MicroMachinery Posted January 27, 2016 Report Share Posted January 27, 2016 Hey guys, just wondering what kinda MPG's you're getting out of your LZ engines. Mine are low. Like, f*cking low! Getting between 10-14mpg, depending on how I drive, and that's not with low gears, either; 3.9's. Not sure if my Dual Hitachis are just tuned like shit, or if this is what's to be expected. Thanks! Quote Link to comment
Doctor510 Posted January 27, 2016 Report Share Posted January 27, 2016 Hey guys, just wondering what kinda MPG's you're getting out of your LZ engines. Mine are low. Like, f*cking low! Getting between 10-14mpg, depending on how I drive, and that's not with low gears, either; 3.9's. Not sure if my Dual Hitachis are just tuned like shit, or if this is what's to be expected. Thanks! Dual Hitachis, what type? Quote Link to comment
thisismatt Posted January 27, 2016 Report Share Posted January 27, 2016 Dual Hitachis, what type? 5 Quote Link to comment
MicroMachinery Posted January 27, 2016 Author Report Share Posted January 27, 2016 Dual Hitachis, what type? Well, I could say "Dual SU's", but that would be incorrect. Not as incorrect as the answer above, but technically incorrect. 1 Quote Link to comment
MicroMachinery Posted January 27, 2016 Author Report Share Posted January 27, 2016 This is what I'm working with: The ones I'm using are 46mm Z carbs, as opposed to the 38mm ones. 1 Quote Link to comment
flatcat19 Posted January 27, 2016 Report Share Posted January 27, 2016 uberkevin said around 15 with his. He had the SUs EagleAdam had before he went KA-DE. Adam said bigger jets, fuel dumpers really. The one I had was about 18-22 depending on driving habits. 40mm Roadster SU's. Not super positive mine was the big bore or the Rebello copy LZ22. I've heard many different things about that motor. Quote Link to comment
MicroMachinery Posted January 27, 2016 Author Report Share Posted January 27, 2016 Interesting. I figured fuel economy would be not as great, but not downright shitty. It doesn't really bother me if I'm just out having fun, but if I have to take a trip down the highway a bit, it really makes a difference.. Quote Link to comment
wayno Posted January 27, 2016 Report Share Posted January 27, 2016 I have got as good as 23mpg going fairly fast with the LZ23 in my work truck, it was empty and not pulling my trailer, would have been more except I was going 90+ a couple times, I was breaking in the engine at the time, going fast and then letting off a lot. I have 38mm SUs on mine, they are plenty of carb for me, the thing will go way faster than I want to go, I have 437 gears in the rear, and I was going past 5000rpms a few times, and that was in 5th gear, I broke the speedo needle off on one of those high RPM events that trip. I must have done the correct things, because it doesn't use much oil at all, and i am hard on that truck, I haul heavy loads all the time. 2 Quote Link to comment
uberkevin Posted January 27, 2016 Report Share Posted January 27, 2016 I got 17 one time.. Quote Link to comment
MicroMachinery Posted January 27, 2016 Author Report Share Posted January 27, 2016 That gives me hope. I figured that since the 46mm carbs were used on the L24, that they would be appropriate for an LZ23. Perhaps I assumed wrong. The 38mm's felt to me like they didn't have much top end, and ran out of breath much earlier than the 46's. I guess there's always a compromise. Quote Link to comment
datzenmike Posted January 27, 2016 Report Share Posted January 27, 2016 10-14 is just wrong. You should get better than a Z24 in a truck. In a light car probably in the 20s on a trip. Hell my last Canby trip I got 34 MP(Imperial gallon) that would be over 28 US gallon highest and about 23 US gallon worst. 25 MPG on average... now this was on a trip. I'll say 20 ish all round mix. So how would a 15% larger displacement engine use up to twice as much gas? 46mm carbs are still too big? Jets wrong size? What color are the plugs? Short trip to work and back home? Chokes stuck on Quote Link to comment
Lockleaf Posted January 27, 2016 Report Share Posted January 27, 2016 I get 16 in my Weber 32/36 Z24 powered 720. That's a 4x4 with a three inch lift rolling 31x10.5s. There has got to be some more mpgs you can pick up. If it's that terrible, I'm much less interested in building one... Quote Link to comment
