KAZ24 build thread / compression questions / cam / header / DONE!!

[HRH]

And here's the block back from the machine shop. We ended up cutting .012 off the block surface, and .020 off the head for a total of .032 off. Need to clean up the welds a little bit still, but it's mostly ready to go. Now just waiting for the rod bolts to come, and maybe tonight I'll lap the valves. SIDE NOTE: IT'S TOO HOT HERE!!! Temperature hit 50 degrees, I'm freakin' dying! My garage is soon to be flooded due to all the snow getting rained on and melting. Not supposed to get below freezing for the next week.

I decided to move the engine assembly to the kitchen since outside humidity is 96% at current and the block alone is heavy enough. If I assemble it in the basement, then we have to carry it up the stairs to get to the garage, and that sucks. Hope my trusses support the motor!

[HRH]

Got the crank in tonight. Took exceedingly long, probably due to not having done it in a while and my anal-retentive nature. Got it juuuust right though. I'll throw up some pictures later.

[HRH]

Okay, here's pictures! Put in the rear main seal tonight. Put in too much rtv down the side seal holes and consequently couldn't get the rubber seals in far enough. So yanked them back out and found a #0 phillips to stick down there and scoop out some. Anyway, it's all sealed now. Greased up the rear main and rtved the edge. No freakin' leaks! I hate oil leaks!

Last time I forgot to put in the rear main until I had the whole motor assembled except for the oil pan. Then had to hang it from the cherry picker and put it in. THAT is a pain in the ass, so this time we thought ahead! What I really need is a slick motor stand that bolts to the motor mounts, not to the trans mounts. That would solve that problem.













And as a bonus, here's a SUPER SEXY chick with some fat beats! I like that!

Well, now that I updated the pictures, it apparently didn't keep the video link.  Boooo.

[HRH]

Heeeeeeey kids! Krusty has a video on how to properly install freeze plugs since I screwed it up the other night and had to do it over this morning! :)

 

[HRH]

Okay, so here we go with the analness of assembling motors! After opening the Datsun bible, top ring end gap figures are .005*each inch of bore. So we have a 3.520 bore now, and .005*3.520=.0176 top ring end gap. Second ring is the same multiplied by .004. This is according to the Datsun bible for race motors.

 

Have not put the 2nd ring in the bores yet. Have the top rings in and getting .015-.016 end gap which is close enough to equal where I'm not going to bother filing them down. BUT, the Haynes manual states .0157 at the end of the ring gap specs, but does not specify whether that accounts for overbore or not. If I go with the Datsun bible, I need to shave a few thousandths off the rings. But then, that's generally for race motors which run looser tolerances due to the heat generated.

 

However, we're raising the compression, granted not anywhere near to race motor specs, but a significant amount from the 8.6:1 stock compression. So I'm wrestling with whether to trim a little more off and risk less seal, or to leave where they are and worry about being the ends hitting and snapping the ring. Realistically I got the rings for an overbore, so they should be just fine, and I'm tempted to leave them. But you know that ADHD thing I mentioned? ;)

 

Input? Datzenmike? Basically I'm debating whether or not to shave 1 - 1.5 thousandths off the ring ends.

[HRH]

Alright, got ahold of my Datsun guru and he said he sets them up tighter than that, should be fine. Think I'll go with that and start putting them in. Yay!

[HRH]

SONOFABITCH!!! So I just put the second compression rings down the bore, and go figure, they had about .26-.030 end gap! NOT FUCKING ACCEPTABLE!!! They're the rings for the overbore pistons too. Oil rings were about right, 2nds were just not good. So now I get to figure out what's happening there. They're Japanese rings. Funny it seems the top comp is chrome, while the second is iron. I'm not a fan of chrome rings to begin with, but oh well. I just don't see any way these could be right. 2nd rings according to the Datsun bible are always tighter than the top ring end gap. Never had a problem with that, but these sure are too sloppy.

