irab88

iTrader: (4)

this sounds pretty neat. you should get a photobucket account and post pics of all this great work

BMcEL

Pics or it didn't happen!

HappyCamper

i'm pretty sure 50mpg is attainable if you only drive downhill

Outsane

botfly yota could do it!

troyjmueller

I've been doing a bit of research on cam selection. figured the gear ratios with my combination of gears (W4x 2wd, W50 2wd, 3.42:1 Axle, 195-75-R14 tires.

Turns out that my useable RPM ranges is as follows:
Low RPM High RPM MPH Low MPH High
1st 0 2425 0 15
2nd 1425 2350 15 25
3rd 1575 2525 25 40
4th 1825 2050 40 45
(5th) (1725) (45)

Cruising @ 75 MPH would put me @ ~3375 RPM in 4th and ~2875 RPM in 5th.

Suggested shift points are from the owner's manual.

There is a handy calculator for rpms & mph at

http://www.bokchoys.com/differential...calculator.htm

transmission gear ratios can be found by internet search.

This means I should probably tune for a wide, flat torque peak in the 1400-1800 rpm range and a HP peak at or near 3500 RPM.

Stock figures place torque @ 2800 and HP @ 4800 RPM. Does anyone know what type of camshaft specs, intake combinations, exhaust combinations, will do this?

I am thinking short duration, advanced timing, lower LSA. maybe something like 0.375 lift, ~190 Intake @ 0.050", ~ 200 Exhaust @ 0.050".

Nearest Stock Cam specs I can find are
272 Intake, (Advertized), 248 Exhaust (Advertized), 0.382" Lift Intake, 0.398" Lift Exhaust. Nothing to be found on OEM specs @ 0.050", or Valve Event Timing (Intake Open, Intake Close, Exhaust Open, Exhaust Close.)

22RE is supposed to have a shorter intake duration, milder intake lift with a wider exhaust duration at the same lift. Local Dealer says that cams have the same part number., no available specs. !!??

Possibly there is some low end torque to be gained from using a 22RE cam in a 20R/22R carbureted setup.

A tuned Intake manifold, runners matched to the head, would probably have a length something in the order of 36" for a boost @ ~2750 rpm, on the 3rd set of pressure waves, or 57" for a boost @ ~1750 rpm, on the 3rd set of waves; Verry long intake runners. Tuning the Exhaust for scavenging is calculated in a similar manner, and can actually improve back pressure at certain ranges, but I haven't done the math yet.

Has anyone run a tuned intake, other than the stock EFI manifold?

there is a good write-up by grape-ape-racing called induction systems that details how to do the math.

I have pictures of the test mule.. err- victim- and some of my accumulated parts to post shortly.

irab88

iTrader: (4)

good research and numbers...


but...







just sayin'

DAW

Great thread Troy. Almost all of the replys I've read so far are way below your level of expertise. Good intentions, but they don't know what they don't know.

What you are doing and your approach makes sense but forget the multiple carbs (that said; some SU-type sidedrafts could be an exception, but tuning/machining the needles can get tedious). I would stick with a single 2 bbl progressive Weber 32/36 on an Offenhauser Dual Port (to fit the 20R head) and tune it in with a wide-band O2 sensor.

You could work with a 4 bbl Dual Port manifold, but they come with a square bore carb flange; but a small spread bore carb (Quadrajet or Thermoquad) with vacuum secondaries makes a lot more sense for this manifold design (you can just limit the travel of the large secondary throttle plates when you tune for WOT so as not to over-carb), and you'd have the small high velocity primaries plumbed into the manifold primary runners of the Dual Port for excellent efficiency and response.

Crank-fire ignition like an Electromotive HPV-1 is nice (which you could source from classified ads, like from an older Toyota SCCA car), reliable, and easy to set up. Compression ratio is key (within sensible streetable limits), and consider advancing the cam just a bit to improve the MPG.

Top it off with a high-flow catalytic convertor to really confuse them.

Leviticus6432

All this work and money... why not just convert to propane, then make efficient... I've never seen someone do both.

