate induction stroke on cylinder 1 using Alpha-N. Clearly its a clever EMS and not all would be able to do that.
     
    tyroguru likes this.
  12. tyroguru

    tyroguru
    Z Club Member

    Managed to obtain permission to spend some time hiding in the garage over the Christmas break! Over the last few months I've been thinking through the things I want to do on the car and I came to the realization that I'll not be happy going forward unless I really know what state the engine is in. The engine that the car came with was a bit of an unknown. It wasn't installed really - it was sitting in the engine bay with the transmission connected but that was about it. We've had the engine running and done a grand total of about 20 miles but as mentioned previously I'm heading down the EFI route and it's off the road anyway so why not put it right out of action and take the engine apart?! Why not indeed.

    Armed with a copy of "How to Rebuild Your Nissan and Datsun OHC Engine", an engine hoist and stand from SGS and a bucketful of naivety I started spannering. All-in-all it's gone pretty well (yes, I know that taking things apart is the easy bit :) ) . Apologies for the quality of the pictures that follow - I'm blaming poor lighting and also I've no idea how a camera works really.

    I've yet to go through the book and look in detail at any components but things don't seem bad on the surface (but what would I know?). The conrod bearings appear to be in good shape with no visible scoring except on piston 4 which has some minor scoring. IMG_9999.jpeg


    The main bearings and the crankshaft journals have no visible scoring as far as I can see or feel. Before I lifted the crankshaft out it span very smoothly and freely.

    IMG_0003.jpeg IMG_0004.jpeg


    The only real snags I hit in this process was removing the front cover as a number of the securing bolts had completely rotted and therefore they sheered easily and welded themselves into the block pretty tightly. It was touch and go but in the end I managed to tap them out without busting any threads. I'm assuming there has been some gasket failure or something which lead to all the water ingress in the bolts? The bolts that failed were the ones around what I think is the main water jacket inlet/outlet on the left front of the block.

    Everything's mostly apart now with only a couple of minor things to do (although I haven't done anything about the oil galley plugs yet...). Obviously, I've not touched the head yet but it's next on my list.

    I'm still forming a plan on what to do as next steps so all input is welcome! I'd like to get the block cleaned up really well inside and out - a thermal pyrolysis/blasting/ultrasonic treatment if possible but not sure how feasible that is from a price perspective! I'll look to overbore by as much as I can so I'll be looking for a machine shop who knows what they're doing with L6's - I don't want a lead paperweight because it got machined out too far!
     
    Woody928, Rushingphil and Huw like this.
  13. yellowz

    yellowz
    Z Club Member

    Whereabouts are you?
     
  14. Rob Gaskin

    Rob Gaskin Treasurer Staff Member Moderator

    Well when I did my first Z engine dismantle every piston ring was broken! So :thumbs:
     
    tyroguru likes this.
  15. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

  16. tyroguru

    tyroguru
    Z Club Member

    Near Camberley in Surrey. Prepared to travel a fair distance for people really know what they're doing.

    Thanks Jon. I'd been reading up on a few ultrasonic testers but I've read reports on problems some have when dealing with cylinder walls. Some are designed to measure bore walls (e.g., https://www.advanced-ndt.co.uk/cb110.htm) but some report that they have problems measuring surfaces that aren't flat and they tend to attribute this to the measuring device being flat itself (more investigation needed though). I do note that the images used in the advert you gave are all flat surfaces. I'd definitely like to get the block ultrasonically tested to get a correct view on what the cylinders can be bored to though.
     
    Last edited: Jan 1, 2020
  17. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    Yeah, I don't have any personal experience of them. Which block are you using?
     
  18. tyroguru

    tyroguru
    Z Club Member

    It’s a P30 with an E88 head.
     
  19. Turn & Burn

    Turn & Burn
    Z Club Member

    I’ve tested my block using ultrasonic, only time will tell how effective it was but I got fairly usable readings. There is a skill to using them and interpreting the data (we have a dept at work that specializes in them so I got their help), to overcome working on the inside of the bore rather than a smooth surface u can profile the sensing head using a fine emery, but the skill of the user contributes too.
     
    tyroguru likes this.
  20. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    tyroguru likes this.

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