All the low RPM carb talk... we ARE talking about a ONE BARREL... right?? Hey...what is your rear diff gear??? I feel good on the fwy at 65-70.. @ 2400 rpm's. I can go faster but i feel the windage.. I cruise just faster than Semi's and slower than the 75-85 folks... Engine 180 degrees, tranny 140.. (huge cooler) I'm getting about 21 -23 mpg.. if I go over 65 it drops fast.
that's a fact. Just imagine a 1.8 liter with a powerglide behind it! You'd have to put 4.xx+ gears in the rear just for it to get out of its own way. lol
true to a degree.. but it's still a low compression/low torque motor we're talking about here.. and very valid points have been made about driving the carb in and out of the transition circuit with final gears like that combo would give. Of course the car is light.. so that helps a bit too.. but imagine your same scenario while running at 1,700rpm in lockup. Does the car still have enough torque in reserve to cruise up light grades at 65-70 without downshifting or keep you from pushing the pedal far enough to avoid gear hunt? There's a very real reason that mfgrs don't combine tall diff gears with deep or double overdrives on small displacement motors. And that's even considering they have variable cam timing, multiplenum intakes, direct injection, and even turbo-deisel to broaden the power bands. There's simply not enough torque right off idle to make most drivers happy with the result. I'd bet that tired old low-po 200 doesn't even make 70 ft lbs of torque at 1,700 rpm.. and much less than that after you mate it to a slushbox. Just not enough there to begin with to start talking about using final drive ratios in the sub 2.0 range. Not even close. Because if it was really that easy to get a carb'd combo such as that to work efficiently?.. we would all be getting 50 miles to the gallon from our old 4 and 6 cylinders. Only reason that the Vette(and similarly powered GM vehicles) could use a double overdrive was that it had enough displacement(read as low speed torque).. to keep pushing it down the road at 75. You'll also notice that they don't run 2.79 rear gears while doing it either. So, we're right back to square one here. Can you do it? Well sure. Is it a good idea to do it? I certainly wouldn't unless I specifically built the motor with high compression(10.5+) and low speed torque in mind. Tough to do economically with that particular motor unfortunately. Seems as though most here wouldn't do it either and they've been around long enough to give valid viewpoints on the matter too. PS. if the torque converter needs a spacer/bolt pattern adapter?.. and it will with a bellhousing adapter such as this would require.. good luck keeping it all in balance. There's yet another hidden cost to add into the equation right there.
some one here said with the five speed it wouldn't be an issue because of rpm control. If I went that rout I'd still need an adapter wouldn't ?
If I had the desire to dump the C4 w/ the low/pwr/torque 200 I wud consider the T5/WCT5 or something similiar. Even w/ the stock rear gears it wud be more effiecent than the parasitic AOD. No worry abt the trans hunting for gears at certain times and situations. If I had the skills to make adapter plates and a friend who had exceptional fab skills -- converting to a manual shud'nt be much of a challenge. If I had the AOD and decided to install it, I wud steepen the rear gears . Imformation I have, say's 4speeds will bolt directly to the 200, so I assume the 5 spd will too. Someone else here w/ a lot more knowledge on this subject hopefully will chime in.
What I forgot to mention about the 4cyl T-5 is it only has a 20% O/D, so doesn't totally kill your gear, but does bring down RPMs enough to improve mileage... I dunno how difficult these trans are to find today, 10-12 years ago could be found for under $100(no not at your average salvage yard)... As far as not being able to run O/D on the steeper hills, few vehicles can... Every 5.0/4.6 Grand Marquis I've owned(five to be exact) has hunted in & out of O/D when in the mountains, requiring a shift back to drive(all these had 2.73 or 3.08 gears)...
i dunno tzayoh..yes a 250 works but its iffy on the power too. groberts101- smart post. with low power in OD, at some point it is just lugging.. Thats why I never went that way.. Did Ford make a lower (numerically) rear gear than the 2:79 for 8" rear?? anybody know?? My plan is to mildly build my 200 next time... get the hp by increasing compression, and maybe a three angle valve job.. and a header.. pick up 20-30 hp hopefully and not hurt mpg. As far as no power in my 72 200... y'all should have seen me cresting the Tioga Pass in Yosemite, CA at 10,000 feet!!! 2nd gear the whole way, no problem or overheating.. yes... nuns in wheelchairs and covered wagons were passing me.. but the lil ol 200 never quits... what a lil workhorse. Cool engine. And going down hill the other side after visiting Yosemite park, its 3 hrs or more at 5-7000 feet on the windiest road u never want to be on... and I have close to 100 lbs less weight to swing around corners cuz there aint no bent 8 under the hood
tzayoh... why dont you just do some power upgrades on your 200, and get a freeway gear and tall tires like me??
I'm sorry, I thought I had already said earlier that I was going to upgrade the engine, I juust went through and noticed I didn't. Yeah I'm going to port and polish, headers, and in a few months I have an idea for a three small carb intake, with equidistant runners I plan on making. This 200 isn't going to be left stock.
