Gollum Posted November 22, 2012 Share Posted November 22, 2012 One of the best cams to use in a turbo setup is the early "a" cam, though I don't have first hand experience, just plenty of the gurus here saying so. My point isn't to go find that cam, but rather that using an OEM cam isn't going to kill you or matter all that much. The factory ECU won't run "as well" as it would on the factory cam, but who cares? Right now you just want the thing running, I get that. A NA cam isn't going to make such a huge difference you'll be in danger of breaking something. Just be careful before doing any WOT pulls. Get a wideband on it, even if you have to borrow one, to find out what it's doing under part throttle and low load, and slowly work up the throttle and load once you know it's safe. People have gotten 300+ hp out of the factory ECU, and I'd love to get more just to prove it can be done. Is it "optimum"? Hell no. But if you went back to the 80's nothing was optimum by today's standards. Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 23, 2012 Share Posted November 23, 2012 "I am not doing anything half assed. I have just made the determination to use my 77 280z Cam, because input from the crowd for or against was never answered." You just aren't looking for the answer. It's there and has been said over and over again: if you are BUYING a cam, don't waste your money on ANY stock cam! I've see more than one idiot pay more for some supposedly "desirable" USED STOCK CAM than you would pay for a PROPER REGRIND that would net you REAL results. But there is a slothful ness that has permeated this line of thought from the outset, and dooms the project. Everything being asked about has been discussed. Ad Nauseam. Or it's in any of the basic printed reference material out there everyone building their first engine should have on-hand for the effort. Gollum nails it once again: it just isn't going to matter that much from one stock Crappy Bumpstick to the next. You wanna plunk down $100 for a cam, call Isky, get a 460 or 470" lift regrind of the stock cam with slightly altered valve events (closer to N/A than Turbo)--- that grind will be head and shoulders a bone ANY stock cam you can buy from some Dilbert on eBay. Now, if you're like me, and have a Class 5 Hoarders in the back yard, you COULD experiment quite a bit. IMO there is one word for ANY stock Nissan "JAPAN" Cam: C O R E ! Quote Link to comment Share on other sites More sharing options...
Pyro Posted November 23, 2012 Share Posted November 23, 2012 Use a stock NA cam (internally oiled, 1977+) in your P90 head and you will be fine. In fact, a stock NA cam works better then the turbo cam in my opinion. Good for another 500 rpms of usable power Quote Link to comment Share on other sites More sharing options...
Ben's Z Posted November 23, 2012 Author Share Posted November 23, 2012 "I am not doing anything half assed. I have just made the determination to use my 77 280z Cam, because input from the crowd for or against was never answered." You just aren't looking for the answer. It's there and has been said over and over again: if you are BUYING a cam, don't waste your money on ANY stock cam! I've see more than one idiot pay more for some supposedly "desirable" USED STOCK CAM than you would pay for a PROPER REGRIND that would net you REAL results. But there is a slothful ness that has permeated this line of thought from the outset, and dooms the project. Everything being asked about has been discussed. Ad Nauseam. Or it's in any of the basic printed reference material out there everyone building their first engine should have on-hand for the effort. Gollum nails it once again: it just isn't going to matter that much from one stock Crappy Bumpstick to the next. You wanna plunk down $100 for a cam, call Isky, get a 460 or 470" lift regrind of the stock cam with slightly altered valve events (closer to N/A than Turbo)--- that grind will be head and shoulders a bone ANY stock cam you can buy from some Dilbert on eBay. Now, if you're like me, and have a Class 5 Hoarders in the back yard, you COULD experiment quite a bit. IMO there is one word for ANY stock Nissan "JAPAN" Cam: C O R E ! Mr. D, send off any stock cam to Isky and tell them to do that? Once again this is using the factory ECU, at least from the onset. Anyone think Isky could fix that first damaged cam I got before it becomes a table lamp? I could use my 77 cam to get this thing running and put in the reground P90 at a later time. Thanks again fellas. Quote Link to comment Share on other sites More sharing options...
Ben's Z Posted November 23, 2012 Author Share Posted November 23, 2012 LOL at the broke azz United States Postal Service. Camshaft just arrived; from Cal. to Texas? 18 days! They must have walked the cam here. GO OUT OF BUSINESS ALREADY! So go with the P90 or my 280z 77? Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 23, 2012 Share Posted November 23, 2012 Start an anonymous poll thread. Should Ben use the 77 cam or the P90 cam? That way no one gets the blame if it fails later. You could also call Isky and ask about the cracked dowel pin hole. They might tell you not to worry about the crack and it will be a no-brainer. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 8, 2013 Share Posted January 8, 2013 Look at this cam specs from the list I gave you, should give an idea whether it will work or not. The valve lift figures from that chart are completely inaccurate. Quote Link to comment Share on other sites More sharing options...
