need help with M30 cylinder head install

[NestoL4]

I'm fixing a friend's car after a relatively non-damaging timing belt break. The heads have new valves (replaced all though only a couple were bent) and are ready to reinstall.

I'm a BMW guy - this engine is not my familiar territory and the manuals I have for this M30 are no help on one important question --

How should the camshafts be positioned before installing the heads? I don't see any positioning marks on the heads to indicate how the cams should be positioned.

With the heads flat on the workbench, it looks like tha manual says straight up (cam's 'key' nub facing up) is TDC position. So with the heads set on the engine block, the left side cam key will look like it's pointing about 30 deg. left (10 oclock) and the right side 30 deg right (2 oclock) --

Is that correct??? Thanks for any advice you guys might offer -

[DAEDALUS]

Not familiar with that engine in particular, but on the few engines I've seen, the dowel pins do point up, more or less, for #1 TDC, so yes, 10:00/2:00 sounds about right. But can you not install the head without the camshafts, and then install them after the head is torqued up? You can rotate the crank back a little to provide clearance for the valves just in case, and then time using the marks on the belt and sprockets. If the marks are missing on the belt, you'll need a new one.

How many miles on the car now, and what year is it?

[Q451990]

It's possible that Joe could get an answer, or provide some of the relevant details. (Joe is the parts manager at http://www.everythinginfiniti.com 1-888-216-5328)

The M30 was fairly rare, but he may have a long-term tech. still there that would know. I'd think the engine is somewhat similar to the J30 and Z of the same era. I like Daedalus' idea of using the belt marks to set everything up.

Where are you located in SC?

Heath

[qship96]

if i remember correctly,the m30 used the old 3.0v6 from the 84-89 300zx,not the twin cam version used in the newer body style 90-96 300zx. look for any nissan or z car shop to help you.a very simple and long lasting motor,about 160hp if i remember correctly.

[DAEDALUS]

Hehheh. Just re-reading where I mentioned you *might* have to replace the belt if the marks are missing. Add to that, "Or if the belt's broken!"

[NestoL4]

Thanks for your help guys.

I was 90% sure about the procedure already based on Nissan info -- With the heads set on the block and new timing belt in place, it sure looks and feels like we've got it right

It's a 1990, 97,000 miles and the engine is about the same as the J30 and 300ZX, and Nissan Maxima. I'm liking this little car, unexpectedly. But finding tech info on this one is sketchy. It gets put back together tomorrow. Should be running again Sunday.

I'm in Columbia - Forest Acres

-Jay

[Q45tech]

The engine is nothing like that found in the J30 but very close to Maxima of that era except of course RWD vs FWD.

[VimyJ]

I believe the M30 used one of the VG series incarnations (VG30E). That's not to say there there aren't major head differences from the early single cam to the double overhead VVT VG30DE. Addtionally, the E had a displacement of 2960 cm3 vs the DE 2998 cm3. The VE engine was used on early 90s Maximas and is descirbed as having a block similar to the VG.