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V8 Economy
Posted: Sat Jun 14, 2008 9:49 am
by ZAPPA
I know people have been over this but I cant get any solid answers, want to put a V8 in my coilcab but want to know fuel economy to expect. I got onto a rolled gq with a 350 chev the guy said when he first put the engine in he was getting 260k to 90l after a ignition upgrade and a carby swap got it up to 320k to 90l on petrol. Ihave heard that chevs in general are very thirsty. Are the 308s any better?, I have enough parts to build a couple. If someone has a 308 in there patrol could they give me some figures please. The chev I think was overcammed which wouldnt help.
Cheers
Zappa
Posted: Sat Jun 14, 2008 2:20 pm
by chunderlicious
have you thought about injection setups. they get alot better economy.
Posted: Sat Jun 14, 2008 4:18 pm
by to4zgtr
You could use a vh41 or vh45 nissan v8 using a marks adator plate to mate it to the gearbox. Both those v8;s would be significantly better on fuel economy then a chev or 308
Posted: Sat Jun 14, 2008 5:59 pm
by PGS 4WD
It takes a certain amount of power to push these things around, even a late model engine isn't going to be that great.
Assume that you will get around 20-25l/100 with a carby 308, 350 or alike and as good as 16-20l/100 with an EFI engine, be it a Gen 3, Gen 4 or VH 45 it dosent vary that much unless you drive hard everywhere in which case it will be worse. I get 16.5l/100 from my 5.7 Gen 3 turbo cruising on 36" simexes with a 4L80e auto and 100l/100 klms while competing and Boosting lots.
Joel
Posted: Sat Jun 14, 2008 8:25 pm
by ZAPPA
Yeah I guess it just comes back to economics, I have enough parts in my shed to build 5 308's, and I have had alot to do with them. If I buy one of the injected 4.5 Nissan V8 the conversion will be so much dearer. I had plans of building a pre-efi bottom end and putting the 304 injection on top. I reckon I would have a rebuilt efi 308 for not much more than $1500-2000. Does anyone have an injected 308 in there truck? There must be someone
Posted: Sun Jun 15, 2008 12:35 am
by gq351
my GQ LWB with a mild 351 ford cleveland running a 750 holley & emco gas gas system gets 2.3klm per litre which is pretty shit,,
& my brother has a old FJ55 land cruiser with a 420hp 350 chev running a 650 holley & emco gas system which gets 5-6 klm per liter so i would say the chev is not to bad going by that,,
Posted: Sun Jun 15, 2008 6:11 am
by nzdarin
With a turboed VH45 running on avgas my fuel economy is........... shit I'm too scared to fit a fuel gauge!!!!!!!!!!!
Highway running is very very good as all it does is idle but when you put your foot down you can hear the fuel tank emptying. V8, Patrol and econmy don't really go together.
Posted: Sun Jun 15, 2008 8:38 am
by ZAPPA
Well the plan was to put an injected 308 in and go back to 33' tyres which would let me do 110km/h at about 2600rpm . The chev that I can get would probably go alright. Havent had much to do with chevs, I wonder if you can bolt the TPI manifold onto the old topends? The ute is used for work (plumber) and I have been doin sometimes 1000k a week. Im only getting 420k to a 90l tank now from the td42 and it struggles to hold 120.Cheers for your input guys I will do somemore research.
Posted: Sun Jun 15, 2008 12:44 pm
by macneil
try a turbo on the td42.. and 2.5" zorst if you havent got one..
Posted: Sun Jun 15, 2008 1:28 pm
by chunderlicious
sounds like something is wrong with your engine or you have a large load on the back.
Posted: Sun Jun 15, 2008 5:48 pm
by love ke70
as a plumber i doubt your pulling all that much weight, and struggling to hold 120, sounds like there is something wrong with that motor
my td42 in my ute gives under 12L/100km or in other words over 750km to 90 litres.
i dont drive over 105 and i dont drive it like a racecar, but seriously dude, thats some shocking fuel consumption for a diesel
Posted: Sun Jun 15, 2008 6:28 pm
by stool
Have you ever seen the amount of tools and supplies a plumber needs to cart around
I drive a 2t truck and its still to small loaded to the hilt
Posted: Sun Jun 15, 2008 7:35 pm
by ZAPPA
The car has only done 230k. Except when I bought it 100k ago someone had played with the fuel screw. Ive been playin with it ever since. It has extractors and a 2.5 exorst, snorkel and I went from 33 to 31 to try and make it not so scared of hills, I thought havin a few more revs up at 110k would help but I think it actually went better with the big tyres!! Just had the injectors done and it hasnt made much difference. But get this, around town got 320 k to half a tank and the open road get 430k from 90l.
Doesnt make any sense if anyone has any suggestions Im open I have almost had enough. It battles to hold 110k on a slight grade and if you have a headwind forget it.I thought5 maybe the compression was down but it starts cold easily and doesnt use any oil.
