dat77sun Posted January 19, 2011 Report Share Posted January 19, 2011 ok so in june me and a freind are planning a 950 mile trip one way to wyoming for a freinds graduation from wyotech. my truck is a 1977 620 kc, has 225/60 r15's on it. has a 4 spd now, will have a 5 spd, weber carb, and the motor has about 90k on it, original miles. we need to calculate the gas money, so does anyone know how may mpg's these motors get? Quote Link to comment
Guest kamakazi620 Posted January 19, 2011 Report Share Posted January 19, 2011 ok so in june me and a freind are planning a 950 mile trip one way to wyoming for a freinds graduation from wyotech. my truck is a 1977 620 kc, has 225/60 r15's on it. has a 4 spd now, will have a 5 spd, weber carb, and the motor has about 90k on it, original miles. we need to calculate the gas money, so does anyone know how may mpg's these motors get? 18-20 city 22-25+ highway Quote Link to comment
metalmonkey47 Posted January 19, 2011 Report Share Posted January 19, 2011 about 30MPG rolling downhill in a tail wind. Quote Link to comment
Guest kamakazi620 Posted January 19, 2011 Report Share Posted January 19, 2011 about 30MPG rolling downhill in a tail wind. With the motor SHUT OFF!!!!!!!!! hahahahahahahahahahaha #1 reasonj i love L16s!!! Quote Link to comment
datzenmike Posted January 19, 2011 Report Share Posted January 19, 2011 Assume about 25 to be safe. You should be able to get better. I have traveled across Canada 2,800 miles and got about 30 Imperial gallon. US would be less. Air up the tires to max so they are easier to roll, drive at speed limit (you are supposed to anyway and a $200 fine is a lot of tank fulls right???) and keep in mind the the fuel used to push the truck along at 80 is 4 TIMES that needed to drive at 40mph!!!! Driving 10mph over the limit eats up lots of gas. Enjoy the trip 1 Quote Link to comment
dat77sun Posted January 19, 2011 Author Report Share Posted January 19, 2011 wow, this is why i love ratsun lol, answers very quickly, but yea it should be fun, hoping the datsun wont break down or anything Quote Link to comment
69FJWagon Posted January 19, 2011 Report Share Posted January 19, 2011 when I meet up with Beebani and picked up my KC with L20b SUs header EI 5 speed and a gear ratio of either 3.70 or 3.50 cant remember what Jester said he had installed I used less fuel than the girlfriends moms Hyundi at our fill up point and she got almost 30mpg and we were moving at a steady 75mph the whole time so I figure I got around 30mpg +/- not bad for an old carbed truck IMO Clayton Quote Link to comment
dat77sun Posted January 19, 2011 Author Report Share Posted January 19, 2011 yea, i hope the datsun gods willl look down on me and give me good mpg's and not let us break down Quote Link to comment
jesusno2 Posted January 19, 2011 Report Share Posted January 19, 2011 Damn my 720 wishes it got 20mpg it ranges between 11 to 16 mpg its freakin worn out with almost 270k with my 12 gallon tank its not passing a gas station too often! Quote Link to comment
yello620 Posted January 19, 2011 Report Share Posted January 19, 2011 If i can get somewhere near half of a full tank run out on the freeway, i can easily pull 25 mpg. L20b, 5spd, 3.90 gears, and 225/45/16 tires Quote Link to comment
HRH Posted January 19, 2011 Report Share Posted January 19, 2011 Make sure your carb is good, but if you keep the speed down you should be okay. EFI conversion would also be ideal! I just finally checked the mileage on a trip to Coeur d'Alene and back and I got 24.1 mpg in the 510, crusing between 3500-4000 rpm with a side wind. Pretty freakin' good for that kind of revs. I should install the 3.90s again, but I like the 4.11s. Lots of torquey grunt in the corners. Your gearing if stock should be 4.375 which equates to less mileage. My '78 620 got around 20 mpg if I was nice to it. It had an L20B with a 32/36 weber also. Quote Link to comment
dat77sun Posted January 19, 2011 Author Report Share Posted January 19, 2011 Make sure your carb is good, but if you keep the speed down you should be okay. EFI conversion would also be ideal! I just finally checked the mileage on a trip to Coeur d'Alene and back and I got 24.1 mpg in the 510, crusing between 3500-4000 rpm with a side wind. Pretty freakin' good for that kind of revs. I should install the 3.90s again, but I like the 4.11s. Lots of torquey grunt in the corners. Your gearing if stock should be 4.375 which equates to less mileage. My '78 620 got around 20 mpg if I was nice to it. It had an L20B with a 32/36 weber also. my carb is good, just rebuilt it, and i dont wanna do efi, i hate it Quote Link to comment
nathan_454 Posted January 19, 2011 Report Share Posted January 19, 2011 my 80 720 singlecab longbed with 140K on the clock and a weber carb gets 26 average all around city/freeway. Quote Link to comment
HRH Posted January 19, 2011 Report Share Posted January 19, 2011 What?! Hate EFI? Are you kidding me? Best thing I ever did to my 510, despite banging my head for a few weeks after I wired it wrong and couldn't figure it out! :D I daily drive it now in the winter, whereas I used to sit there with the carbs, warm it up if I could get it started, then they'd get bitchy if too cold, then they'd get heatsoaked after idling too long. EFI is where it's at unless you're on a race track and it's a complete race motor, then a nice set of sidedrafts is fine. But try jumping or off roading with the carbs. They don't like that. EFI on the other hand, doesn't care. My driveability has improved 50%. Quote Link to comment
