Fuel regulator/bypass

[ZERO25]

Which one are yall using on a 602 with the rear mounted fuel pump?

After chasing carb problems for the last 2 weeks, our local crate builder believed we had the wrong regulator, too small he said.(it came with the car)

[brad hibbard]

rear mount belt pumps deliver quite a bit of volume and a crate engine does not use much volume so the regulator and return line are critical ---also do not forget the fuel cell vent needs to be adequate and clear

as for the pump---do you know what size it is 300-400-500?? this is determined by the length of the gear
for crates we use the 300

if the pump is bigger than a 300 definitely use a a regulator with a bleed

the aeromotive stuff is real nice but the universal bypass regulator from them does not have a bleed---it works well with a 300 pump but if you are larger I recommend something with a bleed

make sure there are no dips or kinks in your return line (-8 minimum -10 is better)

Brad
www.race-1.com

[ZERO25]

Thanks Brad! This is kinda baffling us. It was a 3 race old Hendren 602, tuned on his dyno. We've adjusted the floats both ways and adjusted the front squirters, but nothing seems to help. We've checked the filter and lines and there were no issues. Our local builder adjusted the fuel pressure from 6.5 to 7.5 to no affect.

[brad hibbard]

OK lets get more specific---originally you just asked about a regulator
What is the actual on track problem?
What fuel are you using?

Brad
www.race-1.com

[ZERO25]

Yeah, because our local builder said we were using the wrong one.(it was changed tonight)

Our car has been stumbling at the end of the straightaway.

We are using VP x85.

[brad hibbard]

did changing the regulator fix your problem?
I am going to interpret your "stumbling" as a misfire
on E85 a high end misfire is a rich condition
we do not like dead head regulators for E85 that have 3/8 pipe fittings as they will go lean at high end---and I am going to assume that is why your local builder didn't like the regulator you were using but I do not think that was the "stumble"

I hope your problem went away but I am guessing that it did not

Brad
www.race-1.com

[ZERO25]

Dont really know as it doesn't do it until it has a load on it.

We had the regulator with the return on it but our local builder said it was too small, so we purchased a bigger one.

I just find it odd that it had 3 races on it with no problem or at least according to the prior owner ( we did verify that it was dynoed by Hendren)

[brad hibbard]

have you called Steve Hendren to ask specifically about the situation?
he is pretty easy to talk to

Brad
www.race-1.com

[ZERO25]

have you called Steve Hendren to ask specifically about the situation?
he is pretty easy to talk to

Brad
www.race-1.com

Yes, he helped us sort out the regulator.