Project1 Posted January 7, 2015 Author Share Posted January 7, 2015 You need a head before Pistons so you can plan your cr. Run the cr that the cam grinder recommends. Probably 9-9.5:1. I was going to use the N42 head that I have, unless it would really benefit me to find a p-79/p-90. My plan was to have it hot tanked/pressure tested/ and milled down to resurface. I was going to rebuild it with new valves, springs, pads and cam. I was going to get this cam and springs, however I'm totally open to a better sugestion. http://www.thezstore.com/page/TZS/PROD/classic12e03/10-2002 http://www.thezstore.com/page/TZS/PROD/classic12e04/10-2011 Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 7, 2015 Author Share Posted January 7, 2015 New Zed speaks with wisdom. You still need to do more searching. Skirkland is right, spend your $ on MS before getting an aftermarket intake. The"mess" should be your target plan if you are going MS. If you have searched you have realized that a great TUNE will get you further then headers, intakes, SS valves. You still haven't answered what head you are using? The head is everything done right. The MS is a plan. I have read about it a little, seems awesome. If you have anything you recommend me reading about it, that would be great. I was trying to figure out how the sensors work, how many there are, and do I use the stock sensors at all? Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 7, 2015 Share Posted January 7, 2015 Stock valves and springs are great pieces. Stay under .460" lift. You can get a cam regrind from delta and resurfaced rockers for around $100 plus shipping. Just check their work especially on the rockers. They tend to not be resurfaced parallel. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 7, 2015 Share Posted January 7, 2015 Ouch. These engines do seem to generate the occasional odd noise that can't be identified or fixed. It kind of looks like your fix actually led to the final demise. You didn't mention any measurements or observations of old bearing quality. Or oil pressure/flow. Might have been better off to have just put the old bearings back on. Many people do just fine installing an old high-mileage motor to make a nice daily driver. The engines don't seem to show significant signs of wear until over 150,000 miles. They're super durable. On the other hand, many people seem to destroy/damage newly rebuilt engines,or parts of them, because the aftermarket parts just aren't as good and don't break-in right. It's a dilemma. Anyway, you've noticed that nobody can offer an opinion on your piston choice, because it can't be determined without knowing what the other engine parts are. Build an engine on paper first. Good luck. Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 7, 2015 Author Share Posted January 7, 2015 Stock valves and springs are great pieces. Stay under .460" lift. You can get a cam regrind from delta and resurfaced rockers for around $100 plus shipping. Just check their work especially on the rockers. They tend to not be resurfaced parallel. Awesome .. I'll check them out. Thanks again for all your help ... I'll post pics as we go. Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 7, 2015 Author Share Posted January 7, 2015 (edited) Ouch. These engines do seem to generate the occasional odd noise that can't be identified or fixed. It kind of looks like your fix actually led to the final demise. You didn't mention any measurements or observations of old bearing quality. Or oil pressure/flow. Might have been better off to have just put the old bearings back on. Many people do just fine installing an old high-mileage motor to make a nice daily driver. The engines don't seem to show significant signs of wear until over 150,000 miles. They're super durable. On the other hand, many people seem to destroy/damage newly rebuilt engines,or parts of them, because the aftermarket parts just aren't as good and don't break-in right. It's a dilemma. Anyway, you've noticed that nobody can offer an opinion on your piston choice, because it can't be determined without knowing what the other engine parts