Head work and Valve seals

Post by **Datrock** » Sun Aug 06, 2006 1:51 pm

Yesterday I removed the head off of a 1600 due to bad machine work. It had been machined down to 3.120 on one end and 3.185 in the middle and 3.130 on the other end. I went to install a newer valve cover and it would not seal on the back near #4. The head has an arch to it, and has been way over cut, and only on the bottom.
So I dig out an old pre-pollution head that has been sitting for 20 years. It measures 3.242 to 3.244 all the way across the head. Rallye says 3.248 is new and this site says 3.246 is minimum. By the looks of the combustion chambers I would lean towards Rallye's numbers!

Here is my question.

I removed the valve springs and notice that the head has a step on it where the valve seals go. The seals that were installed do not. Do I need seals for an early model head or is there supposed to be a 2 mm spacer between the head and seal???
Then I realize the extra rocker arm assembly I kept is for a metric engine so the rocker shaft bases have a smaller hole. Plus I need to find the four non-metric studs that hold the valve train to the head.

Some positive things are that the engine still has hone marks in the cylinders from being rebuilt and it also has flat tops so clearance won't be an issue.

Thanks... Bill

Post by **spl310** » Sun Aug 06, 2006 2:03 pm

You have a fairly early 1600 head. Rallye has a page with the details here:

http://www.datsunroadster.com/PIC_PAGES ... nfo_16.htm

They list the valve guide seals for that head at $13.86 each (ouch!) The later type head seals are $8.47 each.

If you need a rocker shaft with the early stands, I think I have a spare in the garage. Heck, I have a complete 1600 engine out there!

Post by **Datrock** » Sun Aug 06, 2006 2:22 pm

Hi Sid, I looked at the info from Rallye and it mentions that the early style valve springs do not sit on the seals. They can't sit on the aluminum or it would not last, or can they... Am I also missing a spacer that would go under the springs, if I had the early style seals installed.
I might take you up on the rocker arm assembly.. let me know what you want for it or I can trade with you with other parts. Bill

Post by **spl310** » Sun Aug 06, 2006 6:20 pm

Bill,

I will go out in the garage to ensure that the spare that I have is a standard unit. I will let you know.

On the head, I don't recall Nissan ever using spring seats on the early heads, but I have not played with that many of the early aluminum ones.

Post by **itsa68** » Sun Aug 13, 2006 1:25 pm

The SAE valve spring spacers seats for the inner and outer springs are .040" thick.
Inner spring spacer seat is .580" i/dia x 1.00" o/dia and the outer spring seat is 1.00" i/dia x 1.500" o/dia.

Now if I can only find out where the missing pair of valve colletss and a retainer, I would be a happy guy.

Ray B.