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Sun Apr 12, 2020 9:10 am

Anyone have experience converting weber IDF's to run on methanol?

Long story, but a buddy of mine has a 500 cu in BBC streamliner project, and wants the simplicity and old school visual effect of running 4 x 2bbl webers. My go-to is IDA's, but I don't think he will have enough room between the manifold and body, so I'm thinking IDF's.

One of the challenges with IDF's might be the accelerator diaphrams, not sure they will tolerate methanol.

Then there's float bowl volume... at 3-1/2 to 4-1/2 psi, getting a larger needle and seat that can keep up with fuel demand could prove challenging

What say you?

Sun Apr 12, 2020 11:23 am

Fuel infection?

Sun Apr 12, 2020 1:16 pm

IDA's are too small for a 500 CI v-8, that's like a 4000cc vw, clearly not large enough.

if it was 300 ci, maybe

Sun Apr 12, 2020 5:01 pm

The correct air-fuel ratio for gas is in the range of 14.1 to 15.1 or as close to stoichiometric as possible. But for alcohol it is 7.1 to 9.1 so that means you must flow at least twice the weight of alcohol and you will need much bigger Jets. The good news is you will not overheat your engine. Running alcohol has serious cooling effects.

Sun Apr 12, 2020 5:03 pm

IT's 30% more fuel with E85, and it will eat the carbs up. It will need to be drained and flushed after each use. That's why people go to EFI so they can eliminate the corrosion issue.

Sun Apr 12, 2020 5:16 pm

modok wrote: IDA's are too small for a 500 CI v-8, that's like a 4000cc vw, clearly not large enough.

if it was 300 ci, maybe

about 8200cc...

If they could squeeze 8 of them (idf's) in there, it would be a pretty trick looking intake.

Sun Apr 12, 2020 5:29 pm

ivkings4 wrote: IT's 30% more fuel with E85, and it will eat the carbs up. It will need to be drained and flushed after each use. That's why people go to EFI so they can eliminate the corrosion issue.

I am not sure if he meant E-85 or 100% methanol? I guess we will find out. He wont like the maintenance of running methanol or the cold starts, milked oil, flushing fuel lines. The list can go on.

Sun Apr 12, 2020 7:14 pm

How about a "Cross Ram" style of manifold with four 55mm DCO's

eQ

Mon Apr 13, 2020 4:49 am

I guess I should have mentioned he plans on using a plenum type manifold, not single runner "1bbl per cylinder" like most of us are used to thinking about. Completely different animal when calculating cfm requirements.

He plans to build a low-rise version of this:

He thinks 8 40mm throttle bores will be enough to feed a 500 cu in V8. (4 IDF's) a plate top manifold will give him some flexibility if needed (just make a new plate if needed)

EFI or MFI : yeah, I lost that argument, he's got his heart set on methanol thru carburetors. They always work. Visually he wants 8 velocity stacks. It's hard to argue that with my friend, he's done a lot in his lifetime, kinda like the Farmer's commercial "He knows a thing or two, because he's seen a thing or two..."

Mon Apr 13, 2020 5:23 am

vwinnovator wrote: modok wrote: IDA's are too small for a 500 CI v-8, that's like a 4000cc vw, clearly not large enough.

if it was 300 ci, maybe

about 8200cc...

If they could squeeze 8 of them (idf's) in there, it would be a pretty trick looking intake.

4100cc with only 4 cylinders. Basically 1 L per hole.

Mon Apr 13, 2020 5:29 am

I run E85 on a type 4 vw aircooled , due to the fact that aircooled engines run richer to keep them cooler (than water-cooled) which is no longer necessary as E85 burns quite a bit cooler and that the higher residual heat temperatures in the combustion chamber (in aircooled engines) means a lot less wasted combustion fuel is burnt to transform the E85 to vapour and I have only encountered a 15 to 20% increase in fuel consumption and in the hot summer months I actually burn slightly less E85 and have quite an increase in low down torque.
Here in France E85 is made from waste bio products from agricultural and wine industry its less than half price than regular gas and for 4 months of the year from late Summer to the beginning of winter when the wine industry is in full processing season its a third of the price.
Alcohol fuels seem quite a good option here. And there are some good additives out there deveioped from the dragster scene that are quite good for protecting the top end and some that help protect neoprene parts.

