Leon

That's the point of the gear tensioner, you don't need tower shims since the idler takes all the slack out. It's a matter of adjusting the cam to where you want it. http://www.kameariusa.com/L6_Twin_Idler_Gear.php

You can run the current EFI pump using a return line (equal in size to feed) and an inline pressure regulator.

Ok, we're talking about the OP's '76 Coupe. I have no idea why you're bringing up '74 specs. What I said is correct, ALL '76 Z-cars (whether 2+2, coupe, auto or manual) came with a 3.54 R200.

Whoops, looks like I'm off today. I need more sleep. Yes, crank degrees is the important number. As for your last statement, you've got that one backwards. Rocker arm wear patterns change because of shimming the cam towers, not milling the head. That's when you get into needing different lash pads, since cam-to-rocker distance changes.

9 cam degrees is 18 crank degrees. However, 9 degrees is the relevant number in this discussion, and that is correct. Correct, but only if you're referring to crank degrees. Cam degrees are more pertinent when talking about cam timing. OP, perform the calculation that I've laid out. That will let you know how much the cam will be retarded. You can then leave it retarded for some more top end, advance for more low end, or test both conditions and see what you like best. Don't skip teeth, there is not enough resolution there. An adjustable cam sprocket and a degree wheel is the better solution. I'm somewhat perplexed as to why an engine with a Kameari chain tensioner would have a stock cam sprocket. If I dropped that much dough to be able to take up slack in a timing chain, you bet I'd get an adjustable sprocket as well.

Incorrect. ALL of them had a 3.54 R200. The 3.9 R200 did not come to the US until the '80 ZX.

Nice find!

Take a look at the post date...

You can easily figure this out using the arc length forumla, S=R*theta, where S is the arc length, R is radius of cam sprocket and theta is cam retard (in radians). Your arc length would be the .080" and you'd have to measure the cam sprocket radius, in inches. Solve for theta: theta=S/R Plug in your numbers (I'll plug in an educated guess for R): theta=.080/2 theta=.040 rad Convert radians to degrees: theta=.040*(180/pi) theta=2.3deg Plug in your measured value for R, and that should get you close to what you should expect if you were to actually degree the cam before/after. Of course, nothing beats actually degreeing your cam.

Yes. Consult the BE section of the FSM. Download at xenons30.com

Online. I got it from here, it's the cheapest place I've found: http://www.texasaircooled.com/catalog/Weber-Carburetor-Syncrometer-SK-Type-1-30-kg-h.html

I don't want to drag this on either, hence why I posted the link. I'm assuming you haven't had a chance to really look it over. In a nutshell, the long pipe to the back of the car has nothing to do with scavenging, that's the job of the header and collector. You want the pipe to be as big as possible as to not create more losses, post collector. Therefore, the bigger the better. A smaller pipe will not make for less losses. You make a lot of assumptions about exhaust dynamics that are just not true (explained in sticky). I don't want to take this off track, and we both agree that this is not your problem. As far as your running issue goes, start simple. Check the charging system and make sure it kicks out the proper amount of voltage. Then check each ignition component for proper operation, checking timing is the last thing you'll do here. After that, and maybe a valve adjustment, go to fuel and carburation. Cam timing would have to be way advanced to cause such a seemingly huge hit on performance. Retarding the cam will shift your power curve to higher rpm. Also, make sure to check throttle linkage and the pedal stop.

FWIW, I don't think a 240Z front valence fits the early 260Z. I have an early 260Z front valence and a 240 shell, and I believe the holes don't line up, or something to that effect. Maybe a '73 240Z valence can bolt up, but I'm unsure of that.

One tip, don't get the Unisyn tool. The Weber STE SK syncrometer is much more user friendly.

Plus, they are 15 minutes from where I work!

Wink-wink, nudge-nudge...

I was thinking the exact same thing as John, your timing is way too retarded. Advance your timing to 34 or so degrees with mechanical all in. Low speed cruise and transition will be slightly weak if the vac advance is broken or disconnected. BTW, 2.5" exhaust is definitely not too big. There is no such thing, take a look at the exhaust sticky. I'm running twin 2" pipes on my L24 without a hitch. That is 100% not your issue, unless someone stuffed a banana in your tailpipe.

I guess I'm lucky enough to have a few local places that stock SA helmets. You probably already have, but search around and see if you can find some local places. Racetracks, race-shops and circle-track equipment suppliers tend to stock this kind of stuff. If there are absolutely no places in your area, then I'd go to bike shops and try on M-type helmets. Sizing should be similar within product lines of each manufacturer, i.e. a Shoei M helmet should fit similar to a Shoei SA classified helmet.

The HEI is the cheap and proven solution. ZX modules are much more expensive and both options require some wiring work.

Yep, use KVL loop equations. You'll end up with 6 equations and 6 unknowns. You may be able to parse that down to 3 eq, 3 unk. Matrices would make quick work of the math.

This is how they all come, whether you get them from MSA or elsewhere. Holes are drilled "to fit".

DAMN! There is a local guy here that would do it for less than half that, and do a nice job as well.

Let's take a step back and realize that heat transfer has a very minor effect on combustion efficiency at high engine speeds. There simply is not very much time to transfer an appreciable amount heat to the cylinder walls during the time in which the piston is being actively pushed down by combustion. If you're looking to eek out every tiny bit of hp then so be it. If you cool the piston, there will be more heat transfer. The larger benefit in these "squirters" would lie in keeping the cylinders and piston cool, thus fighting off some detonation and keeping coolant temps at bay.

If I have it right, the hole in the passenger side will be your intake and the hole on the driver's side just admits air into the engine bay? Not a great idea, IMO, but I suppose you can try it. Just watch coolant temps and see if you have a lot of front-end lift at high speed. You'd have to have substantial engine venting to not cause a bunch of lift or at the very least your hood bulging/flying open. I do know Glenn, and of course wouldn't mind stopping by the shop! I assume it's in SJ. I'm not in the South Bay often but PM me and I'll try to stop by sometime.

I haven't played with Mikunis but they're similar to Webers. Those jets all sound way too big. I have an L24 with stock cam, header, electronic ignition, so a very similar setup. I'm running 40DCOE's and from memory: mains are 125, air correctors are 170, idle jets are 45. I still run too rich at idle and cruise. I'd be surprised if you were running lean. The only functional differences I can expect between the carbs would revolve around the progression hole locations, emulsion tube design and idle/pilot jet design, and I bet they're not worlds different. Again, I don't have direct Mikuni experience.