turboHLS30 Posted July 28, 2011 Share Posted July 28, 2011 I'm having problems find a decent L28et in my area. So I was planning on taking my L24 block, put a P79 head with L28et cam and intake, and put all of my turbo parts on it. If you see any faults in my plan let me know, and possibly recommend a part to replace it. I just don't want to get it together and realize that a setup like this yields a 11:1 compression or something (That's an exaggeration) Any help is appreciated Quote Link to comment Share on other sites More sharing options...
S30TRBO Posted July 29, 2011 Share Posted July 29, 2011 Try this: http://www.atlanticz.ca/zclub/techtips/calcs/engine%20builder/index.html and this: http://www.zcarcreations.com/downloads/lengine.zip Play around with different combos and see what you get with what you got before you get too far. It might end up costing you more in the end than buying an L28ET. Keep us posted Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted July 29, 2011 Share Posted July 29, 2011 If the P79 is in good shape and has never been apart, leave the cam it has in it. I swapped a p79 for a p90 and back and have noticed no difference in performance at 8psi boost levels. Quote Link to comment Share on other sites More sharing options...
turboHLS30 Posted July 29, 2011 Author Share Posted July 29, 2011 Try this: http://www.atlanticz...lder/index.html and this: http://www.zcarcreat...ads/lengine.zip Play around with different combos and see what you get with what you got before you get too far. It might end up costing you more in the end than buying an L28ET. Keep us posted Will do thanks If the P79 is in good shape and has never been apart, leave the cam it has in it. I swapped a p79 for a p90 and back and have noticed no difference in performance at 8psi boost levels. Well from what I read, the exhaust valves are bigger in the P90, and the P90 cam has a longer duration. That's what I read, it could be wrong though. I'm planning on running upwards of 15psi. I'm building the car for the Grassroots Motorsports $2011 Challenge, and I'd like to finish mid-pack Quote Link to comment Share on other sites More sharing options...
neotech84 Posted July 29, 2011 Share Posted July 29, 2011 The stock turbo cam has it's pit falls i.e. lack on the mid- high RPM. From my experience a 260 cam is a better stock option. But if you are pressed for time/money just go with what you have. There are a few posts about which cam is "better" but if its just a mild build you should be fine with what ever just make sure you keep the oil setup correct for the cam (internal/ spray bar or both). Quote Link to comment Share on other sites More sharing options...
turboHLS30 Posted July 29, 2011 Author Share Posted July 29, 2011 Ok, thanks. I'm only looking to make ~300hp, if I make above that I'm happy. So I guess you can consider it a mild build. I'm just worried that I can't reach my bechmark with the L24. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted July 29, 2011 Share Posted July 29, 2011 300 whp from an L24 without any headwork using a stock cam (and I'm assuming pump gas) seems optimistic. What will you be using for engine management? Quote Link to comment Share on other sites More sharing options...
turboHLS30 Posted July 29, 2011 Author Share Posted July 29, 2011 Here's a breakdown of my setup: P30 block (L24) P79 head (Port & Polished, and cleaned up) Supra 440cc injectors Pallnet Fuel Rail Megasquirt v2.2 FMIC T3/T04 turbo Possibly meth injection Possibly a 60mm throttle body Like I said, I'm doing the GRM $2011 Challenge and so far I've only spent $1035.96. I have room for an aftermarket cam, head bolts, rod bolts, and any other little thing to take that extra step to make 300hp. Quote Link to comment Share on other sites More sharing options...
sweetleaf Posted July 29, 2011 Share Posted July 29, 2011 I would get an L28 block. Shouldn't set you back much but the additional displacement will be well worth it. They should be pretty abundant in Florida. Quote Link to comment Share on other sites More sharing options...
turboHLS30 Posted July 29, 2011 Author Share Posted July 29, 2011 I found a guy that is coming down and picking up a 280z mootor for free and I'm supposed to buy the block from him for $50 so I'm most likely going to do that. I'm in a time crunch right now though because school starts on the 22nd and I need it running before then, and I won't be able to get the block until the 13th. Which leaves me with 9 days to wire megasquirt, run fuel lines, get it running, etc. So I'd like to use my current block and a P79 head just so I can start wiring everything and getting it running so that it's just a matter of swapping out blocks when I get it running. Quote Link to comment Share on other sites More sharing options...
