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Tips
Tips

Pressure!!

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N

nomad

Yoda
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Will an SU hs6 handle 3.8 psi fuel pressure?????
If not what fuel pressure regulator works best?

Kurt.
 
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.
 
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.


Kurt.
 
Kurt
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.
BillM
 
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].

Kurt.
 
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.
 
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!!!]


Kurt.
 
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.
 
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!]

Kurt.
 
Just bought the Airtex pump on line for $37 from Rock Auto.

Kurt.
 
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