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RetroRocket

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  1. Time Left: 27 days and 9 hours

    • WANTED
    • USED

    This is a unique must-have opportunity for the true Datsun L-engine aficionado. One-of-a-kind reverse-engineered LD28 engine fitted with aluminum head and upper physical engine components of 1975 280Z with efi. 10.0:1 c.r. gasoline engine runs very strong. Now has been parked for a long spell but ran great when parked. I got t-bone/sideswiped and lost interest in the car. Then other things came up and I had no time. Also I parked it because I had a header tube with a leak so I parked it for safety. Details: CAR: 1982 Datsun 910 Diesel Maxima sedan. IRS, and the chassis is basically the S130 chassis design. I fit 280ZX Turbo sway bars F&R. Trans: L3N71B shifts great. Infinity G20 15x6.5 wheels with proper offset. Handles fine for what it is, could use performance springs/struts to improve. 280ZX stuff fits mostly. ENGINE: LD28 short-block in car after cast iron head removed (engine in car). Fitted N42 L6 head (open chamber head) with stock cam/intake and entire efi upper-end of engine from 280Z, complete with AFM and air filter. Required the modification of head bolt hole diameters from 10 to 12mm and fitting of various head bolts combinations from sources BMW, Volvo, etc, retrofit per dimensions and function. largely L20B front timing components & cover components but kept LD28 water pump. LD28 bore is only 84.5mm so I eye-browed the tops of cylinder bores on the exhaust side of the chamber for valve clearance. Note LD28 and L20B share exact block height. PERFORMANCE: I crudely tuned it by placing inline potentiometer in the coolant temp input to efi, and weakened the spring tension a bit on the afm air vane. I had the potentiometer/mixture control with me in the cabin. I drove it around town and it seemed fine at the baseline I chose. I could enrich it to put black smoke out or lean it to ping with the knob control. But I wanted performance road testing so I took the ferry across to Seattle and got right on I-90 East which climbs the Cascades. I'd pick a truck lane and floor it starting from a known rich setting and tweak until I saw black smoke behind disappear and then carefully lean it. At the slightest ping I would back-off the knob setting to halfway between black smoke and ping while pulling. That became my prescribed setting and i left it there. The diesel trans must have a lower stall speed than the gas engine trans, IDK, but the car tends to jump off the line at a stoplight. The throttle response with the high compression is instantaneous and it is just funny to have to be careful of the throttle. Audi 4000 front air dam and later Nissan trunk lip spoiler. Has water to oil temp oil cooler stock LD28. ROAD TEST: Ski trip. From Bremerton to Stevens Pass (map it to see), skied, and then onward to stay in Leavenworth. Return next day skiing again at Stevens. Driver me, one of my teenage kids and two of his friends on board plus all of our ski gear. Car performed flawlessly [except for a snowboard started to slip off of the roof rack]. Climbed strongly, no problem passing trucks on mountain climbs. A month later I got T-boned/sideswiped by a Ford Expedition. It was in slo-mo but crushed the R doors in. The car still drives straight but makes me sick to look at it and I just parked it over a decade ago. I had it stored on a friend's farm for many years after it got hit but he sold property. Now it is overflow parking at my shop. This is a unique car. I did the work on it about 20 years ago. For many years I've crunched Datsun engine spec numbers so much that it would make Jason Grey look like a dilettante. I determined on paper that this hybrid build would work. I even discussed it with NISMO staff long long ago (Ron) and he said naw, it won't work; but I was certain it would and I was right. If it were me, if I were to continue the evolution of this prototype engine rather than sell it, I would explore tall-block L6 possibilities re long rod/stroke L6 engines using this concept (a tall block L6). LD28 rods are 140mm with pistons of huge compression ht (like 46.5mm or so)...so there are available Nissan rod lengths possible in the 140+ range (L20B,Z22etc) using compression ht of normal gas pistons for higher rpm use and r/s ratios of 1.75 and higher......but even as-is the present bottom end would stand up to turbocharging well. No high rpms use in store for it but tune it for torque. It would mean fitting a modified P90 head to drop c.r. to turbo it. Plus P90 has a quench chamber advantage over the N42. Since the diesel engine used a vacuum pump, there is an oil drain already in the pan which could drain the turbo. Lots of possibilities to explore. It fits under the Maxima hood with the taller N42 vs diesel head on engine, not sure if a Z car would need a scoop/space for valve cover. Block is 19.7mm taller than L28. I hate to part company with this successful experiment but I'm getting too old for having as many cars as I do. Serious inquiries only. I'm not here to teach you how to do it on an LD28, I'm selling a car. Sold as complete car only. Clear WA title. Driveshaft is disconnected for tow-dollying; but trailer if for more than 40 miles or so. Tires have deep tread but are old and should only be used for transport. Pick up only, no delivery. I'll get photos up when I have time and if I have genuine buyer interest in the info provided thus far. (This ad was supposed` to be in 'Vehicles for Sale' not 'Wanted' ad. I asked mods to move it though.)