dat77sun Posted January 19, 2011 Author Report Share Posted January 19, 2011 i hate wiring, and efi is too damn complicated, we have always wheeled a carb'd truck adn they did just fine, jumped the piss outta them too lol ;) , but i like the results you guys are telling me, as long as it gets better than a freinds fsb...and i like that its over 20mpg :D Quote Link to comment
HRH Posted January 19, 2011 Report Share Posted January 19, 2011 Do the setup most do on the cheap for an L series. 1980 200sx stuff. Only three wires to hook up. I'm not saying it's easy, but the amount of wiring to hook up that system is akin to the amount of wiring it takes to install a stereo system. Super simple. Granted, carbs work great most of the time. But eventually if you want something better... http://community.ratsun.net/topic/22074-510-l20b-efi-conversion-the-project-is-finished Quote Link to comment
dat77sun Posted January 19, 2011 Author Report Share Posted January 19, 2011 this little 620 has been the best starting carbed vehicle ive known, 1 pump, and starts on first crank, even in the 20's :cool: Quote Link to comment
mike Posted January 19, 2011 Report Share Posted January 19, 2011 If your hitachi carb is rebuildable (ie: no throttle shaft play) and youve got all the vacuum hoses hooked up correctly you will get better mileage than a weber with half the work. If its only got 90K and hasnt been messed with too bad it should be good. Datzenmike is probably right on the money but if you plan for 20 youll probably end up with beer money for the celebration :cool: always err on the side of caution when a long ways from home. Youll get better mileage if you can find a taller geared rearend in a yard. Make sure your alignment is dead on also. Also for breakdowns, bring a headgasket, waterpump, antifreeze and spare hoses filters oil and the proper tools to fix it... if you plan for it it never happens... and if it does youll have a cool story. About the best advice I can give you is to make a couple cardboard signs that say "show me your tits!!!" and bring a camera, youll get some stories that will last a lifetime ;) Quote Link to comment
dat77sun Posted January 19, 2011 Author Report Share Posted January 19, 2011 If your hitachi carb is rebuildable (ie: no throttle shaft play) and youve got all the vacuum hoses hooked up correctly you will get better mileage than a weber with half the work. If its only got 90K and hasnt been messed with too bad it should be good. Datzenmike is probably right on the money but if you plan for 20 youll probably end up with beer money for the celebration :cool: always err on the side of caution when a long ways from home. Youll get better mileage if you can find a taller geared rearend in a yard. Make sure your alignment is dead on also. Also for breakdowns, bring a headgasket, waterpump, antifreeze and spare hoses filters oil and the proper tools to fix it... if you plan for it it never happens... and if it does youll have a cool story. About the best advice I can give you is to make a couple cardboard signs that say "show me your tits!!!" and bring a camera, youll get some stories that will last a lifetime ;) haha yeah, i always keep tools in my trucks, and this trip im gonna bring more than i will probbly need, and definetally coolant. and i will make a cardboard sign like that lol, but im hoping to have my own camera by then instead of using my dads, so ill take pics of any other datto's i see :) , and as for my hitachi carb, its fucked, so i pulled that off and smog stufff and put the weber on it. Quote Link to comment
MicroMachinery Posted January 19, 2011 Report Share Posted January 19, 2011 When I first got my 610(has an L20b), 3-spd automatic, and 3.90:1 gears out back I believe, I was getting all around 27-28mpg. After the summer driving it around, somehow I'm down to 24-25mpg.. might just be the colder weather, though. Someone said something about the quality of fuel changing during different seasons, too. Quote Link to comment
datsunaholic Posted January 19, 2011 Report Share Posted January 19, 2011 I've always gotten better mileage with a Weber. They key though is not having it over-jetted; I run mine really lean, just before pinging lean. I got 35 with one in a 5-speed 620 (with 4.38 gears) but that was an L18. The same carb on a 4-speed L20B raised the mileage from 24-26 to 28-30, and the stock carb was brand new. Heck, I get around 25 with a 38DGAS on my '74. It got under 20 with the Hitachi, though it was worn out. Only good Hitachi I ever had was the one on my old '78 510 Hatchback, which got 35 regularly back in the early mid 90s. But Ethanol-laced fuel ruined the carb in the late 90s. All the rubber parts turned to goo. Quote Link to comment
DatLuv Posted January 19, 2011 Report Share Posted January 19, 2011 my carb is good, just rebuilt it, and i dont wanna do efi, i hate it I get 25 MPG city and around 30 highway on an L28... Yeah, keep hating EFI, meanwhile ill be saving up for a KAde or researching an EFI swap onto an L20b. Quote Link to comment
dat77sun Posted January 19, 2011 Author Report Share Posted January 19, 2011 i just hate it, its too complicated, ive never had problems with carbs as long as there tuned right Quote Link to comment
DatLuv Posted January 19, 2011 Report Share Posted January 19, 2011 i just hate it, its too complicated, ive never had problems with carbs as long as there tuned right Same thing goes for efi, if everything it connected right you don't have an issue... Ever since I got a carbureted engine I have had endless problems, even after I bought a new carb. Quote Link to comment
dat77sun Posted January 20, 2011 Author Report Share Posted January 20, 2011 ok so does anyone know how many gallons my gas tank in my truck will hold? how many gallon tank it is? Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.