Rock Valley fuel tank/pump

[streetk14]

Just wanted to know if anyone here knows what fuel pump is used in the Stainless Tanks from Rock Valley. Mine has an "LS1 pump upgrade" but I'd like to know exactly what pump it has. I think it may be a Walbro 255l, but am not sure.

I'm trying to figure out if my pump will work with my 500+ rwhp blown LS1. If it is a 255l, I will keep it and install a Kenne Bell boost a pump to bump up the flow when there is boost.

If anyone knows about these tanks, let me know.

Andy

[Hammered]

You need to request the 255l/hr pump when you purchase the tank or you'll get the next one down. At least that was the case when I bought my RV tank.

[CarlC]

Andy,

The stock LS1 will just barely work, but it's pushing it. The 255 is a perfect pump for us and no need for a booster.

[streetk14]

Andy,

The stock LS1 will just barely work, but it's pushing it. The 255 is a perfect pump for us and no need for a booster.

So, I wonder what pump I have. Do you think I have a stock LS1 pump? How much power is the 255 good to? I'm planning on at least 500 rwhp, possibly closer to 550 with my bigger blower and other engine upgrades I've done.

Maybe I'll call Rock Valley next week and see if they can help.

Andy

[Hammered]

My car is generating about 550 at the motor and there is plenty of pump. I think I got this formula from Mr. Gasket:

Horsepower x .314 = liters per hour @ 45 psi

Example: 550hp x .314 = 173 liters/hr

For supercharged engines, add 25% which would give 216 l/hr.

I'm thinking of dropping back to the next size down, 190 l/hr, because I'm circulating too much fuel and my tank gets too hot.

[streetk14]

My car is generating about 550 at the motor and there is plenty of pump. I think I got this formula from Mr. Gasket:

Horsepower x .314 = liters per hour @ 45 psi

Example: 550hp x .314 = 173 liters/hr

For supercharged engines, add 25% which would give 216 l/hr.

I'm thinking of dropping back to the next size down, 190 l/hr, because I'm circulating too much fuel and my tank gets too hot.

I'm looking at 625-650 flywheel horsepower with this motor and I'm supercharged, so I may have higher requirments. My LS1 is also supposed to run at 60 psi, I believe.

I found my Rock Valley invoice, and it has the $50 LS1 fuel pump upgrade listed on it. I'm still not sure what pump it is at this point. It could be that 190l that you are speaking of.

The over-heating of the fuel is the main reason I'm looking at using a boost-a-pump from Kenne Bell. It allows you to run a smaller pump, keeping the fuel cool when cruising around. It then pumps up the voltage when you hit boost (on FI cars) or WOT (on n/a cars). I've heard good things about them. The other good thing is that the boost-a-pump acts like a voltage regulator for your fuel pump, and it will maintain a set voltage at the pump to compensate for electrical loads, etc.

Andy

[Hammered]

Well the math comes out to 245 l/hr for 625 HP and 255 l/hr for 650 HP. I think there is already a factor of safety built into the equations so I'd try the 255. The one catch might be the 60 psi. Call RV to make sure, but it sounds like you got the 255 with your tank.

John

[CarlC]

I was given a range of tuning for the initial PCM burn, and 550RWHP is no problem with the 255. 550 is OK for a the occasional blast, but for long-term reliability (i.e. track days with lots of boost time) a 490 tune is recommended with the stock piston. This is basically the Lingenfelter tune/cam setup that I'm shooting for. I may opt for a second tune to download and have the 550 for the occasional fun time.

Magnuson also sells the voltage boosters but I'm opting for the 255. Lots of over-voltage time on the track concerns me.

[streetk14]

I was given a range of tuning for the initial PCM burn, and 550RWHP is no problem with the 255. 550 is OK for a the occasional blast, but for long-term reliability (i.e. track days with lots of boost time) a 490 tune is recommended with the stock piston. This is basically the Lingenfelter tune/cam setup that I'm shooting for. I may opt for a second tune to download and have the 550 for the occasional fun time.

Magnuson also sells the voltage boosters but I'm opting for the 255. Lots of over-voltage time on the track concerns me.

Carl,
I think you are going to be driving your car harder than what I have planned for mine. With that said, reliability is something you need to shoot for. Keeping the power to below 500 rwhp will help that motor stay together when you are beating on it at the track. I think you have the right ideas.


They (Kenne Bell) say bumping up the fuel pump voltage @ WOT has no effect on pump life, but who knows the truth. I need to first figure out what pump I have and go from there. If I have the 255l, then I'm not going to mess with anything. If I have a smaller pump, then I'll probably go with the boost-a-pump.

