Drax240z Posted December 1, 2000 Share Posted December 1, 2000 Yes you need some 240z rods. Here is the deal: L28 block L24 rods P90 Head LD28 Crank L28 DISHED pistons (more on that later) 2mm headgasket This engine is 10.79:1 compression. You MAY be able to run that on 92 octane. Depending on your timing. Norm on zcar.com runs a setup like this sortof, but he uses 2 headgaskets to lower the CR, I wouldn't recommend that, but it works well for him. My best advice is to run this setup, but take those pistons and have around 0.5mm (about 0.020") milled off the tops of them. This should give you a CR of around 10.25:1. Which is nice for the street with 92octane. (as well as using the 2mm headgasket) ------------------ "Gimme Fuel, Gimme Fire, Gimme that which I desire" -Metallica Drax240z 1972 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html http://members.home.net/drax77/newpage.html Quote Link to comment Share on other sites More sharing options...
Drax240z Posted December 1, 2000 Share Posted December 1, 2000 I would say that you will definately notice a difference in power, mostly low end torque. You will in all likelyhood get better fuel economy too. ------------------ "Gimme Fuel, Gimme Fire, Gimme that which I desire" -Metallica Drax240z 1972 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html http://members.home.net/drax77/newpage.html Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 1, 2000 Share Posted December 1, 2000 why dished pistons? Quote Link to comment Share on other sites More sharing options...
Drax240z Posted December 1, 2000 Share Posted December 1, 2000 Without dished pistons your compression ratio will be over 13.5:1. Not good. I may have been wrong in the assessment that if you shave 0.020" off the dished pistons you'd get the desired CR. You MAY be able to use flattops and just remove a bit more material, or you could have the P90 bowls opened up a bit to lower compression. I don't know if either of these options is practical. The amount of material on the piston tops must be considered. The reason most strokers out there are 3.1L is because they use the KA24 pistons, which have a totally different design than the L series pistons. They give you closer to 9:1 compression. If this seems like too much work to you, (it seems like more trouble than its worth to me) then I would strongly consider running a high compression L28. Sell your diesel crank, and pick up an N42 head, run it with the block you have. (if its got flattops) Spend a bit of money on getting the head in nice condition, pick up a bigger cam. Talk to Norm Simpers on zcar.com, he's the only one I know of running a 2.9L stroker. ------------------ "Gimme Fuel, Gimme Fire, Gimme that which I desire" -Metallica Drax240z 1972 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html http://members.home.net/drax77/newpage.html Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 2, 2000 Share Posted December 2, 2000 ok, i have a ld28 crank and all i need to make my motor a stroker is some 240z rods?? and what will the dismpalcement be(no boring) and will it give me a noticable diff in power? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 2, 2000 Share Posted December 2, 2000 For the money you spend assembling a stroker L6 you could get a turbo engine from a junkyard. It would make much more power and be much less work, as well as having far more potential for future power. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted December 4, 2000 Share Posted December 4, 2000 With L28 pistons, you do NOT want to use L24 rods. If you do the pistons will hit the cylinder head! You'd have to use the shorter L28 rods AND shave the pistons, I believe, to avoid this. This is why most engines with the LD28 crank use either KA24 or Z24 pistons, they have a much shorter distance from wrist pin to top of piston, and allow the use of the longer 240Z rods. Not to mention bumping up the displacement! Can't say I know of anyone with an LD28 crank using L28 pistons. Dan Baldwin '71 240Z 3.1 COMSCC #7 SPB Quote Link to comment Share on other sites More sharing options...
Drax240z Posted December 4, 2000 Share Posted December 4, 2000 Thanks Dan. I am pretty sure I know of someone using the L28 pistons, but he had them all milled down on the top for compression and clearance reasons. And more than likely he would have used the L28 rods too. ------------------ "Gimme Fuel, Gimme Fire, Gimme that which I desire" -Metallica Drax240z 1972 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html http://members.home.net/drax77/newpage.html Quote Link to comment Share on other sites More sharing options...
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