z-ya Posted September 30, 2011 Share Posted September 30, 2011 So I acquired this L24 engine that someone spent some money and time on. Taking it apart, it looks like whoever built it, did a pretty good job. There are signs that it was balanced. This is how I received it: L24 block bored ~0.030" over Arias forged pistons (domed) 9mm L24 rods. E88 head (73-74 open chamber) with Norris 490/490 - 280/280 cam, springs, retainers, lash caps, etc. The head is really the wrong one for the piston dome shape. An E31 or early E88 would have been a better choice. So a I have few options here: 1) Do up an E31 head and build a nice little street NA/mild race motor (might be a good spare for the race car) 2) Turbo charge it and use it in my semi street legal turbo car that has a tiring L28ET. I'm thinking the later. Worth the effort? I figure I'd do something like this: - P90 head (eye brow cylinders, check clearances, etc. Do whatever to make it right). I'm guessing the dome is around 5cc or so. I'd basically shoot for an 8.5-9.0:1 CR. - I can probably locate some RB26DETT turbos and have a manifold and down pipes made. - I'd have a custom turbo grind done. I'm thinking that it would be responsive, and the turbos would spool quickly. What do you guys think, worth it? Or should I just just build an L28 turbo when I need to and do an NA setup with this engine? Thanks, Pete Quote Link to comment Share on other sites More sharing options...
ComicArtist Posted September 30, 2011 Share Posted September 30, 2011 If you're going to go with a custom header, and looking for quick spool response, I'd go with a single Garrett GT2871r. Dual ball bearing, oil and water cooled, should spool quicker than the RB26 turbos. And more than capable of pushing enough boost. Don't see a whole lot of turbo L24's, but it might be worth the effort. I'd like to see it done. Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 30, 2011 Share Posted September 30, 2011 That dome screams small chamber ITB run to 8500 when I see it... Don't know about anybody else, but that's what I personally see... Quote Link to comment Share on other sites More sharing options...
SHADY280 Posted September 30, 2011 Share Posted September 30, 2011 i like the n/a idea, high rpm like tony sees. i have an e31 virgin head if you dont, and you need one. Quote Link to comment Share on other sites More sharing options...
macambra Posted October 1, 2011 Share Posted October 1, 2011 Turbocharged L24 sounds fun. Why not? I've never seen one done. You can be an original. You can make up for displacement with the turbo. Go for it!! Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 2, 2011 Share Posted October 2, 2011 Turbocharged L24 sounds fun. Why not? I've never seen one done. You can be an original. You can make up for displacement with the turbo. Go for it!! Man, look harder! Crown had a turbo kit for an L24 that used a Corvair Turbocharger!!! Curiously, the link between Datsun and Corvair continued later into the 70's when it became common for guys to take the EFI system from a 280Z and install it on a Corvair Engine "for the smoothest running, best cold-starting Corvair you will ever drive!" People have been turbocharging L24's from day one...it's hardly original. Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 2, 2011 Author Share Posted October 2, 2011 (edited) Yes, many have turbo'd L24s, including myself. Here is my L24 when it was running the Crown kit (sorry for tiny pic): Here are the original brochures: For this project I am thinking more turbo than NA. Low boost, fast spooling, high RPM turbo. Probably going with a single, modern turbo selected especially for this configuration would be best. Stay tuned. Edited October 2, 2011 by z-ya Quote Link to comment Share on other sites More sharing options...
