Cam and Ignition timing issues?

[Zed Head]

Thanks oz c... Those might the only two I know though.

I would still rather have a nice dial-back timing light and a few other extra tools. Necessity is a mother though...

[kjphilippona]

I have a similar timing problem with my 1977 280z, i recently purchased a light and decided to check the timing, i had no idea what i would find, this was my dads car and he did or had done so much back yard mechanics it would make your head spin. i marked the 10 BDC mark and crankshaft pulley notch, I warmed up the car, shut it down disconnected the vacuum advance hose and plugged it off, attached the light and started the car. The crankshaft mark was not even aligning with the timing mark bracket, as best as i could estimate 30 BDC. I could not turn the distributor enough to get the timing set correct :disappoin

[acador]

I finally got a few minutes free tonight to put the cam back on the #1 chain position. I put the ignition timing back to 15 degrees base and took her for a spin. The tune is totally jacked now but I can tell it's going to make a huge difference. The GTech power curve looked like a roller coaster from 4-6500 but its making more power at 4k than it was a peak before. My wideband shows that it cruises around 16.5 afr where it was around 14 afr before. It idles at 12.6afr and the full trottle pulls are all over the map. I'm running 20 weight in the dashpots which was great before. I'll trying lowering the jets to see what that does but it may be time to experiement with the springs and needles. I had never had a problem with an erratic AFR under full throttle so this is interesting.

[acador]

I played with the carbs over the weekend and they are now tuned well. Moving the cam was timing was definitely the right decision. The horsepower didn't increase much but the power curve is much better. The torque is flat line from 2000 to 5280 and the horsepower ramps up smoothly the 5280 and then levels out. I'm surprised the peak hp didn't move but the torque curve is much better and it seems to rev faster in the upper RPMs. The graph is just a GTech and not a chassis dyno but it's probably fairly accurate.

I built the car for AutoX but I couldn't resist taking it to the drag strip on Saturday. It ran a 12.18 @ 86 in the 1000ft which would probably translate to low 14s in the 1/4. That was better than I expected for a mildly built low compression setup. I'm happy with it.