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Higher lift cam


78 280zcar

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Is there a higher lift cam that I can put in the 280z without changing the rocker arms valve springs lash pads ETC. I know motorsportz has a few but I dont know if they will work with the stock setup and they want 550.00 for the whole setup :( . Thanks

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truth: higher lift = smaller base circle. smaller base circle = new lash pads.

new lash pads = new rocker arms

higher lift also = better springs (for MOST higher lift cams)

it's probably best to do it right the first time.... i've heard too many stories about new cams getting ruined

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I've swapped 2 cams into 2 L engines without changing rocker arms. So far so good. The first engine had a stock cam, I swapped in a mild cam and ran it for 10K miles, then I got a bigger cam and changed lash pads and ran it for another 30K miles. Then I built a new bottom end when the crank pulley came apart on the first engine and that same head went onto the new engine. It now has about 40K on it and it has no problems with the rocker arms whatsoever. Nobody I know has replaced rocker arms when swapping a cam and I used to hang out with a bunch of 510 autoxers, and nobody I know has had a rocker arm failure at all. If you include all of their cam swaps I would guess that would be at least 5 more cam swaps without replacing rockers. Take that for what it's worth.

Lift over about .470 or .480 requires new springs because stock springs coil bind right about there. The other thing that happens is that the retainers will hit the valve stem seal. I installed a .490/280 cam into an E31 with Schneider springs and retainers and found that even with the aftermarket retainers they still hit the valve stem seal. I had my retainers turned down by a machinist to give .050 clearance. Then later on on another forum someone else found that Ford 2.9L V6 valve stem seals fit right onto an L and give huge amounts of clearance. Viton is just a better material for seals anyway, and I don't hear too many people proclaiming their love for Nissan's valve stem seals. This is a great way to go. Here's the details on this: http://forums.hybridz.org/showthread.php?t=90825

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No problem. :) With a .460 lift cam you technically shouldn't hit the valve stem seals. I'd replace them with the Ford seals anyway. According to the machinist who turned mine you want a little clearance there, at least .050" he said, because the valves can float and the rockers can bounce of the cam lobes and ruin the seals if there isn't clearance.

The one thing you'll have to do is check the lash pad thickness and make sure that is correct. It's tedious, but not hard. Basically I just set the cam in the head and bolted everything down, then took 1 intake and 1 exhaust rocker, painted the rocker surface black with a Sharpie, and stuck them in. Then I rotated the engine a couple turns by hand and looked at the rocker pad. You want an equal amount of black on either end of the pad. If the cam lobe runs right off the end of the pad then you need to adjust the lash pad thickness. I don't remember what happened with my first cam, but with my second the lash pads were 180 and 190 IIRC. They were different for intake and exhaust. I had a couple different sizes at the time, so I was able to look at the difference from say a 140 to a 160, then estimate that I needed around 180 or 190. I guessed and got about 4 sizes (6 of each) then played some more until I got it right. Nissan Comp had them CHEAP. I want to say it was $3 each or $5 each or something like that.

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Yeah, that's $4.57 each, which isn't too bad. At the bottom they say they'll exchange them if they're wrong too, which is nice. As they say at the bottom there, if you're doing a valve job or if a valve job has been done on those valves before it might change which pads you need.

You might check other cam sources too. Isky makes Z cams, Erson makes cams, Sunbelt makes cams, so MSA and Schneider aren't the only ones out there. I have run regrinds myself by American Cams in SoCal. Lots of different sources and grinds. I seem to remember the Isky cams are ~$150, plus the $54.95 for the MSA lash pads (or check with Nissan Comp) and you should be able to get out of it for just over $200 including shipping.

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what about this one it doesnt have as much lift, it looks like but it looks more sutible for stock except for the compression ratio, I would probably have to get a metal head gasket :ermm:

http://www.cranecams.com/?show=browseParts&lvl=2&prt=5&Vehicle_Type=Sport-Compact&Cylinders=6&Engine_Make=DATSUN-NISSAN&Year=1978&Engine_Size=2393-2753%20C.C.&partNumber=168-0014&partType=camshaft

Oh it says that I will have to get springs and retainers also :ermm:

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That's a tiny cam. .460/260 is pretty small. My .490/280 is a medium cam IMO.

I don't know what kind of drugs they're smoking when they say that .450 cam is good for 12:1 compression, it seems like it should do fine with stock compression. It looks to me like the springs and retainers have to go together. With that amount of lift you should be able to run stock springs.

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Well you know I dont really know which one I am going to get yet, I have plenty of time to think about it. Right now I am in the process of getting all my parts together for the 5 speed swap and when I pull the engine is when I am going to get the cam. I am also going to put in that 60mm 240sx throttle body after I get the intake shaved for it. Thanks for the replys and alot of useful info, I will keep you guys updated on the progress of the engine and when I get it out because I am sure I will need help. :nervous: Thanks and if anyone can find a better cam that will work for a stock setup please post a link. shane

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I'm pretty sure you have to use the starter motor and gear set from a manual. Is your 280 automatic in the first place? If so, you will need a lot of manual parts for the swap, including a clutch slave cylinder, clutch pedal and mounting assermbly, flywheel, clutch, driveshaft (i think), modified transmission tunnel, shift linkage, etc. It's a complicated but rather straight-forward swap.

Dave

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Yeah it is an automatic. I have mostly all of that except for the flywheel and the starter. I am not sure which tranny I got from pick and pull but if I have fs57wb tranny it will bolt right up to the driveshaft my pedal assembly has the hole for the clutch pedal bolt and the spring. The firewall already has a hole for the master cylinder too :classic: . Thanks for the help and will have to get the manual starter.

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