Phantom

I know this may seem an inconsequential subject for most of y'all since the primary quest seems to be for gobs of HP which generally results in low MPG numbers. BUT - for those of you in the lower HP ranges (300+/-)- what kind of fuel economy are you seeing? Also, is your vehicle carburated or fuel injected? My current information indicates a fuel injected 300 HP 350 with the right gears should be able to attain about 27 MPG on the highway and probably 21-22 in combined driving. Anyone out there seeing these kind of numbers? Phantom

DJ: First thing. Call an emmissions testing place like Pep Boys. Your cars allowable emmissions are higher than 220. My '77, which had its first Texas "safety inspection" today, was allowed 750 ppm HC and 7.5% CO. That dropped to 650 & 6.5% in '78 and then on down evenlower for the ZX's. It didn't hit 220 & 2.2% until 1983. YOur ZX came originally equipped with a catalytic converter. If they look and don't see it there you will fail whether you pass the emmissions or not because you "don't have all your stock emmissions equipment in place". A high flow cat will not hurt your performance. It will also act as a resonator and improve your exhaust note allowing you to run a less restrictive muffler. Catalytic converters are not your enemy if you know how to work with them. for what it's worth, my cat is a California edition that came with a cat. It passed emmissions last year at 70 ppm HC and .07% CO. That was on a stock motor with 190,000 miles on it. Phantom

Jon; Thaks for the feedback. I understand the fuel injection nightmare part. There are a couple sensors that can really screw it up big time if they get a little bit corroded or their connections get corroded. It took me 8 months to track down and completely cure an over rich condition I was running. Turned out it was two connectors that were buried in my wiring harness. Car always kept running but fuel economy really sucked for a while. Anyway - it's good to know yours has been there for you since the engine transplant. Mine is a daily driver that gets me to and from work so I need the reliability. Thanks again, Phantom

In your early posting you indicated that the original car had been a maintenance nightmare. How has it been in the 10,000 miles you've driven on it since the V-8 conversion. Any problems? What specifically? I'm planning conversion and am driving a stock 280Z that has been phenomenally reliable for the past 10 years and 100,000 miles. It has over 200,000 on an untouched engine at this point. Thanks. Phantom

Lone Star: I still need to get out to your place and get a peek at your ride. I am currently captive to a major front yard project that my bride of almost 30 years has deemed must be completed before my sons wedding on June 8th. She wants to put on the dog for all the relatives. How are you with mortar & stone? I'm willing to train. Chuckle - I'll take a box end and a socket any day to a cement mixer & a trowel. Phantom

Guys: Thanks for your reply. Reliability will be a primary concern for me when I do this conversion and I know it will cost me extra to ensure it. I love driving my Z, http:/www.zcar.com/1999/02. It makes my daily commute fun instead of tedious. The basic plan is the fuel injected LS-1 with the T-56 ant the 87-89 3.7:1 R200 LSD. I plan to convert my AC over to the new refrigerant at that time too along with a few consmetic touches to bring the engine bay on par with the rest of the car. At this point I'm in the cheap phase - talking. I have a few loose ends to tie up and then hope to get into the expensive phase later this summer. Phantom

My '77 280Z just rolled over 200,000 miles on the original stock engine. I have owned the car for 10 years now and, in ten years, purchase price, insurance, fuel, maintenance, and improvements have cost me $31,000. At this point the car is totally reliable and provides my daily fun trip to and from work. Is there anyone out there that drives their V-8 Z daily and finds that it provides the same kind of reliability as I've seen so far? What's the use of having a hot rod if I can't enjoy it every day of the week, rain or shine. Comments will be greatly appreciated!! Phantom

Steve: I have a '77 that I swapped out the 4-spd and 3.54:1 differential for an '83 5-spd. and 3.90 differential. If you go with the 81-83 5-spd. you will need to do the differential swap or your car will accellerate like a slug. The new combination will give you equivalent accelleration in 1st & 2nd to the old 4-spd. & 3.54:1 but will be noticably stronger in 3rd & 4th with 5th for a really nice cruising gear. You have the best transmission but don't ruin it by not changing the differential to the 3.90:1. Phantom

I'm actually planning the same conversion for my car. Contact Grumpyvette. He knows some websites where you can get the complete LS-1/T-56 with the fuel injection, auxilliaries, etc. for about $8,350 new with a warranty. If that's a bit steep for you, like most of us, you could try www.junkyarddog.com. I got an offer off them yesterday for the same set-up but used with no warranty for $5,000 out of a late model Z-28 Camero.

