1970's "30mpg" V8 cams, big car, w/14:1 CR on 87oct

[Vman455]

Originally Posted by cosmick

So much to comment on there. The Prius is a lousy reference because it's 1.5L is an old design that was relatively inefficient even when new.

How so? The Prius, and the scads of other cars that use late-valve-closing, simulated-Atkinson cycle, are not actually Atkinson cycle engines (four strokes in one crankshaft revolution) or Miller cycle engines (which use a supercharger), and function on exactly the same principle as the Hot Rod article engine you're searching for. Someone above asked why this technology didn't "go anywhere"--the answer is, it did. It is even used in high-performance cars today.

Also, the 1NZ-FXE was a clean-sheet design in the mid-90s, and efficient enough that Toyota still uses it in the current Prius C.

[oil pan 4]

Well tomorrow or the next day I pick up my engine block its gen IV chevy big block bored 0.030 over going to be a 11:1 engine that hopefully runs off regular gasoline.

[slowmover]

Super tight quench, huh?

[California98Civic]

Originally Posted by Beau

I believe it was called the Crower Mileage Maker Cam.

I did a LexisNexis search for this. Nothing. Changing terms to "Crower" AND "mileage" yielded only a 1989 article from the Toronto Star on a dragster for sale. It had a Crower crankshaft.

Changing the terms again to "Crower" AND "Camshaft" comes up with the company info (the link works):

TELEPHONE: 619 690-7810
FAX: 619 661-6466
URL: Camshafts | Connecting Rods | Roller Lifters | Rockers | Crankshafts |

Google search gave this:
http://www.automotiveforums.com/t525...leage_kit.html with this post:
"Hello, I built 2 engines in the 70''''s with these cams (mm-1 and mm-2) from crower and used 12 to 1 compression on 1 and 11 to 1 on the other. They idled bone stock, had great pulling power on 89 octane gas with no ping and had great acceleration while getting 18 mpg in a 3/4 ton pickup pulling a 7000 lb trailer full of concrete finishing equipment! The cams hold the intake open about halfway up the compression stroke which cuts the cylinder pressure at low speeds, but gives you the same expansion ratio as the 12 to 1 compresion at speed. The other one got 25mpg in a full size chevy blazer! Crower acts like they never existed, but Predator cams is about to grind me something similar to play with as the price of fuel makes it worth looking at again. If you still check this forum, let me know and I will keep you informed if I can make it work as before since it will be a proprietary grind this time.By the way, the intake lobe looked like a roller lobe it was so wide across the nose and the exhaust lobe looked like a STOCK FLAT TAPPET LOBE."

[freebeard]

...it's funny; when I search on 'crower mileage' within Ecomodder I get 17 hits.

[cosmick]

Originally Posted by slowmover

Super tight quench, huh?

I've seen the broken hypereutectic pistons from a balanced and blueprinted LSx that went together with 0.021" quench, there's good reason for the 0.035" minimum rule of thumb. The difference in engine output or efficiency is too small to measure, but having to replace pistons every week is senseless.
Tight quench can help emissions, but only if used right. There are also modern examples of "excessive" quench clearance reducing emissions without measurable compromising power output. Cranking compression over 200 psi, in fact.
So better to have .045 than .030

[cosmick]

Originally Posted by Vman455

How so? The Prius, and the scads of other cars that use late-valve-closing, simulated-Atkinson cycle, are not actually Atkinson cycle engines (four strokes in one crankshaft revolution) or Miller cycle engines (which use a supercharger), and function on exactly the same principle as the Hot Rod article engine you're searching for. Someone above asked why this technology didn't "go anywhere"--the answer is, it did. It is even used in high-performance cars today.

Also, the 1NZ-FXE was a clean-sheet design in the mid-90s, and efficient enough that Toyota still uses it in the current Prius C.

Today's most efficient new engine has neither of those.

[California98Civic]

Originally Posted by freebeard

...it's funny; when I search on 'crower mileage' within Ecomodder I get 17 hits.

Not sure if this was for me, but I was trying to locate the Hot Rod article or a specific citation to it or something similar. That's why LexisNexis. It is a pay-walled database of published stuff going back decades. I didn't search Ecomodder and didn't realize this was an old thread.

[freebeard]

I wasn't going to go through all 17 links to find anything of interest, but yeah.

[racprops]

I have read partly though part of this thread, and will be back to read more, BUT 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 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.

Thanks for reading.