Gollum Posted October 2, 2011 Share Posted October 2, 2011 (edited) Funny, when I see that head I think E85. Freakin' screaming at me actually. Slap a P79/90 on there with some quench and ADD BOOST. I'm not sure what you're looking to spend on this, but I personally don't see the point in spending a ton of money on a fancy dual ball bearing turbo if you've got E85 combined with decent compression. I'd definitely also go the solo-turbo route, not twins. But that's just me. Some people get all crazy for fast spooling turbos, but I just never seem to have an issue with it personally. When racing it's not really an issue, and I'd rather it be easier to stay out of boost when I want to. I've driven cars with very fast spooling setups and it seems like it looses half the benefit to me. I Like that a turbo is a dynamic power adder, and can be turned off with a careful foot. I've ridden in 400hp STI's that use the stock turbo, which is NOT ball bearing and they spool PLENTY fast from 2500rpm on. An example of this would be that in this setup you can take off mildly from a stop light and make a turn through the intersection, put the car in 2nd and mash the throttle and suddenly you're sideways even though the engine was bellow 2k when you put it in 2nd.... PLENTY of oomph. A similar pairing in a L25 could be pretty lethal. Give if boost-happy E85 and that piston with a matching head chamber and you have a recipe to cause a pretty capable turbo to MOVE. Edited October 2, 2011 by Gollum Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 3, 2011 Share Posted October 3, 2011 Damn you Pete, more Obsolete Parts I now must possess! I do have a nice SK Turbo Conversion for the L20E though...it has a BOV on it...where's Crowns? Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 3, 2011 Author Share Posted October 3, 2011 Damn you Pete, more Obsolete Parts I now must possess! I do have a nice SK Turbo Conversion for the L20E though...it has a BOV on it...where's Crowns? I sold the old Crown stuff a long time ago. Here is a 240Z in Maine that has the kit: http://cgi.ebay.com/ebaymotors/?cmd=ViewItem&_trksid=p3984.m1423.l2649&item=300602822505&sspagename=STRK%3AMEWAX%3AIT#v4-37 Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 3, 2011 Share Posted October 3, 2011 Looks like that guy treaded the same water as I did with the Turbo Vair, it's got all the high tech goodies from the era on it. But I bought mine from Spearco! Quote Link to comment Share on other sites More sharing options...
z-ya Posted June 6, 2012 Author Share Posted June 6, 2012 Resurrecting this project. OK, I need a backup engine for the vintage racer that we can also run in the under 2.5L run group. Plans: - Bottom end shown about with upgraded fasteners - I will use the cam (Norris 490/280), springs, and lash pads from open chamber E88 that came with this engine - Use Early E88 or E31 head, should produce around 11:1 static CR with this combination - Looking for some 40mm triples for induction (the 50mm Mikunis I run on the 13:1 CR L28 are too much for the L24?) Questions: - Should I go with L28 valves, or will the stock E31/E88 sizes be adequate for this combination? - Will 40mm triples be sufficient? Please only respond if you have actually experience building an engine similar to this one. I can speculate as good as anyone on this forum. I've attached a pic from the last vintage race we did. Thanks, Pete Quote Link to comment Share on other sites More sharing options...
madkaw Posted June 6, 2012 Share Posted June 6, 2012 (edited) Pete, I stumbled upon a very clean e-31 if you need one-- very clean! I'll add that I would have voted for the 25ett Edited June 6, 2012 by madkaw Quote Link to comment Share on other sites More sharing options...
z-ya Posted June 6, 2012 Author Share Posted June 6, 2012 Pete, I stumbled upon a very clean e-31 if you need one-- very clean! I'll add that I would have voted for the 25ett Thanks for the offer, but I have one of each. If they don't check out, I'll get back to you. Too bad they don't allow turbocharged 240Zs in vintage racing. That doesn't stop me from going fast . Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 7, 2012 Share Posted June 7, 2012 I think with the 40's you will have to do like the old racers did with 44's and run them without venturis. The stock engine was designed around 40PHH's and competition all used 44's. And you got incrementally more with 50's but I don't think you have the cam to handle that... So if you MUST run the 40's from "it's what's in the bin" then run them so they are like 44's to get the most from your L24. Quote Link to comment Share on other sites More sharing options...
z-ya Posted June 7, 2012 Author Share Posted June 7, 2012 I think with the 40's you will have to do like the old racers did with 44's and run them without venturis. The stock engine was designed around 40PHH's and competition all used 44's. And you got incrementally more with 50's but I don't think you have the cam to handle that... So if you MUST run the 40's from "it's what's in the bin" then run them so they are like 44's to get the most from your L24. What about the valves, should I install 280Z valves? If I were to keep the L24 valves, would 40mm carbs be sufficient? I'm looking for around 180-200WHP if possible. Thanks, Pete Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 7, 2012 Share Posted June 7, 2012 big valves help breathing Quote Link to comment Share on other sites More sharing options...
roger280zx Posted June 8, 2012 Share Posted June 8, 2012 Because Racecar, right? Quote Link to comment Share on other sites More sharing options...
Xnke Posted June 8, 2012 Share Posted June 8, 2012 Go with the bigger valves, 44's if you can get them, and a 5-6" manifold length if you can get it in there. Lift the ports and run a milled face mikuni manifold with the air horns coming out a slot cut in the hood! Quote Link to comment Share on other sites More sharing options...
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