 

And of course, now I can't install the pistons and I'm betting no one in town is going to have the rings I need. Especially not on a Sunday. :angry:

 

EDIT: Okay, now that I've been pissed off I started searching google and found some evidence of manufacturers setting it up so the 2nd ring gap is larger so as not to induce ring lift on the top compression ring. It still doesn't make sense to me. I've followed the Datsun bible of about .014 on the bottom ring and about .017 on the top ring and that's what's in the orange car at current. No problems with sealing or oil consumption, and I've already beaten that engine for quite a few miles.

 

Anyone else have any theory on this?

 

Now, even more interesting, I found a Wiseco ring end gap dimension sheet and it's THE OPPOSITE of the stock Nissan information in the Haynes manual and Datsun bible. AAAAA! Who's right? Maybe these rings will work? I still don't understand it.

 

By my thinking and the Datsun bible's, the top ring is the hottest, therefore needs a larger end gap, and the second ring a smaller gap as it's cooler and needs to not let the gas blow past into the crankcase.

 

Bollocks! I'm out for a walk!

[HRH]

I called and left a message at Nippon's Michigan plant today. Not particularly helpful, no idea in what department I left the message. We shall see if I get a call back. Couldn't get the set of .030 over rings like I wanted, so got another set of .020 over and compared. They're exactly the same as the other ones. So either I got two mis-boxed set of rings, or they're just plain incorrect, or NPR thinks you should use twice the gap with the bottom ring. Which does not sit well with me. Think I'm going to go down to the competition now and see what they have. I'd like to find a set of rings today so I can get the bottom end together.

 

EDIT: Sent an email to sales@npr.co.jp. We'll see if I get a reply back before I find another set of rings that works. I'm off to go find another set in town that works at the moment.

[HRH]

Okay, got lucky and Motion had the .030 Nippon rings in stock. Same markings as the other rings, different box. But they are marked 50 and 75, in mm, so .020 and .030.

 

I fit the .030 in the bore and they don't quite fit. Overlap by about 3 thousandths or so. Which is good, but it also means I'll have a lot of filing to do. So now the question is, do I just use a file and go to town, or do I see if I can find a ring filer in town? I could have gotten one at NAPA, but it was in Chicago. Thinking I may see if one of the performance stores has one in stock, just don't want to have my pants pulled down over the price. They're $40-$50 online, fear I might get more on the upside if I have to buy one locally.

[izzo]

Cool video man! I forgot to check out this thread last time i saw there was something new

 

 

Sorry about the ring shit, i know how that goes. Do you know that nobody on the coast here carries metric carb fittings? Not even the hydraulic places here

[HRH]

Metric carb fittings? What kind are you looking for? Weber or stock hitachi?

 

I figured out what I'm going to do with the ring filer issue since I can't find a ring filer in town and I don't want to pay for such a tool since I'm already over-extending myself on this motor build.

 

I have one of those 4"x36" with 6" belt sanders from Harbor Freight. The 6" round sander has a 90 degree platform. Fortunately for me the hub is only a 1/4" wide. And there's enough distance between that and the main body that a piston ring can be layed flat and ground just like the hand version I was looking for.

 

Already tried an old L20 ring I had out of a broken set and successfully gapped it. Need to go get some ultrafine sticky back 6" sanding discs now. I think 320 should do it little enough so I don't remove to much material in a hurry. So we have a ring filer! :D

 

Sandpaper is at least a lot cheaper than a ring filer.

[LenRobertson]

I did a search trying to find out what a ring filler looks like. In the process, I found this thread on ring filling: http://www.hotrodders.com/forum/piston-ring-file-152593.html The parts you might find of interest are the "one end filling or both ends" (I'm not sure the posters agreed on this), and a couple of mentions of grit. I like your solution of the disc sander. I suppose going slow and checking the squareness of the end are what is important. Of course it is the last couple thou when you are tired and tend to hurry that you have to be most careful. I liked what one guy said in the thread, too big a gap is better than not enough (resulting in a broken piston).

