PDA

View Full Version : methanal help



grydergeyer26
03-16-2013, 04:24 PM
okay here is the deal i run a 4 cylinder on methanal i have a holley black electric pump and a holley big port regulater with no return
i keep having problems will not run right just craps on it self i was wondering if i put a return system on will it solve most of my problems like a imca mod

dirtrace09
03-16-2013, 08:51 PM
What kind of fuel pressure are you seeing at idle and at full throttle?

grydergeyer26
03-17-2013, 05:24 AM
its constanly at 8 at idle 7 on throttle just like my carb builder said
but i dont have a return system so do i need one to fix my issues very lost on what to do

Egoracing
03-17-2013, 09:07 AM
If it is having problems due to vapor locking or boiling fuel the return will help, If not then the return line will not to much if anything.

grydergeyer26
03-17-2013, 04:04 PM
not vapor lockin fuel line has no heat by it
now what regulater would u recomend or is the one i have right for my application and fuel pump

joeltjen
03-17-2013, 10:19 PM
okay here is the deal i run a 4 cylinder on methanal i have a holley black electric pump and a holley big port regulater with no return
i keep having problems will not run right just craps on it self i was wondering if i put a return system on will it solve most of my problems like a imca mod

you need a retutrn line! you now have the regulator between the pump and carb and it is starving your carb big time. the regulator needs to be after the carb with a return line so your carb gets fuel right away as you open the throttle and pressure drops. also with the return line your fuel pump will last way longer as it is not working against the regulator with fuel that has no place to go with out a return. do a search online for barry grant carb site as i think they have a schematic on how it should be plumbed if you have any questions.

grydergeyer26
03-18-2013, 01:06 AM
so do i run the return to the cell or do i need to get electic pump with a return is my question
is it demons website or barry grant?

grydergeyer26
03-18-2013, 04:54 AM
i only have a pick up line and vent line n my fuel cell so do i t off for a return at the pump???

raceman17
03-18-2013, 09:25 AM
i only have a pick up line and vent line n my fuel cell so do i t off for a return at the pump???

You have to drill a hole into the top of the fuel cell and install a bulkhead fitting for your return.

dirttrackrocker
03-18-2013, 09:53 AM
Agree with what everyone else said. Get a BG bypass regulator. The kind that has a jet in it to set idle. install it after the carb. Run a line back and put a fitting in the fuel cell for the return.

grydergeyer26
03-18-2013, 02:47 PM
what size does my return have to be the same size as my fuel line or can it be smaller?

grydergeyer26
03-18-2013, 06:51 PM
all so can somebody give me te barry grant art nmber please
question can my returngo straight to the regulate my buddy is trying do his that way fr a return n his

dirttrackrocker
03-19-2013, 09:32 AM
Barry Grant is out of Business. This is the one you want.

http://www.ebay.com/itm/QUICK-FUEL-Bypass-Regulator-LOW-RPM-FUEL-PRESSURE-Adjustable-Jet-tuning-30-899-/230928035898?pt=Motors_Car_Truck_Parts_Accessories&hash=item35c462303a&vxp=mtr


You need a T in the line feeding the carb. Put the regulator after the carb, the return comes out the bottom, and pressure gauge line out of the back. Hope this diagram helps


http://img.photobucket.com/albums/v332/klv8lm/fuelsystem_zps6f4e1fee.jpg

MQueen
03-19-2013, 03:27 PM
Am I missing something here, 7 psi at WOT is not enough presure for alcohol.

dirttrackrocker
03-19-2013, 03:30 PM
I thought the same thing, but, he says it's a 4 cyl. and I have to assume a 2bbl. Not sure if that makes a difference.

joeltjen
03-19-2013, 08:38 PM
Am I missing something here, 7 psi at WOT is not enough presure for alcohol.