    $3,200

  2. RE piston source for GM 90571284 (rare), this set from Enginetech shares the specs. They are $320/set of 6: https://www.ebay.com/itm/363550188284?_skw=Cadillac+Catera&itmmeta=01KX4JK5F5F19WE2KSQCV9HGN7&hash=item54a547a2fc:g:ZOEAAOSwBahVGwca&itmprp=enc%3AAQALAAAA0DKQclQvzFwZQpmMrsO4LuodjIdDq19n%2BrDI78Btm2AXnsjFM4EYrDEDgvOI%2BbrOjscodQWbA0U%2FvmafedYZANrUtwUmtVy6sX89T9RX3LsaLJJ7QvdylBDkVbJLzR9yYBqzl%2BRZRXywvTN2SzJq5JNpIzl4mbqXgUnrL8VO2PVVtjiDn7%2BGaGpCmqQuZoYUoSziDUqnQH0EFlSC6PjbecGbWnLUfnssrxXV%2B3MlRt13lhTrhLwxQBJFbSkBDUqv%2BxfZ2gx8NG0c%2BvsVv%2FBVI7A%3D|tkp%3ABk9SR9bXzJLpZw free shipping, so $53/each. Too bad I don't have six of the L13 rods because If I did I'd build a long rod L28 instead. r/s = 139.9/79 = 1.77. It wouldn't have the 'below deck' issue like the L18 build because stroke is 79 in L28 and only 78 in L18 sharing same rods.
  3. Now re finding obsolete parts.......that part is relevant. BTW, if L18 flat top, = L20B flat top and is a good choice for a budget build L20B. An easy way to boost performance on a truck L20B with W53 closed chamber head is to swap in stock L18 (us market) pistons onto the rods. Same dia and c.ht. and pin. The dish volume change is 11.36 -4.36 = 7cc subtracted in c.r. calculation to a nice streetable c.r. I did this on my 720 with SU's but otherwise stock engine and it pulled hard. I could haul a big load of topsoil no problem. Z20E pistons are the lowest c.ht. of those that would fit bore and are commonly available but they are still way too tall to use with the L13 rods.
  4. what do flat top L18 pistons have to do with this L18 build thread about use of 140mm rod c-c have to do with c.ht 38.1mm you are referring to? Please don't hijack
  5. Time Left: 26 days and 9 hours

