<div style="color:black;font: 12pt Comic Sans MS, sans-serif;">Thanks for the several comments so far. The background for the inquiry is: A friend has an aftermarket fuel pump that delivers 7-10psi & a pressure regulator set at 2 psi. He also has (3) HS6 carbs. The engine starts, idles & runs fine until he stops & turns off the engine. Like at a gas station. Then upon restarting it runs rough & won't idle unless he pulls the choke partially out, I.E. fast idle, not richer mixture. We assume this is due to heat soaking &/or peculating fuel. I thought raising the pressure might help if the peculating was occurring before the float valve & wanted to know the Max fuel pressure to this model SU. I doubt that it will have any effect. We are also interested in any suggestions you may have. Additional facts:
<div>his engine never gets over 190 F when running. He has an electric fan in addition to the original fan. he carbs are not running lean. I am told the timing is correct. </div>
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<div>Thanks,</div>
<div>Gary Hodson <br>
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<div style="font-family:arial,helvetica;font-size:10pt;color:black">-----Original Message-----<br>
From: Michael Oritt <michael.oritt@gmail.com><br>
To: warthodson@aol.com; Austin Healey <healeys@autox.team.net><br>
Sent: Sun, Jun 14, 2020 12:45 pm<br>
Subject: Re: [Healeys] SU carb fuel pressure<br>
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<div class="yiv6584258867gmail_default" style="color:#3333ff;">Gary--</div>
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<div class="yiv6584258867gmail_default" style="color:#3333ff;">2 to 4 psi is the common wisdom. </div>
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<div class="yiv6584258867gmail_default" style="color:#3333ff;">That said, I had a set of HS6's on the MGA engine in my (now-gone) Elva Courier and no amount of fiddling with floats, lid position, etc. would solve a consistent fuel starvation problem when coming of hard, tight right-handers under full throttle as in turns 1 at VIR, Summit Point, etc. I finally solved the problem by installing a Holly Blue (high-pressure fuel pump) and reducing pressure via a regulator to about 5.5-6 psi. Dire predictions notwithstanding I never had an issue with the floats' being overcome by that pressure and causing leaking. </div>
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<div class="yiv6584258867gmail_default" style="color:#3333ff;">I'm not saying anyone should go to such extremes without a good reason but I think the "common wisdom" is just that and not always gospel. </div>
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<div class="yiv6584258867gmail_default" style="color:#3333ff;">Best--Michael Oritt</div>
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<div class="yiv6584258867gmail_attr" dir="ltr">On Sun, Jun 14, 2020 at 12:27 PM warthodson--- via Healeys <<a rel="nofollow" shape="rect" ymailto="mailto:healeys@autox.team.net" target="_blank" href="mailto:healeys@autox.team.net">healeys@autox.team.net</a>> wrote:<br clear="none"></div>
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<div style="color:black;font:12pt Sans sans-serif;">What is the Max recommended fuel pressure (psi) for SU HS 6 Carbs. Is there also a Min fuel pressure?
<div>Gary Hodson</div>
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