 

Len

[HRH]

Okay, so no one gets any bad ideas here, ring gapping with a 6" electric motor is VERY touchy! Not for the faint of heart or those without nimble fingers. I cleaned off my sander and brought inside. Removed the sticky old 80 grit pad and put on fresh 320 grit.

EVEN WITH 320 GRIT, you will grind off material lickety-split! If you choose to use this method, be VERY VERY CAREFUL!!! Also, make sure you have a cup of water handy and be careful not to de-temper the ring. I tested a crap ring before starting on the actual rings I was planning on using and they get hot even after a second of grinding. What I've found works the best so far is to dunk the ring end you're grinding in the water, then lightly grind for a half second. The water droplet should stay on and work as a heat-sink. Feel the end after you've finished and for heaven's sake, GO SLOW!!!

I did this ring all of four times to get the exact right dimension. It's now at .014 and almost perfectly square. Have 3 more to do, and even with 320, it cuts off ring material very quickly. Do a smidge at a time and put it back in the bore to check often! Make sure you have good light as well. I brought the droplight up from the basement so I could better see the ring end.

If you have rings that are correct but need minor adjustment, use a hand file. I'm mowing down .030" rings to fit my .020 bore in case you haven't read the above posts. They overlapped by about 4 thousandths.

[izzo]

Metric carb fittings? What kind are you looking for? Weber or stock hitachi?

 

I figured out what I'm going to do with the ring filer issue since I can't find a ring filer in town and I don't want to pay for such a tool since I'm already over-extending myself on this motor build.

 

I have one of those 4"x36" with 6" belt sanders from Harbor Freight. The 6" round sander has a 90 degree platform. Fortunately for me the hub is only a 1/4" wide. And there's enough distance between that and the main body that a piston ring can be layed flat and ground just like the hand version I was looking for.

 

Already tried an old L20 ring I had out of a broken set and successfully gapped it. Need to go get some ultrafine sticky back 6" sanding discs now. I think 320 should do it little enough so I don't remove to much material in a hurry. So we have a ring filer! :D

 

Sandpaper is at least a lot cheaper than a ring filer.

 

 

Metric, 12mm x 1.5 pitch, for the fuel inlet on the weber dcoe. i tried napa auto parts first, they didn't have. orielly doesn't open up for a little while here.

[HRH]

Hmmm, I thought those were SAE. Guess I've never misplaced one. And here's why I was freaking out about the end gap. Both are Nippon Piston Rings:

Have all the rings done now. They're a little larger than the .014 gap I wanted, more like .016, but that will be fine also. Either way you slice it, they're still a lot closer to correct than the .028 gap of the shown .020 "correct" rings. Have not received an email back from NPR or a call. Not really surprised there. I wouldn't recommend this way of filing rings to anyone. An actual ring filer is a more appropriate way, but seeing as I want this thing together tonight and there wasn't a ring filer to be had in town, oh freakin' well!

[datzenmike]

Cool.

[HRH]

Alright, have the pistons in! I actually made an installation video, both segments are uploading on youtube right now. I'll post those links in a bit.

[datzenmike]

Coolio

[HRH]

Yeah, taking way too long to upload. Have about 35 minutes left for the first one. Trying to get motivated to go start dinking with the head, but just ate lunch and now I'm sleepy. :huh:

 

Okay, here's Part 1:

 

 

And here's Part 2:

 

[LenRobertson]

Cool vids to watch on a Sunday afternoon. Couple of comments &/or questions - It would have nice to have just a little more light, like a dim light beside and maybe above the camera. But the way you did it is WAY better than too bright a light that glares, especially when you stepped closer to the camera. Maybe a bright light bounced off the wall behind the cam (if there is a wall there). I suppose I'm sounding nit-picky, cause overall the vid quality is nice, and it played right through on my computer without hanging up.

