doradox

Typically you can buy fully threaded or partially threaded. Standard partially threaded bolts typically have a range of threaded length defined by a standard. http://www.indfast.org/Default.asp? As an example the standard M10 x 1.5 x 45 from McMaster can have a thread length from 26 to 33.5 mm. Manufacturers can make custom bolts and specify whatever they want but you probably won't find those at McMaster Carr or any of the other fastener resellers. You probably can find something close enough. Steve

The bushing is split. One piece but open. You can just take the clamps off, slip out the old bushing, then slip in the new one. Leave the rack in place. Steve

I put mine in without removing the rack at all. 15 minute job. Are these an aftermarket bushing? Steve

Don't assume that the idle "circuit" is correct and that leaning out is the problem. Maybe the idle "circuit" is too rich. When set for a good idle mixture the carbs go "lean" at cruise. Look for something that makes idle rich and goes away otherwise as well as the converse. Steve

I was a State certified Emission tech in AZ for many years. In my experience the below is generally true. YYMV. In the real world on an engine in good condition and otherwise good tune the base timing alone doesn't make much difference in HC. However. At idle vacuum leaks and poorly metering carbs, contribute to cause poor combustion and cause high HC. Bad oil control introduces an HC that doesn't combust well and ends up adding a few PPM to the readings. If we assume the idle speed will be set back to spec after the timing is changed.... Retarding the timing AND the resultant opening of the throttle to regain correct idle speed helps mask those problems to a great extent. For the vacuum leak opening the throttle at lower timing reduces vacuum, thus the magnitude of the leak, and increases the amount of A/F mixture the engine is consuming thus lowering the relative size, and effect, of the vacuum leak. Lean misfire a very common cause for high HC. Some worn carbs meter inconsistently, causing misfires, when throttle openings are very small and so the increase in throttle opening and airflow required to bump the idle back up helps as well. Ported vacuum advance helps lower HC in worn engines as I have described above. My experience is that, in general, applying manifold vacuum to a vacuum advance unit on an engine designed for ported vacuum advance reduces idle quality. But again YYMV. Steve

I agree about the finer details but exactly where does this torque increase come from? Both ported and manifold vacuum are the same just off idle so where is the advantage? Both engines would be producing the same torque at the same rpm and throttle opening. They are both effectively operating with manifold vacuum just off idle. Steve

Not much, if any, NOX is made at idle as combustion pressure and heat is very low. HC is lowered mostly because of the more stable idle you allude to. An old trick back in the day to get a marginal car to pass the HC requirement on an emissions test was to retard the timing, plug the vacuum advance hose, and jack the idle back up. Engines with hot cams also benefited from that trick. Steve

Just remember that an O2 sensor senses O2 in the exhaust and not the F/A mixture entering the engine. Incomplete combustion can give readings that are not reliable from a mixture standpoint. Steve

Since proper vaporization of fuel and precise metering IS important to power, along with a dozen other factors, what's your point? Steve

It points to a vacuum leak that occurs off idle and not to a persistent leak like an intake gasket, vacuum hose, brake booster. One thing that can act that way is the PCV valve. Since he's running no vacuum advance no cap on the ported vacuum port is another. Steve

Now THAT is genius.

I used to be an avid cyclist myself and yes there are a bunch of jerks riding bikes. There are just as many driving 4000lbs of steel, that unlike a bike, can kill. The guy on the bike was in the wrong just from the fact that he was passing on the right and in a lane already occupied by another vehicle. If the car had turned right the cyclist would be at fault. virtually all cyclists do this but how many realize it's wrong, and dangerous, is anyone's guess. I did it all the time, knew the risk, and never put myself to the right of a car as we passed through an intersection. For all intents and purposes you are invisible to drivers and you need to ride as if you actually are. Steve

Did you ever try this with 30 wt recommended by the FSM? Or maybe some 40 or 50 to bracket the results? Steve

Which is why it runs better with SM needles? And has no other symptoms of being too rich? If it's mixture related yanking the choke will either make it worse or better. I imagine that information would be useful. I can't imagine a single good reason why one wouldn't try it. As a matter of fact I can't imagine a single good reason why it wouldn't be the first thing you would try. Steve

Speaking of that, have you plugged the PCV or tried pulling the choke to artificially enrich the mixture as several others have suggested? Steve

http://en.wikipedia.org/wiki/Jetronic Looks like L-Jet is analog.

Did you ever check this? The PCV valve could be causing you to go lean at tip in if the spring is defective. Simply pull off the hose, cap the valve, and go for a drive. Also, have you tried running at 3, 3.5, 4 turns out on the mixture? If you are lean this should make an improvement. If it does then you can continue on your quest to find out why you are lean. Steve

The SR20DET is a great engine and would be right at home in a Z. However, you need to buy a front clip of a JDM S13,14 ~ $2500. Basically a complete car from the trans tailshaft forward. That gives you everything you need...except about another $2000-3000 of mounts and driveshaft and a dozen other things including a 4.10 rear diff to go with the 5 speed from the Silvia. If you start with just an engine then are setting yourself up for failure. Your will spend a fortune on all the bits and pieces needed. If you are serious then, as others have already suggested, HybridZ has all the info you will need. Steve

One of my favorites. that is oft neglected. http://www.courtesyparts.com/240z-260z-280z-parts-s30-1970-1978-c-7724.html Steve

That would be your "H". Steve

I don't believe the float level is measured with the float hanging on it's own weight like shown in your photos. The measurement is taken as the float lever just touches the needle valve.

Not bad. I just started floor pan replacement as one of my winter projects. It was about as bad as I had expected. I found this gem of a repair riveted and bondoed in on the pass side.

Definitely a step in the right direction. Let the market pick the winners and losers. There is still a mandate to blend ethanol into our fuel though. 11 billion gallons in 2010 and set to increase to 15 billion in 2015 and 36 billion in 2022. http://energy.senate.gov/public/index.cfm?FuseAction=IssueItems.Detail&IssueItem_ID=f10ca3dd-fabd-4900-aa9d-c19de47df2da&Month=12&Year=2007 Sounds like we won't be getting any less ethanol in our fuel any time soon.

If you want to see if you are too lean at the popping rpm then lean on the choke while in the zone. Explore some of the boundary conditions. Go a turn (or two) rich or lean on the carbs and see what happens. Take all the oil out of the dampers and see how it responds, then try it with really thick oil. You seem to be stuck on making very small changes from what is supposed to be "correct". Your system should be insensitive to small deviations from nominal or else these cars would rarely ever have run correctly. If you want some data points that rise above the noise then make some BIG changes and see what happens. Steve

It's been all over the news. And before you cheer for this as good news for your car you might want to read this. http://usnews.msnbc.msn.com/_news/2011/12/29/9804028-6-billion-a-year-ethanol-subsidy-dies-but-wait-theres-more In particular "Ethanol output and exports reached record highs this year, and a federal law assures ethanol a longer-term share of the motor fuel market." And the tariff on Brazilian ethanol has been reduced by $0.54. So basically we may just be paying a little more for our E10.