Villeman Posted July 27, 2016 Share Posted July 27, 2016 (edited) Hello all,I got my Z and well, it really has been sitting since 83. After a day we found out why, seems like cylinder 6 was damaged and driven for some time back in the day. Long story short, we learned that the fastest way is actually pulling the head with both manifolds still attatched and learned what was the cause for the low compression. Our trusty Ikea Ivar cylinder head remover was used 125 psi (roughly) on 1-5 cold, other plugs still in and with bad oil pressure 70 psi on 6 so the head had to come off. Valve seals are rusted but very good, likely it really had only 45k miles. some seals still shine like new, others are rusted, I guess since the engine sat in one position for a long time. and this is what we saw no wonder compression is so low. The pit is quite deep. and this brings me to the next question. Rebore? 2mm over, since I doubt 1mm will do the trick? I want to use the opportunity to also improve on the head. Its N42/N42 from a 76 280z 2+2 so does it make sense to shave the head to a) compensate for 2mm overbore and get compression a bit higher? (good gas here and it will run on LPG along the way, which is 105 octane) for the block, which pistons for a poor mans build? TonyD suggested 88mm VW Pistons once, Tony, is this still peak for your wisdom? Any things I should consider? I want to keep the N42 block but also have a F54. Needs drilling and honing as well and lacks a crankshaft, just for an alternative. I can´t do any wild things here and want to keep the FI. Long story short, is overbore an option for that damage, which pistons for a poor student, and any improvements that are due since "if you already do it you might do ______" as well. The head will be plained anyways, valve seats polished and new valve seals. Anything else needed? Thanks! Edited July 27, 2016 by Villeman Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 27, 2016 Share Posted July 27, 2016 Well that kind of sucks. Good it's an N42... Plenty of boring available. A sleeve on the affected cylinder allows you to retain the stock bore and use relatively inexpensive ITM flat-top Pistons ($300?) That lets you spend the money on someone to weld the chambers closed, maybe port the head....an Isky cam and LPG AWAY! Quote Link to comment Share on other sites More sharing options...
Villeman Posted July 27, 2016 Author Share Posted July 27, 2016 d´oh I completely forgot to look into sleeving it. This + flat tops sound good. I have 2 N42 heads, maybe I will try to port one What Isky Cam would be suited when I want to keep it FI? And where to source one cheap ?^^ Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 27, 2016 Share Posted July 27, 2016 Send in the rusty core for regrinding! Get the open chamber welded closed. Then put a Microsquirt into the stock ECU Box so everything looks legal and fuel away! Quote Link to comment Share on other sites More sharing options...
Villeman Posted July 27, 2016 Author Share Posted July 27, 2016 Micro/Megasquirt will be one step further I guess. For now, can I just run the engine with cylinder 6 sleeved and ITM flat tops as is? Shouldn´t be too high compression and frees funds to finish the car before i start with Porting/cam/MS. Question, flat tops or flat tops with shaved head? more reading up, I guess ^^ Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 28, 2016 Share Posted July 28, 2016 I'd not cut anything at all. just flat tops. Once you decide your path, then start cutting. Best do it once, measure first several times! Quote Link to comment Share on other sites More sharing options...
Villeman Posted July 28, 2016 Author Share Posted July 28, 2016 (edited) wise words ^^ thats what I got the second engine for, a propper money eating nuissance, but now I just want to drive it. Sleeve it and ITM´s is there a good source ? My engine builder does boat engines so I have to supply the stuff. Anybody knows about these Euro Pistons BRAAP mentioned here at # 11? http://s17.photobucket.com/user/BRAAPZ/media/Pistons1Large.jpg.html http://forums.hybridz.org/topic/87963-dished-or-flat-top/ Edited July 28, 2016 by Villeman Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 28, 2016 Share Posted July 28, 2016 Frank280ZX had some of those over in Holland. There may be a chance in some dream world where you could order them from Nissan still....But the ITM's are all over eBay for around $300 in standard and 1mm oversized. Quote Link to comment Share on other sites More sharing options...
Villeman Posted July 28, 2016 Author Share Posted July 28, 2016 (edited) I found 2 suppliers of the domed 280ZX Nismo/Eurospec/whatever pistons, Priced between 120-150€ per Piston NOS. So if you want some Tony? sooo tempted They are also in a Nissan Sunny B20 if I saw this correctly at least one supplier sells them as B20 pistons Edited July 28, 2016 by Villeman Quote Link to comment Share on other sites More sharing options...