Depends on where you live Lee. If you live in Texas like I do the 3-row radiator will barely keep the L28 cool, much less the 2x size 350. If you live in the far North you might make it except in heavy traffic on the 5 or 6 really hot days. I'd save myself a lot of potential heartache and get a better radiator. Overheating is one of the quickest ways to kill a good motor.

While we're talking cats, my '77 is a California version and has an L28 equipped with a catalyic converter. Lonehdrider is exactly right about it dampening the exhaust tone. It acts like a resonator and causes no noticable performance losses - and this is on a 25 year old unit with 200,000 miles on it. My emmission tests have been unreal - 70 ppm HC and .07% CO. 'course the cat is really for the NO's but those aren't showing up either so it must still be working. The best thing now though is that the car is 25 years old and, in Texas, no longer subject to emmissions testing. Yee Haw!!

Thanks Danc. Do they bolt up right at the exit to the headers or after turning toward the rear?

This probably sounds like a strange subject but i am seriously planning on having these as part of my LS-1 installation. The car will be a daily commuter, not a track beast, so want to do the "environmentally correct" thing. Has anyone else out there included the cats as part of the installation? Phantom '77 280Z 2000 Grand Cherokee Ltd. '90 Bronco II

Also try www.junkyarddog.com Phantom

I'll bet the subject of adequate tires vs. V-8 torques has been discussed a million times on this forum. I guess the Z would be like a Chevy pick-up with a 454. Or maybe like my first new car which was a modified '70 340 'Cuda. It had G60/15's and no positrack. Engine was tuned by Bobby Likis and ran like a scalded ape. The car could be a handful but, treated with respect, it was great fun to drive. I expect the Z will be somewhat similar - and that is exactly why I want the LS-1 and a quiet single exhaust that exits where the stock Z exhaust exits. My car doesn't look stock (Feb. '99 Z-car of the month on ZCAR.com) but not too many people will initially suspect the V-8. I would rather have some 275's on the rear but I'm not yet willing to flare the car that dramatically. I'l live with the excitement for a while. Phantom

In response to the concern about having enough tires under the car. That is one that I have considered extensively. Follow my logic. My L28 is putting 135 HP through a 3.90:1 R-200 to one rear wheel now. If I go to the 3.7 LSD I end up splitting the HP and Putting about 160 HP to each rear wheel. That is just under 20% more HP per wheel than the car is carrying now. I'll have to be careful off the line and very careful on wet streets but my 225-60/16's should handle it pretty much ok. Phantom

Spot!!!! Long time no hear! I haven't been on zcar.com much for quite a while. A lot of things going on not the least of which is my oldest getting married. Anyway - Jerry and I have actually discussed the V-8 conversion - about three weeks ago. He's ok with the concept as long as I plan on having the T56. He doesn't feel the other trannies have enough OD in them. I really hadn't thought about trying to get him to do it. He is so busy it would probably sit in his shop for four years or so - kind of like the turbo Z he's been building for himself the past 5-6 years. I haven't thought a lot yet about what I'll do for a daily driver while Zack is having the transplant. It depends on how long the time estimate ends up being. I might just buy one of Jerry's cars and then resell it when Zack is done. Thanks for the hello e-mail. Phantom

Thanks for your replies guys. The info on the later model differentials is excellent. I was unaware of the R230 and coming out of a V-8/turbo car it definitely should be much stronger. I'll have to look at the total costs involved. I can get the 3.7 R200 LSD for about $400 which may be hard to beat. As far as the engine / transmission mount goes I may have that beat too. I live about 30 miles from John's Cars in Dallas, TX and am trying to work a deal with him to develop an LS-1 kit. It is going to take some significant time and $ but I think it will be well spent. Thanks again. Phantom

I've got a '77 280Z in pristine condition and 199,000 miles on the original, untouched, L28. It's starting to rattle at idle indicating I may have a wee bit of wear on the crank & connecting rod journals and my clutch now has about 70,000 miles on it. My current plan is to get the fuel injected aluminum block LS-1 with a T56 out of a donor camero or firebird complete with the engine control unit and the OBD-II. Also figured on using the 3.7:1 LSD R200 out of an 87-89 300ZX. With the second OD of the 6-spd. I figured it would be a stump puller in the low gears but still be able to turn about 1,800 rpm at 60 mph in 6th. Anything that I really need to look out for? I don't want to get way into this project and then encounter a big GOTCHA! I'm quite the novice at this so it would be easy to overlook a problem that would be obvious to y'all. Looking forward to some pointers from those of you that have gone before me. Thanks. Phantom