Anyone Build 302's for MPG? And General Wagon Economy

[gadget73]

The ZF is rather clunky. Not sure if you've ever driven an F series truck with one, but they are absolutely not sporty feeling. Its more like stirring a bowl of mashed potatoes and trying to pick out the lumps. The Supercoupe had some variant of a truck trans with different ratios. I forget what that was, but something makes me want to say it was a Mazda-built 5 speed that was also used in the Ranger or maybe the F150. I've never driven one of those, so no idea how they shift but you're not likely to find a Supercoupe in the yards very often.

I think the torque peak for the non-HO 302 is even lower than 2400. For some reason 1800 rpm comes to mind, but it may be 2000 with dual exhaust. I know it moved up a bit with duals. Its a torquey motor, some 280 ft/lb but it runs out of breath pretty quick so you don't need to be able to run it up to silly RPMs. It won't like it, and it just won't make any power anyway.

[Dave804]

Yep, the ZF 5's aren't bad for the trucks. Better than my worn out NP435 4spd. The Mazda trannies were known to not last well in the trucks, I don't know that the wagon would be any better. But, MB and BMW were building straight 6's almost identical to the Ford 300 back in the day, so with the ZF bell housing a lot of sporty, and car oriented, trannies can be used. Like the 6speed used in the pre-96 hand built M5's. Super car speeds and still nearly 5000 lbs.

Hm, the numbers I'm seeing for the 302 are all over the board. Everything from 2000-3800 for peak torque. Guess so many years of mods has obscured the factory data. Like I said I guess I'll have to get the car running well, do the engine work I want, and then dyno it. I think the 2.66-.63 6 speed will still be the best fit, just a matter of finding the right rear end to go behind it. Certainly no lack of options on these old Fords.

[turbo2256b]

Dyno run 32.9 MPG engine.

[Dave804]

I'd kill for those numbers Turbo. Was that running some sort of FI I'd assume? In what vehicle? I understand the coupes are a different beast, but I wonder how much worse aerodynamically the wagons are than sedans.

[turbo2256b]

I found the coupes got the best economy with the front about 1 to 1 1/2" lower than the rear. Guessing the waggon might be about the same. The front air dam ricently installed on Creamy has made a big differance. Didnt have it on the 32.9 MPG engine setup. Currently geting ready to build another MPG 2 door 87. Hope to baseline it in the next month or so. Will be making changes peice by piece to compair results. Hopping to beat the 32.9 MPG. First differance Casper (the white 2 door) has a 2.73 rear Creamy had a 3.55 gear. Tires on the car were 275 x 50 x 15s on the front 295 x 50 x 15s on the rear. Tried some smaller crosssection tires on the front made no noticeable difference on Creamy. Casper will have perty much stock tires. After baselining first mod to stock motor will be a LOPO upper ported, tappered EGR spacer and a 5.0 TB.

[pantera77]

Pantera, didn't you mention you're putting the T5 back in your car? Are you planning to build it up, or what?

I bought a brand new Ford Racing t5 "z", which is the strongest production t5 you can buy. For what the car weighs, the power it's putting out, and the fact it always has street tires on it, it should live a long and prosperous life.

Pier, who is the master of manual panther conversions, and who's buddy was one of the first people to ever put a t5 in a box, hates stock t5's because of how weak they are, and I agree with him. Most used t5's you find for sale are completely beat to shit (like mine was). Some people get lucky I guess, but I was one hard launch away from grenading mine.

I personally would not put a t5 in a wagon if you plan on beating on it. When I convert the 87 to a standard, I'm just going to buy a TKO-600 so I never have to worry about it.

[t65neon5]

1988 lincoln town car...lopo 302 sefi....only mods are factory duals with low restriction "turbo" style mufflers,and a msd steet fire coil,msd cap n rotor,ford racing wires and bosch platinum plugs,i averaged 25 MPG from checotah oklahoma to akron ohio....used cruise 90% of the time never went faster than 70 mph(mostly 65mph...wasnt in any hurry...lol)....mileage has dropped off a lil as the miles have worn on since,but this is a old tired motor....(not sure about what ratio gears in the rear)....and ill admit to "driving for fuel economy" on that trip....driving style on the highway can GREATLY affect fuel mileage...i planned my trip so when i went thru st louis,indianapolis and columbus that i would miss the "rush hour" traffic also.....

[t65neon5]

was thinking more about this.....i can only think of 3 things that will help....1...efficiantly burn fuel.a better ignition system will burn fuel better,more burn per squirt wilkl make better power faster allowing you to use less fuel to get the same results,which leads to #2....more efficient air management....more cool air in with less restriction,more air(exhaust) out with less restriction,possibly a cold air intake,some porting,then less restrictive exhaust manifolds(shorty headers?....full length headers?)....dual exhaust and less restrictive mufflers(no mufflers?,depends on your noise tolerence,and the local police...lol.)...then #3...gearing,this would be partially dependant upon which transmission you chose to use(AOD...5 speed,6 speed etc....)

[sick88tbird]

Thanks again Don. Sleepless nights are good for reading- got a lot processed about the T-56. Trouble is they're building some crazy things, and calling it all TR-6060. You can order a 56M with non synchro and mechanical clutch haha. They're currently producing two versions made specifically for the windsors. Looks like I can pick up and use a T5 bell housing too. Seems like they've reversed those gear ratios from stock Viper/TR6060 combos Don. It's either 2.97-.5 or 2.66-.63.

