240Z Camshaft - reprofiled cam questions

[blue34]

Hi everyone, new to the forum but had the 240z since '85 and its just undergone a resoration at www.autoactive.co.uk - mine's the car on the trailer - that was 2 years ago. My question.... the cylinder head gasket had broken down after many years of storage it only gave a minor reading on a block tester but on inspection was quite a bit worse than we thought. The head has been surface skimmed and is about to go back on. I noticed some minor surface pitting on the back edge of one of the cam lobes so I'm thinking of fitting a reprofiled cam and towers I bought a while ago (this cam was reported to be a Spike Anderson spec cam but I have no way of knowing for sure). My question is this, the reprofiled cam has a distinct radius on the back edge of the cam lobes which I assume will give more duration, but overall the lift is actually less than the camshaft currently in the motor which may not be standard ( to be honest I can't remember but I may have fitted an aftermarket cam 20 odd years ago... ) - would anyone have any advice to offer as I'm not sure which cam to use. I'm running triple weber 40DCOE's and tubular headers. I'm trying to get the cam dial gauged so I can get some exact figures. Lastly would fitting a different cam absolutely necessitate the use of new rockers? the cam after all isn't brand new either and it's not like the car will be doing high mileages.... I also have a skyline R34GTR and a small runaround. Thanks, Malc

[zguitar71]

Is the car for street use or racing? What is the compression ratio? The cam to use would vary based on what you are doing with the car and its set up. But if it is a street car (I will assume since it is restored) you will not want too large of a cam. I have a 2.8 with 40mm Mikunis and very high compression for the street, about 12:1 and a nice exaust system. I currently have a 270/280 dur. 460 lift cam in the motor. The car pulls hard (no bogging) at low (2500) rpm still and makes power to 6500 or so. At 4K+ it really pulls hard. I think this cam is kind of mild. I would like to go bigger, I have the compression to do it and the springs for it. I think for the street I would like something closer to 290 durration and 490 lift. The 40's would run that just fine and the bottom end, though less than the cam I have now, would still be there and it should make power to 7K. If your rocker arms are in good shape, no wear problems then they should be o.k. to reuse.

[blue34]

I'm guessing i need to find out exactly what the figures are for the cam and maybe get some more advice. The car will be used for street and I'd like it to be useable, but mostly it'll be weekend car meets, and the occasional track day and run what ya brung.