DAW

I know pretty much nothing about propane-fueled performance tuning and it's time I researched it because this has me pondering the disposition of another one of my vehicles. I was trying to piece together a (overly expensive) string of induction components for my '85 amc eagle awd wagon 4.2L L6; akin to what we're talking about for the Toyota L4 topic. I'm adapting a ported '91 Jeep 4.0 head and improving the exhaust exduction, and intake induction; planning it all on a tight budget. I was thinking Offenhauser Dual Port with a spread bore vacuum secondary air valve 4 bbl, but now this propane discussion has me thinking that I could instead use a late model MPI manifold (an advanced design with curvy equal-length runners for enhanced low rpm torque, a generous plenum, and a single throttle plate TB [easy for an LPG conversion]).
Plus, I just saw some big LPG tanks for sale at Costco for $109 each and I already have one on hand that I bought for a heater for the garage. BTW, I noticed they are DOT Approved. I suppose that is for transporting them from filling point to the home, but "DOT Approved" sounds good to me in case I'm asked somewhere along the road when it's powering my car. wink. I'm installing some household LPG anyway, as an adjunct energy source to the public utility electric energy that powers my house. Accordingly, I could get a huge (maybe underground) durable tank for home; replenish it when prices are good; and tap into it for my car refueling when I want to. I'd carry a spare little LPG BBQ tank, like are sold at Wal-Mart, as my ready reserve to limp to an LPG refill station or on to my home personal resevoir/fuel dump. (instead of lugging a red plastic fuel jug of gasoline back to the car if you run out of fuel; you'd be toting one of those BBQ propane tanks back to the car)

Following the discussion so far? I barely am. A disabled MPI induction setup (injectors are shut down/closed and the ECU/gasoline metering is disabled) could make an excellent platform for a grassroots LPG system. The beauty is that the LPG isn't subject to what hinders gasoline fuel droplet technology (carbs vs efi), since LPG is fully vaporized all along its pathway; and this fact lends itself to induction tuning; probably forced induction augmentation too.

A system tuned to optimize LPG performance would need to have different tuning parameters than gasoline-fueled running...so a dedicated, tuned motor specifically for a single type of fuel makes far more sense than a dual-fuel setup with a switch on the dash. I haven't yet seen any extensive resources on fine-tuning propane-fueled engines re compression ratios, cam profiles, ignition and valve timing parameters, etc. BTW, old cars like Model "T" Fords had an ignition advance lever as a steering column mounted controller. Why not have a spark-knock sensor light (most modern cars have such sensors feeding into the ECU) but wire it to a dash-light indicator instead, so that the driver could manually retard the ignition timing some if the light shows there is a (yet inaudible) tendency to knock (for whatever reason, be it poor grade of fuel purchased, engine load high/too lean the stoichiometry, ignition timing, etc)? Combined with an onboard wide band O2 tuning sensor, real-time optimal onroad tuning could be simplified and realized using propane fuel. Who needs an ECU when there is already a computer onboard the vehicle (albeit made of meat)?

Back to the Toyota with the 20R head/intake manifold situation, maybe an L4 VW or Renault progressive 2bbl could be adapted to a Dual Port Offenhauser intake to use with LPG, as I haven't seen an equal-length runner manifold available (not aftermarket; and there was no OEM) like I'm referring to on the L6 Jeep '99+ MPI engine (or many other inline engines, e.g., Volvo, BMW, etc/etc). A staged induction resonance pathway intake like the Mercedes inline engines would be great too, but it would have to be custom fabricated for a 20R. Too complicated, but better-suited to the goal.

Leviticus6432

notice your still dropping LOADS of time and money into a project... what I was referring to by convert then make efficient.. is buy a kit, install it, lightly mod the motor, do a touch of tuning here and there then work on making the vehicle lighter, adjusting gear ratios, reducing drag, etc. The only people I have seen convert their vehicles to propane for street use always just buy a kit and call it good. They end up cutting the cost of fuel in their 15mpg truck in half if not better so they are happy with it. Consider this... say the cost of propane is exactly half that of gas. If your truck got 15mpg and you convert it, it would be the equivalent of getting 30mpg. If you could get your truck to 30mpg with a stock 22r... it would be equivalent to 60mpg with propane. Of course propane is less than half the price of gas so you would save a little more there but it also carries less energy, so you would technically lose a little mpg, but its just an example. lol

DAW

This person can't just slap on a kit. I couldn't either. I want to know, ahead of time, what is optimal; what is not; and do it as I see fit.
I will decide my own compromises for myself when I have the ability or opportunity to do so. It's a philisophical thing.