Posted: Sun Jun 15, 2008 7:38 pm
by love ke70
get it dyno tuned.
most plumbers i see (im a chippie so i see a few) fit all the shit they need on the back of their ute without much hassle, depends what your doing really, but why do you need so much stuff?
Posted: Sun Jun 15, 2008 9:09 pm
by stool
Most people don't keep their tools and material on site and need to carry it with them everyday.
Posted: Sun Jun 15, 2008 9:51 pm
by ZAPPA
I dont have that much gear in there, I would say no more than 400-450 kilos. It has dual 90l tanks and a 85 l watertank though I dont think its loaded by any means. It does have a canopy but it is only about150mm higher than my roof line. I dont know why its so bad on fuel. But its getting dear. The other day put in 150l and it cost $375 not cheap. Thats why I need to sort it.
Posted: Mon Jun 16, 2008 10:33 am
by Captain Datto
Get that on the dyno ASAP. Something very wrong there. My TD42 is tired as all hell (450,000km and the blowby to prove it) and does 750 km a tank easy. It'll pull 150 kph no worries.
Posted: Mon Jun 16, 2008 2:30 pm
by Tony WestOZ
As someone said get it to a dyno and get it checked out, there is something wrong.
My TD 42 n/a 400,000 klm, over loaded all the time (diesel fitter) still sits on 110kph easly. It will go faster but after 110 you are only throwing money away. Runs about 15-16 lts /100 kms.
Posted: Mon Jun 16, 2008 7:22 pm
by madrolla68
My GQ wagon fitted with a vortec 350 gets 350K's around town on 88 litres of gas and about 250 K's out of 75 litres of fuel with rochester on 33's.
Matt
Posted: Tue Jun 17, 2008 2:57 pm
by ZAPPA
I would love to get at least 600 to 90l. When are the injection pumps spose to be done. When I had the injectors done they told me the tell tale signs of a worn pump and I havent got any of them. Ive never had any water thru the fuel system. Like I said that someone had played with the fuel screw, but I hear on this forum that people play with them all the time. I was told to get it bench tested and setup to standard again but if I turbo it Ill have to adjust it anyway!! When you get a pump rebuilt do they just charge u an exchange or fix whats broken on your pump. Dont know. Its cheaper for me to drive my 400hp 1 tonner to kalgoorlie than my patrol.
Posted: Tue Jun 17, 2008 4:15 pm
by Tony WestOZ
ZAPPA wrote: Like I said that someone had played with the fuel screw,
Here in lies the problem. Lots of people might play with them but do they know what there doing.
Find a dyno were they know Patrols, or pull the pump and have it tested.
If your going basic turbo then the fuel screw can be adjusted on a dyno with out pulling the pump. If your going big hp then the pump will have to be pulled out again.
I find exchange stuff can be near as expensive as just having your pump fully rebuilt, specially as some want to check the core first then charge extra if its damaged. If your pump has no major damage then its quite a bit cheaper to just have it serviced.
Posted: Tue Jun 17, 2008 7:25 pm
by PGS 4WD
We work on a lot of these and most return 10-12 l per 100k or 750k to 900k for 90 Liters, some of these are very conservative older drivers but, it sounds as if you have a problem. Most of the figures I have are for turbo engines, I know the feedback I have gotten in the past after fitting turbo kits is that the economy improves.
I'd agree get on a dyno
Joel
Posted: Tue Jun 17, 2008 8:06 pm
by ZAPPA
PGS,
I thought that if the pump was tired it would only be a matter of checking the preesure coming out? Honestly I have had nothing to do with the pumps. I thought it may have to do with the fact that the fuel screw has been tampered with. But on this forum I always read people advising to just give it half a turn. After all my dramas I wouldnt recommend it. I have been playing with it for 5 years and I know u only have to move it a bees dick and it will go from gutless to blowin heaps of smoke. I think I will get the pump checked out. Hopefully it will improve. There is a dyno where I live but they are into the Gen 3 and the petrol gear, dont know how much they would know.
Would I be able to run it on the dyno at speed and adjust the fuel screw? I know it will be hard, hard enuf when the motor is stopped!! Or should this be done with a pyro asawell. Once the fuel gets close to where it should be it should make peak power yes?
Cheers for your inputguys
Karl
Posted: Tue Jun 17, 2008 8:30 pm
by love ke70
they can wack it on the dyno with a probe up the exhaust to measure your air fuel ratio, and then adjust the fueling to a safe level.
with a diesel, the more fuel you put in the more power you make, but at the cost of longevity and fuel economy.
for what its worth mine made around 82 hp at the wheels with the fuel turned back to around a factory spec, it was making about 86 with extra fuel.
didnt notice the difference to be honest
im thinking that if you are always trying to drive at around 120 or more with a reasonable 500kg load and a canopy that sits above the roof line, you arnt helping your cause with getting good economy.
try sitting around the 100 mark and letting it get itself up to speed rather than flogging it, yes, drive it as your granny would.
it made a big difference for me, i was getting around 15 when i first got the ute, throttled back and grannied it up a bit, now get 11 to 12 consistantly