Author Topic: Injection Alky Vs. Carb Gas  (Read 665 times)

Offline lake_harley

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Injection Alky Vs. Carb Gas
« on: March 09, 2022, 05:01:13 AM »
There's a war going on in my head about the fuel system for the FED I'm building. The car is being built to have some fun and do some bracket racing. Not going nuts with needing to have things really "period correct", just want to keep it simple and hopefully have it be somewhat consistent.

I had been planning to keep things to what I know and that for the most part would be a carburetor on gas. Planning to install a small cooling system to be able to 'lap" the car rather than towing back the return road. Lately I was thinking stack injection on alky would be cool so looked into that and it would be a possibility, but it seems that brings up a world of things mostly new to me and also potential for problems and added complexity and maintenance.

Keep in mind that I, unlike probably most here, am not looking for that last .05 second reduction of the ET. It's for bracket racing and keeping things simple.

Thoughts, input?

Lynn

Offline 225digger

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Re: Injection Alky Vs. Carb Gas
« Reply #1 on: March 09, 2022, 05:27:27 AM »
if your going for functionality over looks.   alky carb is a great setup.    i ran a very basic system yrs ago that was very consistent,  350 sbc with iron eagle heads, like 11.1 comp solid flat tappet.

it had a 750 bg alky carb on it, with a BG barrel valve to control fuel pressure, used a edelbrock high flow mechanical pump, 3 gal tank in front of radiator, it was very simple and maintence free, after the car was loaded up i would open the fuel lines, just cracked them to drain back in the cell.... drain the bowls and spray in wd40, if i knew it would sit for a longer period i would spray lube in the hoses and cap the fuel cell so air could not get into it. i had a hose going from the intake under carb to inside car with a barrel valve on it, i would open that up to lean out the motor to build heat faster..... it was a good setup, ran 10;60s in a 68 camaro


Offline JEFF/21C

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Re: Injection Alky Vs. Carb Gas
« Reply #2 on: March 09, 2022, 07:37:47 AM »
we ran a holley alky carb added jet extensions to the back plate.After the event drained the tank added gas ran motor until it smoked shut it off before the next week-end drain gas fill with alky would start up easily on the gas, if stopped for a period of time drain lines filled pump with wd 30 removed carb sprayed it then stored upside down.changed oil every week-end used a belt driven pump controlled pressure (9psi)with a poppet valve on the return line worked well then changed to injection

Offline lake_harley

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Re: Injection Alky Vs. Carb Gas
« Reply #3 on: March 09, 2022, 08:35:05 AM »
Thanks for the replies and experiences. My first post was made rather quickly this morning and thought I should add a bit more information.

My 305 SBC build plan up to now has been to build it very mild and the compression with plan "A" would only yield about 8.8 to 8.9:1 compression. One of my questions about alky vs gas is if that would be "enough" compression for alky? It seems compression needed for alky is about as discussed and debated as what is the best oil. Plan "B" would be different pistons after a minimal overbore and that would take compression to 9.85:1 which would seem at least closer to what some say is needed to really utilize alky.

Quite honestly I don't think I'd ever go the alky carb route. If I were to run alky I'd also want to go with stack injection. As vain as it would seem, and as vain as it is, stack injection would be mostly for the "cool factor", but it would also be a huge plus if it helped consistency through the day and season. Please keep in mind this is to be a fun car for bracket racing so shaving off the last few thousands of a second is not a priority. Priority is simplicity, and not creating potential headaches and problems, or a lot of extra maintenance.

I hope not to many feel I'm completely off my rocker and building a FED for all the wrong reasons, I just want to build a car that's consistent and not break the bank. From a money spent standpoint it's more about how much I'm "willing" to spend, more than how much I "could" spend. That's part of the reason I'm building from ground-up, rather than having a car built or buying a roller or turn-key car.

So, please continue comments....Alky stack injection....or.....Gas carburetor?

Thanks.

Lynn

Offline THE FRENCHTOWN FLYER

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Re: Injection Alky Vs. Carb Gas
« Reply #4 on: March 09, 2022, 09:54:15 AM »
Will you have someone to prime the injector stacks?
If not, consider a priming device, and possibly a way to drive around in the pits on gas.

Offline 225digger

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Re: Injection Alky Vs. Carb Gas
« Reply #5 on: March 09, 2022, 01:39:14 PM »
you need to build what you want, thats a big part of bracket racing, you can race what you want and just change a dial.... race for fun till you get it figured out.....   the FED i have will get a 496 bbc  with a bird on a tunnel ram.

Offline lake_harley

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Re: Injection Alky Vs. Carb Gas
« Reply #6 on: March 09, 2022, 07:03:43 PM »
225Digger.....Quoting you, "you need to build what you want, thats a big part of bracket racing, you can race what you want and just change a dial".....as often as I tell myself that same thing I keep coming back to wanting to be one of the cool kids. But, you're exactly right, and if it's fun and I decide I want to be faster or "cooler" I can always update the package. Thanks for the tap on the back of my head. ;)

Lynn

Offline Rat

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Re: Injection Alky Vs. Carb Gas
« Reply #7 on: March 13, 2022, 03:58:18 AM »
We run Stack Injection on the 392 and add M2 to the methanol and must say even with extended periods between races very little maintenance required. When I had my old 6cyl car with SU carbs on methanol we just turned the pump on to fill the bowls when it went on the trailer and didn't touch them. Mind you the longest break between races in those days was probably a month.

Offline tcoupekyle

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Re: Injection Alky Vs. Carb Gas
« Reply #8 on: March 13, 2022, 04:48:06 PM »
What is M2?

Offline Supercat

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Re: Injection Alky Vs. Carb Gas
« Reply #9 on: March 13, 2022, 05:36:24 PM »