V6Discussion and questions about the base carbureted or MPFI V6's and the rare SFI Turbo V6.
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
Ugh, why would you want to swap in a 4-banger?
Mileage maybe, but this isn't your daily driver is it? You can get more power and spend less with your current engine. V6 = fun with decent mileage; 4cyl = whiney lawnmower exhaust note and no fun. Just my oppinion.
Some 3rd gens came with a 4 cyl from the factory- the iron duke. I'd rather dunk my head in dog poo than put in a 4 cyl.
I dont know...Seems like a lot of time and money for not that much fun.
If I were so worried about gas mileage that I would swap in a new engine I would get a new car or drop in an LS1. At least than it would still be a fun car and get good MPG.
On my 84' I average 12.5-15mpg on a full tune up, i have the carb so that doesnt help.
I get that when I am easy on the gas but for me I get around 9 MPG on a good tune up.
__________________ 1998 Mustang
Might be getting my 83 camaro back for free but it will no longer be my project it will be my winter beater drive it till it drops and junk the POS.
---------------------------------------------------------------------- 1983 camaro berlinetta Sold but might be getting back for a beater
you guys can keep your 4 and 6 cylinder engine, The last time I checked my milage I was getting 25 to 28 depending on how I drive it. BTW, I have all the power a person would ever need for a street car and its a blast to drive.
DSmith says:
"Update, the engine is out of the car due to oil pump failure. I have a Holley Stealth Ram intake with 30# injectors to take the place of the TPI system. Not sure if I will stay with the 270/276 roller cam or not, I think that cam will be nice in my boat and a bigger one needs to be in my car. Time will tell."
So much for gas mileage...
Anyway, the old carb 2.8 setup isn't too bad on gas if you run the fuel injection long block (or at least the cam and heads) underneath it. When I dropped my 90 3.1 into a friend's carb S-10 he got nearly the mileage I did when it was in the bird. He was definitely happy. Those carb heads and cam are just plain awful. Ditto when we put an 88 bird 2.8 long block into an early 80's Citation. awesome power and much better mileage!
----------
Oh, and you need to ditch the 200 and put a 700R4 in.. that will also help A LOT.
Last edited by KrisW; 02-15-2008 at 02:28 AM.
Reason: Automerged Doublepost
You should get a little better than that, 12-15mpg range. If you put your foot in it alot you won't do much better than what you're getting. Try switching gear ratios to something numerically higher and you'll have better acceleration, and hopefully better mileage by keeping your foot off the gas. Mileage works on the psycological level as much as the mechanical level.
You should get a little better than that, 12-15mpg range. If you put your foot in it alot you won't do much better than what you're getting. Try switching gear ratios to something numerically higher and you'll have better acceleration, and hopefully better mileage by keeping your foot off the gas. Mileage works on the psycological level as much as the mechanical level.
my car you have to put it half way down just to get up to speed.
I really think a 700R4 would help a lot with that. You'll have a 3.08 first gear to help get you going. You combine that with some 3.42's out back and you'll be getting along much better!
What do the 305 or 350's get for mileage I was thinking when my car dies I would gut it out and get a carbed 305 or 350 with a 700r4 from a 87 f body and 3.42's.
Agreed, a th700 is the better way to go. Make sure to get an '84 with hydraulic tcc lockup, I don't think your ecm has any tcc control.
All of my other GM cars with the TH200 3 speed and 2004R 4 speed had electric tcc control; what had hydraulic control? 700R4?
----------
Quote:
Originally Posted by 83camaroMN
What do the 305 or 350's get for mileage I was thinking when my car dies I would gut it out and get a carbed 305 or 350 with a 700r4 from a 87 f body and 3.42's.
Too bad you're in Minnesotastan, I was touring my junkyards here and found 5, yes five, 3.4 multiport 4th gen engines in those yards. It would be soooo easy to retrofit your car with one of those...
Have you tried looking around at your local yards?
Last edited by KrisW; 02-16-2008 at 09:27 PM.
Reason: Automerged Doublepost
Not entirely sure, but I think the pre- '85 th700's had hydraulic tcc lockup.
There's quite a bit involved with a v8 swap, but already having a carb makes swapping in a carb'd v8 a little easier. You should look into a 3.4 block/fuel injection swap.
All of my other GM cars with the TH200 3 speed and 2004R 4 speed had electric tcc control; what had hydraulic control? 700R4?
----------
Too bad you're in Minnesotastan, I was touring my junkyards here and found 5, yes five, 3.4 multiport 4th gen engines in those yards. It would be soooo easy to retrofit your car with one of those...
Have you tried looking around at your local yards?