scooter Posted January 27, 2016 Report Share Posted January 27, 2016 You guys are way off on your jets, i would say mine is just slightly worse than stock.. I get about 400-500kms out of a tank so abot 10 liters per 100 k or so. Im jetted for best power all the time basically, 12.5-13 afrs. Thats about 23mpg.. Which sounds about right to me. I could probibly get it to sip even less gas but its really happy with these jets, you can tell the difference if you go up or down a size. I have weber 45's with 40 mil throats and full race cam (300 duration) and high compression. Big bore 2.3 Buy a wideband and a needle/jet kit and reap the rewards. :) Also theres unknowns to me with the su's, like trying different dashpot oils, springs etc. I know on slide bike carbs float height and needle/seat adjustments can do crazy things, and that probibly applys to the su's too Quote Link to comment
scooter Posted January 27, 2016 Report Share Posted January 27, 2016 Also a light car is gonna get alot better milage than a 720 on boggers... That should be obvious enough Quote Link to comment
MicroMachinery Posted January 27, 2016 Author Report Share Posted January 27, 2016 I thought so, too. I don't know why the fuck my 720 4x4 with larger mud tires and 4.375 gears got better than my 610. Quote Link to comment
MicroMachinery Posted January 27, 2016 Author Report Share Posted January 27, 2016 You guys are way off on your jets, i would say mine is just slightly worse than stock.. I get about 400-500kms out of a tank so abot 10 liters per 100 k or so. Im jetted for best power all the time basically, 12.5-13 afrs. Thats about 23mpg.. Which sounds about right to me. I could probibly get it to sip even less gas but its really happy with these jets, you can tell the difference if you go up or down a size. I have weber 45's with 40 mil throats and full race cam (300 duration) and high compression. Big bore 2.3 Buy a wideband and a needle/jet kit and reap the rewards. :) Also theres unknowns to me with the su's, like trying different dashpot oils, springs etc. I know on slide bike carbs float height and needle/seat adjustments can do crazy things, and that probibly applys to the su's too At 10-14, I almost say it's worth throwing my Mikuni's on just for a laugh. There's no way on God's green hell that they could do worse than that and still run. Quote Link to comment
Jester Posted January 27, 2016 Report Share Posted January 27, 2016 D O I T ^^^^ Quote Link to comment
Jester Posted January 27, 2016 Report Share Posted January 27, 2016 I'd be more than happy to put them on my truck and see if my mileage goes down. :D 1 Quote Link to comment
Laecaon Posted January 27, 2016 Report Share Posted January 27, 2016 My L19 with the 38mm SUs got mid 20s... My weber got 28 hwy. Quote Link to comment
MicroMachinery Posted January 27, 2016 Author Report Share Posted January 27, 2016 I've had L20b's get 28-29 on the hwy with a weber. Quote Link to comment
Burabuda Posted January 27, 2016 Report Share Posted January 27, 2016 seems legit i'm getting similar mileage running 44's glad to hear actually since lots of dudes claim 27mpg & shit Quote Link to comment
Laecaon Posted January 27, 2016 Report Share Posted January 27, 2016 Also, they say with SUs, even a slight misadjust and you will get terrible mileage. I would try leaning out the carbs a hair. But you could also try changing needles, and find one for optimal cruising RPM. Quote Link to comment
MicroMachinery Posted January 27, 2016 Author Report Share Posted January 27, 2016 seems legit i'm getting similar mileage running 44's glad to hear actually since lots of dudes claim 27mpg & shit What mileage are you getting running 44's? The 10-14? Or in the 20's? Quote Link to comment
scooter Posted January 27, 2016 Report Share Posted January 27, 2016 If your getting 10mpg with webers you must have fuel pouring out your exhaust, or you drive wfo in first with the brakes on. Also im running avgas which likes to be jetted a little fatter than pump gas. No reason you cant be around 25mpg with twin 44's, 45's or those z car su's.. Im pretty sure 240z's with su's dont get 10mpg. Quote Link to comment
620racer Posted January 27, 2016 Report Share Posted January 27, 2016 i get 1 mpg burning 116 octane with holley 350cfm Quote Link to comment
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