77 280z timing problem ***NEED HELP***

[MH77280Z]

Hi Guys, so i have been working with my mechanic on my 77 280z, it is automatic.

The N47 head was cracked so we found a new rebuilt head and engine giving good compression as well. The CAM was old and had plenty of wear so decided to put a new CAM. New spark plugs off course. Gap set to factory.

The problem coming in setting the timing. My mechanic is very skilled but obviously he has not worked on 280z before. He says everything fires up nicely but we are not able to set the timing. He says the distributor had to be fully advanced to set the timing. But it should not be this way. It has to align with first cylinder/stroke etc. But when you do that timing is a bit off.

There is a new timing kit as well. I told him to open the valve cover and lets make sure original CAM and new CAM is same.

Appreciate some guidance here. We are new to 280z and I am almost there to getting the engine fully operational. Need help with setting the timing ... what do you guys think?

[Zed Head]

56 minutes ago, MH77280Z said:

He says everything fires up nicely but we are not able to set the timing. He says the distributor had to be fully advanced to set the timing. But it should not be this way. think?

What is the timing number with the distributor turned to the limit?

[MH77280Z]

I am checking and get back...hang on...

[siteunseen]

My Dad had a hard time with my 280 when I was younger. The firing order was different from what he was used to. Maybe your guy has it off too.

[MH77280Z]

Is this the firing order for 77 280z? Just confirming with your car!!!

[grannyknot]

5 hours ago, MH77280Z said:

Is this the firing order for 77 280z? Just confirming with your car!!!

Yes, and the firing order for L series engines as far as I know.

[MH77280Z]

28 minutes ago, grannyknot said:

Yes, and the firing order for L series engines as far as I know.

The number #1 position is set how? Is this the position with distributor fully advance? I think not just asking. 

Edited June 12, 2020 by MH77280Z

[Zed Head]

On 6/11/2020 at 12:58 PM, MH77280Z said:

He says everything fires up nicely but we are not able to set the timing. He says the distributor had to be fully advanced to set the timing.

But it should not be this way. It has to align with first cylinder/stroke etc. But when you do that timing is a bit off.

It's very common for the distributor drive gear to be off one tooth.  If he was able to get to the desired advance number on the damper pulley and timing tab then it doesn't really matter.  That's why I asked what the number was.

It's one of those things that won't hurt anything but isn't "right".

[MH77280Z]

Hi guys, so when we got a new N47 head we also got a new Cam. Mine is a 77 280z non turbo. But the guy told me the cam we found was for turbo but there is no difference in the cam. Will turbo cam be ok in a non turbo car? Visually it seems exactly the same?

[siteunseen]

Here's a nice chart on the different cams. Looks like the "M" has the lowest duration.

Thanks @240260280

http://www.240260280.com/legacy/techtips/cam/index.htm

Edited June 14, 2020 by siteunseen

[Patcon]

Visually? or verified with some calipers and degree wheel?

[Patcon]

Good link Site

The short answer is the turbo cam is not going to breath as well in a NA engine. the added pressure makes up for lack of valve lift and other small changes