240z 1973 Valve adjustment if my car has a non-stock cam

[paulreverex]

I have a Datsun 240z 1973, when I bought the car I was informed the previous owner may have added a "hopped up cam". Since owning the car I have had issues with rough idle and pinging and I am curious if this some of this could be related to the valve timing. I have not checked the Valve timing but I am not sure that stock numbers will work if the cam was changed from Stock. Curious advice for a Zcar novice.

 

Thank you for your time,

[Zed Head]

If there's a cam there might be higher CR.  You'll want to check things carefully.  These engines are prone to detonation (pinging/knocking) and can get damaged.

[siteunseen]

My Schneider. 460 lift which is considered a "stage 3" on MSA's website has the same cold adjustment numbers as factory specs, intake .008 and exhaust. 010.

[Patcon]

I agree with Zed

You also need to run premium fuel if you are unsure of the compression ratio. Maybe retard the ignition some until you figure out compression ratios

[siteunseen]

The grinder and their number should be on the front of the cam where the chain sprocket is.

Edited September 28, 2021 by siteunseen

[paulreverex]

Thank you for that info. I did not get a card when I bought the car. So can I take that number and name, and google it to find the specifications? If the cam is stock- will it have Nissan printed in the same place?

Thank you

[dutchzcarguy]

On 9/28/2021 at 3:43 PM, paulreverex said:

the previous owner may have added a "hopped up cam".

 

23 hours ago, paulreverex said:

If the cam is stock- will it have Nissan printed in the same place?

As it happens i have a reserve 1973 240z engine laying apart at the moment and looked at the cam.. it has a big A on the BACK (!!) nothing else.. 

Another new old stock cam i have is a so called slalom-cam and has big lobes.. that one has Datsun and a partnumber on it and the word: brown.  it was in the 70's a original datsun special cam. (new in box.. what's left of it.. cam is as new..)

EDIT:  the letter is on the back ofcourse.. not on the front of the camshaft... silly me...

Edited September 30, 2021 by dutchzcarguy

[Zed Head]

Nissan stamped letters in to the backs of their cams.  You might need a mirror to see it.  Here's an F cam.  Some companies regrind factory cams so yours might have the Nissan stamp and the marks that siteunseen/Cliff showed.  Check both ends.  

You can also tell by the height of the base circle.  take pictures of the cam and post it.