I'm working out the same basic problem (It's a problem in the sense of problem solving or personal challenge only) on Mini Mo-Ho. It runs great as-is but that does not mean I can't make it better. Cost effectiveness and efficiency are the most important factors on this vehicle because serious travelling lies ahead for it. I already have good compression ratio, upgraded electronic ignition, tri-Y header, cam, Weber 32/36 and that is how I bought the vehicle. I know from my 510 that the Dual Port and 32/36 can be highly tuned for performance and efficiency (if you know how to drive it/operate the mechanical secondary carb (it's a MANUAL induction system)

DAW

Ludicrous, it begs the general discussion re propane; and it might be just the thing for "Major-Ho", my hot rod RV (Mobile Traveler fiberglass shell on '79 Dodge 1-ton single rear wheel chassis, 5.9 with Magnum heads (increased c.r. & breathing), headers, tuned exhaust system, cold ram-air, aluminum dual plane intake, Holley 600ish cfm vacuum-secondary, Crane RV cam, Roller Timing Set, Big aftermarket sway bars front & rear, Hummer 8x17 wheels, Trac-Lok Dana 60, gutted interior and weight loss (out goes the water heater, oven, stove, furnace, refrigerator) and Cadillac Eldorado front brake calipers (with E-brake function) on custom brackets using GMC 4WD front vented 8-lug rotors conversion to rear discs...On IT, a bolt-on propane conversion system might be just the thing. The propane tank I was removing (that to power the stove, refrig, furnace, oven, water heater, etc, etc...) That I am 90% on the way to drop that dead weight tank...I might retain instead to fuel the engine. The objective of the weight-loss was in the interest of adding lightness to enhance the performance and braking. The main issue on that vehicle is the trans upgrade/update. I'm researching a current MT to replace the 727 Torqueflite, or the 46H trans that I can flip a toggle switch to lock the convertor or engage overdrive, or whatever.

DAW

Oh, it's Levaticus

Leviticus6432

you can edit your posts. its in the bottom right corner of the post. anyway, I'd definitely swap to a manual. And you would have to consider that you would lose some weight getting rid of your stock fuel tank.

DAW

The fuel tank weight empty/full is an issue. A large propane tank full of LPG to deliver the same range as the equivilent tank of gasoline seems like it would be heavier than the gasoline version (due primarily to the weight of the tank itself, the thick steel walls of the propane tank). Are fork lift tanks lighter weight than other propane tanks? Are there other options to save weight on LPG tanks? I haven't yet dropped the propane tank from the larger motorhome (Major Ho) I was discussing, but it looks HEAVY judging from the beefy mountings to the frame used.
I'll research this factor but maybe someone knows already?

I've been trying to conceptualize a bolt-on system using an air compressor driven off of the driveshaft by a v-belt pulley, activated (electromagnetic clutch engagement of the compressor) as a braking/vehicle deceleration device (harnessing [preserving] energy/inertia otherwise going off as heat [wasted] at the brakes). The compressed air is stored and reapplied when needed as an augmental turning force to the driveshaft through the same v-belt drive; {or used to augment induction pressure somehow}. I would think it would be possible to use some lighter weight tanks to store compressed air than for flammable gas; scuba tanks? Maybe forget using compressed air to augment induction pressure and instead make a closed system using a different gas (Nitrogen?) to compress which lends itself to this "elastic" system of work storage and reapplication. The pump needs to be switchable through controlling valves to essentially function in reverse, driven by the compressed gas (as an electric motor is to a generator depending on how the field is set up). The key is that it be driven by vehicle inertia; not an engine-driven device. Steady state is reached during driving until it's time to capture and conserve work again at vehicle deceleration.