Leon Posted January 8, 2013 Share Posted January 8, 2013 The valve lift figures from that chart are completely inaccurate. How so? Perhaps you can elaborate on that statement. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 8, 2013 Share Posted January 8, 2013 I'm measuring .385"/.390" from an A cam. 9.78mm/9.91mm Which would make it no better than the "tiny" M cam Quote Link to comment Share on other sites More sharing options...
Leon Posted January 8, 2013 Share Posted January 8, 2013 I'm measuring .385"/.390" from an A cam. 9.78mm/9.91mm Which would make it no better than the "tiny" M cam How are you measuring the cam? Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 8, 2013 Share Posted January 8, 2013 I'm not measuring the cam, I'm measuring valve lift with a dial indicator. 0.010" lash intake/ 0.012" exhaust Quote Link to comment Share on other sites More sharing options...
Gollum Posted January 8, 2013 Share Posted January 8, 2013 Valve lift is different than cam lift, and you're going to get different readings than what is advertised as cam lift on websites, catalogs, etc. In the pushrod world this is well understood, and people all understand that catalogs are just showing you "cam" specs on cams, because that's what they are... cams. But then you've got your rockers which can be run at various RATIOS, giving more or less aggressive valve lift. Even the datsun design has a bit of ratio play in the geometry and even how the valve train is setup can effect the overall lift of a cam. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 8, 2013 Share Posted January 8, 2013 Too bad there are no references on the atlanticz page to tell where the information comes from. The L28 A cam specs in the table are 0.1 off from the 1978 FSM, so probably not copied from there. Somebody must have measured or has another document to work from. 0.1 is pretty close though. One A cam measurement shouldn't be enough to paint the whole table as completely innaccurate though. That would be some radical extrapolation. Picture from the 1978 FSM Engine Mechanical chapter: Quote Link to comment Share on other sites More sharing options...
Gollum Posted January 8, 2013 Share Posted January 8, 2013 Oh, I should mention, that if you've really got any of the "A" cams in there, and you're only reading .385 total lift on the valve then you've either got a severely worn cam or you need to work on your rocker geometry quite a bit... it really shouldn't be that low at all. Quote Link to comment Share on other sites More sharing options...
Leon Posted January 8, 2013 Share Posted January 8, 2013 You guys beat me to it! That's what I was getting at... Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 8, 2013 Share Posted January 8, 2013 The cam isn't worn... I stated the valve lift figures were inaccurate, not the entire chart. Has anyone here actually measured valve lift or is everyone completely relying on that chart? Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 8, 2013 Share Posted January 8, 2013 Too bad there are no references on the atlanticz page to tell where the information comes from. The L28 A cam specs in the table are 0.1 off from the 1978 FSM, so probably not copied from there. Somebody must have measured or has another document to work from. 0.1 is pretty close though. One A cam measurement shouldn't be enough to paint the whole table as completely innaccurate though. That would be some radical extrapolation. Picture from the 1978 FSM Engine Mechanical chapter: Are you talking about inches or millimeters? 0.1inches more lift in a cam is very noticeable in drive-ability. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 8, 2013 Share Posted January 8, 2013 10.4 mm vs. 10.5 mm - atlanticz table vs. 1978 FSM data. I thought the topic was about the validity of the data in the atlanticz table, not driveability. You said the atlanticz table was completely inaccurate and we're trying to determine if that's true or not. Quote Link to comment Share on other sites More sharing options...
Leon Posted January 8, 2013 Share Posted January 8, 2013 The cam isn't worn... I stated the valve lift figures were inaccurate, not the entire chart. Has anyone here actually measured valve lift or is everyone completely relying on that chart? We're relying on Nissan's published figures. It's in the FSM, as ZH points out. The atlanticz website is very similar to the FSM's specs. Quote Link to comment Share on other sites More sharing options...
Gollum Posted January 8, 2013 Share Posted January 8, 2013 Nissan's published figures aren't in question, and we're seeing at least a .03" difference between what was measured and what should be there... I'd call that significant. Quote Link to comment Share on other sites More sharing options...
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