Improve mileage 350 with Quadrajet

[billnorman]

I have made some more observations.
1. It looks like you have the dreaded GM no darn good pink coolant, recalled and destroyed. What do the rest of you guys think?
2. There are two timing reference stationary references on your motor. One is way ahead of the other. If LPG uses more timing advance than gasoline, perhaps that's what the bigger one is used for.
3. The vacuum advance IMHO softens the spark curve and allows advance in at high vacuum settings (low throttle positions) for economy. I may be wrong in this hypothesis, but if it's hooked to a below the throttle plate source, it will decrease timing when you step on the throttle, and increase it when you drive gently. If it's hooked to a vacuum port AT the throttle venturi, it will increase timing as the engine increases speed. The timing increase function on a Chevy v-8 is by the centrifugal weights.
4. I am not familiar to the functional envelope of a dual fuel engine. I would recommend you research on line the requirements and limits.
5. Personally, I think you need to operate this engine as warm as possible, and if LPG will tolerate an EGR system, hook it back up,
6. Turning the fan around won't change the way it functions. As you are in a very cool climate, why not do away with it altogether and go with electric? The kits can be ordered by mail, I've used them with no adverse effects and they are easy to install or you can get one off of a wrecked car.
7. Just as an aside, I have used Seafoam oil additive to clean and fix my wife's car. If it is possible to use all the time, I'd check the can to make sure, one can added to the oil will thin it out and clean the internals of your engine. This MAY improve your mileage.
8. Your photographs are exceptional. You are persuing this scenario with scientific analysis; cause and effect. I think if you stick to it you will get the best out of the truck.

[kikkegek]

He BillNorman, thanks for the extensive reply.

some questions on your points:
1. what do you mean? I am dutch and dont understand this.
2. I dont understand this point either. what I can say is that here in the NL they say you should set basic timing to -12 BTDC and disconnect the vacuum advance on LPG.
3. I have the distributor connected to the ported vacuum port on the right of the carb like on the pictures in this topic. Is that right?
4. what do you mean by functional envelop?
5. I have two EGR things on my engineI believe. The EGR valve (currently disconnected) and the Heat riser valve. the last one is currently set to OPEN all the time. Why would I want to run this engine as warm as possible?
6. oh man! I'd love an electric setup. But they are expensive over here. I'll ask around!
7. I'll look into this.
8. hahaha, thanks man! yeah I wanna help others with the info Igather. So good photos help a lot.

hope you can help me some more!

[motornut]

i duno bout it being the pink rad fluid,
(i wondered a mix of red and green or even a sealer?dribbles on the belt?)
i see rust and crud that will block not only the rad but the heater core too.
If you have it inside warm somewhere be sure to remove the lower rad hose and FLUSH this crud out or what you put back will be a waste.
do the heater core too.
You may wana get new bolts for the stat housing,seen those bolts seize and snap off
around hee we have green and red anti freeze,you can't mix them, i believe it wreaks the fluid .....the red is long life so some people figure i can wait even longer lol then the green,what i understand the red breaksdown and wrecks the gasket in some CARS lol like my Grand Am ,the v6 is known for this prob,thank god i got the 4 it just blows the crank seal(thats what i got for Xmas lol)

cheers

[billnorman]

1. General Motors had a pink anti-freeze that they recalled because it tended to sludge up cooling systems. I hope that isn't the type in your engine.
2. The photograph you posted 11-10-2010 at 3:59am show two pointer reference timing markers. The shorter of the two sets occurs in advance of the larger one. It is the one that is all dirty. If you use the one closer to the camera, the timing will be more retarded. Now in a gasoline motor, 12 degrees retarded will just about destroy performance, most like 8 to 10 degrees advance at idle. I will have to read up on LPG conversions, like I said, I don't know anything about them. They might like retarded timing. Which degree mark references do you use when setting the timing? How does this motor run? Is it smooth and powerful? I would estimate that if you use the short dirty timing mark numbers the motor will run about 15-20 degrees retarded compared to the long clean references. The marks nearer the camera look like an add-on set that if used would considerably retard the timing.
3. If it was a gasoline motor, There would be a diagram of vacuum hose routing for proper operation. As I previously said, when you said the motor runs at 12 degrees retarded, I realized I'm lost because this is a complete departure from my experience.
I'll read up and try to learn something and get back to you.

