Opinions on advancing stock cam timing by 4 degrees

[Coelocanth81]

Hello everyone,

 

I'm tuning up a stock L28 in a '76 280z, and I've noticed my cam timing has *slightly* retarded due to chain wear (maybe about 1 degree, but not much). I'm considering advancing the cam timing to the next dowel hole to advance the cam timing 4 degrees ahead of its current position (which would bring it to about 3 degrees advanced of TDC timing. 

 

Has anyone done this? I'm not expecting a dramatic improvement, but this tired old engine never sees over 5000 RPM, so I'm comfortable with the altered powerband dynamic. I'm mostly just wanting to confirm that this change won't create a piston/valve clearance issue. Thanks everyone!

 

Tom

[madkaw]

Do it . Hell - go to #3 . I suggested to my buddy to do his in his 78. It is tired motor too. He was surprised how much a difference it made . It should give you a bump in CR . 

[NewZed]

It will move your torque peak to lower RPM which is probably good, for an old engine.  It makes the engine feel more powerful since most people don't use the high end of the rev range of their engines.

 

Tony D has written some stories about using it as a tuning tool.  There's room for the valves, the engine interference range is not that close for a stock cam.

 

Here's a more "official" writeup about it - 

https://help.summitracing.com/app/answers/detail/a_id/4706/~/advancing-%2F-retarding-a-camshaft

Edited October 12, 2020 by NewZed

[Coelocanth81]

I'll take a look at that write-up.  Thanks for the link and the advice!    I searched the forums for answers, but I'm not savvy enough with the search tool to separate the wheat from the chaff.