 

Lubing the rings - Down on the farm, we've always oiled the hell out of the rings before compressing, and oil the cylinder before sticking the piston in. But this raises concern of attracting dirt. You mentioned using WD40, which seems better as far as not being such a dirt magnet. Do you think it is better to WD40, then oil the cylinder just before the head goes on? Or is it important to have oil around the rings? I suppose once the engine runs, there isn't much oil behind the rings, or is there?

 

I like to slip a short piece of thin plastic tubing over the rod bolts, to protect the crank journal from being nicked by the bolt thread. Maybe I'm always paranoid and over cautious. Also, when installing bearing shells, they should be dry on the back, and check to be sure there is no dirt, hair, lint, anything on the rod or back of the bearing shell. It is worth looking along the edge of the rod where the bearing shell goes in to be sure there are no dings that might keep the shell from seating all the way down against the rod. Look carefully at the rod surface and bearing shell with a bright light just before you stick them together. Matt, I know you know these things, but not everyone else watching the vids may know.

 

Thanks for taking all the time to shoot and upload these.

 

Len

[HRH]

Yeah, I thought about the lighting after I took the videos, but didn't want to monkey with trying to get a drop light above the camera somehow. It is a bit dark though. Can't really see the end gaps. The diagram is in the Datsun bible though.

 

As far as oiling the pistons and rings, I've done it both ways. Generally all oiling the piston does is make a mess and attract dirt. However, WD-40 attracts dirt just as much as oil. I only threw a little WD on the rings and compressor before putting in. I generally install things almost dry now. I had previously lubed the bores with WD to prevent rust and then the motor has been bagged each time I'm done working on whichever stage. It had plenty of WD left, so really didn't need much more.

 

And yes, after you fire it up, there's really no oil in the rings. The oil control ring will have a little, but other than that there shouldn't be any oil. If you get really worried about it, you can just throw some marvel mystery oil down the spark plug holes a little while before the start up. They'll soak down into the rings and make a bit of smoke on start up. For my taste, dry assembly is better, with the exception of assembly lube on the bearings.

 

You're right on about the bearing shells. I wiped the rod clean prior to the video and cleaned all the no-rust gunk coating off the bearing shells. Lubed liberally with assembly lube. I've heard of people putting something over the bolts to protect the crank. I had it straight up and down so there wasn't much wiggle room to get the rod cocked enough. Still not a bad idea though.

[HRH]

Whoo hoo! Finished lapping the valves and got them all put back in the head. Going to leak test it tomorrow with either liquid, or if I can find a cheap big suction cup/vacuum pump at work tomorrow, I'll do that route. Apparently that's what Buddy used to use at the diesel shop for testing the valves. You suck onto the bottom of the cylinder head and hand pump a vacuum and watch to see if it disappears. This is all without the cam in of course, otherwise you'd have valves open.

 

EDIT: There will be leakage through the valve stem, so constant vacuum must be applied. Thought I did a bad lapping job. Had Sunwest check it on their machine and got the low down on leak checking. My head passed fine.

[HRH]

Head is good to go. Tomorrow is the day off. Preparing for head installation tomorrow! Booyah!

[I'm BLUE]

A Very Nice Job HRH :cool:

 

I hate how some of the brands/worn piston ring compressors will tend to "slip" into the cylinders , I have to hold them firmly I have found :D ,,, I am always paranoid that the oil ring will jump a gap since it is sooooo flimsy ,,, my "grant" rings I did my Z car engine with had color indicators thankfully ,,, some brands don't :rolleyes:

[HRH]

So I just yanked off the valve cover on the current motor in the truck. Guess what I found? Yep. The slack side tensioner shoe (the straight one), plastic guide material broke off. Half is still on. This is the new tensioner guide I put on last summer. So that confirms either shit guide or low oil pressure making chain too slack, thus eating through plastic guide. I'd bet the latter.