[billnorman]

O.K. here's what I've determined through research. You are getting 10 MPG plus or minus in a Chevrolet truck with LPG conversion. This is about average. LPG conversions historically get less mileage than a gasoline engine, it's just the nature of the beast. Some LPG conversions eliminate the vacuum advance, some leave it on. I read a report about ignition timing with LPG on a Chevrolet that was turbocharged, which raises the effective compression ratio and packs more air/fuel into the cylinders. The owner experimented with ignition timing and ended with 6 degrees BTDC initial timing. He tried various timing settings and advanced it until he heard pinging, then retarded it until it went away in all load arenas. He was satisfied with the results.
LPG does not require nor respond well with warming of the charge (EGR) but gasoline does.
Anything you can do to remove parasitic drag, such as electro fans, tire inflation, free flowing exhaust should benefit you in the long run.
I'm sure your friends call you if they need anything heavy moved, pulled, or bulky items transported because you have a truck, a REAL truck, a Chevrolet truck. Enjoy it, it's no tinny Eurosled with a 1000cc sewing machine motor. Ride in comfort, and look down at them in their low to the ground econoboxes.
Seafoam says their product improves any engine, especially older ones. I use it in my cars and boats.
Looking at the U.S. gasoline future, I am considering an LPG retrofit on my own 1985 or 1996 Pick-up truck.
In summary, forget the EGR valve, run your engine warm this winter, but in the summer drop the thermostat back to 165 f. If it were me, I'd get a good timing light, decide which set of timing marks is appropriate, and experiment with timing. Disconnect the vacuum advance and see where it's set right now at low idle. Then change it, usually in an advance direction by about 4 degrees. If it pings, go back 2 degrees until it stops. This may change in extremely hot weather, it may ping more if warmer. Each engine is different, each advance system is slightly different due to age and manufacturing tolerances.

[kikkegek]

he Bill,
really appreciate the time you are taking.

This is my timing mark:



and I looked up this picture, to find the marks for 4, 8 and 12 on mine, because mine is so dirty and I cannot reach it to clean it:


Today I took the vacuum advance of, because our fuel pump is broken end I will not replace it until end of januari. I bought a Equus 3568 timing light recently and found the timing was set to "0" ZERO. hahahaha. I then set the timing to 11 BTDC. I couldnt get it to i12 on my own, because I had no one to help me. So I stasyed with 11. Here on the dutch forums they say the best on LPG is about 12 BTDC and that you need to disconnect the vacuum advance. Because it is already so far advanced.

It runs just fine at the moment. No pings, pretty good idle. Just after a drive the engine would idle high. And I guess that because the distributor was still connected to the vacuum advance.

thanks and I will let you guys know how the mileage for the next few weeks advances...

ps. could you point me in the direction of the stuff you read on LPG. I love reading upon knowledge!


@ Motornut: thanks for the heads up. I'll make sure I rinse the complete system when it gets warmer up here. I have no clue though how to clean it in front of my house.

[motornut]

they sell solutions to clean out the rad system
if you can't flush it clean with water
have you used a hydrometer to check how low it will protect you?
If it was my truck i would worry it looks quite rusty
looks like a lot of water in the mix or contaminated with stuff
rad fluid should be coloured but clear -ish (clear like you could almost see through a jug of it)
too much water is bad and can freeze/crack a block,gets slushy and won't pass threw the rad so something has to give

[kikkegek]

okay, okay, true! it would probably be better to flush and clean the cooling system. But still...

isnt it strange that a dirty cooling system cools this good? my engine temp doesnt go over 155 on the highway and through town?

I'll call the local shop to see if they have some stuff that can help me with this.

