Guest bastaad525 Posted October 13, 2003 Share Posted October 13, 2003 I hate waiting... I hate not having my car on the road... heheh had to vent a little frustration there... oh by the way I found the likely suspect for the increase in exhaust smell in the car when it was running... a HUGE leak between the turbo and the downpipe, gasket it toasted... I mean it was bad at idle, i can only imagine how much was pouring out of there on the freeways... so I have high hopes that when I get this other motor in there and fix that, the smell should be back to how it was before which was like 99% not noticeable at all. I swear I felt around there before and didn't feel any leak.... I'll be going to have a look at this used engine hopefully this thursday... it's an '83, with the exhaust manifold and turbo still on it, the guy wants $300, and I've already got the turbo sold, and an extra set of rocker arms that I dont need sold for $150, so it's almost free now Hey, did all '83 turbos come with the P90a head? I'm wondering if I should be concerned here... I know once the lifters go bad you pretty much cant get them anymore or they are real pricey, so I'll have to put another head on there if that's the case. Then again... if it really has less than 70k miles on there it shouldn't be a problem right? How many miles should that head typically go before needing a rebuild? The plus side is he THINKS he may still have the distributor on it too... and I've been wanting to switch to that type of dizzy/cas setup or an N/A dizzy... no extra cost to me if it's still on there, but he says it's possible that he already sold it... got my fingers crossed. Ahhhh and the best part... when I drop this motor in... no break in period!!! okay well I WILL take it easy for a little while be sure everything is okay and try once again to figure out what the hell is wrong with my efi system.. but after that... ZOOOOOOOOOOOM Ah man I can't wait... one more long week... Quote Link to comment Share on other sites More sharing options...
280Zen Posted October 13, 2003 Share Posted October 13, 2003 know once the lifters go bad you pretty much cant get them anymore or they are real pricey Actually there is a member here named jt240z that I spoke to sometime back that said he could rebuild the lifters from the P90A head. You might want to PM him and see what he could do for you. Quote Link to comment Share on other sites More sharing options...
David K Posted October 13, 2003 Share Posted October 13, 2003 They dont need to be rebuilt. A good soaking in deisel fuel for a week or so would probably do the trick. AWD GSX chime in here. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted October 13, 2003 Share Posted October 13, 2003 It may not have the hydraulic pivots at all. My P90A didn't. Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted October 13, 2003 Share Posted October 13, 2003 David is right. I'll try to find the TSB I had posted before. Before I begin..."lifter" is really an erroneous name for the parts in question. They are actually Hydraulic Lash Adjusters (HLA) Most of the time your HLA's make noise for 2 reasons. 1) Inferior oil filter...I've seen HLA's quiet up by simply using a good oil filter. 2) sludge build up in the HLA's itself...this can be cured by simply soaking the lifter overnight in kerosene or diesel. On that note...I actually took apart a P90A HLA to examine it and see what the potential problems are. It's a fairly simple design. In effect, you have a pressurized oil resevoir that via oil pressure pushes up on the cylinder (much like a brake piston). If the oil ports in the HLA get clogged then what will happen is that you won't get proper oil pressure within the HLA itself... If I'd have kept my old engine and the HLA were bad, I was going to experiment withing slightly drilling out the oil ports to make the a little larger to help oil fill up the chamber more quickly. This method was actually put in use by Mitsubishi for their newer style HLA's. Other than that, the only thing I can see that would go bad is if the walls of the HLA itself wore down slightly, not allowing a good seal between the HLA housing the HLA cylinder. Although, I don't know if that would happen...I dunno...the parts are machine with tight tolerances. In either case, I believe that opening up the HLA ports will help...of course, before I did that, I'd soak them in diesel/kerosene over night. I have a special tool for removing lifters from the cylinder head without having to pull the cam or go through any extra work, but, I belive you can probably use a big screwdriver or small prybar to achieve the same effect. If anybody is interested I can post pics of the tool. Quote Link to comment Share on other sites More sharing options...
David K Posted October 13, 2003 Share Posted October 13, 2003 I would love to see pics of the tool. In a few moments, im starting to clean my lifters in the garage. I bought a gallon of deisel today. Think you can make up a cheesy hand drawn diagram on how to open up the ports? You really think this will help and not cause pressure loss around the adjuster piston? I can be your test mule...... I could probably make a fortune getting hydraulic adjusters from the junkyard and cleaning them....calling them rebuilds.....idea Quote Link to comment Share on other sites More sharing options...
David K Posted October 14, 2003 Share Posted October 14, 2003 Bill, I took apart the head today. I removed the lifters and i see what you mean by drilling out the hole to increase oil flow. I was thinking maybe the next size drill up. I took apart the entire lifter, and it was simple. There is a housing, piston, a spring, and a peice that sits on top of the spring. Im going to go by a box of springs, and start rebuilding these adjusters as a service and make a few bucks. I cant believe Nissan sells these for an arm and a leg. Im going to post pics when i get home tonight. Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted October 14, 2003 Share Posted October 14, 2003 a spring? Oops. The lifter I had that was semi-taken apart when I got it was missing the spring, I guess I better go see if I can find it. err...wait...maybe the spring was there...I seem to remember the lifter wanted to push up... Can you post a pic of the spring setup? Does it fit at the bottom of the housing assy? or does it fit up into the piston part? I wonder if a heavier duty spring will help, too... Quote Link to comment Share on other sites More sharing options...
