Crustydog 46 Posted February 18, 2017 Just wondering what sort of economy figures people are getting out of there 351's? My motor is in a xd ute with the original 6 cyl diff and is only running a 2 barrel carby atm. Any idea what sort of feul usage i can expect? Next question is it will need a blue slip before I get it back on the road. Will the 6 cyl diff pass the slip or will i need disk? I can source a xh lonreach diff, will the ratio help the feul consumption or make it worse. The ute will be a daily driver, most of the mileage will be at 100klm/h. Cheers Share this post Link to post Share on other sites
gerg 10,871 Posted February 18, 2017 If the rego guy is doing his job, it won't pass without disc brakes and LSD. Mandatory along with any V8 option on XD-XEs. You didn't specify auto or manual, but for reference, my 302 gets high 14s doing mostly country runs with 3.27 gears and 5-speed. A 351 with a 4 speed and 2.92s would be roughly the same but for auto add another litre per 100. That's jetted and timed properly with decent compression and non-smog cam gears. Two barrels are false economy IMO as you have 2 large barrels doing the work all the time whereas a good street 4-barrel will be on the small primaries until you mash it. Sent from my CPH1607 using Tapatalk Share this post Link to post Share on other sites
Crustydog 46 Posted February 18, 2017 Sorry guys. Is running through a c4 auto Share this post Link to post Share on other sites
GspecZL 979 Posted February 18, 2017 I think the phrase 351 cleveland and economy don't compute comes to mind. I'm glad my ZH doesn't have a trip meter. 6 Crustydog, CHESTNUTXE, hendrixhc and 3 others reacted to this Share this post Link to post Share on other sites
Thom 6,650 Posted February 18, 2017 My 351 used to the 35l per 100 4 XTREME KARTS XF, XPT, Crustydog and 1 other reacted to this Share this post Link to post Share on other sites
CHESTNUTXE 7,310 Posted February 18, 2017 i just forget about economy even with a 302c. Share this post Link to post Share on other sites
FORD_MAN 1,026 Posted February 18, 2017 my mild 302C with 650DP, 2800 stalled C4, 4.11LSD, 27" tyre, 100km/h at 3350rpm uses 23lt/100km, Has only been tuned for Drag Racing, have done 17.8lt/100km but not sure how. Bros 302C ZH with 350 holley used 15.3lt/100km going to the AFD last year with a stuffed slipping C4, 3.00 9", 245/60r14's 3 Crustydog, GspecZL and gerg reacted to this Share this post Link to post Share on other sites
bear351c 10,270 Posted February 20, 2017 I'm an old fart, my XA ute got 18 MPG highway use.....dunno what that is in metric. 1 Crustydog reacted to this Share this post Link to post Share on other sites
Mr Polson 10,214 Posted February 20, 2017 I'm an old fart, my XA ute got 18 MPG highway use.....dunno what that is in metric. 16L/100km Sent from my Pixel using Tapatalk 2 gerg and Crustydog reacted to this Share this post Link to post Share on other sites
gerg 10,871 Posted February 20, 2017 I'm an old fart, my XA ute got 18 MPG highway use.....dunno what that is in metric. 16L/100km Sent from my Pixel using Tapatalk Depends if using Imp gallons or US: 1 US gal = 3.785 litres 1 Imp gal = 4.54609 litres So 18 US gal = 14.98 Imp gal 18 mpg in US gal: = 12.9 l/100 In Imp gal: = 15.5 l/100 I generally use US gal when converting because our engines/carbys, etc are US based so should be compared as such. Ah the wonders of the imperial system Sent from my CPH1607 using Tapatalk 1 stockesp reacted to this Share this post Link to post Share on other sites
Mr Polson 10,214 Posted February 20, 2017 I didn't even know there was more than one type of gallon... Sent from my Pixel using Tapatalk Share this post Link to post Share on other sites
gerg 10,871 Posted February 20, 2017 I didn't even know there was more than one type of gallon... Sent from my Pixel using Tapatalk There's even 2 kinds of US gallon: liquid and dry. If you ask me, anyone who wants to rubbish the metric system can keep their 660 feet to the furlong, 3 leagues to the mile or 32 fluid ounces to the quart... My brain has fucking better things to do Sent from my CPH1607 using Tapatalk 5 2redrovers, dex, Thom and 2 others reacted to this Share this post Link to post Share on other sites
dunsta87 12 Posted February 21, 2017 my 351 c4 2.77 diff get around 5km per litre on long trips on highway about 6.5km per litre 1 Crustydog reacted to this Share this post Link to post Share on other sites
bear351c 10,270 Posted February 21, 2017 There's even 2 kinds of US gallon: liquid and dry. If you ask me, anyone who wants to rubbish the metric system can keep their 660 feet to the furlong, 3 leagues to the mile or 32 fluid ounces to the quart... My brain has fucking better things to do Sent from my CPH1607 using Tapatalk ...and the Firkin. Share this post Link to post Share on other sites
deankxf 20,287 Posted February 21, 2017 my 351 c4 2.77 diff get around 5km per litre on long trips on highway about 6.5km per litre i have to convert all these figures to litre per 100km.. 5km per litre = 20litres per 100, i used to get that on LPG with my 351 and C4 with 2.92.. 6.5km per litre is about 15 litres per 100 which seems pretty normal from what i have been reading 1 Crustydog reacted to this Share this post Link to post Share on other sites
