Stroker Build - How would you do it? | The Z Club of Great Britain
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Stroker Build - How would you do it?

Discussion in 'S30 (240Z,260Z,280Z) Engine' started by Turn & Burn, May 17, 2017.

  1. Turn & Burn

    Turn & Burn
    Z Club Member

    I've now collected a few bits and pieces towards a stroker build including: N42 block and head, Ld28 complete motor. So assuming the block is good I've got the basis of a stroker along with the LD28 crank.

    The main concern is what to do with the rods and pistons, so I thought i'd ask for opinions and advice. What have you done, what would you do?

    L24 (133mm) rods seem an obvious choice and the Maxspeeding H-Beam rods seem like great value at £300. This then leads me towards using KA24E flattop pistons. I can't find a Kameari piston set suitable for these rods.

    L28 (130mm) rods can be used with Kameari piston set, but they seem a little short so rod ratio low.

    FJ20 rods (138mm) can be used with pistons from JE (I believe, not researched this yet). Disadvantage is I would have to buy two sets of 4 rods.

    LD28 (140mm) rods can be used with Datsun Spirit / Kameari racing pistons (or u can use their own rods (139.5mm), expensive option though) The 140mm rods give an excellent rod ratio, but the LD28 rod is quite heavy 80gr more than an L24 rod, is this an issue?. I'm also concerned that these slipper pistons can be quite noisy and I'm not sure if they're good for putting the miiles in, ie they are a race piston.

    What have you guys done?

    Cheers
     
  2. franky

    franky
    Z Club Member

    I'm pretty sure the Datsun spirit rods are those on ebay but logo'd. Their pistons are Kameari ones(well once were). I'm sure if you sent Kameari an email they'd reply with what you need.

    Isn't the ld28 block taller than an l28, you could save some of the hassle by getting an l28 block?

    The main question is what sort of engine do you want? what are you wants/plans for it? Go from there.
     
  3. richiep

    richiep
    Z Club Member

    Kameari do have pistons for the 133mm rods. These:

    https://www.rhdjapan.com/kameari-street-piston-kit-l28-l31-for-l20-rods.html

    Ignore where it says "crankshaft: L28" - it's a mistake on RHDJapan's part (I confirmed that with them a while ago but they haven't fixed it yet). Those have the correct 33.5mm pin height for the 133mm rods.

    KA24E pistons are basically truck slugs. For a proper build (not an American-style "cooking" stroker) there are better alternatives like the Kamearis, or cut in a custom order with JE Pistons.

    The Maxspeeding rods are a good deal. They've been used successfully by enough people (not just in Z engines) to get past the "made in China" stigma.
     
  4. Turn & Burn

    Turn & Burn
    Z Club Member

    The Ld28 block is taller, the intention is to use the bored L28 block, I have the whole engine though. Makes for interesting planning trying to work out if you could use the LD28 block. There's not many people successfully bored one to 89mm, but 86mm would go ok. The crank would need offset ground to increase the stroke, with custom rods. All do-able but prob not cheap. I haven't worked out capacity but would guess something around 3.2ltr. The height of the block causes problems, you would need to lower the engine on the mounts, but this may tip the g/box tail up.

    Plan for the engine is 250bhp ish but strong torque for fast road, Don't need another cammy race motor.
     
  5. Turn & Burn

    Turn & Burn
    Z Club Member


    Thanks for the rod info, I'd briefly looked at these but as it said L20 rods I'd assumed that these were for the shorter 128mm rods (Ozdat shows L28a rods at 128mm). They may be, but as you say the pin height is perfect for a LD28 crank, L24 rod stroker build.
     
  6. richiep

    richiep
    Z Club Member

    The Ozdat info on the L20a rods is only partially right. Pre-79 L20 rods are 133mm, same as L24 rods with 9mm rod bolts. Post-79 are 135mm, and were found in things like Skylines from what I've seen mentioned. Just go with the L24 133mm rods, unless going for one of the longer options like Kameari, or Datsun Spirit.