    • WANTED
    • USED

    This is a unique must-have opportunity for the true Datsun L-engine aficionado. One-of-a-kind reverse-engineered LD28 engine fitted with aluminum head and upper physical engine components of 1975 280Z with efi. 10.0:1 c.r. gasoline engine runs very strong. Now has been parked for a long spell but ran great when parked. I got t-bone/sideswiped and lost interest in the car. Then other things came up and I had no time. Also I parked it because I had a header tube with a leak so I parked it for safety. Details: CAR: 1982 Datsun 910 Diesel Maxima sedan. IRS, and the chassis is basically the S130 chassis design. I fit 280ZX Turbo sway bars F&R. Trans: L3N71B shifts great. Infinity G20 15x6.5 wheels with proper offset. Handles fine for what it is, could use performance springs/struts to improve. 280ZX stuff fits mostly. ENGINE: LD28 short-block in car after cast iron head removed (engine in car). Fitted N42 L6 head (open chamber head) with stock cam/intake and entire efi upper-end of engine from 280Z, complete with AFM and air filter. Required the modification of head bolt hole diameters from 10 to 12mm and fitting of various head bolts combinations from sources BMW, Volvo, etc, retrofit per dimensions and function. largely L20B front timing components & cover components but kept LD28 water pump. LD28 bore is only 84.5mm so I eye-browed the tops of cylinder bores on the exhaust side of the chamber for valve clearance. Note LD28 and L20B share exact block height. PERFORMANCE: I crudely tuned it by placing inline potentiometer in the coolant temp input to efi, and weakened the spring tension a bit on the afm air vane. I had the potentiometer/mixture control with me in the cabin. I drove it around town and it seemed fine at the baseline I chose. I could enrich it to put black smoke out or lean it to ping with the knob control. But I wanted performance road testing so I took the ferry across to Seattle and got right on I-90 East which climbs the Cascades. I'd pick a truck lane and floor it starting from a known rich setting and tweak until I saw black smoke behind disappear and then carefully lean it. At the slightest ping I would back-off the knob setting to halfway between black smoke and ping while pulling. That became my prescribed setting and i left it there. The diesel trans must have a lower stall speed than the gas engine trans, IDK, but the car tends to jump off the line at a stoplight. The throttle response with the high compression is instantaneous and it is just funny to have to be careful of the throttle. Audi 4000 front air dam and later Nissan trunk lip spoiler. Has water to oil temp oil cooler stock LD28. ROAD TEST: Ski trip. From Bremerton to Stevens Pass (map it to see), skied, and then onward to stay in Leavenworth. Return next day skiing again at Stevens. Driver me, one of my teenage kids and two of his friends on board plus all of our ski gear. Car performed flawlessly [except for a snowboard started to slip off of the roof rack]. Climbed strongly, no problem passing trucks on mountain climbs. A month later I got T-boned/sideswiped by a Ford Expedition. It was in slo-mo but crushed the R doors in. The car still drives straight but makes me sick to look at it and I just parked it over a decade ago. I had it stored on a friend's farm for many years after it got hit but he sold property. Now it is overflow parking at my shop. This is a unique car. I did the work on it about 20 years ago. For many years I've crunched Datsun engine spec numbers so much that it would make Jason Grey look like a dilettante. I determined on paper that this hybrid build would work. I even discussed it with NISMO staff long long ago (Ron) and he said naw, it won't work; but I was certain it would and I was right. If it were me, if I were to continue the evolution of this prototype engine rather than sell it, I would explore tall-block L6 possibilities re long rod/stroke L6 engines using this concept (a tall block L6). LD28 rods are 140mm with pistons of huge compression ht (like 46.5mm or so)...so there are available Nissan rod lengths possible in the 140+ range (L20B,Z22etc) using compression ht of normal gas pistons for higher rpm use and r/s ratios of 1.75 and higher......but even as-is the present bottom end would stand up to turbocharging well. No high rpms use in store for it but tune it for torque. It would mean fitting a modified P90 head to drop c.r. to turbo it. Plus P90 has a quench chamber advantage over the N42. Since the diesel engine used a vacuum pump, there is an oil drain already in the pan which could drain the turbo. Lots of possibilities to explore. It fits under the Maxima hood with the taller N42 vs diesel head on engine, not sure if a Z car would need a scoop/space for valve cover. Block is 19.7mm taller than L28. I hate to part company with this successful experiment but I'm getting too old for having as many cars as I do. Serious inquiries only. I'm not here to teach you how to do it on an LD28, I'm selling a car. Sold as complete car only. Clear WA title. Driveshaft is disconnected for tow-dollying; but trailer if for more than 40 miles or so. Tires have deep tread but are old and should only be used for transport. Pick up only, no delivery. I'll get photos up when I have time and if I have genuine buyer interest in the info provided thus far.

