[6pack] Crankase breather strategy when Strombergs are replaced

[Robert Lang]

On Tue, 8 Jul 2008, Henri Lefebvre wrote:

> Stan,

{stuff deleted}


> At this time the only issue I have is that the engine stumbles and
> bucks when I drive on rough roads. I have not yet found the cause. The
> next steps to try to solve this issue are:
> 1 - Check for possible electrical problems;
> 2 - Check/adjust fuel pressure;
> 3 - Change float valves, again;
> 4 - Change throttle from TR6 rods to cable;

I know this problem well.

It turns out that the extra linkage mass is the problem. When you hit the 
bumps, the throttle linkage moves up down - and the down motion is like 
tapping the gas with your foot only with a shorter period.

The fix was EASY. First off, we assume that you have the stock firewall 
linkage and then you run a rod to a bell crank under the Webers and then a 
rod comes up to the carb cross linkage.

If that description is true, then you can do one of two things.

The least obvious fix is to replace the return spring on the firewall with 
something a bit heavier than the stock piece. I pulled my stock spring off 
and went to the hardware store and found something that was almost the 
same dimensions but the wire was heavier. This spring is a LOT more beefy 
than the stock piece. Install the beefy spring in place of the stock one 
and you're all set.

Some folks try hooking springs from the valve cover hold-down nuts to the 
linkage arms, but this looks crappy and (interestingly) doesn't work all 
that well.

But putting that spring it totally fixed the problem.

> Suggestions???

You just got 'em.

But going to a cable will also work.

Me - I like the solid linkage setup because it makes me feel like I can 
un-stick the linkage by getting my toe under the accelerator pedal and 
pulling. Of course, I HAVE had the linkage stick (the firewall bell crank 
over centered) in the past and it was a very, very hairy experience. I 
tried to unstick it to no avail and turned the ignition off. In the 1 -2 
seconds that it took to realize, attempt a fix and then shut the car off, 
I was up to about 55 mph (well over 5500 in second), I had travelled 
nearly the entire width of the parking lot we were autocrossing at. But I 
managed to stop the car without hitting anything. I was pretty scared, 
though.

That's when I came to understand the accelerator pedal stop on the 
firewall. :-)

> Henri

regards,
rml
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