Fri Apr 17, 2020 6:34 pm

Nitramrebrab72 wrote: I run E85 on a type 4 vw aircooled , due to the fact that aircooled engines run richer to keep them cooler (than water-cooled) which is no longer necessary as E85 burns quite a bit cooler and that the higher residual heat temperatures in the combustion chamber (in aircooled engines) means a lot less wasted combustion fuel is burnt to transform the E85 to vapour and I have only encountered a 15 to 20% increase in fuel consumption and in the hot summer months I actually burn slightly less E85 and have quite an increase in low down torque.
Here in France E85 is made from waste bio products from agricultural and wine industry its less than half price than regular gas and for 4 months of the year from late Summer to the beginning of winter when the wine industry is in full processing season its a third of the price.
Alcohol fuels seem quite a good option here. And there are some good additives out there deveioped from the dragster scene that are quite good for protecting the top end and some that help protect neoprene parts.

are you still running webers with this setup? I played with e85 on a set of 48 dellortos on my 2332and could never get enough fuel above 5500 showed lean on my wide band. My fuel system is not stock and fuel flow isnt the problem. I switched to a lower compression 2275 so currently running pump gas. I would like to run e85 again on my next engine. was wondering what you where using as far a emulsion tubes. My fuel system held up fine to e85 but menthol is totally different but is the way to go on a race engine. He is probably better to go with 2 four barrels

Fri Apr 17, 2020 6:56 pm

Alcohol likes compression. Low compression engines on methanol are tough to tune. You want to look at the cadmium burnt off on the plugs as it will tell you if you are close to a good tune. 10.1/1-12.1/1 is a good tuning compression for an methanol engine. Above and below that they become a nuisance to tune. Keeping cly. temps up will be a hard. I have found that I need to run a lean out system at low speeds and idle just to keep the engine worm.

Fri Apr 17, 2020 9:07 pm

I watched a few methanol cars start up at Bonneville, where if you read the original post, is where this engine is for. They fired them on gas or propane and high idled them to get heat in them. Less than a minute before they launch, they change to methanol and then they live at 80-100% throttle.

Tom , I think I remember seeing an article years ago about someone running webers on alky and they no longer used floats just a return loop like an FI system. I doubt you guys would be breaking new ground, but VW forum isn't the place to look for info. I'd ask on the Landspeed Racer page on FB and see if you can find some V8 guys who been dere done dat.

Fri Apr 17, 2020 9:18 pm

fuelinjectionent.co He has been setting up my magnetos and methanol injection systems for years. He can help you. They are located in Oregon.

Sat Apr 18, 2020 4:54 am

I remember a drag car that had two fuel systems, he would start up and shut down on gas to keep the other fuel from gumming up the carbs. I just can't remember which fuel he was using when going down the track.

There are a couple people that can enlarge the passages of the carbs for you, I forget their names right now.

Why not compromise and run the 4x2IDA's as throttle bodies and put someinjector ports into the manifold? You could get the look that you want and then also not have the problems with the fuel and benefits of fuel injection.

Sat Apr 18, 2020 5:46 am

TomSimon wrote: Anyone have experience converting weber IDF's to run on methanol?
seeing that no one answered your question I'd say no :roll:

i'd say IDAs would take a lot of the guesswork with diaphragm material and so on

Sat Apr 18, 2020 7:29 am

No useful experience with carbs.....but a lot with metals and plating.

As others have noted.....alcohol (especially methanol) is going to eat the magnesium alloy most carbs are made of. However if you must use carbs.....look for a good plating house that does ELECTROLESS PLATING.....NOT electroplating......and specifically "zinc-nickel" electroless plating.

After zinc-nickel plating.....nothing with touch/harm the metal in your carbs except for an oxidizing acid. The electroless process with give a dead even, perfectly consistent layer of plating inside and out in every vent, tube, pore and crevice of your carbs (unlike electro-plating).

This process is and has been used by manufacturers for parts inside fuel pumps, injectors and carbs MADE for alcohol for many years. Ray

Sat Apr 18, 2020 8:55 am

vwinnovator wrote: modok wrote: IDA's are too small for a 500 CI v-8, that's like a 4000cc vw, clearly not large enough.

if it was 300 ci, maybe

about 8200cc...

If they could squeeze 8 of them (idf's) in there, it would be a pretty trick looking intake.

i think yall are confusing cc's with cfm. according to online calculator a 497 ci engine pumps less than 600 cfm at 6000 rpm. im not sure about idf's but i know a 45 dcoe flows about 500 cfm. id assume idf and ida's flow about the same as a dcoe. ive seen several v8's running webbers but i got no idea about the alcohol part