    $3,200

    Tracyton, Washington - US

  6. I ordered two 90571284 GM pistons for $50/each but days later received notice that they are no longer available as the part is discontinued.....How about deleting their own ad if the item is not for sale?? This has happened with several Ebay sources for these genuine GM pistons. They process the payment and then figure out they have nothing available, then refund the purchase price. What a PITA these online dealer/suppliers are.
  7. yeah, I know. I've been working on Volvo redblocks, datsun L's and mercedes inlines for a long time. Yes everything you said and that's why the piston top should be in one plane, parallel to the flat of the head. Did you see my design for 0.060" overbore L28 to 87.5mm and use of eyebrowed Toyota v6 sohc same side pistons? For use with P90 head (closed chamber like A87 shape)...here, image: The flat table locates at the flat quench pad on the head. Due to datsun asymmetric pairing of valve ports the valve pocket cuts on piston tops only line up half the time. I am cutting valve reliefs (project) to make the eyebrows symmetric Int. and Ex. on every piston. Here; I need an actual piston vice to accomplish what I'm doing.. The point is, quench is going to be far more optimal with a flat top section or area of a piston top than curved (unless the curve of the combustion chamber matches the shape of the dome. I was hoping in the L18 case for there to be too much overdeck piston ht and that I could machine (lathe) down the dome to be a more flat area for quench. Anyway, the c.ht. on these 3VZE IIRC pistons and the partial dish-top configuration allows for high quench effect in L28 block without creating a too high c.r. I can't remember the spec..21cc maybe of dish region but with a functioning flat top region. The clay volume rests above the dish area which creates a distinct combustion chamber combo, no? Back to the L18 build, maybe I'll force induction and not worry the c.r./below deck issue. I'll get a pic of the efi intake I have yet to use. BTW, anyone know the proper bore finish to best suit the type of OEM piston rings that piston #90571284 comes equipped with?
  8. I went ahead and ordered the two @ $50/ea but I'll likely get a response that they are NLA in spite of their Ebay ad. BTW, the same log rod approach would work with L28 and FJ20 or L13 rods but with 79mm stroke they wouldn't be so far below deck. The photo makes the dome look huge but it is really subtle. It could be machined flat for L28 use.
  9. Here's a source for $50/each: https://www.gmpartsonline.net/oem-parts/gm-pistons-90571284?srsltid=AfmBOorfUboZcD10q9pqP7SpHliHdiklU0vw7kMPgqOaX0tmor_3Oi8R Otherwise I'm seeing them for about $160-$180/ea. I may pay the $100 for the pair I need for the set because half a set is useless and they are getting scarce. They are floating pin pistons but the rods aren't oil hole drilled and I'll just go with fixed pins.
  10. Yeah, it is a European engine but it's good because there is a Euro Quality conformity standard that applies to such parts. I don't understand the details but it's good for quality assurance. I don't know the dome volume and haven't seen any specs for it anywhere. I'd rather have it flat for a better quench to the closed chamber head but this is a budget build and I can live with the baby dome. List price is about $300/each for that GM part#. I think that they are available aftermarket but for more than I want to spend on them. I'll keep searching the part # on Ebay. That is how I stumbled on two for ridiculously low $13/each.
  11. Typo on the LD28, I meant L28. I'd use the optical plate from a Z24i into the L28ET distributor. By block ht I';m referring to the distributor shaft/housing length, i.e., can't use a Z24i distributor because it is too long. But L28 is correct length/height distributor to fit L16/L18. I have Electromotive crank trigger now on my L18 in the car now but I think it is squandered on my engine compared to an engine (like my '75 20R toyota chinook) where distributor mounted on the cyl head gets signal from a flopping timing chain drive. The L engine is basically right off of the crank coupled by helical gear with little slop/spark scatter. On the toyota I could adapt the cyl head distributor to become a cam angle sensor and take the crank angle directly from the crank with a trigger wheel (the electromotive setup) and get a lot more bang for the buck vs using it on the L18. I'm thinking that 1mm cut from the deck would solve the low c.r. easily. I do like the elegant simplicity of the SUs. I've used them before and tuned by changing springs and carefully sanding needle valves to eliminate flat spots in acceleration. I disconnect the choke actuation so that the jet isn't moved around and instead configure a cold-start system using an antique aircraft primer pump for cold-start. Plus auxiliary air valve with thermal spring actuation can be adapted for fast idle.
  12. What do you think re the optical feed LD28ET distributor as a crankfire (it is directly gear driven off of crank rather than any timing chain involvement) and it works on the same ht block L18 = L28. This is a budget build. I have a homemade f.i. manifold available which I've bought but never installed. Or I have SSS twin SU's that I have dual Patton injectors kit for conversion. Is a camshaft angle sensor timed off of a cam sprocket-attached trigger wheel, with sensor attached through valve cover, something that is done?
  13. Yeah, I'm getting about 1,5mm below deck too. The dome is slight, it reminds me of a roadster piston with a curve to the top. Maybe I'll search for another piston source with a bit more c.ht. I haven't searched for a long time so there might be something interesting in 86mm available now. I'm having difficulty finding my last two pistons after having great luck at first (brand NOS Genuine GM with rings for $13/each). They are discontinued and some online dealers want full price. To the back-burner for now....although I could deck the block down...
  14. RetroRocket

