Mn_Z_Man

OK, so I did a valve job to fix a bent valve, and am seeing something weird- lower, but more even compression across all the cylinders. Before I was seeing 175 +/- 5 psi, now I am seeing 155-160. 2 ideas- valve timing is slightly advanced (2 deg on the cam), maybe due to new timing chain guide which is giving a slight inward curve to the tight side of the chain. My other thought was could the carbon buildup on the head and pistons have raised the comp by 15psi? It didn't look that bad, but I don't have much experience to judge by. Obviously its all cleaned up now after. Head was milled 0.003". Valve lash are all properly adjusted, wipe pattern double checked and OK, cam OK, new Felpro gasket. Engine runs OK, maybe not quite as punchy as before. I've put on about 100 mi since the build. Someone on another forum suggested maybe the Felpro gasket having a larger cutout for the L28 engine, as they claimed to have had the same experience, but I can't remember how close the fit was, and they never followed up with a reply. I was hoping the compression would go UP with a shave and valve job. Any ideas appreciated, thanks Eric

Long story short , I bent a valve during a timing chain replace. Oh well, good excuse for a valve job. Small nick in the piston, otherwise no apparent damage. Intake valves and guides seem OK, exhaust needs some work. I was planning on new guides for the exhaust, and valve and seat grinding for all, and of course new seals. What I'm wondering is will a valve job require new lash pads to keep the wipe pattern centered on the rocker? I don't know how much they typically take off and if it is enough to matter. I have no confidence that the shop will be able to tell me, as one guy told me the lash pads aren't there for shimming, that the lash adjustment takes care of that, which is wrong. Most of the pads seem to measure the same at 0.12". Have no idea how much seat is left, but they don't look too bad If it is likely to change the geometry, would I be better off grinding the valve tips to keep the same height, or experimenting with new lash pads, (which sounds lie a PITA)? Engine had 120K, great compression, etc. Cam and rockers look good. thanks a million Eric

I had the same problem. I think it would fit, but it won't fit through the firewall without cutting the hole bigger. I cut off the plastic, and am going to use a hose clamp, or wire or something to hold in the speedo. The alternative is $90 for a nissan part.

Yep, then tape all the openings with duct tape. Pour the sealer in through the filler opening, then tape that up real good. Slowly rotate the tank 360 degrees, uside down, sideways, for 10 min. let it sit for a few, then repeat. Hang the tank upside down, so the extra stuff drains out the filler tube. blow through the 2 fuel lines to make sure there open, and let it cure according to the directions. What brand did you get?

The POR15 kit works great IF you follow the instructions exactly regarding the tank drying before you coat it. Cost is $70.

I paid $2500 for a stock '73, zero rust, minor colision damage, decent interior, not running, but got lucky, and it runs great with tune up , exhaust, and carb work (still ~$2,000) I looked at every Z that came on the market for two years (in minnesota) and this was the first one with zero rust. Was almost ready to fly to Phoenix when this came along. All depends on how bad you want it, and what the local supply issue is where you live. Like my dad says, something is "worth" exactly what soemone is willing to pay, at the time you want to sell.

Getting ready to reassemble my 180 after cleaning, checking lash and new seals. I noticed 2 1/8" holes inside the hub where the side flange stub inserts, and 1 slight flat spot on the flange stub, just ahead of the splines. Should this flat spot line up with one of the holes for oil circulation to the spline area? FSM appears mute on the subject, and I didn't know to look when I took it apart. Can supply picture if I got my terms messed up. thanks E