are. Build an engine on paper first. Good luck. Thanks again for all your help. It is a process figuring this out. The old barrings looked brand new, so idk..but it's a done deal now. When planing the CR, besides the piston/stock stroke, is that largely controlled by how much the head is milled or shaved, or the head gasket used? I guess the flat to pistons bring the CR from 8.3 to 8.8. How do you get in the 9s, just milling? I also read in a tread, that the flat top pistons w/ the n42 head puts you right under 9, but some save over? Is that depending on which head is used? .... Is there something good to read that shows different setups and the compression they yield? Maybe I should ask the question, for a daily driver ...what is a healthy CR to aim for, and what is the best way to build that motor? Edited January 8, 2015 by Project1 Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 7, 2015 Share Posted January 7, 2015 Yes it's mostly based on bore, stroke and head volume. Other things to calculate for cr is how far the piston is "out of the hole", valve relief volume or dish volume, and head gasket thickness. 9-9.5:1 would be a healthy upgrade. Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 7, 2015 Author Share Posted January 7, 2015 (edited) Yes it's mostly based on bore, stroke and head volume. Other things to calculate for cr is how far the piston is "out of the hole", valve relief volume or dish volume, and head gasket thickness. 9-9.5:1 would be a healthy upgrade.Thank So the flat top pistons +.030/ stock rods/ stock crank; w/ the N42 head with a mild cam should be a good combo. All the other parts will basicly be new stock spec replacements, except maybe the valve springs. So what I need to really understand is the clearance volume. W/ the n42 head and flat top pistons, is there a good recommendation on how much to mill/shave the head to get to CR=9.5. I can maybe make some guesses and try to figure out the math. The last head I built was shaved 0.025, I thought that was a lot but I have read on some Z threads people posting the shaved 0.08-0.1. If I have the block resurfaced, is there a good recommendation on how much to mill? Should I leave the block alone and just work with the head? Edited January 8, 2015 by Project1 Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 12, 2015 Author Share Posted January 12, 2015 (edited) In my reading about building this motor I found a ton of helpfull stuff. I thought I would post this one page. If I get anyother good stuff I'll just edit this post and add to the list. Might help someone else at some point in time. Bloc/head L28/LD28 Stroker: https://niyonmaru.wordpress.com/ AKUMA-Z motor build: http://akuma-z.blogspot.com/2011/04/more-progress-on-l28-motor.html TexasZ: http://texasz.net/allan_and_rosanne/Z-Car_Stuff/Bryan-Little/P79-P90%20head%20modding%20tips.htm Fuel cell: http://www.improvedtouring.com/forums/showthread.php?24279-240z-Fuel-Cell-Install-looking-for-advice Timing: http://atlanticz.ca/zclub/techtips/timing/mechtime.html http://forums.hybridz.org/topic/99664-l28-timing/page-2 P79 Head build: http://datsunzgarage.com/p79/ P79/p90 start at post #15: http://forums.hybridz.org/topic/39134-big-and-nasty-headwork/ Megasquirt: 1. http://www.megamanual.com/MSFAQ.htm 2. http://datsun1200.com/modules/mediawiki/index.php?title=MegaSquirt 3. http://forums.hybridz.org/topic/23244-megasquirtnspark-mssmsns-installation-guide/ 4. http://www.zcar.com/forum/10-70-83-tech-discussion-forum/294570-how-install-megasquirt-spark.html 5. http://forums.hybridz.org/topic/23244-megasquirtnspark-mssmsns-installation-guide/ COMP CALC: http://www.ozdat.com/ozdatonline/enginedesign/ EFI/ Vacume/ Fuel: This really helped me a lot -- http://www.atlanticz.ca/zclub/techtips/efisystem/280zfuelinjectionbook.pdf Cooling: http://forums.hybridz.org/topic/115160-l6-cooling-system-diagrams/ 83 dizzy on 75 w/msd: http://atlanticz.ca/zclub/techtips/distributor/index.html http://forums.hybridz.org/topic/119662-msd-6alpainless-ignition-issues/ Edited March 23, 2015 by Project1 Quote Link to comment Share on other sites More sharing options...
