Page 2 of 2

Re: Carbs meant to be mounted 'loose'?

PostPosted: Mon Nov 14, 2011 5:45 pm
by elansprint71
I thought I saw the ghost of Keith Frank a moment ago...

Re: Carbs meant to be mounted 'loose'?

PostPosted: Mon Nov 14, 2011 5:56 pm
by Esprit2
twincamman wrote:what ever !!!!--think about it !!!! --YOU DONT CRANK THEM UP TIGHT :roll: --GEEEEZ you think like a Chevy guy -ed
I did not say crank them up tight. I wrote, ?But split washers, even two stacked, are much more stiff than a Thackeray washer, and they don't provide the degree of compliance needed to let the soft mount do it's job.? I?ll stand by that statement. And unlike you, I made no assumptions, or comments, about how tightly you cranked them up.

Using two split washers in lieu of each Thackeray washer changes the harmonic frequency response of the soft mount, shifting it closer to that of a solid mount.

I won?t debate your point with you any further; let?s just agree to disagree and to not help each other with our engines.

One thing of which I am certain, you don?t know me well enough to be claiming to know how I think.

Tim Engel

Re: Carbs meant to be mounted 'loose'?

PostPosted: Mon Nov 14, 2011 6:54 pm
by CBUEB1771
Esprit2 wrote:Lotus' unique mount was die-cast metal and had a tapered, funnel-shaped bore which extended slightly to one side, forming a lip. The mount is to be installed with the funnel pointing toward the engine (large diameter toward carb / small diameter toward engine). There are some strange, complicated flow dynamics inside an intake manifold, including reverse flow. The lip is a dam meant to inhibit a reversion wave from reaching the carb and messing with the calibration. The funnel & lip may look restrictive to the eye, but the net result is really an improvement in flow and mixture control. It was a Lotus innovation.


Lotus used these anti-reversion bits on the carbureted 907 (45 mm carb) engines. Dave Bean explained this to me many years ago. I don't think they were ever used on the Twin Cam. I have a set for 45 DCOEs and will try to post a picture soon.

Re: Carbs meant to be mounted 'loose'?

PostPosted: Mon Nov 14, 2011 9:45 pm
by twincamman
Geez Tim ,,,you sound like my wife :lol: Ed