Xnke Posted March 10, 2008 Author Share Posted March 10, 2008 So i guess it's gonna be a non-stroker, but still an L30. kinda busy atm, but more details later. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted March 10, 2008 Share Posted March 10, 2008 The LD block looks the same as the L block at a glance. The block is about 19mm taller and requires a L20B timing cover. The oil pickup is located in a forward location. The passages can be drilled to relocate that pickup to the center or lengthen the pickup tube. I chose to drill/tap the block. There's also a couple of small oil passages that need to be tapped and plugged. I've heard rumours that the oil filter pad has some differences as to ports but I suspect that just isn't the case. No matter, it will be addressed as required. My LD block is at the machine block getting sonic testing to determine how much I can punch it out and still have material for a future rebuild. I'm looking at a 2.9 or 3.0 (at the most) and slapping on a Eaton M62 4th gen SC to boost. I'm using L20B rods and custom forged slugs (not ordered yet). I have a P90a (mechanical) head getting rebuilt and drilled to accept 12mm head bolts. I'm waiting on Justin's intake flange to complete the porting. Quote Link to comment Share on other sites More sharing options...
Xnke Posted March 10, 2008 Author Share Posted March 10, 2008 The biggest problem I foresee is the oil filter, but i guess we'll see when you get your block back. I'm also looking at making an LD version of Raami's block brace, integrating the front oil pickup block off plate into the brace. Here's the proposed setup: L20B timing cover L20B timing chain LD28 block bored to 87mm LD28 block brace L28ET oil filter cooler plate (maybe it'll fit...might not be needed) L28 crank, offset ground out to 84mm 4G63 rods Z22S pistons And one of the two following cylinder head choices: 8.7:1 compression: E88 cylinder head with 12mm headbolts Delta Cams .480/284 cam L28-sized valves OR 9.5:1 compression: MN-47 cylinder head with 12mm headbolts Delta Cams .480/284 cam L28 valves The high compression choice is marred by the pistons, because they are dished. For best possible performance, I'd need custom pistons for it, and those are (at the moment) out of the budget. If anyone else has any ideas on ~87mm pistons with a 21mm pin, and a 35.5mm compression height, I'd be glad to hear them. So far, the Z22S is the only one I've been able to locate. Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted March 10, 2008 Share Posted March 10, 2008 why not go with the lower compression and turbo it? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 11, 2008 Share Posted March 11, 2008 You've seen the Ross racing piston deal through Summit Racing that has been posted before, right? I figure you would have based on the threads you've been looking up. Full set of 6 with pins and retainers somewhere in the $400's last time I checked. Just specify what you need and don't say Nissan and you'll be good to go... Quote Link to comment Share on other sites More sharing options...
Xnke Posted March 11, 2008 Author Share Posted March 11, 2008 That seems like a much better deal, but alas, another 400$ that I don't have. So far, almost all the machine work is going to get done for free, due to my student status at school. We have a crank grinder in the basement of the engineering and welding shop. Needs a bit of TLC and a new grinding wheel, but the school will cover the cost of the wheel if i get it going again. Also, the big CNC milling and turning centers are available to me as well, so if i can get some good aluminum billet, that's an option as well. So far, no one wants to sell me unfinished forgings for pistons... Pretty much, if it weren't for the very low cost machine work, then i wouldn't be able to do it at all. Quote Link to comment Share on other sites More sharing options...
Daeron Posted March 11, 2008 Share Posted March 11, 2008 pistons are NOT the place to scrimp. I know ALL about the zero budget build.. but live on one meal a day for a month for your pistons. JY every other part if you want.. but new pistons, specifically designed to your application, will probably make more difference than any other single (times six) part other than the camshaft. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted March 11, 2008 Share Posted March 11, 2008 I don't see how you'll get 87mm out of the LD block. From rough measurements I've taken the upper limit should be 86mm. Beyond that the walls become too thin and require sleeving. My sonic testing results will tell the tale. Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted March 11, 2008 Share Posted March 11, 2008 Your kidding me.. ross pistons for 400 bucks a set? I paid at least 2x that! Sorry this is kinda OT but it shocked me! Good luck on your build. Evan Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted March 11, 2008 Share Posted March 11, 2008 Yeah I didn't know about that either, I'm definitely going to pick up a set now! Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 11, 2008 Share Posted March 11, 2008 Your kidding me.. ross pistons for 400 bucks a set? I paid at least 2x that! A couple years ago it was $463 I think. I also thought that the block would need to be sleeved to go with the 240SX pistons, but that info should be in the older threads on this subject so if you're unsure it shouldn't be hard to find the answer. Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted March 11, 2008 Share Posted March 11, 2008 I think ross makes 87mm or 88mm pistons with the 240sx pin height, which is what I'm going to try to get, so I don't have to sleeve the block and can run the LD28 or offset ground L28 crank. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 11, 2008 Share Posted March 11, 2008 The idea behind the summit piston deal is that they're custom, so you specify your bore size, pin height and diameter and your ring land sizes and they build it for you. When you ask for Nissan 240SX pistons, suddenly the price jumps. Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted March 11, 2008 Share Posted March 11, 2008 Jon, I figured that was the case. I would have to spec out RB25DET pistons and give them the info. Garrett has custom pin height pistons in his L28. Just a good piece of information to know, if I ever decide to blow a hole in one of my current units. Evan Quote Link to comment Share on other sites More sharing options...
Xnke Posted March 12, 2008 Author Share Posted March 12, 2008 I anxiously await your sonic test results, ezzzzzzzz. Pushing in a sleeve isn't as inexpensive as just boring it, but it's certainly doable. I pour cast iron every now and then, so casting a sleeve blank should not be a real problem. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted March 12, 2008 Share Posted March 12, 2008 The LD block looks the same as the L block at a glance. The block is about 19mm taller and requires a L20B timing cover. The LD block is 19.6mm taller than the L24/L28 height block. The LD28 front cover can be retained if you are going to be using a DIS on the engine. Just hack off the mount for the I.P. and weld on a cover. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted March 12, 2008 Share Posted March 12, 2008 True about the stock LD timing cover usage. I may still have one buried in the garage somewhere. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted March 13, 2008 Share Posted March 13, 2008 I just received the sonic testing results. On the thin side it measured .165" wall thickness. I want a second rebuild option so a .020" bore is where I'm heading. Tops would be a .040" bore. Abacus Racing and I both agree that a .120" wall thickness is minimal for durability and longivity. .040" converts to 1.02mm. Stock LD bore is 84.5mm. Max overbore would be 1.5mm for 86mm IMHO. I'm happier with the .5mm overbore for a 85mm. That just exceeds the stock 2.8 displacement but with a much nicer bore/stroke ratio. Using the L20b rods and custom slugs allows for a perfect fit. It would make for a nice NA although I'm still pushing towards the SC conversion. Quote Link to comment Share on other sites More sharing options...
Xnke Posted March 13, 2008 Author Share Posted March 13, 2008 guess it's time to start casting 4" rounds of cast iron... Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted March 13, 2008 Share Posted March 13, 2008 The idea behind the summit piston deal is that they're custom, so you specify your bore size, pin height and diameter and your ring land sizes and they build it for you. When you ask for Nissan 240SX pistons, suddenly the price jumps. Wow, so basically it's a loophole for a great deal eh? Ring land sizes, is that the depth and thickens of them? I wonder why they have things set up like that though. Quote Link to comment Share on other sites More sharing options...
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