Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Some deep thinking on getting Best MPG in a VAN

racprops · 09-22-2018, 12:12 AM

OK I jumped in to another thread that was about cams and engine, but it was hinted I was high jacking the tread SO I am starting one of my own, (sorry guys..was so impressed by the thread I though you would help me...)

So let me try this as my own thread.

I wanted to throw my plans and ideas out for feed back, as much as I THINK I have a good plan and idea, rather than waste time and money, this is the first place where I think I will get good feed back and good info rather than the knee jerk reaction I get from every hot rodder..."It will not work and you NEED RPMS and HP...."

I regret to inform everyone that my 93 G20 Full Size Custom Chevy Van suffered a major lost of oil because of a failed hose clamp connecting my 15 year old oil cooler. The engine has totally seized.

BUT she will be back, as this means I have to and can do my super drive train, something I just could not justified with a good running engine.

Here is my thinking and a fairly old plan:

From all I have read about MPG I come up with two ways SMALL and LIGHT with small motor, to make them work they run higher RPM.

But I am driving a BIG van, big in wind resistance (pushing a box though the air) and heavy.

The trick seems to be a big TORQUE motor. There is a reason diesels are used on big rigs, TORQUE.

Diesels make torque and at low RPMs, they can barely get over 3500RPMs. The only thing that makes better torque is an electric motor which has all its torque at 1RPM…

IF there was a replaceable power supply I would be going to electric motors BUT there are none so far. Not for nonstop long road trips anyway.

So I am building a gas engine as close to a diesel as possible.

It is not too farfetched as some might think, a 1990 Cadillac came with a Chevy 350 with a low RPM cam that had its torque peek at 2200, and the earlier Chevy 400 in a big station wagon had a cam that peeked at 2000. The Olds 403 has similar cam timings.

Torque is what gets you down the road.

So here is my lay out: A 385 Chevy with 192 Swirl port heads, max RPMS with them stock 6000, they have been cleaned, no polish as the ruff walls are better for low RPM power…3 angle valve seats, Perfect Circle valve seals (Chevy has a history of bad valve seals) like new guilds or replacements as needed, stock valve springs, new keepers, and roller tip rockers to minimize pushing the valves back and forth.

The stock Chevy/Cadillac cam, or a 400 aftermarket cam IF it can be had With Stock timing and built for a roller) as is the cam I have as a roller cam.

The block is cleaned and ready to go, I have Keith Black “D” Shaped disc pistons (allows running low Octane gas) with a stock 350 crank so all I need is a 400 crank fitted.

Feeding it will be a 85 to 92 Chevy TPI intake. Again these intakes are said to produce 30 to 35% MORE torque, HP and MPG over the same engine running a carb.

Running the PCM will be a add on computer card that give me almost total control of the fuel system.. http://www.dynamicefi.com/EBL_P4_Flash.php

Once all of that is done I will test drive it and see how things work.

Then I plan on putting in an 8L90 transmission which has some very nice low first gears and then rebuilding the rear end with a possi and a set of 243 gears.

My numbers show it will be able to do 80MPH at 1700RPMs.

My 2000 Mercury with a similar setup got 27 to 30 MPG at 65 MPH. And 25/26 MPG at 80 MPH. It has a Ford version of a tune port intake and running 343 gears.

The big problem is running an engine too far below from its torque peek, doing so can cause bucking (lugging) and poor MPG.

By building a high torque low RPM motor I should be right on the money. I expect to get MPG in the 20s.

I wish I could find someone whom has built such a set up but so far everyone builds for HP and higher RPMs and running in higher RPMs just seems to mean more fuel to keep it happy.

I am posting this to see if I can get either confirmation or real proof I am wrong.

PS Here is a few reasons why I want to save the Van: https://www.facebook.com/richardacoy...X9e4B82CGvS3pA

I love this van as a high way road machine BUT as other van owners say, She has a drinking problem...

More: A few of the questions I have not been able to find answers: The 1990 Cadillac cam: was it straight up or as I have heard tweaked, either advance or retarded?? Every time I look into replacement cams they always push the torque peek upward, anyone know of a good (or) better roller cam??

Or the specs or numbers of the Peanut Cam??

And is the any problem running it any of the lower gears for a long time such as I figure I will be doing with he 8L90??

I also am aware that a number of engines like the OLDs 403, and the Chevy 400 ran torque peeks at 2000 RPMs, so I am not so "out there."

Thanks for reading.

