Curt Posted December 27, 2014 Author Report Share Posted December 27, 2014 you know what... Could they be L-16 pistons? that are .75 over? They visually don't have as much dish as the l-20b pistons. Quote Link to comment
Doctor510 Posted December 27, 2014 Report Share Posted December 27, 2014 They better not be L16 Pistons, at .75 over (0.030") they'd measure 83.75mm (3.297") Dish has no part of the issue. Are you sure the block is an L20B? Take a picture of the FRONT of the block and post it. I am curious as to which block etc you actually have. Doctor 510 AZ gearhead@cox.net Quote Link to comment
Curt Posted December 27, 2014 Author Report Share Posted December 27, 2014 It's an l20b. It's right on the side of the block and I pulled it from a 1980 720. They should have noticed something was up when it didn't clean out the rust damage. The pistons also come all the way to the top of the deck. I think Mike should change the title to, huge newb mistake...Always measure and verify. I think I'm going to re ring and bearing the L-18 I have that I know at least ran decent. And wait until I can buy new pistons to salvage this, whatever it turned out to be... Quote Link to comment
Curt Posted December 27, 2014 Author Report Share Posted December 27, 2014 Ohh good lord. They are 3.3754 not 3.31... That number had terrible writing. So they are in fact 85.73mm wide. However. They still have way less dish than the L20b pistons. They look like more dish that the L-18 pistons in the other block though. Quote Link to comment
Doctor510 Posted December 27, 2014 Report Share Posted December 27, 2014 They are supposed to have a zero deck height. The pistons look to be L18 which is good since it will give you a bit more compression. Don't get too hung up on the hone job, more than likely it will run just fine, all other things being OK. Be sure to use a good FelPro head gasket. Quote Link to comment
Curt Posted December 27, 2014 Author Report Share Posted December 27, 2014 Ok, good on the deck height. What about the victor reins gaskets? I read somewhere here they are wider than the felpro. The head is the semi open A87. just fully rebiult with the u20 "c" cam in it. Kinda has a wedge shape in the cylinder. not the kidney bean shape. I'd rather run one of those nismo gaskets but they are hard to find these days. Thanks for the help and the heart attack, lol But really, thanks a lot for your help. Quote Link to comment
Doctor510 Posted December 28, 2014 Report Share Posted December 28, 2014 Use what ever gasket (EXCEPT DNJ) you want as long as the "fire ring" bore is at lease 0.020" larger than the cylinder bore. The NISMO gasket is about $100. 2 Quote Link to comment
Curt Posted December 29, 2014 Author Report Share Posted December 29, 2014 Ok, so the metal filter in the block under the pcv tube was rusted out to hell. It had huge holes in it and I assumed it is just to prevent splashing. Here is the deal, I ordered what I thought was the right replacement part for it but it is made of a cotton type material. I assume this would go in the air cleaner housing from the valve cover vent. My gut feeling is this does not go in place of the metal screen that was in the bottom end. So what exactly can I use down there to replace the screen that was there? Can I leave it screen-less and just put the plate back in? Quote Link to comment
datzenmike Posted December 29, 2014 Report Share Posted December 29, 2014 They are supposed to have a zero deck height. The pistons look to be L18 which is good since it will give you a bit more compression. Don't get too hung up on the hone job, more than likely it will run just fine, all other things being OK. Be sure to use a good FelPro head gasket. Actually 0.45mm below but you can safely run up to 0.3mm above by decking the block. Ok, so the metal filter in the block under the pcv tube was rusted out to hell. It had huge holes in it and I assumed it is just to prevent splashing. Here is the deal, I ordered what I thought was the right replacement part for it but it is made of a cotton type material. I assume this would go in the air cleaner housing from the valve cover vent. My gut feeling is this does not go in place of the metal screen that was in the bottom end. So what exactly can I use down there to replace the screen that was there? Can I leave it screen-less and just put the plate back in? You need part number... 11037-21001 under $10 or fold metal flyscreen in a pleated pattern and bolt in with the baffle. I would not run without it or you'll wonder where your oil mileage went. 1 Quote Link to comment
Curt Posted January 3, 2015 Author Report Share Posted January 3, 2015 Got two more head gaskets. They were nos napa made in japan. Victor reinz from rock auto apparently. One was almost wide enough but still in the chamfer in a few spots. I guess my options are the nismo gasket or the datsport gasket? I remember seeing someone had a post for custom gaskets but I can't find it now. Can anyone chime in on the datsport gasket that has ran it? It's about half the cost of nismo gasket. I'm hoping this is the correct gasket? http://www.courtesyparts.com/head-gasket-p-622284.html Quote Link to comment
red13 Posted January 3, 2015 Report Share Posted January 3, 2015 Use what ever gasket (EXCEPT DNJ) you want as long as the "fire ring" bore is at lease 0.020" larger than the cylinder bore. The NISMO gasket is about $100. Whats the problem with DNJ head gasket? Quote Link to comment
