alright guys, the way gas is i've decided against beefing up a v6, instead i want to build one to get the best mpg outta it possible.not saying i want a gutless wonder, but i figure i can build a v6 that has more power then my current one and get better gas milage. right now i drive roughly 800 km a week, and getting only 470 km (works out to 18mpg) to the tank i think i can do better.

where would all of you start.

this is building a 2.8 (3.4's are next to impossible to find and shipping one costs more then its worth)

i think a full port and polish of heads and intake is a good start, i'm mainly looking for cam suggestions.

 

I'm only getting 300-350km per tank.

 

you doing mostly city driving?


90 percent of my driving is highway

 

Yeah, I suppose that's an important factor. Most trips I take include some time on the freeway, but just short stints between 1st Ave and Gaglardi on the no. 1.

 

lol, yeah that burns a fair bit of gas, most of mine is driving between surrey and abbotsford

 

Yeah, that'll do it.

As far as modifying an existing engine to get better mileage, I'm not too sure on that, especially as far as cams go. I'm sure stuff like proper lubrication of the drive train (good rear-end lubricant, good trans fluid, good engine oil), maybe reducing the rotating mass (lighter flywheel, lighter driveshaft, lighter pistons), and also reducing the weight of other pieces of the engine (rockers) might help. I'm not expert, but these are just a few ideas. Anyone feel free to jump in and agree or disagree with me.

 

what rpm do you cruise at? I know for a fact that these motors burn more fuel at lower rpm's than above 2500. Perhaps a gear change, and a big reduction in vehicle weight and engine rotational mass.

 

under drive pulleys, free flowing exhaust (i use to run a dynomax 2 1/2" catback, sounded pretty mean on the little 6 as well), k&n's, gut the air box. do away with smog equipment. put the car on a diet. at least 3.42's if not 3.73's. my car use to get 28-30mpg on the highway, and that was with the air on going through the mountains @80-85mph.

make sure your cruise control works too. as far as cam selection goes, i would look at what is available first, cause there isn't too much that is. maybe putting in a 3.4 stock cam.

 

Your mileage sucks. I don't drive my V8 car but maybe a few months a years as all its gets is 18.

Id just get the motor nice and fresh. Switch to a stick. These cars come with 3:42 stock and you want to go lower for more mileage. Like a 3:08 2:73. high means faster and less mileage.

 

while you're building the engine up, incorporate the TomP* tune up as you go.

 

pullys
intake
exuast (including headers)
lighten driveshaft
ligthen break drums
a smoothing out of the upper intake
debur the heads (dont smooth them out, just make sure their are no burs)
full roller rockers, reduces friction, but quite expensive for the gains.
good clean proper injectors
finely tuned ecm
manual trans if your efficent at driving one
stay with the 3.42, or maybe swap to 3.23's or whatever the next step would be.
proper alighnment and suspension geometrics (front and rear)
lighten other parts on the car that would not cause safety factor.
keep the 195 t-stat

 

He's got a stick already, so he's good to go there.

 

its stick, 3.42's out back and i cruise along at 2700 rpm

 

alright the plan so far

- full port and polish of the heads (flowmatched)
-pacesetter headers
-under drive pulleys
-aluminum driveshaft
-sending injectors to cruzin performance for cleaning and flow testing
-all new sensors
-all new accesories


as far as internals of the engine go any recomendations? i do need to keep this smog legal but i figure a freshly rebuilt 2.8 should already be giving me better mpg.

 

Aluminum pistons I guess? but that is quite costly.

I'm not sure what a full port on the heads will do(mpg wise)? I just slightly deburred mine as it was eating up bits. It had alot of burs.

reliablity, you could always cryo the block n other parts, but thats about 600 for a full engine.

 

Cryo?

 

Synthetics all around, well the mpg won't be to noticeable, but the protection will definately suit your reliability needs.

 

basically they deep freeze the block, makes it stronger

 

I assume it's a heat treatment then? Probaby heated then quenched?