    There's a lot of misinformation and repetition of inaccuracy on the web about L20 rod lengths from what I've seen - largely because the accurate info about L20s tends to be in Japanese...
     
  7. johnymd

    johnymd
    Z Club Member

    I was going to start another stroker thread but this one looks to be exactly what I'm trying to build. I'm not bothered about HP and I'm just after a torquey road engine without overkill on parts that are not required. I do want to make sure I'm not cutting corners though. I can't see myself reving over 7k and most of its life will be between 2 and 6k. I was going to use the n42/n42 2.8 I have but now I'm considering a minor upgrade to this with the LD28 crank.
     
  8. jonbills

    jonbills
    Z Club Member

    Apparently the LD28 water pump has a bit more displacement than the L28. There’s a thread on hybridZ about clearancing the L28 timing cover for it.
     
    johnymd likes this.
  9. franky

    franky
    Z Club Member

    The best starting point is a cheap engine, which you have :)

    Why build an N/A torque monster, why not build a really special engine of big displacement?
     
  10. Tommi

    Tommi
    Z Club Member

    I would have a chat with Eiji at datsun spirit. I have known him for several years and has always given great, unbiased advice. He is very knowledgeable and all of his products are the real deal. I’m pretty sure he would be horrified that people out there think he is just re branding cheap con rods and selling them at four times the price. Really good guy.... drop him an email if you are thinking of going that route.

    Cheers
    Tom
     
    johnymd likes this.
  11. johnymd

    johnymd
    Z Club Member

    I like the phrase "torque monster" but "big displacement" sounds outside of my budget. Torque monster's little brother would be more fitting.

    I have seen mention of using the water pump so will look further into this.

    I'll drop Eiji a message.

    I've been digging around my lockup this morning and in addition to the 2 L28 complete engines (N42/N42 and F54/P90) at the workshop, I have couple of L28 short blocks (F54's) plus a ported P90 and Spike ported N42.

    So I'm now thinking, leave the 2 complete running L28's and build another with the bits I have in the lockup. Bore an F54 out to 88mm, set of maxspeed L24 rods, LD28 crank, "Spike" N42, aftermarket damper(Which one?), Forged pistons?, under 0.5" lift mild cam, 10.5ish:1 compression.

    Any thoughts on this?
     
  12. jonbills

    jonbills
    Z Club Member

    Already sounds like it’s going to get expensive!
    Get a turbo oil pump too.
    Get the bottom end rotating assembly balanced.
    Does the spike N42 not have a cam already?
     
  13. franky

    franky
    Z Club Member

    Whats a spike head?

    you've got all the bits there(cheap engine/crank ;) ), a set of rods etc.
     
  14. jonbills

    jonbills
    Z Club Member

  15. Rob Gaskin

    Rob Gaskin Membership Secretary Staff Member Committee Member

    :conehead:
     
  16. bluejon

    bluejon
    Z Club Member

    I have no clue if this is helpful to you, but I believe my stroker (L28 with E31 head) has Toyota R20 (20R?) pistons. The block was bored I think to 3.0 litres which if the quick googling look up I have just done is correct is an 88.4mm bore .. at least that would be the size of those pistons
     
  17. Turn & Burn

    Turn & Burn
    Z Club Member

    After loads of looking at various rod lengths and ratios I’ve been told by an Oz engine builder not to get too carried away with this and it’s only a 1 percenter in terms of the overall build, 1st thing to look at is getting the block sonic tested for bore thickness before you commit to your bore dia. If you can then find the right piston for a set of L24 rods I reckon you’re in business.
    The Toyota R20 pistons look worth a look, are they 30mm ish compression height?
     
  18. franky

    franky
    Z Club Member


    Whatever a spike head is, surely you'll have to CC it etc to work everything out anyway?
     
  19. jonbills

    jonbills
    Z Club Member

    Yes, lots of work to do, esp if fitting a new cam - lash pads and spring heights and such.
     
  20. atomman

    atomman Forum User

    Last edited: Apr 10, 2018

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