MFI pump

randywebb · 02-10-2007, 10:41 AM

Anybody know the weight of a MFI fuel pump? I tried to weigh one recently but the sucka was so heavy it bottomed out my scale...

andyjboy · 02-10-2007, 11:39 AM

I haven't got one to hand at the moment but I seem to remember that the last time I shipped one it was something like 8 kg.

356RS · 356RS's Garage

Randy, my 0408 126 014 with mfi pulley and full of oil weights in at 17.5 lbs.

boba · 02-10-2007, 11:51 AM

Randy,
My 009 is 15.5 with pully gear.
I have a 019 I can check Monday.
Bob

Grady Clay · 02-10-2007, 01:54 PM

Randy,

I don’t have the parts available but I suspect you are trying to compare carbs to MFI. There are three considerations; mass, GC position and HP increase with MFI.

The MFI system consists of:
Pump
Mount
Mounting hardware
Belt and cam pulley
Extra sheet metal on LF of engine
Extra weight of warm-up air system
The high pressure steel fuel pipes, brackets and fuel injection nozzles
Throttle bodies & Stacks – there is significant difference between the ’69-71 and ’72-’73 and later.
Linkage & plumbing

Now, the fuel filter console (’69-’73) and fuel pump (’71-’73) originally was in the rear. They can be repositioned to the front cross member and gas heater well. The fuel pump weight is the same Carb and MFI. The MFI filter console is heavier than a carb fuel filter. Moving all this to the front moves the CG down and forward.

Carburetors consist of:
Carbs (Weber or PMO – I’m ignoring ’64 - mid ’66 Solex))
Intake manifolds (911 Alu, 911 Mag, 906 tall Mag and various PMO aluminum configurations.
Linkage & plumbing

The various air filter configurations can be similar or dramatically different. The steel ’69-’70 are slightly heavier than the ’71-’73 plastic versions. The advantage of the steel is fire resistance but there is an issue with rust in the crankcase breather area. The advantage of the plastic is slightly lighter weight but far more susceptible to fire damage.

Non-Factory air filter assemblies don’t reduce the susceptibility for fire damage. They are relatively light weight and some claim HP increase. I can see some serious improvements in the aftermarket filters for MFI that carbs can’t use.

When discussing either carbs or MFI, having the systems working properly makes a HUGE difference. There is a lot of information about both here on Pelican. In general, MFI produces about 15 more HP, everything else the same.

Best,
Grady

Jim Richards · 02-10-2007, 01:57 PM

Randy, you're not gonna go off and swiss cheese one, are you?

Turbo_pro · 02-10-2007, 02:25 PM

Speaking of MFI.

Check out this system I saw on a 2.5 racing engine built at Supertec.

Is that really a five bladed fan?

randywebb · 02-10-2007, 03:00 PM

Thanks all. I'm not going to be drilling holes in any MFI pumps! I picked up a friend's pump a while back and the wt. really surprised me -- made me reflect back on its origins in diesel engines...