Modified Cars

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Comment by Thumpin455 on January 21, 2009 at 1:38am

I modified the Quadrajet on the 9:1 455 in my 70 GTO to run ethanol in May of 08. Currently it is running rich but making more power than ever. It broke the 2004R behind it, so when the snow melts it will get a Th400. I didn't get to make any mileage tests prior to winter, now I must wait until the snow is gone to proceed. The GTO was more of a test mule to see if I could make it work with E85, and it worked great, Only one issue, the needle valve sticks open if the car sits for a few weeks, and the bowl dries out. A slight tap and it stops shooting fuel from the vent. Its also difficult to find accelerator pump diaphragms for the Qjet that are Ethanol compatible, the older black ones swell or fall apart, the new blue ones aren't in many kits, but I have a reliable source for them. This 455 will probably get some different heads to raise compression, but it currently has cast pistons, so I cant ask too much of it After all I built that engine 15 years ago.

Yes the GTO is a mule, there are two more mules underway, another low compression Ford, and a 13:1 compression Pontiac. It uses 1969 small chamber - big valve heads on a 455 with a forged bottom end. It doesn't sound like it, but it is a budget build and I got a number of the parts either free or very cheap. The nice thing about Pontiacs is a head swap changes compression, if you get the right casting.

Lastly I plan to put my toy on ethanol as well, its a long story but I doubt I will ever be able to afford an engine like that one again. Its around 700hp on camel whiz, I hope to make more power with some 190 proof. It wont be a demonstrator for mileage, just something to start a conversation about, and have fun in the short summers here.

Time permitting I will have the Qjet figured out and have a recipe for them this summer. If anyone else would like to have a carb with impressive economy as well as power, I can lend a hand with them.

Comment by Shawn Gabriel on January 5, 2009 at 1:55pm

Sodbuster,

thanks...

I am going to try this with the new re-jetted carburetor...

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With the new carburetor that is jetted for Ethanol you want to increase (advance) the timing.

It all has to do with how much Ethanol you are going to run, a engine running on E85 is almost imposable to foul a plug, Ethanol burns clean so there for no contamination.

Anyways back to your question: your timing is at 8 deg now try 10 with the Ethanol carb. Take the truck for a drive and listen for ping (a ping is when the gas in the combustion chamber fires early do to timing advance and the engine will ping under a load).If the truck does not ping advance the timing even more try 12 deg advanced and repeat the process.

Now when you switch back to pump gas you need to go back (retard) the timing to were you started 8 degrees.

Most likely you can still run the carburetor that was jetted for Ethanol on pump gas, small block chevys can take the fuel just as long as you have good compression 125 psi +

Now if you want to optimize your small block chevy for Ethanol you would change the compression ratio, stock is like 9.0 to 1
You would replace the pistons for a compression ratio to 12 or even 13.0 to1
This gets expensive, and I am sure you don't want to go that rout, but you need to remember your motor was optimized for pump gas at like 89 octane, now were at 105.... E85 Ethanol we have to increase the fuel and we have to increase timing.
+++++++++++++++++++++++++++++++++++++++++++++++++++

One other question, could I use this on my old un-jetted carburetor, but advance the timing more than with the new jetted one???

That page in David Blume's book, says to just advance the timing if I anticipate switching between ethanol and gasoline...

I noticed that the size between the old un-jetted carburetor and the new re-jetted carburetor aren't much of a size difference...

I followed the guide that David Blume had for re-jetting as well as others on the Internet...

I am not going to worry about changing the compression ratios right now, but maybe in the near future, when I save up some money...

Comment by Sodbuster on January 4, 2009 at 7:15pm

Shawn,

With the new carburetor that is jetted for Ethanol you want to increase (advance) the timing.

It all has to do with how much Ethanol you are going to run, a engine running on E85 is almost imposable to foul a plug, Ethanol burns clean so there for no contamination.

Anyways back to your question: your timing is at 8 deg now try 10 with the Ethanol carb. Take the truck for a drive and listen for ping (a ping is when the gas in the combustion chamber fires early do to timing advance and the engine will ping under a load).If the truck does not ping advance the timing even more try 12 deg advanced and repeat the process.

Now when you switch back to pump gas you need to go back (retard) the timing to were you started 8 degrees.

Most likely you can still run the carburetor that was jetted for Ethanol on pump gas, small block chevys can take the fuel just as long as you have good compression 125 psi +

Now if you want to optimize your small block chevy for Ethanol you would change the compression ratio, stock is like 9.0 to 1
You would replace the pistons for a compression ratio to 12 or even 13.0 to1
This gets expensive, and I am sure you don't want to go that rout, but you need to remember your motor was optimized for pump gas at like 89 octane, now were at 105.... E85 Ethanol we have to increase the fuel and we have to increase timing.