    L18 build.

    One-off engine design. Long-rod engine. L18 block & crank (five-bolt, fully counterweighted). Overbored from 85 to 86mm. Rods: L13 with Arp bolts (yes I have them in hand) c-c 139.9mm, 21 pin. Rod/stroke = 1.79. Pistons: Genuine GM fitment 1999 Cadillac Catera, also used in Saturn engines and others, same part #. I have two; need two more. Compression ht 1.079" [27.4mm], pin dia .8268". The pistons have a very slight symmetric dome which I may need to bring flat to comply with deck ht and quench with head table; or not. It should work out just right. Stock L18 has pistons below deck with 78mm stroke. You can just crunch the numbers using L18 rod c-c and piston c,ht [38.1mm] and do the math against those numbers. So, 130.2mm + 38.1 = 168.3. In L18 this combo lies 0.50mm down below deck because it uses same c.ht and rod length as L28 but has a 1mm shorter stroke (78 vs 79), so add back 0.5mm distance, now 168.8 length to zero deck. 168.8 - 139.9 = 28.9mm..The GM piston is 27.4 c.ht and therefore should be below deck by 28.9 - 27.4 = 1.5mm dome and all. I'll have to mock it up and check it. My past calculations brought it to deck and I thought I had to shave the slight dome...maybe not. The Catera c.ht. spec I'm using might be off slightly (low) can't find my notes. Compression ratio with the closed chamber head should be reasonable. I want to keep it below 10:1. It is an engine for street use and occasional autocross. I have a five-bolt aluminum flywheel for it. I have Electomotive crankfire on the car now but I want to configure an optical L28ET distributor with wasted spark for ignition. I thought up this engine design about 30 years ago, bought the L13 rods ordered from a local Nissan dealer and they've been in storage since. I've built the taller block engines in various configurations but I want a five-bolt sohc low block engine for my 510. Thoughts?
  15. I don't need all the coils, cap, etc, only a spare Z24i distributor. If the spare you have available is in good shape how much would it cost shipped to 98393? Thanks
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