Leon

I want!

That's a sketchy ad. The S31 VIN prefix means it's a '76-78 car, definitely not a 1970. I hope he has receipts for all he says he's done...

Clean workshop! I'm excited to see this finally coming together!

I should have my new-to-me car on Monday! It's been a really hard decision process but I had to decide at some point. Stay tuned!

I'll second that.

Yes, EGR dilutes the mixture and thus you have less combusibles in the cylinder. Think about it though, if you are putting in less fuel, that means you are losing power compared to 0% EGR. You require less fuel to maintain the same AFR, but that also means you also have less fuel to burn. When thinking along these lines, it would seem as though EGR will have a negative effect on cruise performance. This is where those 2 factors I mentioned come in (less pumping and heat losses). Because of improved thermal efficiency and lower pumping requirements, the engine doesn't need as much power to maintain operation. You're making less power at part-throttle cruise, but because of EGR, you don't need as much power (fuel) to keep going, hence the mpg benefit at steady cruise. Bingo!

Nice job, thanks for documenting! I took the noxious route, but did use a round wire brush which worked great. Good luck with your project!

Brady, with all due respect, it doesn't work that way. If I inject a bunch of Nitrogen into my cylinders, it will not mean that I can use less fuel. I'll reiterate the reasons behind getting better fuel economy at cruise with EGR:

Yes, rsicard is right, Tony has the burn rates backwards. A rich mixture burns faster and a lean mixture burns slower. Therefore, the slow burn of a lean mixture allows for more heat transfer to the cylinder walls. This is one of the reasons for a cooler EGT with a lean mixture.

I'll try to briefly summarize this. Exhaust gas temperature (EGT) depends on combustion temperatures. The hotter the mixture burns inside the cylinder, the hotter it will be coming out. Theoretically, combustion temperatures are at a maximum at stoichiometric, but realistically the maximum occurs slightly rich from peak because of the dissociation of Oxygen from the combustion products (CO2, H2O). Why temperature drops when rich or lean is described by the energy released caused by the chemical reactions between the fuel and air. Too little fuel (lean) and there is less energy contained within and more heat is transferred to the cylinder walls (no fuel evaporation or boundary layer), thus the lower temperature when it burns. Too much fuel, and combustion efficiency drops thus generating less heat. I know, this is not too detailed, but it gets the point across without involving too much technical jargon. Of course, this all assumes MBT timing and stable combustion. You can also change exhaust temps by varying spark timing, arguably moreso than by just varying AFR. EGT is increased when spark timing is retarded since you are giving the gasses in the cylinder less time to cool off before the exhaust valve opens.

Check for exhaust leaks first, then get quieter mufflers if no leaks are found. I'm sure there are plenty of V8 guys here that have a more detailed solution, search the Exhaust and V8 sections.

Very well done, nice work!

And people don't believe me when I tell them that gas mileage goes up with properly functioning EGR... Actually, the reason for better fuel efficiency has nothing to do with spark timing. As far as timing goes, it's not that it can be increased, it's that it needs to be increased when using EGR. EGR increases mixture burn time, thus you need to light the mixture off sooner in order to get back to MBT (Max Brake Torque) timing. Engine efficiency increases when using EGR at cruise mainly because of these two reasons: (1) EGR reduces pumping losses by increasing intake pressure, and (2) the lower combustion temperatures lead to less heat loss through the cylinder walls (better thermal efficiency).

You're welcome!

They should work just fine, I've not heard of differences in piston pin geometry that would affect anything. Just make sure that you get the right diameter pistons for your cylinder bore (i.e. +0.5mm if you've overbored by 0.5mm).

Yes, sir! The S2000 seems to be the best choice for my current situation. I really want an M Coupe, but I think it will have to wait a few years (hoping for that 100% pay raise ). We've settled on a price, but I think it's still a tad high. I feel so nitpicky when looking at cars, but it's worth it in the end.

Well, took a look at another car today, and have a pretty good feeling about this one! If anybody has Carfax access, would you mind running JHMAP214X4T003987? It would be MUCH appreciated!

Late ('81-'83) NA 280ZX (F54/P79) http://datsunzgarage.com/engine/index.htm

Exactly how I feel!

That is awesome, Alec! Congratulations on all that you've been able to accomplish! Pretty crazy how quickly life tends to happen and progress. I hear you on the handling/comfort of a modern sports car, things have definitely improved since the good ol' S30. I'll be getting a new DD soon as well, so it's awesome to see your new ride. Good luck on that "free time to work on the Z" thing though, I find that there isn't much of it, especially when you already have a running, driving Z!

Nice! I envy your garage space...

No problem and good luck. I'll have to check out your Z sometime!

Guess I'm feeling generous today... "Custom molded steel fender" http://forums.hybridz.org/index.php/topic/98624-1971-240z-v-8/ I saw this car at a Z-show last year, it is a very clean build with nice attention to detail.

Todd at Exhaust Works is great, he did the twice pipes for my Z. His number is (650)591-7062. Tell him Leon with the orange 260Z sent you. His price should be very good.

Send duragg a PM, he has done this.