Comment by Shawn Gabriel on January 4, 2009 at 3:06pm

Sodbuster,

thanks...

I already have a device that will advance my timing from 0 to 15 degrees from the original physical position of my distributor... I don't need to mess under the hood after I install this...

My distributor is set at 8 degrees..

I have another carburetor that I re-jetted for ethanol...

The question is would I need to retard my timing closer to TDB when I put the other carburetor that I re-jetted for ethanol when I run 100% gasoline???

This is the question I would like to know before I install timing advance kit and the new carburetor...

I know that my truck will run higher percentages of ethanol with the old carburetor..

Comment by Sodbuster on January 3, 2009 at 7:26pm

Hi Shawn,
I would think www.jegs.com would have what you are looking for.
I am sure there is a kit for your distributor that would allow you to adjust the timing inside the cab.
Back in the day I had a motor home with a small block chevy in it and what I did is i just left my distributor a tad bit loose. When I was able to get good fuel than i would advance the timing a little to it would ping than just back it of.
Now I no what you are after, and yea adjusting the timing in the cab would be a hole lot easier but it is going to cost you some bucks.
When you are jetting to run Ethanol you need to increase the main jet, so if your main jets are like a 55 try 60. That should get you close, also the timing needs to be advanced ( rotate the distributor counter clock wise) If you have a timing light and you started at lets say 3 deg advance than bump it up to 8 and take it for a drive and make sure it does not ping. If it does ping retard the timing a small amount till it goes away.

Comment by Shawn Gabriel on January 3, 2009 at 3:32pm

Sodbuster,

I have already found out that my truck unmodified doesn't like more then E-56...

One day I ran the gas to less than an eighth of a tank my Crysler New Yorker (non-FFV) and my truck. my neighbor had 5 gallons of E-85 for his lawnmower... I was afraid of putting in my New Yorker, so I put it in my truck... I was going to fill up my gas can so I can get the New Yorker to the pump to fill up...

My truck didn't like it.. Too lean...

After that... I decided to find out how much my truck would actually take... I then started by blending my the two E-85 and E-10 until my truck started to act up... That is where I found out about E-56 is the maximum for this unmodified truck...

Comment by Shawn Gabriel on January 3, 2009 at 3:23pm

Sodbuster,

What I don't want to do is to change the jets or adjust the carburator's timing mechanically from inside the engine compartment at the pump to switch between ethanol and regular unleaded gasoline... I would rather do that at home, but from time to time I won't be close to home... I would rather do that from the cab when I am at the pump....

Comment by Shawn Gabriel on January 3, 2009 at 8:31am

Sodbuster,
Thanks...

If I re jet my jets for ethanol, would I have to retard my orginal timing more than the orginal setting or would I have to advance my timing when I would want or need to go back to 100% gasoline...

The timing advance electronic kit advances my timing from 0-15 degrees from the original timing...

Do they make any timing advance electronic kits that have say 0-25, 0-30, or 0-45 degrees of timing advance.. And where would I purchase it...

Comment by Sodbuster on January 2, 2009 at 5:49pm

Hi Shawn, for some reason I can not post this under your question so I am just going to have to post it here.
Anyways your 77 pick up from the factory runs real rich meaning there is a lot of fuel being delivered via the jetting at the carburetor so you may not have to re jet.
The problem you are seeing is your motor has bean optimized for gas not alcohol, so without turning up the compression and spending big bucks try these few things.
Mix your fuel 50 /50 and take it for a drive you may notice that the truck has lost some power or is hard to start. Advance your timing by turning the distributor counter clock wise, if you do not have a timing light advance the timing to the engine pings on acceleration than back it of just a tad to the ping goes away. This should take the hesitation out and give you back the power you lost, however if you go back to 100% pump gas you need to put the distributor back were it was. a timing light makes things easier so you no were you started at and were you ended up.
Now you can also re jet the carb to flow more fuel witch ethanol needs but if you are not familiar with rebuilding a carb than try this for now.
Hope this helps and good luck to yea!

Comment by Shawn Gabriel on January 1, 2009 at 5:00pm

I have a 1977 Chevy 350 truck... I wanted to convert it to hydrogen as well as ethanol...

I have ran it on various blends of E-10 to E-85, and found out that I have had problems when I go about E-50...


According to the David's book, if i want to switch both ways for gasoline to alcohol, I would need a timing advance circuit... Is this all I need, for now... I just bought a timing advance kit, so I can adjust my timing from the cab...

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