Are those 3.4L engines pretty reliable, say as mileage wise? I havent seen many with over 150k? Im going to do the swap if mine ever dies along with a 87+ 700r4.
I think all of the 87-95 rear drive 2.8/3.1/3.4 engines are about the same level of reliability. My experience has shown that these all tend to get well over 200k miles before needing a teardown.
So, in reality, if reliability and mileage are your only worries, then a low mile 87-up rear drive 60* engine is all you'll ever need!
So what your guys are saying is; messing with my timing is not a good way to acheive mileage? Roger that, I wasn't sure. One of my friends with a ***** messed with his timing and got 40 mpg but it took his car from 120 to 90 HP. But those are probably alot more computer controlled than our cars. The vacuum leak is interesting. I do get a CEL sometimes, but it never stays on. The only line I havn't replaced is the one the goes from the back of the intake and then snakes around by the battery and disappears into the fender. I havn't had the time to pull the tire and the platic fender well in order to find out where it goes. But if there's a leak it's got to be that one. I already replaced the coolant temp sensor located under the TB.
How do you time it to get that?? i have a 86 2.8. I swapped the fuel injection for a 2 throat carbie but the back one is busted so it only has the small throat... any suggestions to get my mpgs better? i'm not sure how much i'm getting because its a project car and i'm not done! but i just need to paint now
Maybe I'm alone on this, but please dont necropost. What is the point in replying to a post that hasn't been commented on since February of LAST YEAR!!!!
I think this is the downside of telling people to use the search button all the time. They do, then ask again on an old thread.
__________________ Increasingly I find the difference between a 'fact' and opinion is the number of people that believe it.
3.4 block converted to roller valvetrain with 220/225 cam on 115 lsa, early '769' heads with 3500 valves, LS6 springs & mild porting, worked over heddman headers, 3500 plenum with ported 3400 lower & 'short star' 65mm throttle. 210hp at 5800ft (that's 270hp at sealevel )
I'm getting 13-15 around town and 20-26 highway. My best was 28 on a all highway run. I'm running a carbed 2.8 with a full tune-up. When I rebuilt the carb I took my time tuning it so its on the edge of being too lean but it still runs good. Compared to everyone elses carbed mpg's I'm happy
Didn't feel like reading every post so, I might repeat something but just my thoughts:
1. Better intake usually helps, if you have a dual snorkel don't buy a CAI, as dual snorkel is CAI by default, just gut the air boxes or ram air it.
2. Headers will help, as will a decent exhaust system, true duals is absolutely overkill for a stock-mild v6, honestly, true dual would probably LOWER your mileage because of the added weight.
3. I noticed BLC85 above me implying someone's thinking about a 4 banger, all I can say is NO, this is a ~3200 lb car, yes a 4 cyl uses less gas, but not if you have to gun it all the time to make your car get out of its own way, this would probably negate any decreases in fuel consumption due to smaller displacement/less cylinders, also even if a 4 cyl has as much power, look at the tq, I can pretty much guarantee it will be lower, a v just has more leverage.
4. I have yet to do my homework on timing, but I believe that advancing it helps highway mileage a little bit.
5. Generally speaking things that make an engine more powerful make it more efficient as well, provided you don't drive like I do.
6. The best way to increase mileage is probably tuning the crap out of your ECM, in which case you would also want to do an ECM swap: http://www.thirdgen.org/techboard/di...take-look.html (V6 owners, take a look)
7.Also you might try buying an airfoil, though I have no idea if they work as well as implied in their descriptions.
8. Full tune up like everyone else has said, although they might not have mentioned seafoam, read up on it, you don't even want to know what my intake manifold looks like after 116k miles...the gunk is thicker than the metal its sitting in....
"premium" gas is just regualar old gas... that burns slower. Dosent help a damn thing if your engine dosent need it. You dont have a turbo and you dont have high compression. your actually paying more AND hurting performance by buying premium.
with 42 degrees of advance, lean cruse mode enabled and averaging a 16.0 afr (on the wideband) i was getting right around 35 mpg on the highway in my 3500 swapped cavalier. That was a steady RPM in 5th, minimal passing.
The problem was that $A1 doesn't have "highway mode spark advance" so when i got back into town and was running through the gears i'd hit the high values in the SA table and the car would buck. i set it back down to 35 degrees and left it alone till i could find a better code to run. I'm probably going to use $DF which is for the 3.4 DOHC. It's got some nice extras in it.
Maybe I'm alone on this, but please dont necropost. What is the point in replying to a post that hasn't been commented on since February of LAST YEAR!!!!
I use the justification that If I'm reading the year old post, someone else probably is or will too.
my car you have to put it half way down just to get up to speed. 