[motornut]

yes the cooling might be icing....
surprised no one else here said anything
either to say yes or no
i'd hate for you to do all this work and lose the block

[kikkegek]

Originally Posted by motornut

yes the cooling might be icing....
surprised no one else here said anything
either to say yes or no
i'd hate for you to do all this work and lose the block

what do you mean by "the cooling might be icing?"?

[motornut]

too much water and it gets slushy in the rad,and driving, it would freeze up worse trying to thin out, to go threw the rad,would blow the hose hopefully first
not sure how cold it is there but in the morning or when it hasn't been driven take off the cap and see if it's fluid or slushy
of course one day it's -5 it's ok but
then may drop to like -25 or-30 and thats gona be a problem
but in the pics in a couple of drops on the belt it looks like bits of rust,sludge?
it looks to have material in the drops
it should be clear drops like water but green or red
but it could have been rust bits on your fingers working on it
i also thought the red was for newer stuff
and can't be mixed
then the bucket and the look inside intake same non clear fluid worries me

[motornut]

copied from another source
but look it up


I own a 2006 Chevy Impala with a 3.5-liter V6 engine. The odometer is at 25,000 miles and the coolant has never been changed. The other day when I checked the overflow tank the coolant was low so I added a gallon of green anti freeze to the tank. I told my mechanic this and he said to have the system flushed immediately or trouble will crop up. Is this true?

Stanley from Reno, NV




Yes, get that cooling system flushed immediately or you are in for massive trouble (if it hasn’t already occurred)! Your car takes the coolant Dexcool. What you added is Ethylene Glycol, a chemical that is not compatible with Dexcool. Flush the system now before you end up with major engine failure.



This is one of those questions that I get after the fact and usually engine damage has already occurred. The green and orange coolants do not mix. There are some coolants that claim compatibility with Dexcool, but I would rather err conservatively and add what the system is supposed to take rather than take the gamble. Guard against major engine failure read on.

Can I add the green coolant to the orange stuff?
As I stated above, the two chemicals of Ethylene Glycol (green) and Dexcool (orange) are not compatible. When mixed together they form a gel-like substance that stops coolant flow and consequently the engine overheats.

What exactly happens when these coolants are mixed?
The coolants chemically react and form a gel rather than a liquid. The coolant stops flowing through the system, clogs up coolant passageways and water jackets, radiators, and heater cores. The water pump overheats and fails due to a lack of lubricant in the coolant. Head gaskets blow, heads warp, and the engine suffers major damage.

If I have Dexcool in my car can I leave it in for the life of the car?
GM suggests flushing Dexcool for the first time in the life of the car at 150,000 miles.

Here’s the skinny on Dexcool
Eleven years ago GM introduced an engine coolant called Dexcool. It’s supposed to last 5 years or 150,000 miles but there have been problems with this coolant. Cooling systems that use Dexcool exhibit more acid buildup and rust in the system when the coolant level gets low and oxygen is allowed to enter the system. The acid eats away at head gaskets and intake gaskets. Rust builds up in the system, inhibiting coolant flow, which causes overheating. Overall, numerous cooling system problems have been attributed to the use of this controversial product, although GM sternly stands behind it. There are class action suits against GM on this issue, but no settlements have been made to date.

So what are the guidelines on maintaining Dexcool?
Here’s the bottom line when it comes to cooling system maintenance. Whether you are running Dexcool (the orange stuff) or ethylene glycol (the green stuff), inspect the coolant level and the condition/protection of the coolant at every oil change. In addition, completely flush and refill the system every 2 years or 25,000 miles whichever comes first. These actions will avert the problems associated with Dexcool or any other coolant product.

When I check my engine coolant what do I look for?
Color, consistency, and smell.

Color
The color of healthy engine coolant is green (for ethylene glycol) or orange (for Dexcool). A rusty color indicates that the rust inhibitor in the coolant has broken down and it can no longer control rust and scale buildup. The system must be cleaned/flushed and a fresh 50/50 mix of coolant installed to restore integrity. A milky color indicates the presence of oil in the system. This is not good; it usually means that a head gasket, intake manifold, or transmission oil cooler is leaking oil or transmission fluid into the engine coolant. This is a deadly mix that will kill an engine or transmission in short order. Address the problem immediately!

