2003z Posted January 29, 2007 Share Posted January 29, 2007 I don't know if its the way I am measuring, if I got the wrong rings sent to me or what! To start: F54 block / P90 head, standard dished pistons. The engine ran fine, no blow by or excessive oil consumption, just lower compression than I wanted. I am upgrading to Nissan Motorsports cast pistons, in stock bore. I had the block hot tanked and honed. I measure the bores at 3.386 inches, 86.01mm which is in spec according to the clymer manual, but when I slide a ring into the cylinder to check the end gap, it comes out to about 4mm instead of the .2 to .4mm it should be. I don't know what to do at this point. I thought the machine shop took too much material off when honing, so first I bought a set of used oversized pistons from Dannys Datsuns and was going to bring the block back to get it bored, but they wound up being L24 oversized pistons when they arrived, so that was a waste of $150. I thought maybe I got rings for an L24 instead of an L28, but the rings I have are larger than the L24 rings that came on the above pistons. I just got another block from a friend, but its actually been overbored already, as its got 87mm bores. Quote Link to comment Share on other sites More sharing options...
2003z Posted January 29, 2007 Author Share Posted January 29, 2007 a couple of pictures I didn't use this caliper to measure the bores, I used a dial gage, this is just for illustration and is not accurate. Quote Link to comment Share on other sites More sharing options...
LineC Posted January 29, 2007 Share Posted January 29, 2007 If your bore is 86mm and the new rings are coming up with measurements of 4mm end gap that should be .2 to .4 you have wrong parts. I would send back the pistons and rings and then email Danny Datsun and let him know he sent the wrong pistons also. No business should have a policy of not letting customers return parts if they are the wrong parts. What are your old pistons and rings end gapped to when they are in the block? Quote Link to comment Share on other sites More sharing options...
2003z Posted January 29, 2007 Author Share Posted January 29, 2007 What are your old pistons and rings end gapped to when they are in the block? I don't have them anymore. I sent them to Yasin, since I didn't need them. As for the Dannys Datsun stuff, I will probably keep them (use the 240 rods with AZC pistons, maybe) or just save them, as they are getting hard to find. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted January 29, 2007 Share Posted January 29, 2007 How is the gap half way down the bore? I can't imagine taper that bad but... I'm thinking the these are not the correct rings for the application. Quote Link to comment Share on other sites More sharing options...
2003z Posted January 29, 2007 Author Share Posted January 29, 2007 How is the gap half way down the bore? I can't imagine taper that bad but...I'm thinking the these are not the correct rings for the application. gap is consistent anywhere down the bore. Quote Link to comment Share on other sites More sharing options...
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