improving emissions and fuel economy

I see, now it makes sense that it passed, I didn't know if things were old enough our state stopped inspecting them. I'm sure the O2 sensors, higher compression, ECU will help get it more efficient.

For towing as heavy a load as you will be an ecoboost or similar engine is the right tool for power and efficency. But it doesn't come in a vehicle you want. Maybe when this car is through it might look better, but don't check it out on our account.

water injection acts like an octane boost, allowing you to run a leaner mixture in those cases without knock. You want to have it under control to inject at those high throttle or high rpm situations when you might knock. If the car doesn't need higher octane on the tune you have, then no need for the injectors. You mix the water with methanol so it doesn't corrode. I would not expect it to help much on your engine.

 

Is kickdown an issue? I've got a $30 kit from B&M (B&M 70237) in my '91 Formula. It does allow higher speed cruising in overdrive....

You'll like the synthetics. Last summer I converted my wife's '04 Mustang GT to Royal Purple & Amsoil in engine, trans and diff. She picked up 2 mpg just from that.

 

If you a stuck on this Detroit iron, cast off the engine and drive train and install either a modern GM or MB Sprinter drive train. A 10,000 lbs sprinter will get 20 mpg, will tow a pretty good load. 3 liter turbo diesel, and it will move down the road quite well. Mine does 75 all day long at 20 mpg at nearly 10k gross.

A small Cat or Cummins conversion might do fine too. Problem is you really have to do the the tranny if you wish to get any kind of performance. You could probably find an old GMC/Chevy diesel 5.8 and convert it really easily, but those were pretty shitty engines.

Icarus

 

9 city, 15 hwy I hope I'm wrong and you are doing much better.

 

What about the 6.2 Detroit diesel GM offered in some trucks, and military Humvee?

 

You can measure the applied HP by doing a timed, maximum acceleration test to say 45 mph to stay out of significant aerodynamic drag. But you'll need to get the weight with driver (and any other load) to calculate the HP. If you had an iPad or iPhone, there are apps that automate the whole process including measuring the acceleration.

Given the dusty conditions in Texas (I grew up in Oklahoma,) you might consider doing an early engine and transmission oil and filter change before running the benchmark.

Bob Wilson

 

The peak hp of that model engine was 400 gross bhp in 1970 with 10:1 compression - that was measured in the old way without pollution control, tail pipe, other loads. Th ecoboost is net hp. My guess is your net hp is less than 400, but definitely check it out. Congratulations on getting 20 mpg hwy, that's a huge improvement.

hp/mpg = hp*gallons/mile which is a pretty meaningless measure. hp/lb and hp/cdA (hp divided by drag) are much more meaningful.

I think you need to paint - "fear the reaper" on your car.

 

Yeah, '76 was measured the same way we do today, and was down under 200 ponies. That 400 gross bhp was not measured with any exhaust. I forgot that you got your injectors up, and didn't know about the intake manifold. That should push it passed that '70s one.

I'm curious to see what it will do on a dyno. I don't think that stage 3 motor will help you on mpg if you are going 4wd

 

It's actually better, since you have reduced the total frontal area along with reducing airflow underneath. I didn't think of it because all the ones I see on the road are done half nice person with the wheels off camber. Unless that's on purpose, which is just dumb. As long as won't effect the towing or getting where you need to go, do it.

 

lol. If you turbo charge it for efficiency, you probably end up with around 750hp Which I thought might be a problem feeding air into those turbos. Removing the hood and putting a big scoop up there definitely solves that problem, but looks like it would hurt your aerodymaics at 80mph.

If you do forced induction, and want to do it right you definitely want turbo, not super charging. The super charger puts a parasitic load on engine, which increases with power. In other words the more you ask of it the more the vapire sucks life from your engine. Its advantage is power in low rpm ranges, ease of install, and lack of turbo lag. With that big block there is no reason to worry about power at low rpm or turbo lag. A supercharger can make that 3L engine feel like a 5L, but you already have a 7.7L monster. You already did a full head job, I'm sure you can handle adding the turbo chargers. You do need to run oil to cool the turbo charger, and need to go low or let the engine idle before shutting down. The biggest efficiency hit with a turbo is high rpm mode. When getting in that high rpm range, the mixture needs to get rich to avoid detonation and that wastes gas. It also leaves efficiency up to the driver, drive at low rpms and the engine is efficient with more power, and high rpms you get monster power and low efficiency.

 

Hey you were doing things so much less expensively than I figured you might have some secret amount of cheap parts. The original head would give you proper compression for super or turbo charging, and either would need more fuel flow from the injectors. If you turbo charge it, there will be more torque, so the trans needing an overhaul is correct. Rods, pistons, crank may also need replacement. That makes it an expensive project. If you turbo charge it for torque, not hp you don't need to worry about being off boost, it will act great at low revs. I don't think supercharging it will get you where you want to go though.

Tune is very important. Good job.

Doh. I'm not used to thinking in cubic inches, they are so before my time. 8.,2 liters it is. That means you even need less boost if you are doing forced induction ;-)

 

I have no useful technical advice to add to this thread. I only wish to comment that a non-prius driver has come here, spoken (faintly) ill of that car, and expressed a personal lack of concern for vehicle pollutant emissions. Despite all that, the discussions have been cordial and probably useful to TxMan.

It supports my long-held idea that there are some fine folks here. I am not at all sure that the reception would have been as warm at many other car-affinity discussion sites.

Anyway, I hope your hearse continues to improve and I think we would all enjoy seeing some pictures posted

 

That's because when the need arises for a high horsepower hearse, we will have the inside track.