Consistency
The engine coolant should feel slippery to the touch and smooth (like the engine oil). If it feels gritty, the coolant is dirty and should be flushed and replaced with a fresh 50/50 mix. If the coolant does not feel slippery then it has lost its lubricity (the lubricating and rust inhibiting agents have deteriorated) and the system is at risk for rust and scale buildup, as well as water pump wear.

Smell
Change the coolant if it smells burned. Also change the thermostat; it’s probably gone bad because it was exposed to overheating (or it caused the overheating). Overheating damages the bi-metallic spring that opens and closes the thermostat valve. Most importantly, find out what caused the system to overheat and repair it, or face major engine damage.

[kikkegek]

He Motornut,

thanks for all the info. I will for sure change and flush the cooling fluid. Just not sure yet if I will do that using coolant and some type of pump. or with a gardenhose and just clear water. I am afraid water will stay behind in the engine en cause for more rust after I flushed it and filled it with new coolant.

I probably wanna get a flush-kit as mentioned before. And probably wanna get a big tub like this for under the car to catch all the fluid while flushing:

[motornut]

you do use some water mixing it
unless you get the premix stuff but i prefer to topoff with the pure
keeping it in the upper 60-70 %
got a sink you can hook a hose to use warm water?
Run the block a bit get some heat in it not much
could take the rad/heater core out

[kikkegek]

Originally Posted by motornut

you do use some water mixing it
unless you get the premix stuff but i prefer to topoff with the pure
keeping it in the upper 60-70 %
got a sink you can hook a hose to use warm water?
Run the block a bit get some heat in it not much
could take the rad/heater core out

no way my wife will let me use the sink in the kitchen to rinse the heater core and rad. hahahaha...no, no sink with hot water elsewhere on groundlevel in our house.

[motornut]

haha ok
what about the drain on the tank itself?

[kikkegek]

Originally Posted by motornut

haha ok
what about the drain on the tank itself?

I dont know what you mean?

and can I just loose the coolant though the radiator plug? or do I also need to open up the plug in the engine? (somebody told me the engine also has one? (got any pictures?)

[kikkegek]

OK, I had ordered the parts. But the lower radiatorhose has a special form and wasnt in stock. Now I have to waite for a week before this parts comes and before I can treat the cooling system.

I did install a new radiatorcap, because I was loosing coolant and one of the places was the cap.


since the thermostaat change the cooling system is leaking coolant at the thermhouse and at the radiatorcap.

I dont feel like opening up the thermostathouse again. too much of a mess in front of our door...

I guess I'll have to fill her up every now and then for a week..

this is a picture of the rad. looks bad doesnt it?




my shop didnt have Wynns in stock

Wynns Cooling System Flush


he now delivered me WOMI Koelsysteemreiniger. I guess a dutch or european product.
http://translate.google.nl/translate...D82083&act=url


I am not sure if the WOMI is what I need...since is treats chalk and sludge...

by the way? is sludge what you see in my radiator pic? is that the orange thick stuff???

Since Wynns from America I guess the best way to go would be Wynn's.

any of you guys know WOMI?

[billnorman]

You are one hard working man! However, you should repair the thermohousing before you replace the fluid. The fluid looks to me as if it has caused corrosion and deposits in your radiator and system. Be careful where you dispose of the used anti-freeze as some types are very poisonous to pets, and they like to drink it. Nothing will make you more hated by your neighbors than killing their pets. I am not sure if your truck uses an "o"ring or/and a paper gasket, but you should clean the surfaces of the housing and use good bolts and nuts to retain it. Make sure the housing has not warped from overtightening if so, make it flat again.
Sometimes electrolysis causes corrosion in radiators, but I don't know how to cure it except keeping clean anti-freeze in it. Your photographs, as usual, are great, but they do make the radiator look rather dirty inside. I'm afraid to look at mine.

