David K Posted September 27, 2002 Share Posted September 27, 2002 Ok this is for the turbo guys or whoever has a p90a head. im getting the p90a rebuilt in 2 days and i also bought a high capacity oil pump for a nissan bluebird. I cant remember when and when i heard this, but somebody told me to drill out the passage that goes from the block to the head. were they right? i will drill it a tad before the head gets machined. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted September 27, 2002 Share Posted September 27, 2002 I have a P90A. Which passage are you talking about? Quote Link to comment Share on other sites More sharing options...
David K Posted September 27, 2002 Author Share Posted September 27, 2002 the one that brings the oil up from the block into the head. It shoots oil into the camshaft tower to distribute to the camshaft. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted September 27, 2002 Share Posted September 27, 2002 David, the oil passage that you are talking about is on the block side, there are too bronze(brass?) oil jets on the block. one in the center and one in front of the #1 cylinder bore. You can drill some out but don't go too big because you will starve the bearing. Quote Link to comment Share on other sites More sharing options...
David K Posted September 27, 2002 Author Share Posted September 27, 2002 yeah those are the ones. hold on ill brb gonna take pics real quick. Quote Link to comment Share on other sites More sharing options...
David K Posted September 27, 2002 Author Share Posted September 27, 2002 ok here is the number one oil squirter number 2 oil squirter in middle of block. Can i drill the squirter all the way to the iron material? or should i drill halfway in between the existing hole and the outer part of the squirter? Remember i am using a high capacity oil pump so i dont think starvation would be a problem. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted September 27, 2002 Share Posted September 27, 2002 no! you can't drill out that much you'll need more oil on the bottom end. I've read up to 2mm is okay. I drilled mine but I went just tad larger than stock hole. 3/32 inch I think?? I just picked out a drill bit that fits in the oil hole then got one that's one size bigger than that to drill out the hole. Why are you doing this for again? Quote Link to comment Share on other sites More sharing options...
David K Posted September 27, 2002 Author Share Posted September 27, 2002 im prepping the block for turbocharging. im taking every step i can ahead of time to relax me and assure me my engine isnt gonna blow up this time round. I also wanna take advantage of my new oil pump. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted September 27, 2002 Share Posted September 27, 2002 Ok, I remember that you are doing that now. Anyway, yeah, don't go crazy with the drilling. not worth it. I was told to really worry about the pistons pins and make sure they are not siezed. The floating pin supposed to be the way to go but there are ways to modify the press-in pins to kind of float so they won't seize. Are you going to rebuilt the stock spec motor or go wild and use longer rods? Quote Link to comment Share on other sites More sharing options...
David K Posted September 27, 2002 Author Share Posted September 27, 2002 no im just gonna use the stock n/a pistons, stock crank, and stock rods. i just wanna make sure it all stays together i dont wanna keep boosting and then break some funny stuff. what do you recommend i use along the lines of pistons and rods? hows your project coming along? as i can recall we are in competition to build a turbo engine, remember? my AIM is black79280zx Quote Link to comment Share on other sites More sharing options...
Bob_H Posted September 27, 2002 Share Posted September 27, 2002 Don't touch it. The bigger that hole, the more pressure you are taking away from things like your turbo, the main bearings, etc.. I am running a bigger cam in my P-90A than you ever will in a turbo motor and I have no problems at all with the stock size openings. Trust me, you need that oil in other places, not the lifters. -Bob Quote Link to comment Share on other sites More sharing options...
David K Posted September 27, 2002 Author Share Posted September 27, 2002 you sure man? i have a good pump and im gonna beat this subject till its dead to get a for sure answer. Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted September 27, 2002 Share Posted September 27, 2002 Stick with the stock size - Nissan made sure that there would be lots of oil up top from the factory. The mains need it more than the cam and lifters. I run the same head and have no problems - I am using new stock valve springs. The turbo oil pump still only runs 10 psi at 750 RPM on my engine with an oil cooler. 2500 RPM when hot is 45 PSI. 4000 RPM is 58 PSI. This is with a calibrated gauge which was verified by a dead weight tester. There is still not a lot of volume out of that pump so I personally wouldn't what to increase volume demand by lowering restrictions to the head. You will just end up lowering your pressure to your mains which will not thank you for it. As always - just my opinion Cheers - Doug Quote Link to comment Share on other sites More sharing options...
David K Posted September 27, 2002 Author Share Posted September 27, 2002 sweet no drilly for me! Quote Link to comment Share on other sites More sharing options...
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