Villeman Posted July 28, 2016 Author Share Posted July 28, 2016 (edited) Damn, I guess no high compression pistons for me. Engine builder said that 1-5 are perfect, just new rings are needed. Nr. 6 need a sleeve+piston. the good news is that its quite cheap this way including head work (valve seals+seats) Any advice where to get sleeve+standard piston? (I guess i will try to get euro domed flattops for a more reasonable price than 160$ per piston and try that next time Edited July 28, 2016 by Villeman Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 29, 2016 Share Posted July 29, 2016 At that price, you can buy custom Arias, Ross, Venolia, Weisco in just about any configuration you want! The set of ITM Standard Pistons and rings is $300 on eBay... Standard or 0,5 oversize! http://pages.ebay.com/link/?nav=item.view&alt=web&id=331908278613&globalID=EBAY-US Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 29, 2016 Share Posted July 29, 2016 Any machine shop can spin a shouldered sleeve on a lathe, check Darton or some others for spun cast or ductile iron sleeves. The can be had for $30 to $100 each... Exotic stuff can go stratospheric. Quote Link to comment Share on other sites More sharing options...
Villeman Posted August 1, 2016 Author Share Posted August 1, 2016 So, the original Nissan liner is 11012N4200 and I could get one for 115$ shipped, seems fair to me (out of stock in Europe as per statement of a big Nissan parts dealer). One last question, can I mix one ITM piston and 5 stock Nissan ones or is there a risk of unbalancing the engine (I honestly don´t know ^^ ), in that case, anybody has a NOS Nissan piston (no oversize)? Quote Link to comment Share on other sites More sharing options...
CRAracer05 Posted August 2, 2016 Share Posted August 2, 2016 (edited) Send in the rusty core for regrinding! Get the open chamber welded closed. Then put a Microsquirt into the stock ECU Box so everything looks legal and fuel away! Tony D, do you know any source to get an N42 head welded that is cost effective? I have been quoted anywhere from $2,500 to $6,000! Makes me want to buy a TIG and try my luck after I practice on some scrap heads. Edited August 2, 2016 by CRAracer05 Quote Link to comment Share on other sites More sharing options...
Chickenman Posted August 2, 2016 Share Posted August 2, 2016 Rock Auto has ITM flat tops for L28 for $34.78 USD each. Available in standard sizes and over bores. Just order 6 and be done with it. Rock Auto ships worldwide Order for a 1983 a non-Turbo 280ZX . These are flat tops. http://www.rockauto.com/en/catalog/nissan,1983,280zx,2.8l+l6,1209394,engine,piston,5620 Quote Link to comment Share on other sites More sharing options...
CRAracer05 Posted August 2, 2016 Share Posted August 2, 2016 Rock Auto has ITM flat tops for L28 for $34.78 USD each. Available in standard sizes and over bores. Just order 6 and be done with it. Rock Auto ships worldwide Order for a 1983 a non-Turbo 280ZX . These are flat tops. http://www.rockauto.com/en/catalog/nissan,1983,280zx,2.8l+l6,1209394,engine,piston,5620 Be careful as Rockauto only has rings available in standard and .040" oversize even though they have pistons in .020" and .030". I ran into this issue when I purchased mine awhile back. Quote Link to comment Share on other sites More sharing options...
Villeman Posted August 2, 2016 Author Share Posted August 2, 2016 I need a dished top piston anyways. For now I will just replace the one broken piston. Quote Link to comment Share on other sites More sharing options...
fraz Posted August 2, 2016 Share Posted August 2, 2016 Rock Auto has ITM flat tops for L28 for $34.78 USD each. Available in standard sizes and over bores. Just order 6 and be done with it. Rock Auto ships worldwide Order for a 1983 a non-Turbo 280ZX . These are flat tops. http://www.rockauto.com/en/catalog/nissan,1983,280zx,2.8l+l6,1209394,engine,piston,5620 I just got a set of itm flat tops. They look waaaaaay more China than those photos that all the sellers use. Not going to rev it super hard so hopefully will be OK. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 7, 2016 Share Posted August 7, 2016 Tony D, do you know any source to get an N42 head welded that is cost effective? I have been quoted anywhere from $2,500 to $6,000! Makes me want to buy a TIG and try my luck after I practice on some scrap heads. $2,500 is about right with the port work. I don't know about "cost effective" -- you're in the wrong hobby to be using that phrase. Dighera's Law of Performance Automobile Ownership: "A Car is a hole in mid air supported by four inedible rubber doughnuts. Into this hole, you throw buckets full of cash which you will never see again." Quote Link to comment Share on other sites More sharing options...
Villeman Posted August 10, 2016 Author Share Posted August 10, 2016 Hi, bad news, x-ray says waterdamage on 3 more cylinders but testing on the lower end confirms everything is like new. Now i have to decide, move to another block (really don´t want to) or put in 3 more liners. Well, if I put liners in all 6 pots I can make a stroker in 10 years Quote Link to comment Share on other sites More sharing options...
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