[kikkegek]

Originally Posted by billnorman

You are one hard working man! However, you should repair the thermohousing before you replace the fluid. The fluid looks to me as if it has caused corrosion and deposits in your radiator and system. Be careful where you dispose of the used anti-freeze as some types are very poisonous to pets, and they like to drink it. Nothing will make you more hated by your neighbors than killing their pets. I am not sure if your truck uses an "o"ring or/and a paper gasket, but you should clean the surfaces of the housing and use good bolts and nuts to retain it. Make sure the housing has not warped from overtightening if so, make it flat again.
Sometimes electrolysis causes corrosion in radiators, but I don't know how to cure it except keeping clean anti-freeze in it. Your photographs, as usual, are great, but they do make the radiator look rather dirty inside. I'm afraid to look at mine.

thanks. the thermhouse has a paperp gasket and I replaced it when I changed the thermostat. I also cleaned the engine en house, but probably didnt tighten it well or too loose. the bolts are bad as you might have noticed.

that is why I ordered a new house and new bolts.

I also told the guy from the shop to dump the WOMI and order WYNN's flush and leak stop for me.

I'll flush the baby first and then put leak stop in the new coolant to make sure it doesnt start leaking after I flushed it. because the rust and sludge seem pretty bad.

I'll post some more pictures when I get results. probably in a week.

thanks.

[Space Truckin']

Hey man this is quite a thread! First I would like to point out that the vacuum valve on your thermostat housing is only open when the engine is warm and is intended to prevent the vacuum advance from being pulled in when the engine is cold. Also your vac source to that valve should be ported (no vac at idle) The EGR system is also a good thing to keep!

Another thing that helps the HEI ignition setup is a good 12 volt lead direct from the battery. Like so:

Example of bosch relay:
Amazon.com: 12 VDC Tyco Relay SPDT 20/30A...
Be sure to use a fuse in the lead from the battery to the relay!!!

Also this thread here on the forum has the vac diagrams for your engine:
http://67-72chevytrucks.com/vboard/s....php?p=3287463

Basically the EGR should see vac at idle with the ngine warmed up but not cold
The distributor should only see vac with the engine warm but not at idle.

There should be 2 temp valves on your engine one is for EGR and the front one is for everything else if I remember correctly.

Several of the ports on the front temp valve are common to each other while one is closed. This is when the engine is cold. The one that is closed should get the vac source (ported) from the carb.

Hope that helps not hinders! I will try to come up with a diagram but I need to know exactly what was removed from your engine and what is left to work with.

[Space Truckin']

Also try to use a thin gasket on that thermostat housing! Thicker ones will increase the likelihood of warping or cracking and they are easy to crack! I'd say .5mm or thereabouts.

[billnorman]

Hey SPACETRUCKIN no offense meant but this guy runs his truck on LPG or LNG, not gasoline. Therefore, EGR and manifold crossover is unnecessary or counterproductive if he is running on compressed gaseous fuel. I made the same error earlier. Kikkegek, normally "stop leak" products should be avoided as they can block off necessary cooling passages. Cleaners; yes, stop leak; no, unless you are driving a "junker" and have no long range plans to keep it.

[Space Truckin']

Oh no offense taken, you are correct. I was thinking about him running so much advance that it could cause knock and forgot to include that it should be switched off for the LPG. Though if you only run gasoline on the very rare occasion Kikkegek, its just as well to remove the EGR system entirely and block off the port for the valve, while you're at it remove those A.I.R. diverter tubes coming off the exhaust manifold and all their associated tubing. Seems like 3/8 (~9-10mm) brass pipe plugs seal up the holes in the manifold perfectly and it will give a much tidier engine bay.

Also the temp switch on the thermo housing comes in different temperature ranges. They are color-coded in blue, gray, black, and I think yellow or orange. You will need one that matches your thermostat or your vac advance will come in to early or not at all. Their proper name is "water thermo switch" IIRC.

+1 on "stop leak" for anything! Those products are for shady mechanics and used car salesmen!

[motornut]

don't use the stop leak it will just clog your rad tubes up or worse places like the core