Thanks Tom......I'll give the machine shop these numbers and we'll see what happens.

Thanks for the reply. To clarify.....I'm running a stock cam and slightly dished pistons, so that shouldn't be an issue. I currently have 30mm & 35mm valves......the new ones are 30mm & 37mm, so the intakes are going to be slightly bigger. I think that is why the shop was asking the questions. So......what should the installed height be so we can measure it? Is there a factory spec and what is it?

I appreciate it......I want this to go back together correctly! :)

I have an A15 with a GX/competition head in my '59 Austin Healey Sprite. It has had at least one valve job before and the head was resurfaced at that point and may be resurfaced again this time as well (if it needs it).

My question is this.....by milling the head do I need to shim the valve springs? What should the installed height be?

I am fitting new SI valves (30mm & 37mm) and I also have new GX springs, retainers, etc. that will be going on it and want to make sure everything works as it should when all is said & done.

Any help would be great. I've done a lot of searching here and on Google and can't seem to find what I am looking for. Sorry if this is a stupid question......the machine shop guy asked me and I had no idea what the answer was.

Thanks.

I've adjusted and readjusted the valve clearance numerous times and that noise is still there. The head is the same as was on it before, just new guides, a regrind on the seats and resurfacing were done to it. The cam is stock.....I didn't touch the bottom end.

I plan on rechecking valve clearances and removing the valve springs this weekend to see what it all looks like.

Thanks for the replies! So, assuming that the tighter coil end should be installed towards the head, would installing them any other way create a noise issue?

Ever since getting a valve job done a month or two ago there has been a noise in the valvetrain that I haven't been able to figure out. It moves with RPM's, so that is why I figured it might be the valve springs.

Is it possible to install the valve springs upside down? I have a GX head with the double valve springs.

If so, what are the consequences of having them installed improperly?

If it doesn't make a difference then I will have a few more questions! :)

I've got an A15 in my Bugeye Sprite and I just rebuilt the head (valve grind & resurfacing). I have reassembled everything and adjusted the valves, but when the engine warms up it chatters. I have tightened up the clearances a bit, but it still makes noise when it is hot (runs quiet when cold). Any ideas?

The specs say .35mm hot.....I have them at .28mm hot. I'm afraid to go any lower.....how much tighter can I safely go? What else could it be? It didn't make this noise before and the only thing I did was get a valve job.

I'm at my wits end!

Are the plugs dry & sooty or wet & oily? Dry & sooty would indicate a rich mixture while wet & oily would mean an oil control problem.

My plugs would get wet & oily and even crusty every couple of weeks. I finally had the time to tear it apart and discovered I had broken two valve guides in half.

Here are some pics of the carnage. Busted two valve guides.....#3 & #4 intake.








Also discovered that the previous owner overbored it .75mm.....I think that adds up to about a 1520cc engine now.

I believe mine is the performance head offered in the Nismo catalog and not one from an A12GX per se. I do have the twin Hitachi SU's and the big oval ports, etc. so it isn't a regular head.

I've pulled the engine, but I haven't taken the head off yet. Once I do I can snap some pics.

I ordered the bronze guides from a place in Alabama a few days ago. If they are not the correct ones then I'll get them from Nissan.