Mr Polson 10,214 Posted February 21, 2017 There's even 2 kinds of US gallon: liquid and dry. If you ask me, anyone who wants to rubbish the metric system can keep their 660 feet to the furlong, 3 leagues to the mile or 32 fluid ounces to the quart... My brain has fucking better things to do Sent from my CPH1607 using Tapatalk 4 GspecZL, thorne, Slow250XC and 1 other reacted to this Share this post Link to post Share on other sites
dex 2,065 Posted February 21, 2017 There's even 2 kinds of US gallon: liquid and dry.If you ask me, anyone who wants to rubbish the metric system can keep their 660 feet to the furlong, 3 leagues to the mile or 32 fluid ounces to the quart... My brain has fucking better things to doSent from my CPH1607 using Tapatalk A Chain is 22 yards isnt it ,,? Or a cricket pitch ,? Share this post Link to post Share on other sites
gerg 10,871 Posted February 21, 2017 Couldn't have said it better Polson Sent from my CPH1607 using Tapatalk Share this post Link to post Share on other sites
gerg 10,871 Posted February 21, 2017 There's even 2 kinds of US gallon: liquid and dry.If you ask me, anyone who wants to rubbish the metric system can keep their 660 feet to the furlong, 3 leagues to the mile or 32 fluid ounces to the quart... My brain has fucking better things to doSent from my CPH1607 using Tapatalk A Chain is 22 yards isnt it ,,? Or a cricket pitch ,? Fucked if I know... But sounds good Sent from my CPH1607 using Tapatalk 1 dex reacted to this Share this post Link to post Share on other sites
GspecZL 979 Posted February 21, 2017 Funny timing with this topic actually. Despite my less than helpful earlier comment my ZH has been pushed into daily duties by the demize of my XR8. So far I'm finding the economy atrocious. My carby is a standard thermoquad that's a bit tired. Car is dead stock. I'm not measuring the economy but it feels like 30 per hundred. And the gauge is against me. And honestly I'm cruising not pushing it. Why must our beloved Clevos drink so much. Share this post Link to post Share on other sites
Trevor 326 Posted February 21, 2017 last time we measured our 351 Clevo we got 65 litres per 100 k's, is that OK? 2 FORD_MAN and gerg reacted to this Share this post Link to post Share on other sites
Thom 6,650 Posted February 21, 2017 last time we measured our 351 Clevo we got 65 litres per 100 k's, is that OK? Not bad for a race car 1 Trevor reacted to this Share this post Link to post Share on other sites
gerg 10,871 Posted February 21, 2017 Why must our beloved Clevos drink so much. I've wondered the same thing, especially since 302 Windsors are so much better on juice than 302 Clevos. I have a theory: that many of the clevo's faults conspire together to make for poor overall economy • 351s are all open chamber (with poor efficiency) unless they're early 4Vs. • they run high oil pressure • large main and big end bearings, causing extra friction • despite large ports, they are inefficient and have dead spots (yes even 2Vs), atomisation suffers. Exhausts are poor too. • on 302s, factory piston to deck height is huge, resulting in poor quench action. Zero decking helps a lot. • factory timing is very conservative. Advancing a few degrees helps, especially if running 98 • standard camshafts are retarded from '76 onwards, which is bad for efficiency. • they're a physically big engine with a large surface area, losing a lot of heat from combustion. • they're cold-blooded: 82 deg thermostat means that even more heat gets lost to the radiator. • crank and flywheel are heavy, with lots of inertia to overcome • They're a race engine de-tuned for the street. In your case Gspec, it sounds like you need a new carby. Thermoquads were considered pretty good on fuel and while the above reasons would all explain bad economy regardless, 30 l/100km is just ridiculous. You might actually have a flooded or stuck float. Instead of trying to find bits for it and fix it, you'd actually be better off screwing on a clapped-out eBay Holley. My 600 vac was an $80 gumtree special and got 17 l/100km with just a bit of jetting. Not great but at least average. Sent from my CPH1607 using Tapatalk 1 GspecZL reacted to this Share this post Link to post Share on other sites
GspecZL 979 Posted February 21, 2017 Yeah a few of those things are true for mine. Stuffed old carby, stock headers and shitty twin system, currently had no thermostat and i run 98 petrol. I've bought the thermostat, I've got a full exhaust waiting (need headers actually) and I will overhaul the carby. I have a spare 600 holley off my 350 chev land cruiser I may rebuild. Sent from my HUAWEI Y600-U151 using Tapatalk 1 gerg reacted to this Share this post Link to post Share on other sites
GspecZL 979 Posted February 21, 2017 My old zh. Had a proper full exhaust had a proper thermostat and a rebuilt thermoquad. It was much cheaper to run. Faster to. Sent from my HUAWEI Y600-U151 using Tapatalk Share this post Link to post Share on other sites