banzai510(hainz) Posted January 3, 2015 Report Share Posted January 3, 2015 the Datsport gasket is 87mm .what Baz told me. he has 2 types a grafite type like the stock Nissan and a composite type which is cheaper. These are just common gaskets for the aussie market (made in Japan)for some reason they don't sell them here thru our suppliers. Had mine Fed ex or DHL shipped Buy a couple to make it worth it and maybe a pakage deal somebody said on here a long time ago the beckarnely one was a 87mm but cant confer this or it was a Victor Renz. I wrote it doen but lost my cheatsheet book. since all my motors are l16s I just use the Felpro but I have one leaky already with only like 10k if that on this head change Quote Link to comment
datzenmike Posted January 3, 2015 Report Share Posted January 3, 2015 http://www.courtesyparts.com/head-gasket-p-622284.html MPORTANT: This product is from Nissan Motorsports. That means this product may be a Genuine Nissan part from a local or overseas market, or it may be an aftermarket part and not a Genuine Nissan part at all. So basically 'ya gits what ya gits' Ive used NAPA L20B head gasket, worked just fine. Back from the edge is fine, at the edge will work and the head/block will draw the heat away. In the cylinder it will get very hot and erode away. Quote Link to comment
banzai510(hainz) Posted January 3, 2015 Report Share Posted January 3, 2015 $79 is not a bad price Quote Link to comment
Curt Posted January 3, 2015 Author Report Share Posted January 3, 2015 Alright, thanks guys. It's right at the outer chamfer edge so I think it'll be fine. It was one of the napa gaskets. How do I keep it from shifting around when I put the head on. If it wiggles just a bit parts of the ring slide into the bore more. Quote Link to comment
Doctor510 Posted January 4, 2015 Report Share Posted January 4, 2015 Be sure you install the TWO hollow dowel rings in the bock. DNJ head gaskets do not seal well. Quote Link to comment
Curt Posted January 4, 2015 Author Report Share Posted January 4, 2015 I've got them both in there. You can still shift the gasket around when them like that. I'll just be careful when I put the head on and not move it around and shift the gasket as little as possible. Quote Link to comment
banzai510(hainz) Posted January 4, 2015 Report Share Posted January 4, 2015 buy 2 gaskets Quote Link to comment
Curt Posted January 4, 2015 Author Report Share Posted January 4, 2015 I've got two of the napa gaskets. I put both hollow dowels in there. The gasket still wiggles around. I'm gonna clean the threads once more and clean the deck, then install it. Hopefully it'll be fine. Quote Link to comment
Curt Posted January 5, 2015 Author Report Share Posted January 5, 2015 I've got the head on. timing kit on. At tdc the timing plate mark is slightly to the left of the notch in the cam pulley. like halfway. It's on pin position 2 and everything is lined up correctly. Is this because the block and head were decked? Should I try and find a pin location that is closer? My gut says it's fine but with the possibility of having L18 pistons in there I don't want to destroy it on startup. Quote Link to comment
datzenmike Posted January 6, 2015 Report Share Posted January 6, 2015 Looks good enough. Each adjustment hole is 4 degrees or about the width of that horizontal etch mark. If you were to adjust back it would be over on the right of the notch. Perfect is the notch just barely to the right of the center of the mark. L18 pistons have nothing to do with where the notch is. At TDC compression the valves are both closed. On exhaust stroke TDC the exhaust valve is only 14 degrees away from being closed and the intake has barely been open for 16 degrees. They are, for all intents, barely off their seats. Quote Link to comment
Doctor510 Posted January 6, 2015 Report Share Posted January 6, 2015 Looking DAMN GOOD!!!! Don't forget to pressurize (oil that is) the motor before you start it up. Valve cover off, spark plugs out, timing set, fuel lines hooked up (OIL WITH SOME ZDDP IN IT IN THE OIL PAN), using a remote starter or screw driver, spin the motor until oil squirts out of the cam lobes. Button it up and fire away!!!! Quote Link to comment
Curt Posted January 6, 2015 Author Report Share Posted January 6, 2015 Sweet, I'll leave it be then. I was going to prime it with the ground down distributor drive shaft trick. I still need to have the flywheel surfaced and get that all squared away so it'll be a bit before it gets fired up. I was thinking of priming the oil sooner rather than later though. Quote Link to comment
Doctor510 Posted January 6, 2015 Report Share Posted January 6, 2015 The "ground down dist shaft" trick is good for Chevys not for Datsuns. If you do it the way I suggested, you will fill the carb(s) while you are spinning the motor and you will NOT have to drop the Oil Pump to re-install the Dist/OP drive shaft. Just an FYI for you Quote Link to comment
Curt Posted March 3, 2015 Author Report Share Posted March 3, 2015 Ok, this thing is ready to go back in the truck. The trans is still in the truck and it was a bitch getting the motor out without the trans connected to it, it would hang up really bad on the center link/oil pan. Is the best way going to be to pull the trans and put the engine and trans in mated together? Thanks for the help... Quote Link to comment
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