Comments on: When you’re a Jet…

By: george.w

george.w — Sat, 23 Sep 2006 19:40:51 +0000

Jack - Alas i don’t remember the size of the original jets but they were visibly smaller than the new jets. What you describe sounds like my engine was acting when the needle valves were overwhelmed by fuel pressure and failing early. I’d turn the air idle screw and it really wouldn’t make a difference because the carb was slobbering fuel into the manifold. (Eeeuwww!)

Just this morning I compiled everything I’ve done with the 34PICT-3 into a single post that may help.
34PICT-3 Carburetor Final. That will be the post I will continue to update with fuel issues from now on.

After a bit of tweaking later I’ll make that post into a .pdf for people to print out who want it but it is up to read today.

By: Jack

Jack — Sat, 23 Sep 2006 03:16:07 +0000

I have three 34PICT-3s apart on my workbench right now. I’m trying to find one whose idle rpm reacts the way the book says it should to adjustments of the volume and mixture screws. So far, no luck.

Can you tell us what idle and main jet sizes you had originally before replacing with the 55 and 130?

By: george.w

george.w — Sat, 03 Jun 2006 12:58:19 +0000

I’m not terribly worried about it. Ethanol, like hydrogen, can be produced in many ways and new ways can be found. This is a fundamental difference from oil, which can only be produced by finding underground deposits of fossil carbon, and pumping or digging them out of the ground and processing them into gasoline.

In the ‘kill two birds with one stone’ department, cellulosic production of ethanol looks very promising. If that happens, the price of newsprint will go up and recycling paper will suddenly become a paying proposition. :coolsmile:

By: WeeDram

WeeDram — Sat, 03 Jun 2006 03:51:57 +0000

I hadn’t considered the petrochemical component of producing ethanol, but that is indeed a concern.

While not a scientist, David Olive’s recent column in the Toronto Star regarding the current Canadian government’s affair with ethanol fuel is pretty interesting. I’m betting ethanol is a net loss in terms of the whole energy equation. Reduction of pollutants is important, but a net loss in efficiency is a loss in the long term.

By: interested

interested — Thu, 01 Jun 2006 18:20:15 +0000

From what I understand the calorie deficit in producing ethanol is mostly due to the dependence of agriculture (corn specifically)on petrochemical fertilizers. Energy concerns aside, this is reason enough to question ethanol as a fuel source.

By: zilch

zilch — Wed, 31 May 2006 09:13:14 +0000

Here are the first two articles I could find on the efficiency of ethanol production: one says it uses up more, and one says less, fossil fuel calories than are produced. Obviously, this is not easy to calculate- how far do you go evaluating things like farm equipment maintainance, road construction to factories, etc? But I agree that experimentation is a good thing- as long as it’s critically vetted for pork barrels.

By: george.w

george.w — Tue, 30 May 2006 14:53:10 +0000

I would also like to know the fossil fuel efficiency of ethanol production, if anyone knows of an objective study. Even if the balance is negative, obviously a wider range of fuels is becoming available at the pump, which means technology will begin to improve and it may become a positive balance in time. I hope so.

The effect of politics on engine tuning, what fun.

By: zilch

zilch — Mon, 29 May 2006 14:06:29 +0000

I would be curious to know the fossil fuel efficiency of producing ethanol. Last I heard, agriculture in First World countries was running at a net caloric loss- that is, it took more than one calorie of fossil fuel to grow and bring one calorie of plant material to the consumer. I don’t know what the figures are for ethanol, however.

By: george.w

george.w — Mon, 29 May 2006 03:35:49 +0000

That would be really cool to run on homegrown ethanol but I’d have to do a conversion - rubber fuel system parts are iffy enough with 15% but with 85% they’d corrode pretty fast. Also different jets again for it to run right, and change the timing, etc.

Some fuel-injected engines can switch back and forth because they can change their fuel mixtures and ignition timing by sensors and the onboard computer. Carbureted engines don’t have that flexibility so they have to be used for one or the other.

Back in the ‘50’s my dad and his friend converted a CHP cruiser to propane for a pilot program. It ran great, officers liked it, and when they tore it down after 180,000 miles it was clean as a whistle inside. Don’t know why state cars didn’t all end up with propane tanks, must have been some reason.

By: GUYK

GUYK — Mon, 29 May 2006 01:16:11 +0000

I have read that vehicles made now in Brazil will run on 85 percent alcohol and some on pure alcohol. Will your VW do that or would it need a conversion? Brazil is energy independent I hear mostly due to ethanol. Might be an answer for us to look into.