I'm thinking of the 2.66 gear box with a 3.73 rear. Everything I've been able to find has peak torque for a stock 302 listed 24-2800rpm. I'll probably dyno my car before blowing $ to be sure. But if that's accurate the 2.66 box would give me the ability to cruise at most any speed in the 80% efficiency band.

50mph in 1:1 4th gear- 2238rpm
65mph in .8:1 5th-gear 2328 rpm
85mph .63:1 6th gear 2397 rpm.

I hit each of those speeds in an almost daily basis with my DD. Additionally, the 56mag box is rated at 700# torque, and the stock weight on most of the OE applications is around wagon weight.

I hate having so many numbers in my head...I have a hard time keeping them in order! I had those gear ratios listed backwards, thanks for the corrrection, I'll try to remember...lol. If you're looking for economy, I would still go with the shorter first gear and taller 6th gear(2.97/.50) and probably 3.90-4.10 gear depending on tire size. The 2.97 first will require much less effort to get that 4400lb tank rolling easier and with the .50 OD, you'll be in a much happier rpm range at 85mph if sticking with the LOPO. I've seen peak torque listed as occurring at 1600rpm on the SEFI 5.0...higher with CFI. An HO or explorer 5.0 will be happy cruising at 2000-2400 for sure, but that's a different monster compared to the stocker. If you actually put a T56 in your car, I will be super jealous...lol.

Good luck,
Don

[Dave804]

No worries, Don. Looks like they had the ratios arranged like you were thinking for a lot of the OEM applications. And it'll happen, don't worry. Last night I was talking this over with a friend. He informed me he has a few TR6060's leftover from his drag cars. Or, for about $3200 you have UPS deliver a brand new setup to your door. American Powertrain has more info and parts for SBF bolt up than Tremec itself. They've even go the adaptation to mech and hyd clutches.

But it looks like the trans will be going in last. Seems to be no general consensus on specs. And I'm sure 30yrs of mods and age haven't helped. So it seems I'll be putting on intake, exhaust, and heads of my choice first. Spend some time on a friend's dyno and cruising around to find sweet spots. PRobably drive the car this coming school year, doing weekend projects, then take it off the road next summer when I'm driving the truck.

[BerniniCaCO3]

"more efficient air management....more cool air in with less restriction,more air(exhaust) out with less restriction,possibly a cold air intake,some porting,then less restrictive exhaust manifolds..."

In reading on engine theory, I do know this can be taken too far... there's tuning involved, deliberately restrictive intakes and exhausts so that the reciprocating "shock wave" of air pressure can help to cram fresh air into cylinders, and help to scavenge exhaust gas out of cylinders. As I understand it, when the the intake valve opens, air rushes in, when it slams shut, that moving air hits the valve, and the pressure front/wave bounces away, hits the next obstacle (throttle plate?) and then bounces again... and you want to time it so that pressure wave arrives at an intake stroke again right when it opens.
Hence different length runners for different applications, both on the intake manifold past the throttle and on the exhaust runners before the collector: a lopo intake, an HO intake, a truck intake, all designed for different rpms. And variable length intake runners on many modern cars (so, like variable timing, you can be efficient at some lower rpm range, AND switch runner length to develop efficient power at some higher rpm range).
So don't throw on long tube headers unless the rest of the engine is designed around the very high rpms those give you benefits at.

I'm wondering if the stock lopo isn't a very well engineered engine, even the best for its intended purpose of low-rpm torque and fuel economy, and to just leave the engine bit alone: I like the idea of instead having enough gears in the transmission to just ride the peak torque (and therefore peak fuel econ) curve of the stock lopo all the way.

[Dave804]

It's certainly amazing what they did to it for economy, especially in a giant scaled down box truck. The thing that has me interested in the -P heads still is the more efficient placement of the plug, and the weight savings. A lot of experimentation to be done here for sure. I may pick up some (good) junked gt40 heads for $50, run them and check fuel usages for a couple months, and sell them if it's not worth it.

And that's the goal with the 56 Magnum trans. I don't plan to be launching a family car older than I am. But the gearing 3rd-6th is great. Just using a general 2000 rpm speed I can cruise at that speed for a good 60+mph range.

[turbo2256b]

My experance with the P heads is the plug placement is realy off a bit. Testing has proven its a bit shrouded aimed too much atthe exhaust valve. The protrusion of the plug boss into the chambrer isnt that good for spark travel or air flow into the cylinder. I perfer the GT40s over the Ps.

[pantera77]

I'm wondering if the stock lopo isn't a very well engineered engine, even the best for its intended purpose of low-rpm torque and fuel economy, and to just leave the engine bit alone: I like the idea of instead having enough gears in the transmission to just ride the peak torque (and therefore peak fuel econ) curve of the stock lopo all the way.

Honestly, the lopo isn't as terrible as many make it out to be. My winter wagon, with it's 250k mile lopo with very basic mods (HO upper, TB, EGR spacer, 1.7 rr's, factory stang headers, 2.5" exhaust, a/c and smog delete, and a full tune-up), runs really well. It still pulls 22mpg with 3.55's out back and a very shitty AOD.

[turbo2256b]

My plan at some point is to pocket port a set of LOPO heads as part of the economy build I have planned.