Z Greek Posted July 29, 2011 Share Posted July 29, 2011 You were concerned about compression ratio. From my research (I am using a P79 on my 3.1 build), stock chamber volume of P79 is 53.5cc. Assume a 1mm thick head gasket, and you end up with a total chamber volume of 55.2cc. Swept volume of L24 with standard bore of 83mm would be 398.8cc. 398.8/55.2 gives you a static compression ratio of 7.48/1. Everything I have read says the P79 flows pretty damn well, despite the exhaust liners. All of these numbers change as you increase bore, increase/or decrease combustion chamber volume. There's my two cents. (might be worth a penny!) Quote Link to comment Share on other sites More sharing options...
DatsunZman04 Posted July 29, 2011 Share Posted July 29, 2011 I wouldn't recommend the l24 block either. If your spending that kind of money right off the start , begin with something with a little more cubic inches. You might be able to get away with swapping a 260 0r 280 crank to a l24 block to give you a 2.6 liter AKA 260z platform. I would recommend new head bolts and the 240sx 60mm throttlebodie upgrade. Thats just my 2 cents, It isnt worth much but can point you in the right direction. Good luck on your build. Quote Link to comment Share on other sites More sharing options...
Z Greek Posted July 29, 2011 Share Posted July 29, 2011 Just checked my math, must be getting old. Assuming flat top pistons. L24 with standard bore, and P79 head, 1mm head gasket would yield 6.7/1 (398.8 swept area, 53.5cc combustion chamber, 1mm head gasket) L28 with standard bore, and P79 head, 1mm head gasket would yield 7.65/1(458.9 swept area, 53.5cc combustion chamber, 1mm head gasket) Somebody get me a new pair of glasses, or a new calculator! Quote Link to comment Share on other sites More sharing options...
turboHLS30 Posted July 29, 2011 Author Share Posted July 29, 2011 I wouldn't recommend the l24 block either. If your spending that kind of money right off the start , begin with something with a little more cubic inches. You might be able to get away with swapping a 260 0r 280 crank to a l24 block to give you a 2.6 liter AKA 260z platform. I would recommend new head bolts and the 240sx 60mm throttlebodie upgrade. Thats just my 2 cents, It isnt worth much but can point you in the right direction. Good luck on your build. Ok, well the L24 might just be temporary if I get this F54. If anything I will just swap heads and start wiring MS and drive it like that until I get the F54 cleaned up. Once it get's running with the F54 block then the L24 will be a back up just incase I do something stupid, or it blows. Quote Link to comment Share on other sites More sharing options...
Gollum Posted August 15, 2011 Share Posted August 15, 2011 There's nothing "wrong" with that combo. And I'd echo others to just run whatever cam you have. If you have a "a" cam from a 240Z head then go with that, as it's actually shown to make good power in turbo application. Either L24 block or L28, 300hp with that turbo and MS2.2 shouldn't be an impossible goal. In fact since it's a GRM challenge I'd be shooting for like 350 whp with a L28 bottom end. Some people have had success with the liner'ed P79, but you can also remove the liners for sanity if you'd like. There's people all over the internet that seem to have really bought into this myth about the P90 being some amazing head that's the "only" head to use for turbo application, and this couldn't be further from the truth. ANY L head can do just fine in turbo application provided the compression ratio is in the ballpark and you've got the means to tune it, which you DO. I've had plenty of P79's and a couple P90's now and I really can't see any reason the P90 should flow considerably better than the P79. I'd even venture to guess (out my guess hole of course) that there's less than a 2% difference in flow which just isn't worth the headache people make it. Quote Link to comment Share on other sites More sharing options...
Xnke Posted August 15, 2011 Share Posted August 15, 2011 I'd not worry about the head bolts as much as the rod bolts. Definitely make room in the budget for a set of ARP rod bolts. Quote Link to comment Share on other sites More sharing options...
neotech84 Posted August 17, 2011 Share Posted August 17, 2011 +1 on decent bolts and stroking your L24 if needed. Definitely fits into your budget. Also a good headgasket. I don't see why you COULDN'T sit around 350hp with your setup. Just make sure you put some time into tuning. 9 days will be tight for the MS install/tune. Quote Link to comment Share on other sites More sharing options...
turboHLS30 Posted August 25, 2011 Author Share Posted August 25, 2011 I'm going to be running the L24/P79 combo because it's what I can afford for the build. I still need to buy tires and of misc. stuff for the car. If there's a good chance it will make in the 300's, I'll be happy. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 25, 2011 Share Posted August 25, 2011 I believe the P79 valves will be very close to the L24 bore. You might need to eyebrow the block. Not hard, but might be necessary to prevent contact. Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted August 25, 2011 Share Posted August 25, 2011 (edited) Shameless self-plug: http://www.ozdat.com/ozdatonline/enginedesign/ Only really gives you the basics, nothing like checking the valve clearances like Jon is talking about. Good luck, Dave Edited August 25, 2011 by thehelix112 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.