09-22-2018, 12:12 AM	#1 (permalink)
racprops Master EcoModder Join Date: Oct 2009 Location: Phoenix AZ Posts: 799 Thanks: 4 Thanked 66 Times in 58 Posts	Some deep thinking on getting Best MPG in a VAN OK I jumped in to another thread that was about cams and engine, but it was hinted I was high jacking the tread SO I am starting one of my own, (sorry guys..was so impressed by the thread I though you would help me...) So let me try this as my own thread. I wanted to throw my plans and ideas out for feed back, as much as I THINK I have a good plan and idea, rather than waste time and money, this is the first place where I think I will get good feed back and good info rather than the knee jerk reaction I get from every hot rodder..."It will not work and you NEED RPMS and HP...." I regret to inform everyone that my 93 G20 Full Size Custom Chevy Van suffered a major lost of oil because of a failed hose clamp connecting my 15 year old oil cooler. The engine has totally seized. BUT she will be back, as this means I have to and can do my super drive train, something I just could not justified with a good running engine. Here is my thinking and a fairly old plan: From all I have read about MPG I come up with two ways SMALL and LIGHT with small motor, to make them work they run higher RPM. But I am driving a BIG van, big in wind resistance (pushing a box though the air) and heavy. The trick seems to be a big TORQUE motor. There is a reason diesels are used on big rigs, TORQUE. Diesels make torque and at low RPMs, they can barely get over 3500RPMs. The only thing that makes better torque is an electric motor which has all its torque at 1RPM… IF there was a replaceable power supply I would be going to electric motors BUT there are none so far. Not for nonstop long road trips anyway. So I am building a gas engine as close to a diesel as possible. It is not too farfetched as some might think, a 1990 Cadillac came with a Chevy 350 with a low RPM cam that had its torque peek at 2200, and the earlier Chevy 400 in a big station wagon had a cam that peeked at 2000. The Olds 403 has similar cam timings. Torque is what gets you down the road. So here is my lay out: A 385 Chevy with 192 Swirl port heads, max RPMS with them stock 6000, they have been cleaned, no polish as the ruff walls are better for low RPM power…3 angle valve seats, Perfect Circle valve seals (Chevy has a history of bad valve seals) like new guilds or replacements as needed, stock valve springs, new keepers, and roller tip rockers to minimize pushing the valves back and forth. The stock Chevy/Cadillac cam, or a 400 aftermarket cam IF it can be had With Stock timing and built for a roller) as is the cam I have as a roller cam. The block is cleaned and ready to go, I have Keith Black “D” Shaped disc pistons (allows running low Octane gas) with a stock 350 crank so all I need is a 400 crank fitted. Feeding it will be a 85 to 92 Chevy TPI intake. Again these intakes are said to produce 30 to 35% MORE torque, HP and MPG over the same engine running a carb. Running the PCM will be a add on computer card that give me almost total control of the fuel system.. http://www.dynamicefi.com/EBL_P4_Flash.php Once all of that is done I will test drive it and see how things work. Then I plan on putting in an 8L90 transmission which has some very nice low first gears and then rebuilding the rear end with a possi and a set of 243 gears. My numbers show it will be able to do 80MPH at 1700RPMs. My 2000 Mercury with a similar setup got 27 to 30 MPG at 65 MPH. And 25/26 MPG at 80 MPH. It has a Ford version of a tune port intake and running 343 gears. The big problem is running an engine too far below from its torque peek, doing so can cause bucking (lugging) and poor MPG. By building a high torque low RPM motor I should be right on the money. I expect to get MPG in the 20s. I wish I could find someone whom has built such a set up but so far everyone builds for HP and higher RPMs and running in higher RPMs just seems to mean more fuel to keep it happy. I am posting this to see if I can get either confirmation or real proof I am wrong. PS Here is a few reasons why I want to save the Van: https://www.facebook.com/richardacoy...X9e4B82CGvS3pA I love this van as a high way road machine BUT as other van owners say, She has a drinking problem... More: A few of the questions I have not been able to find answers: The 1990 Cadillac cam: was it straight up or as I have heard tweaked, either advance or retarded?? Every time I look into replacement cams they always push the torque peek upward, anyone know of a good (or) better roller cam?? Or the specs or numbers of the Peanut Cam?? And is the any problem running it any of the lower gears for a long time such as I figure I will be doing with he 8L90?? I also am aware that a number of engines like the OLDs 403, and the Chevy 400 ran torque peeks at 2000 RPMs, so I am not so "out there." Thanks for reading.