Alky system siphoning?

TR Custom Parts

Mark Hueffman - Owner
Hey guys, had my intercooler out while installing an aluminum crank pulley on my 87 GN and figured I would clean it while I had it out. Moved it over to my work bench and heard a sloshing noise. Turns out that there was about a 1/4 cup of alchohol in it! This was after the car was only sitting two weeks! Needless to say it looks like I have a siphoning problem. I have a kit based on what Steve Monroe designed with a Shur-flow pump. What can I do to stop this. BTW the nozzle is mounted into the outlet pipe of my stock location intercooler. Should I plumb a solenoid in line before or after the pump?
How about a 1 way check valve. I have one make for Kerosene that will probably work. Not sure how quickly the alky. will open it and flow through but I imagine it would be as quick as an electronic solenoid unless you are running a closed loop system.
I have seen his setup. Very stealthy.

Washer bottle holds the alky. and the nozzle is low on the back of the intercooler neck.

Would be difficult to do.
Probably will end up mounting a NOS fuel solenoid right before the pump. Will wire it so it will open when the pump comes on. Will a fuel solenoid hold up to alcohol? I know they make one specifically for nitro/alcohol but don't know if that is necessary. I am only running diluted 90% isopropyl. Don't think the remaining alcohol in the braided line will hurt anything. Now that I think of it, wouldn't normal engine vacuum be drawing fluid from the alky setup all the time right thru the pump?
Hey there Mark. All you need is a check valve. You could use a solenoid but it is overkill with a single nozzle. Alcohol solenoids hold up very well to 90% alcohol. I am using denatured with my own configuration solenoid specifically made for me for methanol. Not one problem as of yet and no siphoning with the solenoid or the check valve. The check valve will work just fine though and are cheaper.... I would install the check valve just after the pump if you have the pump hooked up to only come on as needed.
A regular fuel solenoid will work but for a shorter life span.
Yes there is always vaccum sucking on the pump when the engine is running. Never install a solenoid/check valve before the pump always after.
Joe Tripodi

Notice you sell check valves from your website. Will I be able to just plumb this in to the output side of a ShurFlo pump? Any ideas on what adapters I would need? I am running -3 braided line after the pump. How does your check valve work? I am assuming it will not open until it reaches a certain pressure so as long as the pump is not running it shouldn't open? Will high vacuum situations open it though?
the check valves are 1/4" in/out male NPT. I can get them in 1/8" NPT males threads also .
the valve will not open under normal vaccum. Tested it to not open. It only opens when the pump kicks on. If it was used on a NA motor (84-85) it would open under normal vaccum and for that motor only a solenoid is required.

I am not sure what threads are on the shurflo so I'm lost there.
I was getting a cloud of smoke behind my TR because the SMC alky kit was siphoning above 1/3 throttle, whether on or off. Sent it for a repair.

Would one of these checkvalves install between the reservoir and braided line on the SMC kit?
Joe, Shur Flo has 3/8" NPT but I am using a bushing down to a 1/8" adapter that allows me to connect a -3 braided line. Would you have a check valve that has a 1/8 npt female on one end and a male end on the other so I don't have to stack up a bunch of adapters for this to work? Your valve has a 10lb cracking point but what happens when you have more than 10lbs of vacuum, can't it suck the check valve into an open position?
mark no you would need an adapter to make one end female.
10psi is equal to 20.36021Hg. My idle is 14Hg.

mrtpolton it would go between the nozzle and pump somewhere before or after the braided line.
So what is the worst that can happen with the alcohol siphoning into the intercooler? Like I said there was about a 1/4 cup of it in the bottom of the i/c after a two week period of not driving the car. Would it just disipate after starting the car up or would there be a danger of hydrolocking the motor? Man, I just think of the times that the car sat there for a month without driving it. I thought the shur flo pumps would not let that happen. Who knows, maybe it was just sucking whatever was in the braided line and that's it. I am running a 7 ft line from the pump to where I plumbed the nozzle into the outlet of the stock i/c. Maybe I should mount the check valve on the other end of line closer to the nozzle? Joe, how much for the check valve with shipping? Would need the 1/8npt size. Let me know and I will shoot you a Paypal payment. Thanks.