David K Posted October 14, 2003 Share Posted October 14, 2003 Ok wait till i get home and ill post plenty of pics, as im bringing all 12 home with me and laying down some newspaper on my workbench. If you want, ill send you my phone # so you can give me a call tommorow. Quote Link to comment Share on other sites More sharing options...
fl327 Posted October 14, 2003 Share Posted October 14, 2003 83zxt had all kinds of funny configurations going on with them, as Nissan was emptying backstock on these cars getting ready for the switchover to vg series. My 83zxt donor had a P90 head on it, and was the typical mechanical lifter type. My 83zxt driver right now has a p90a with hla's on it. I kinda like the p90a, havent had to pop valve cover off yet, anyone out there running a lot of boost on one? I kinda like the idea of running a nice quiet hla head. Quote Link to comment Share on other sites More sharing options...
David K Posted October 14, 2003 Share Posted October 14, 2003 Alright i got the pics up. Here they go. Pic #1. This is a picture of the pivot unscrewed from the head. Not hard to remove it, i used a cresent wrench and a hammer to break it loose. Pic #2. Here it is all taken apart. In order of assembly: 1. pivot housing. 2. spring, sits at bottom of cylinder 3. cup with small ball pressure release thingy 4. piston/pivot, slides up and down to oil pressure 5. securing ring, holds the whole thing together Pic #3. Here is a poor pic of that ball in the bottom of the cup. pictured above, image #3. My best guess is that is opens under pressure? Pic #4. Here is where the oil enters the HLA cylinder. Bill suggested it be drilled wider? Maybe i can drill it out to the next size up? The head oil passage might need a little widening also, but im not sure if this will drop pressure instead of raising it. Thats all there is to the HLA's on P90a heads. I cant believe Nissan sells these for an arm and a leg!!! On top of that, they are VERY hard to find. When i took all 12 apart, i did not notice one bit of wear on any of them!!! I believe they are 100% cleanable, and reusable! NOTE: when i took them apart, they all had water/oil mixed in the housing. Since water doesnt compress, maybe this is why they fail? Quote Link to comment Share on other sites More sharing options...
David K Posted October 14, 2003 Share Posted October 14, 2003 I have been busy since my last post in this thread. I boiled all the disassembled parts in a pot on the stove. Its is unbelievable how much gunk rose to the top of the bubbles, ewwww. I let it boil for about an hour. I then ran cool water in the pot so i could pick up the parts by hand. I picked up every single part and wiped them down throughly with a towel. I then layed them out on newspaper upside down so they can dry overnight. Tommorow morning i will take them with me, and wipe the insides out with rubbing alcohol and cotton swabs. I will then put them back together and screw them back in the p90a. Call me meticulous, but everything has to be in order when im working on my car. NOTE: i wonder if the springs can be changed to a tighter, stronger spring so an aftermarket hotter cam can be run? Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted October 14, 2003 Share Posted October 14, 2003 NOTE: i wonder if the springs can be changed to a tighter, stronger spring so an aftermarket hotter cam can be run? Funny, I was wondering the exact same thing. Keep us updating on how your HLA's turn out David. You know I've been interested in repairing/rebuilding Datsun HLA's for a long time and I'm glad to see that you're taking it to the next level. Quote Link to comment Share on other sites More sharing options...
David K Posted October 14, 2003 Share Posted October 14, 2003 I dont understand why people say you cant use a hotter cam in a p90a with hydraulic lifters. You can turbocharge a stock sr20, which uses hydraulic lifters. You can turbo an Eclipse, which i assume uses hydraulic lifters.......it CAN be done with our heads. We might need to modify the lifters, but im 100% sure any cam can be run in a p90a with hydraulic lifters. Another rumor debunked? 8) Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted October 14, 2003 Share Posted October 14, 2003 The engine I just sold had a higher lift/duration cam in it. Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted October 14, 2003 Share Posted October 14, 2003 Your wrong, hydro cams have a different cut than a solid cam. If you mix the two the valvetrain will be noise and maybe throw rockers at high RPM. The rockers are different on a hydro motor also and you cant get replacement parts. Quote Link to comment Share on other sites More sharing options...
David K Posted October 14, 2003 Share Posted October 14, 2003 Rockers are different? I got a major plug in the oil passage to the head, and it fried the cam and rocker arms. I went to the junkyard, bought N/A rocker arms, lash pads, and cam. They all look the same, even held up next to one another. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted October 15, 2003 Share Posted October 15, 2003 I was told at one point in time by a what is supposed to be a very relieable sorce that the hydralic lifter heads cost you about 15 to 20 hp over the other head. Anyone know if this is true? I've got a P-90 on the car now but, I also have a P90A at the house on a spare engine and I thought I might swap it over when I do a cam change so I wouldn't have to mess with the valve adjustment anymore. Anyone? Anyone? David, have you ever tried using Chem-Dip? It's a nasty chemical that you can buy at just about any autoparts house for about 12 bucks a gallon. It has a metal basket and all in it and is made to soak parts in. This prduct would be perfect for cleaning these lifters of all the junk in them. That way you wouldn't have to do it on the stove. Just a thought. The stuff is really bad a** but, don't get it on your skin!!! Quote Link to comment Share on other sites More sharing options...
David K Posted October 15, 2003 Share Posted October 15, 2003 I love to take pics. I used it before i boiled them, and some of the gunk still wouldnt come off. It was annoying me, plus i wanted to go sit down, so i threw everything on the stove, lol. Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted October 15, 2003 Share Posted October 15, 2003 Thanks David, I think you're doing the Z world an invaluable service. Quote Link to comment Share on other sites More sharing options...
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