Heroez Posted April 8, 2012 Share Posted April 8, 2012 (edited) Hello guys. Im new to the under hood stuff but not completely clueless either. Usually I would have an experienced person build my engine like I did last time. I have a desire to learn and maybe save a few bucks by getting involved in the build process. I have these parts to work with- 1 n42 L28 block which was disassembled by a mechanic to use the crank in my last engine. The rods, pistons, oil pickup tube and a few other bits that came off of it are boxed. 1 L26 block still assembled, it has the same crankshaft as the L28. I have another L28 N42 assembled with the n47 head on it. I also have a naked N42 head, E88 with no cam, Maxima N47. All of these parts have been laying around quite a while. The rods that are boxed up have a bit of surface rust on a few of them. The blocks are just typical old condition. How can I tell what is useable and what is junk? I would like to isolate the best condition parts so that they may be considered to be used in a learning project engine build. I just dont know where to start. Its not going to be a high output build. Perhaps a little work on the head, stock cam. Flat top pistons. I may source a p79 or piece together the N42 head. My instinct is to take the naked L28 block to a mechanic to be inspected. Is there any indications that I may be able to spot before loading it up? I would likely be using the crank out of the other L26 block assembly. What should I look at on that one? Just check for play at the crankshaft bearings? I can see step one is to wash the parts, but what then? Any advice on how to sort the good from bad would be helpful. Edited April 8, 2012 by Heroez Quote Link to comment Share on other sites More sharing options...
johnc Posted April 9, 2012 Share Posted April 9, 2012 Get the factory service manual and the book, "How to Rebuild your Nissan/Datsun Engine." Quote Link to comment Share on other sites More sharing options...
BrandenZ Posted April 9, 2012 Share Posted April 9, 2012 If you're not looking to make a high-output build, and are more in it for the experience, why not simply use the existing and assembled bottom-end? You can take some very simple measurements using the FSM John mentioned and plastigage to determine if the main and rod bearings are in spec. If so, focus on making any modifications to the head that you're interested in, bolt it together, and run it! Someone with more experience on the subject may have a differing opinion, but I'm not sure I see much value in completely disassembling and rebuilding an L28 bottom-end unless you're going the 3.1 stroker route or looking to add forged internals for a high-output turbo build. From the reading I've done, the bottom-ends, and combustion chambers tend to be extremely stout. Mine needed nothing aside from a good hone and rod bearings. If I were to do anything in your case, it may be to add flattop pistons to bump compression. In general, I agree with what John said. Additionally: search, search, search! There is an incredible wealth of knowledge to be found just on the L6 forums here. Aside from HybridZ, here's a couple of links I found that proved extremely useful to me when I was doing my rebuild: Amazing overview that covers most items end-to-end: http://datsunzgarage.com/rebuild/ Differences between heads / blocks of different years: http://www.zhome.com/ZCMnL/tech/128combo.html Another head overview, including compression ratios for various combos and flow charts: http://www.viczcar.com/forum/index.php?topic=6012.0 Differences between cams: http://xenons130.com/cams.html G'luck with the build! Quote Link to comment Share on other sites More sharing options...
Perfect240z Posted April 9, 2012 Share Posted April 9, 2012 (edited) Sent you a pm. The search button on hz is your friend, if nothing is found there is no harm In asking Edited April 9, 2012 by Alex731 Quote Link to comment Share on other sites More sharing options...
Heroez Posted April 10, 2012 Author Share Posted April 10, 2012 Thank you for the replies. I forgot about the Datsun z garage site. I suppose I didnt pose my question very well. From reading and searching I havent found the exact information I need regarding old parts. The disassembled L28 and assembled L26 were stored in a barn with the heads removed and I can see rust on the cylinder walls. I cant find mention of what to do about the rust there. Its not real bad. I suppose it could be honed out or bored to refresh that area. A few places on the outside of the block have surface rust to, which I will spot blast. From the information gathered I feel like I can move forward and check the bearings and check for broken bolts in the block. Quote Link to comment Share on other sites More sharing options...
BrandenZ Posted April 10, 2012 Share Posted April 10, 2012 You can hone it yourself with a power drill and a $30 kit. I'd go for it, if it comes out rust free with nice crosshatching, run it. Also save yourself the trouble I experienced and go ahead and replace the rings. Although I didn't have rust in the combustion chambers, the F54 I used sat for an unknown period of time, and I found out the hard way that the oil rings in 2 / 6 cylinders were rusted and stuck in place. Perfect compression, perfect leakdown, total neighborhood fumigation -- had to pull it, tear it all back down and rering it. Last thing -- your head bolts are probably fine to reuse, but do not reuse the rod bolts (thanks John for passing that knowledge along!) as they're a torque-to-yield design. I picked up a set of ARP rod bolts on eBay for half of what MSA sells them for, cheaper than I could've gotten replacement stock ones for. 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.