dangerZone Posted January 12, 2015 Share Posted January 12, 2015 Your engine will probably be different to mine, but as reference my n42/n42 combo is at 9.69:1 cr with 30 thou over bore, stock rods and crank and some material taken off the cylinder head and block. Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 12, 2015 Author Share Posted January 12, 2015 Your engine will probably be different to mine, but as reference my n42/n42 combo is at 9.69:1 cr with 30 thou over bore, stock rods and crank and some material taken off the cylinder head and block. Thanks for the info . Do you have a build tread? Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 12, 2015 Author Share Posted January 12, 2015 (edited) I found this motor for sale locally for $1000 ( I didn't buy it yet ..just saw it for sale) The guy didn't know much about it. I asked him if I could pull the head and check it out. All he said is the motor has been rebuilt and has a lot of power and proformance internals (whatever that means). It could be a good buy to use and just drop in maybe. I could put what I have for fuel injection on it and convert to MS. Or maybe worth it for parts or just too build on. The core I found to build, that I currently have, Is pretty rough, I'll try to put up some pics tomorrow of the core I have now. Any thoughts? Edited January 13, 2015 by Project1 Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 13, 2015 Share Posted January 13, 2015 $1000 The guy didn't know much about it. I asked him if I could pull the head and check it out. All he said is the motor has been rebuilt and has a lot of power and proformance internals (whatever that means). That's a lot of money for a mystery motor. Did the guy have it built or just end up with it? What are you going to see if you pull the head? Besides piston tops and valves. Quote Link to comment Share on other sites More sharing options...
(goldfish) Posted January 13, 2015 Share Posted January 13, 2015 All power and money should be in the head. A well done documented head is worth some money. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 13, 2015 Share Posted January 13, 2015 (edited) My experience with people who say they don't know much about what they're selling is that they actually do know, and that there are problems and they don't want to be responsible after they get your money. Or they're selling it for someone else who wants to be even farther from the sale. Or it could actually be a decent buy, but you won't know until you find the guy that knows. The thing about modified engines is that they tend to be used hard, often breaking. Edited January 13, 2015 by NewZed Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 13, 2015 Author Share Posted January 13, 2015 That's a lot of money for a mystery motor. Did the guy have it built or just end up with it? What are you going to see if you pull the head? Besides piston tops and valves. I just wanted to do a visual inspection, look for damage and try to identify parts. Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 13, 2015 Author Share Posted January 13, 2015 My experience with people who say they don't know much about what they're selling is that they actually do know, and that there are problems and they don't want to be responsible after they get your money. Or they're selling it for someone else who wants to be even farther from the sale. Or it could actually be a decent buy, but you won't know until you find the guy that knows. The thing about modified engines is that they tend to be used hard, often breaking. Totally understand ...I was worried about the same thing. Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 13, 2015 Author Share Posted January 13, 2015 (edited) So I talked to the seller on the phone today. The story: He said he races ford trucks. He bought this motor from a guy with a shop who builds trucks. He put this motor in his truck with a datsun 5 speed tranmission. He ran it one time and blew the transmission. He built a new transmission and ran it one time and broke the new transmission where it hooks to the drive shaft. He said he has both the tranmission still, and I could have thoes as well. Now he's running a 305 motor. End of story. I never know about trusting random people selling stuff like this. But if this were the case, maybe if I put a less aggressive cam in, i could use that as my staring block and head. It's worth a thought. The pics attached are the core I have. It's not pretty but it was the only one in a reasonable distance I could find. I'm sure it will clean up nice with a bore and a hot tank though. Edited January 13, 2015 by Project1 Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted January 13, 2015 Share Posted January 13, 2015 (edited) Too much money for a mystery motor. You should be able to negotiate to much lower, and if not, walk away. Edited January 13, 2015 by SleeperZ Quote Link to comment Share on other sites More sharing options...
Project1 Posted January 13, 2015 Author Share Posted January 13, 2015 (edited) Too much money for a mystery motor. You should be able to negotiate to much lower, and if not, walk away.That's probably really good advice. I'll offer $500 on mystery motor basis. Not even knowing what cam and such makes it a long shot. Like NewZed added, it's probably beat up a good bit. If I can get it pretty cheap it's probally worth the headers and some parts at the least. If not, I'll just stick to my current build plan and strip this block and get it to the machine shop. Thanks a lot for everyone's opinion. I appreciate everyone's experience. Edit: lmao ...he said hell no he will throw it in the trash for $600 . Well, back to building. Edited January 14, 2015 by Project1 Quote Link to comment Share on other sites More sharing options...
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