6inline Posted April 27, 2016 Share Posted April 27, 2016 I have been reading (long enough) everything I can get when shearching for this kind of set up. I have a fullt restored N42 head all stock, a fully restored F54 bloc .050 over bored with flatvtop piston. 72 S.U. (i like them and do not plan to change them). And stock ignition, but I do plan to upgrade it. I know I know, this will ping and it those. Enough to blow my head gasket...I learned to read more (and this "class" cost a lot lol) So now, I ordered a 2mm MLS head gasket, a pack of ARP head stud and the edge in the head chambers will be nicely remove. The thing I want to do is, not run super rich and full retard. This kills hp. I want the more reliable engin I can do with that. I have read a lot and I dont realy know how to calculate what cam I need. I readed someone still had ping with a 286 cam... I would like to have a good dayli engine, of course I will race it sometimes, but I have a AE86 for that. Anybody has done this set up before or can give me a hint? I never bought a cam before netheir so a good brand would be a start. My friend keep telling me to change my springs if I change the cam, but I never realy readed about valve floating in a L engin, am I wrong? Quote Link to comment Share on other sites More sharing options...
nico Posted April 27, 2016 Share Posted April 27, 2016 hey where are you in quebec? Quote Link to comment Share on other sites More sharing options...
Leon Posted April 27, 2016 Share Posted April 27, 2016 Stock valve springs max out at .460" lift. Call a cam grinder and give them your specs. Webcams, Isky, etc. Quote Link to comment Share on other sites More sharing options...
malibud Posted April 28, 2016 Share Posted April 28, 2016 let us know what you find out. I have stock zx engine in a 72 on su carbs. so same boat. I too have a n42 with a .480 cam. Wouldn't the thick head gasket negate the added benefit of the n42? Like Leon says you will need springs, retainers possibly lash pads. Number your rockers, lash pads, springs etc. you may want to use that old cam sometime . Quote Link to comment Share on other sites More sharing options...
Chickenman Posted April 28, 2016 Share Posted April 28, 2016 You're in Canada. That makes a big difference in fuel quality compared to most US blends... and for once it's in our favor. Can you get 94 Octane Chevron or Petro Canada Ultra 94+? Either fuel will support an F54 with flat tops and N42 head with no problems. I run a 1976 280Z with an F54 with Flat tops and N47 head. CR is calculated at 10.3 to 1. I run 12 to 14 degrees Static advance and 34 degrees total mechanical. Ported Vacuum advance adds another 15 degrees at cruise. I've pulled 28 MPG out of this car. ( 3.9 gears with 1983 ZX NA 5 Speed ) I run a 280 degree cam with .480 lift. Car has tons of Torque and pulls HARD to 7,000 RPM. I can run it quite happily on Chevron 91 Octane fuel, but I do get a slight pinging between 4,500 RPM and 5,500 RPM. The only reason it pings ( slightly ) at that RPM range is because of the Factory ECU and stock injectors is causing it to run lean at that range. I have a solution on hand, but am waiting to schedule some Dyno time. Tons of guys out West running Nissan L series engines on Chevron 94 with CR in the 10.5 to 1 range every day in their Daily Drivers. They do have to back timing off by about 2 degrees when they go South of the border though. Same on the East Coast. BTW, I also have an Audi Quattro with a 1.8 Turbo engine. These have a 9.5 to 1 CR and are then boosted. I can run Chevron 91 Octane fuel at 15 to 18 lbs boost and only see about 3 degrees timing pull from the Knock Sensor logging. With 94 Chevron I see Zero...Nada...Zippo timing pull at 18 lbs boost. Canada has some pretty darned good pump fuel. Quote Link to comment Share on other sites More sharing options...
Xnke Posted April 28, 2016 Share Posted April 28, 2016 Delta Camshaft's "280-.480" grind is what I'd run. It's actually a 0.455" lift cam-they assume a 1.6 rocker ratio and it's actually 1.48-ish. If you order it "as it comes" then it'll arrive on a 108 LSA and the intake will close approximately 72* after bottom dead center, so it will help with the high compression by bleeding off compression back out the intake at lower RPMS, and as the revs climb, the inertial ram of the intake runner will help stop the reversion and cram more air into the cylinder, making higher power from 3000RPM up. Quote Link to comment Share on other sites More sharing options...
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