Tightening torque, hunting idle

Started by 88v8, July 28, 2023, 09:52:15 AM

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88v8

Edelbrock 4bbl, manual choke....

The Rover V8 is still not running right since it came back all fouled up with ethanol and I cleaned it up .

At first it seemed OK hot and cold, but now it's still fine when hot, but not at all when cold. Started up this morning, air temp around 67F and the idle was hunting up and down between 1200 and 700rpm, or 1200 and stall, without me even touching the throttle.
Any idea what's going on?

If it's this bad in summer, it's going to be even worse in winter.

Another thing... tightening the carb onto the manifold I can't find a torque spec. The Edelbrock manual says 'snug' but one person's snug is another person's slack, that's why torque wrenches were invented....
I tightened the hold-down nuts to 60 in lb, is that enough?

Ivor

DiDueColpi

The Holley spec is 60 to 80 in. lbs. I would suspect the Edelbrock to be the same.
The hunting idle  is generally a lean problem. Possibly some debris still in a transfer port or idle jet?

MGBV8

Carl

88v8

Snug by feel, yes but you might be Charles Atlas lol

I was afraid there might still be carp in there. Got fed up with the thought of stripping and cleaning it again, so I just bought a 1901 AVS to put on there. I can swap the tune.
It has an autochoke. Never had an autochoke, complexification, hmm we'll have to see how that goes.

MGBV8

No one will mistake me for Charles Atlas, Ivor.  :)

Snug up by feel, mechanic tight based the size of the fastener, etc.

I didn't have torque wrench for a long time.  Generally only reach for it for the serious stuff,  head bolts & such.
Carl

Spitfire 350

Carburetors are tough to torque down because you seldom have a straight path to the bolts around the body. I tend to use the calibrated wrist snapping method to get them all equal.

MGBV8

Boxed end wrench.  Do not overtighten.  I have seen the mounting ears broken.
Carl

BlownMGB-V8

If they are too tight the throttle shafts tend to bind.

Jim