 

nope just frozen, i have a link to it i'll post it up and pm it to you

 

Well I pm-ed you back, but just for the interest of anyone else, cryo is a continuation of traditional heat treatments that goes to very low temperatures to complete certain material property transformations.

edit: Oh yeah, and you can get cryo processing done for a decent price to all sorts of vehicle parts including brakes (lengthens the life) and of course, engine parts.

 

maybe someone can do some ecno prom tuning.

 

You could try an MSD ignition box like the 6A. And a high voltage aftermarket coil like a MSD blaster or Accel. It will give better gas mileage and give a little bit more power. Also helps your car to start on those cold days. Just remeber to open up the gap on your spark pulgs or they will get too hot. The msd box will run about $100-140 and the coil is about $30-50

 

Is there a consensus on opening the gap when you go to a higher voltage coil over stock?

 

My manual calls for .045, but I gap them at .049.

When I bought some plugs at autozone the guy offered to right down the gap on the boxes so I said sure. The computer told him .054 though. hmmm.

I installed all the msd stuff, underdrive crank pulley, dynomax muffler, homemade intake, synthetic oil, and check my tire pressure often. by the time the needle hits the 1/8 mark I've usually gone about 340 miles (around 28mpg). Pulled of 370-80 several months ago.

I need to get my CC working, fix my exhaust manifold leak, install roller rockers, and replace my squeeking alternator.

and get a 3.4.

I drive at a moderate pace, and also don't slow down around corners so I don't have to speed back up

 

So you just want good gas milage and reliability.
Look for lower tention street rings, get the wrist pins floated.
The stock pistons are cast Al, get some cast hypereutectic alloy pistons. There run you about 2X the cost of stock pistons.
Get a filter relocater, you can put in a cooler easy and a big honken oil filter will help you keep your oil pressure up.
The headeres are a good idea.
The high power ignition is a good idea, toss the stock coil.

 

ok guys i'm just trying to figure out which cam to use

either this one
http://www.cranecams.com/?show=brows...tType=camshaft

or this one
http://www.cranecams.com/?show=brows...tType=camshaft

 

Get the bigger one.

 

Could run an enrichment system of propane or hydrogen.

Both will drastically improve MPG but but, both explode nice during a crash.

 

alright, so i should stick with the 2030 as i thought

now heres the big question, are the 1.6 gold race rockers worth the $300 canadian? i've read that they give marginal gains, and for the price i could a few other goodies for the motor

 

Alright.. let me get this straight.. you're building for fuel economy, but you want a bigger cam... and people are telling you to use a bigger cam..

When did all sense of logic leap its way out of this thread?! What is the point of an MPG thread when you're doing gas guzzler mods?!?!?!

 

This is not about to help fuel economy either. Polished intake ports will reduce turbulence at the port, reucing fuel atomization prior to entering the combustion chamber. Any enlargement of the port will reduce efficiency at lower RPMs by reducing port velocity, also further reducing fuel economy.

 

i said i'm building this for better fuel economy(than i'm currently getting) i was looking for mods that would get me to 20- 22mpg tuned. With a custom burnt prom and finely tuned motor even with a bigger cam members on the board have gotten upwards of 26-28, while still adding a bit of pep to the 2.8

right now with my motor (200000km or 135k miles) i'm getting 18 mpg, i figure freshning up (with a rebuilt motor) and new parts should already get me to atleast 20 (hopefully more). i'm looking for something thats gonna give me a bit more power while still retaining reason i bought a v6(fuel economy).

i pretty much started this thread to find mods that would , in combination with performance parts, that would get me above 20 mpg so gas would be a bit cheaper

 

double post

 

My new LG4 was getting 25mpg-26mpg driving back home from texas.
Most of the atomization is done by intake being partly open on a small camed engine, the mixture does swirl, there is a quench aera on our heads.
Get after market injectors to help with atomization, that is one thing you have to do when you grind out the vane in the heads.
I say get even lower tention rings and run a vaccum pump.
Up the C/R if you can, you can run less timing and have more intake manifold vaccum. You will get real good scavanging with high c/r. A small cam will fight off detonation because it will keep the VE low, a stock 2.8's VE is just over 75% a hoped up 2.8 won't be much higher.