Or, the system could work (literally) to create vacuum in one tank by (valved) shuttling the media to the compressed side of the system and this effect increases the amount of work which could be harnessed/stored. Pulling and pushing at the same time takes more work than either action alone.

Functionally, it's like electric regenerative braking but using a different media than electical energy (with the heavy batteries for storage). Preserving work instead of losing it as heat into the air through the conventional brake system is the same concept for both.

Ultimately, a tube-chassis could be the storage tank (vessel) itself for this type of system incorporated into the vehicle design, but for now it's an add-on idea for RWD (driveshaft equipped) vehicles.

irab88

iTrader: (4)

psst...

https://www.google.com/search?rlz=1C...s+propane+tank

DAW

thanks!

troyjmueller

Sorry for the delay on getting back. Apparently 'shortly' was in terms of geologic time. (had to dig up my camera interface cord).

First pic is the Test Vehicle.
second pic is my collection of most aplicable available parts to utilize.

I am happy to here about your project with the propane. If you google propane, you should be able to find octane properties. I seem to recall propane having an octane somewhere around ~ 104.

CNG, Hydrogen, Methane, Wood-Gas (synthesis-gas), should all have similar plumbing characteristics, with differences in fuel btu's, octane, stochiometric ratios, etc. Storage can be tricky, and availablitly (and self-manufacturability) varies.

Moonshine - er - E-85, will have an octane rating somewhere around the high-90s to 106 (depending on the denaturant and the quantity).

I have read about people running 10.5:1 CR small blocks with 10-15 pounds boost on E-85, a combination which sends experienced racers running for the hills with even high-octane race or aviation gas.

If you don't know about CR, it isn't static compression ratio that makes the knock - it's peak compression pressure, which varies with cam timing (intake close), and atmospheric pressure (altitude), and boost, of course.

Higher CR will allow more expansion during the stroke, and the charge will have lower pressure at the exhaust, if it has expanded say, 10x versus 6x during the power stroke. Thus, more of the heat/pressure will act on the piston, versus providing a fluid flow out of the tail-pipe.

Water injection can mitigate knock, allowing higher Compression pressures, in two ways.

First, it cools the intake charge, thus preventing locallized 'hot spots' and pre-ignition.

Second, the liquid-gas phase change (which requires a lot of btus for water) produces a significant amount of pressure, at a relatively cool temperature. thus, the piston might see several percent more pounds force at ~ 500 degrees, versus sever percent less pounds force at ~ 2500 degrees.

It is the pressure increase generated by the combustion which allows the engine to make power; more pressure increase will produce more power. Without the thermal input by the combustion, and conversion to pressure by whatever means used, the piston would simply rebound from the compression stroke, and stop before the start point because of mechanical losses.

troyjmueller

For those of you curious about the parts list, there are three 20R heads, one 22R head (potential valve, cam, rocker donor), several 20R intakes, three 20R carb cores, three 4 cylinder motorcycle carb banks, one 3 cylinder motorcycle carb bank, one 22RE lower intake, two mazda 12A 4bbl spread-bore vacuum secondary carbs, two motorcycle mufflers, four early toyota tail-lights (convenient for tail-lights for a flat-bed).

I couldn't find a partrige and a pear tree. sorry.

Also, in pursuit of mileage, you can get a significant gain by installing a belly pan, ground effect stuff, and a tonneu cover.

This fellow has gained approximately 25% more mpg's on his rig.
http://evworld.com/article.cfm?story...6362&end=6361#

troyjmueller

Got the head in the shop. 80 20R head, will probably get milled ~ 0.008" for warp, and aditional to clean up some pitting in the metal. I have the mechanical pump (bleh), and the P/S boss. (won't be needed).

does anyone have experience with over-tolerance head shaving on the early hybrid?

I hear that the cam timing is affected, and that compression doesn't really change as much with a hemi head as with a flat quench head.

I may have to take ~ 0.020" past the maximum recomended limits - I'm not sure whether this is set by the cam timiming dynamics mainly, or because of some of the coolant passages.

I read that milling the head for the differences between the early and the late style can compromize some of the head passages.