View Full Version : Pressure!!

05-21-2011, 07:30 PM
Will an SU hs6 handle 3.8 psi fuel pressure?????
If not what fuel pressure regulator works best?


05-22-2011, 08:47 AM
Not sure specifically about the HS6, but in general, for SUs, that's a bit on the high side. I use a regulator, and it's set for 1.5-2 psi at the carbs.

I think there is a consensus that the Holly 12-804 is a pretty good choice for a regulator; that's what I use.

05-22-2011, 10:57 AM
Thanks Steve, I was wondering if that may be a little high for SU's.
I'll keep that in mind. I may try it first though, its the pressure the mechanical pump on a A15 Datsun swap will put out.


05-22-2011, 01:13 PM
That mechanical pump is the weakest part of the A15 series engines and is fairly expensive. You may want to think about going electric now.

05-22-2011, 06:06 PM
Carter P4070 and you don't need a reg. Best pump ever but heavy.

05-22-2011, 08:27 PM
Good point guys, Save the money on a regulator and put it towards a electric pump!! Give me a little more room to change my lawn mower oil filter! [Remote filter needs plumbing I hav'nt rounded up yet].


05-22-2011, 09:52 PM
Ah, I didn't realize that you were using a mechanical pump. The papers that come with the Holley regulator specifically say that it shouldn't be used with a mechanical pump. I agree, replace the mechanical pump with an electric one.

I am using a low-pressure Facet, which puts out about 4 psi at backoff, followed by the Holley regulator. One thought I've had--use a little higher pressure pump (say about 8-10 psi) and use the regulator to keep it about 2 psi at the carbs. This would help a bit with avoiding vapor lock. I'm planning to do that with my Porsche, if I can find someplace to mount the pump.

05-23-2011, 06:04 AM
Well, on checking, the Holley puts out 6 on the high side and the Airtex that was discussed a while back puts out 4.5. I don't care for the hammering cubes by Facet. I have several that came off of various things. I must say they never seem to fail though. I sold my MGB with a pump that I got second hand back in the 60's that was made by Bendix. Its still running. Facet now has what appears to be that pump and I'm temped to give it a try. Its the pump that looks a little like a tin can with a dome on top and a removable bottom with a filter inside. For now I'm looking at time constaints and already have the mechanical pump plumbed in up to carb hook up so may chance it. [Midget 50 bound!!!]


Hap Waldrop
05-23-2011, 06:57 AM
Kurt, the Facet pump, I've ran them on race cars , so quite familar with them, are constant running pumps, and noisy, so if you don't like the Holley, you'll hate the Facet, if you want a intermittent pump that shuts off as pressure is reached, try the Carter, or the SU electric pumps.

05-23-2011, 09:27 PM
Thanks Hap, I'll check on the Carter, very familiar with the SU and like it but not nuts about reliability.
The Facet that looks like my old Bendix is a PUR 480534. Unfortunatly it costs a $100 and would need a regulator since its pressure runs up to 7.5 psi. Facet claims it has run twice as long as other pumps it has been tested against. I can agree with that since I know it has run 100K on my MGB and I got it second hand off a friend's wrecked B. I have no idea how long he ran it but it has been running now since the 60's.
So, if anyone needs a super reliable pump you may want to keep it in mind!
[It makes noise but nothing like the hammering cube!]


05-24-2011, 08:12 AM
Just bought the Airtex pump on line for $37 from Rock Auto.