Andy

[MonzaRacer]

Hey hammered if the fuel is heating up in 2 different car we added a cooler to the return line. One was a simple looping coil of tubing that GM used for powersteering cooling on suburbans in late 80s early 90s.
The other we used a simple tranny cooler and small fan.
on the coils we used a louvered coverthat the louvers scooped up air. He tried to put the coil up in front of the condenser but he didnt like the fuel lines ran up front.
The tranny cooler worked great amd dropped the fuel tank temps by like 30 to 40 degrees.
As for dropping fuel flow capacity that wont change your amount of heat going in just cause a lower flow and a better chance of actually starving the engine AND it will allow the return fuel vapor problems.
I had never seen it before but we had a car come in with super charger and a fuel pump much smaller than I figured should be on there but the kit came with it and stated it would handle it.
I actually upgraded to same size lines on pressure and return and we still had running issues.
We found the fuel was actually perdolating in the return line. When we upgraded the return line it helped but we still had problems.
I called a friend of mine who has helped me before on fuel systems, and he told me that the slower it goes through the return the MORE heat it picks up.
So we upped the fuel pump flow and tada the problem went away. We never had any more problems. We found the percolation in the return when we pulled it off, man was the fuel hot coming out.
I always wondered about building a fuel cooling fan that ble air over the tank.
Me I prefer to install a pwm fuel controler. I found one that uses a fuel pressure guage and keeps the pressure/flow constant for proper performance and its rampable. You set its flow increase ramp so as to not starve the engine.
I found kit online and havent found it again. BUT it worked great.
And no return line.

[streetk14]

I'd have to say that going from an excessively high flowing fuel pump to one of the proper size will definitely help with a fuel over-heating problem. A big pump that flows way more fuel than is needed (especially at light-load cruising) will have a lot of fuel being returned to the tank. This is a lot of friction and a lot of heat.

Andy

[Hammered]

Andy,

I agree - I'm way over pumped! I have 1/2" supply and 3/8" return so that's not my problem. I've also insulated the lines where possible, but the aluminum fuel rails attached to the aluminum intake through aluminum bosses and all bolted to a high compression aluminum heads dumps a lot of heat into the fuel at the rails.

Also, from heat transfer principles, it is impossible to dump more heat into the fuel by slowing it down. The exit temperature of the fuel may rise, but less mass flow means less heat into the tank and cooler fuel returning to the engine. I can see Monza's point about the fuel going so slow that it percolates, but I can't believe I'm anywhere close to that. A pwm would be a neat solution, but I don't want to go there yet.

Good luck with your combo - it sounds awesome.

John

[streetk14]

Andy,

I agree - I'm way over pumped! I have 1/2" supply and 3/8" return so that's not my problem. I've also insulated the lines where possible, but the aluminum fuel rails attached to the aluminum intake through aluminum bosses and all bolted to a high compression aluminum heads dumps a lot of heat into the fuel at the rails.

Also, from heat transfer principles, it is impossible to dump more heat into the fuel by slowing it down. The exit temperature of the fuel may rise, but less mass flow means less heat into the tank and cooler fuel returning to the engine. I can see Monza's point about the fuel going so slow that it percolates, but I can't believe I'm anywhere close to that. A pwm would be a neat solution, but I don't want to go there yet.

Good luck with your combo - it sounds awesome.

John

Hey John,
I know that you know your pump is too big . My comment was pointed towards Monzaracer and his thinking that a too small of fuel pump would cause fuel heating problems.

My point was simply that an oversized fuel pump on a street car is constantly pumping excessive fuel back and forth the entire length of the car, and that it is not a good thing. This is one of the reasons why the OEMs went to return-less style fuel systems.

BTW, I forgot to call Rock Valley today

It's just so hard for me to find time to do anything during the work week, then when I have time off (on the weekends) nobody is open for business. Oh well, I'll try to get to the bottom of my fuel pump mystery tomorrow.

Andy

[Hammered]

Thanks - sometimes smaller is better

I know what you mean by the work week.

Good luck with RV.

John

[CarlC]

Hey John,

My point was simply that an oversized fuel pump on a street car is constantly pumping excessive fuel back and forth the entire length of the car, and that it is not a good thing. This is one of the reasons why the OEMs went to return-less style fuel systems.

That's exactly why I'm going to run this setup. Simple, effective, and replacement parts are everywhere.

If the return line has boiling fuel then something in the system is too close/attached to a waste heat source.

[streetk14]

Andy,

The stock LS1 will just barely work, but it's pushing it. The 255 is a perfect pump for us and no need for a booster.

Good news, the tech guy at Rock Valley said that my tank does have a Walbro 255l pump. That means I'm set and have no need for any fuel pump booster. That's great, one less thing to have to worry about with my blower install.

Andy

[CarlC]

Good news Andy.

Did you purchase the tank, or was it on the car?

I'm looking hard at modifying my stock tank with a Fuelsafe collector.

[andrewb70]

Just saw this. I have a Rock Valley tank with the upgraded pump. I have a fuel pressure gauge in the car and I have never seen any pressure drops at WOT. 502, bbc, 500rwhp...

Andrew