Some deep thinking on getting Best MPG in a VAN

[freebeard]

I'm curious about the aerodynamics, but no way I'm going to touch Facespook.

Can you add the materials to an album here?

[racprops]

The problem is after the 80s TPI motors, and the Fords TPI 4.6 motors it seems everyone is into a HP race, to see how much HP they can get.

I have not seen any MPG motors.

To make HP takes lots of Air and Fuel..specially fuel.

Again: 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.

My Ford 4.6 can really pump it in at WOT...BUT it is moving a lighter car than my van, and the next step up in Fords have a rep for being gas gushers. Bad MPG.

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.

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.

I am now thinking of a Comp Cams cam Exreme Energy Cam # 08-500-8 with perhaps a set of Rhoads Lifters…

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

This is my planned motor so I am looking on how to make it even stronger at low RPMs.

I feel I am nearly there.

Rich

[racprops]

The problem with posting pictures here is you need a URL. I no longer have a web site to host pictures.

Most sites now host pictures but this place does not.

Facebook is NOT the Bogyman site some make out it is...simply do not post anything you do not want seen or known.

Rich

[Ecky]

I use imgur. It's free.

[rmay635703]

There is a manage attachments button here to upload photos

[freebeard]

Most sites now host pictures but this place does not.

Facebook is NOT the Bogyman site some make out it is...simply do not post anything you do not want seen or known.

You can create on or more albums in your user profile, and upload from your desktop/hand.

You misspelled boogyman.

I resent that even though I never have, and never will, submit my life as material to their marketing algorithms, they maintain a shadow profile on me "in case I ever decide to join" "to serve me better". I visited with some friends in a bar and they posted my picture to their page without my permission. When I said something, they couldn't see why they needed any.

https://duckduckgo.com/?q=facebook+shadow+profile

Why should I be pleased about this?

[aardvarcus]

Raceprops,

I don't know how you are missing the threads on the trucks, vans, and suvs on here getting good MPG, that is the reason I am a member of this site as opposed to others. There are several members on this forum getting pretty decent MPG out of vans, trucks, and SUVs, you should look to those threads for ideas. I seriously considered for a while modifying the 350 in my 1991 Chevy K2500LD for higher torque at lower rpm for MPG but ultimately decided to pursue other avenues mainly because it was a regular cab and I needed more seating.

You are correct that a high torque at low RPM engine combined with tall gearing is a potentially good combination for MPG in a larger vehicle. I don’t think there are a lot of people on here that are going to have experience with your specific setup modified in the specific way that you are suggesting, which is part of why you keep getting suggestions for other engines. I will refrain from suggesting other engines in this thread as you do not seem open to the idea.

My suggestion is that if you are set on using this engine modified in this manner, look to the other forums that have modified engines similar to this way (but for HP) and try to find a dyno sheet where you can get feedback on a torque curve. That should influence your gearing decisions on RPMs to run based on your torque requirements at a given speed. Sometimes they even have BSFC information on dyno runs. I am running a few engines in manners contrary to popular opinion with great success, but it requires legwork to connect the dots and sifting through lots of non-relevant information.

You also seem set on your transmission decision, but my personal experience is that stick shifts get better MPG than automatics with similar gearing. I saw a 4-5 MPG gain swapping a 4l60e (11-13 MPG) to a NV4500 (15-18 MPG) in my aforementioned 1991 K2500LD, note that the overdrive ratios of the two transmissions are very similar and no other changes were made to the vehicle. Treat that as a data point and draw your own conclusions, many people prefer an automatic for other reasons.

My experiences with tires has been different than you suggest, I strongly prefer stock or narrower tires on my vehicles versus wider. I may be leaving something on the table in dry weather, but in adverse conditions I have had much better luck handling and braking. To me tire width should be a function of vehicle weight and PSI to maintain a similar contact area force. However I have found tire tread pattern has just as much to do with it as size, I prefer tires with large amounts of sipes. Back when I had a sporty car I had "hard" tires outhandle "soft" tires in all conditions because the tread pattern was better despite the rubber compound.

[racprops]

aardvarcus

Thanks a fairly helpful post. Will search for pickup trucks and Van on here.

I live in AZ and 90% of the weather is dry, I am somewhat aware of hydroplaning with wider tires, and these are only a couple of inches wider than stock, and from what I have read tires that give any real improvement in MPG are much thinner and harder which translates to much less much less stopping power and much easier skidding.

I normally try to avoid rain.

I feel the newer autos with their lock up torque convertors and add in in that torque convertor which really does allow an engine to rev up into more power, that and the 8 gears out weigh to slight improvement from a stick, and I have seen clutches wear out in 70,000, and it is a lot easier to lug a engine with a stick.

I have looked and looked though a ton of other sites, they ALWAYS go for the power and thus move the power curve up. Hot Rodders simply do not build my kind of engines.

You said "I am running a few engines in manners contrary to popular opinion with great success, but it requires legwork to connect the dots and sifting through lots of non-relevant information."

Could you tell me about them??

Thanks for your help.

Rich

[aardvarcus]

Raceprops,

Didn’t notice you were in Arizona, rain probably isn’t as big an issue for you as it is in TN. I run Michelin Defenders or similar on all my vehicles now, while not a “MPG” specific tire, the return pretty good mileage but still have great traction. Yeah, hot rodders won’t build a low end torque engine, but you might find something related to towing or an RV engine build that would be close.

My first atypical engine is my 6.5L Diesel in my 1994 K2500 Suburban (NV4500, 4x4, 4.10). The atypical part is I am running it naturally aspirated not turbocharged. It is widely accepted on the internet that the engine would be more efficient with a turbocharger, however after much digging I have found evidence that suggests otherwise. Thus I run it naturally aspirated. Right now it is basically stock and is getting 24MPG based on the last four tanks, and should do much better when I upgrade the gearing (0.73 OD to 0.65 OD, 4.10 to 3.42 Gears) and improve the aerodynamics.

My other atypical engine is the 8.1L gas big block in my 2001 K2500HD. (8.1L, 4x4, Allison Auto, ECSB) The atypical part is I bought the 8.1 over 6.0 because I wanted MPG. It is widely accepted on the internet that the 8.1L engine would drink gas like it is going out of style, but mine gets 14MPG not towing. The mileage doesn’t drop much towing my equipment trailer when it gets more like 12MPG. That is based on many tanks hand calculated, not some instant readout going downhill. I have not heard of many other gasoline engines in three quarter or one ton pickups with automatic transmissions and 4.10 gears that do much better than this in real life conditions. I believe this is because the engine can lug along at lower RPMs while other engines would be downshifting. I would gladly swap the gearing to be taller, which is the biggest MPG hindrance on the vehicle, but I don’t put enough miles on the truck to justify the expense. Honestly if I could regear it to turn 1000 RPM at 55MPH I would.

You will notice that both of these are torque down low engines in heavy vehicles with the aerodynamics of a brick.

[racprops]

Sounds about right, and for a long time most diesels were naturally aspirated, it is only lately have to gone to turbo or supper charged..at least in small rigs.

AND yes I to am driving a brick...I do not plan on doing any trailer pulling...

It looks like the smallest gears I can get for my van will be a 2.14 and that will allow me to run at 989 RPMs at 55, and 1258 at 70 and 1438 at 80MPH.

Of course these RPMs and speeds will only be possible on level grown and low head winds...

Which causes some concern if I can run a auto in lower gears most of the time??

Rich