Recommended setup for 350hp small block mopar

Propane, Butane, LPG, GPL, C3H8, C4H10
Posts: 703
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: Recommended setup for 350hp small block mopar

Post by storm »

C3H8 wrote:That's a good point. I am quoting numbers based on the rating of the tank service valve both manual and electric. I never calculated or looked up the flow rating of the lock off itself. Accepting you numbers are correct 31 GPH or (120 LPH) that is still enough fuel to satisfy the most thirsty street engine. Thanks for the correction.
That's 31GPH at burst pressure (4.5 MPA) not at operating pressure (3.0 MPA). I must find the mathematical equation for the fuel flow requirement for horsepower. I have it for petrol but it will be different for LPG.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

Posts: 394
Joined: Sun Sep 02, 2007 3:29 pm
Location: Netherlands

Re: Recommended setup for 350hp small block mopar

Post by BigBlockMopar »

This is the type of lockoff/filter that's mounted near/on the convertors in 80% of the LPG-fueled cars overhere;

Image ... 028022.jpg

No vacuumlines, just a simple lockoff which is controlled by a timed relais that keeps the power up as long as it feels (spark-induction)current.
I've never seen any specs about these lock-offs but recently when I had one opened up it was that I noticed the 2.5mm internal opening.
Compared to a regular 6mm (outside) supply line, that quite a restriction.
Although I agree this should/could also result in high rpm supply issues, but then again, I never get above 4500 rpm with my bone stocky-ish 318. Let alone for a longer period of time.
'73 Dodge Dart - 360ci - 11.3:1cr
MegaSquirt + HEI 7-pin timing control - Edelbrock AirGap - Cold Air Intake
IMPCO E / 425 mixer - A518 OD-trans - 3.55 gears - 225/50/17" tires.

Post Reply