3-4 at idle 9-10 at wot you gotta have the high dollar floats to go past that . with a two barrel you might have enough volume with that pump that you will need to control flow at wot, but you need the pressure to force it threw the needle and seat ( make sure you have the right one= high flow neesle and seat) i run 5/8 line from cell to pump and to carb and 1/2 line return to cell

grydergeyer26
03-19-2013, 08:51 PM
can this cause it to cut out at 4500 rpm too
i replace coil and msd tested dist is the only question and fuel

joeltjen
03-19-2013, 09:21 PM
usually if you run out of alky its gonna lean down and backfire and pop and bang like crazy, right before it melts a hole in a piston or two!!!!!

grydergeyer26
03-20-2013, 03:08 PM
its a 4412 from a carb specialist all new not old
so if i am runnng dash 8 for fuel line i can run the return dash 6 line
another question does the jet in the regulater control idle pressure or wide open throttle what controls what

so then i run the feedline to the rgulater or straight to he carb
and the the return comes off the regulater on the other out side
right or am i wrong

i use a pump that puts a consisent pressure so how do set idle pressure and wide open pressure

dirttrackrocker
03-20-2013, 04:09 PM
The electric pump is the unknown variable here. I would say, your idle pressure is gonna have to be the same as your WOT with an electric pump. For best results I would get a belt drive pump. Yes, a -6 for return is fine. Just run it according to the diagram above. The should have a T at the carb one pat of the T going to the carb, the other going to the regulator.

let-r-eat
03-20-2013, 06:56 PM
What you have should work. 5.5psi or so is enough to run a 4 cylinder and I like to get the genuine holley needle and seat for alcohol for it will hold 7psi easily. Run at 7 psi. Double check everything. An alky carb designed for a v8 with 3-12 pressure may need tweaked to get it to work on your 4cyl. The main change will be the original holley needle and seat for alky. Plug gaps at .030 or so is fine. Plug wires and all the common stuff. If you have a tack unhook that. What you have should work fine so check everything over close.............compression readings from cylinder to cylinder/idle vacuum/valve lash sealing. 4500 is around max torque for the combo and is the likely point of a miss for weak cylinder pressure/spark.Make certain the boosters are not dripping fuel at idle. Make certain the throttle blades aren't open too far at idle. With the carburetor off you will see the T slot and if the carb was new they set that idle screw appropriately. If you had to jack up the throttle blades to get it to idle you could have uncovered the t slots too far causing your issue. Also check when you pump the throttle that the squirter is working and that fuel is squirting out. Alky carbs have a tendency to not squirt after periods of setting. Hope some of these tips can help you get it figured out. Just to give you an idea the 500 holley float bowl is capable of around 350hp on alky. You could add bowl extensions and go more than that. V8's need the 11psi but 4 cylinders don't because it's not making enough hp. You could put a block pump on there and run alky on a 4 cyl just like a gas engine. The supply is sufficient on the 4cyl. I assume you are using electric because your block isn't drilled for manual pump. A bypass system is ok but an electric pump setup for a 5psi system just like a gas engine will work. Also, the black pump is setup for 14psi and will require a regulator for sure. Just to give you an idea 60 gph pump will feed 350 hp. A standard holley red pump with no regulator will run that engine easy. I know you got that black pump because it says its alky compatible. Keep some top end lube in the deal and don't sweat it if you start every week. Now don't let it set all winter without taking it apart and lubing it up.

grydergeyer26
03-21-2013, 02:06 PM
carb is all set up fine and everything else is brand new
so set it at 5.5 and tht all i need not 9 to 12crapping on it self on top end wont turn rpm with the system i have is the issue
i know i turn 8000 on gas and now on allky wont do it

let-r-eat
03-21-2013, 03:52 PM
carb is all set up fine and everything else is brand new so set it at 5.5 and tht all i need not 9 to 12crapping on it self on top end wont turn rpm with the system i have is the issue i know i turn 8000 on gas and now on allky wont do itYou don't need all that. Set it at 5.5, make sure float is set properly and let it eat.If its missing up top I'd be looking elsewhere. On the 4 popper if its lean up top it will feel like you threw out an anchor or like your dragging the brake. Shut it down because it won't last long if its doing that. More likely that you have some other issue.

grydergeyer26
03-21-2013, 10:37 PM
st i at wide open or at idleat 5.5 and i that for any engine

let-r-eat
03-22-2013, 09:51 PM
5.5 idle should be fine. Just make sure it isn't dropping like a rock at the end. a good steady 5.5 is plenty.