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Author Topic:   fuel pressure
posted July 07, 2000 09:37 AM
What should the fuel pressure be for an alky motor?

posted July 07, 2000 01:00 PM
You need around 6psi at idle and around 9-10 psi on the straightaways. This is very important. Too many people try alky for the first time (myself included) and aren't aware of the importance of enough fuel pressure. It will explode your motor before you finish the first heat. Make sure you have the plumbing and fuel pump correct for an alky setup. and make sure you check it under load at the end of the straights. If you are running under 500 hp you can probably get away with a block mount 8.8 psi pump with no return. but if you're over that get the belt drive variable pressure with the regulator and return line.

posted July 09, 2000 02:02 PM
Been running a KSE tandem set-up for 4 years with methanol and a gaerte carb and have never had more than 4 lbs at idle or 8 lbs at speed. Running 550-600hp Wissota spec engines (362). No fuel related failures in that time. I know a lot of guys running the mechanical fuel pumps without any trouble also.

The biggest thing to look for is how long your methanol has been sitting before you bought it. DO NOT buy second-hand! Buy it only from a dealer who moves a lot of it. If it sits too long the barrel or jug can take condensation and you'll get a lot of water in your fuel if it's not absolutely airtight. As long as it's airtight, though, you shouldn't have any problems.

Also, I've found that a fuel filter element will last about exactly 30 shows...replace it after 20...better safe than sorry.

My 2 cents...

[This message has been edited by GnarlyCar (edited 07-09-2000).]

posted July 10, 2000 07:23 AM
Thanks for all the input, ran the fuel pressure at 4lbs at idle, 8 at max. Also replaced radiator saturday, ran great last night (sunday), temp though only got to 160, but would rather have that then the 230 - 240 I was getting. So figure it was either a combo of both, or the new radiator.
Anyways, broke an upper control arm bolt in lap 4 of the feature, done for the night.

posted July 16, 2000 06:40 AM
not to step on any toes i run a 600 or better horse 383 with a block mounted holly pump
and a garte carb and i have never run lean im fat if anything so i dont really buy that belt drive stuff and i turn like 7400 rpm so im toping out the biggest thing if yeer not sure take plug readings and go from there
and adjust as needed lean mixture is a engine killler no doubt burn it down in a heart beat
so just make sure u take readings after hot laps and adjust yer regulator ( my set up is as follows line size 10 from tank to filter
afco steel screen filter size 10 line to pump size 10 to fuel log size 8 comming to bowels and a size 8 return with a in line adjustable regulator)works grate for me
sorry for rambling on but i found out the hard way ( BOOM )

posted July 16, 2000 07:09 AM
thanks reign!

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