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Re: [Fwd: MG Q&A]

To: mgs@Autox.Team.Net
Subject: Re: [Fwd: MG Q&A]
From: Jack Severson <jesevers@students.wisc.edu>
Date: Thu, 17 Dec 1998 16:24:29 -0600
>

>>Csooch1@aol.com wrote:
>>> 
>>> Listers,
>>> I personally would not use anything that thick(20w50,10w30) in the dashpots.
>>> Throttle response will be horrible until the carbs come up to temp. and the
>>> oil thins out.  I have used Marvel Mystery oil in every SU, stromberg,
dashpot
>>> type carb, and have never had any problems since it is pretty thin.  You can
>>> get this red oil at most hardware or auto stores.
>>> Cheers,
>>> Chris
>>> BJ8...many,many pieces
>>
>>Chris,
>>
>>Could you explain a bit more about how and why the viscosity of the oil
>>used in the dampers has anything whatever to do with "throttle
>>response"?  My understanding (perhaps mistaken?) is that the function of
>>the oil in the carb dampers is to provide for mixture enrichment upon
>>throttle opening (an accelerator pump function) and that the the height
>>of the piston in the SU carb affects only the mixture, not the amount of
>>air/fuel getting into the engine.  
>>
>>(I did switch to 5W-30 when operating an MGB in Montana and North Dakota
>>winters, but have never sensed the need to use anything of lesser
>>viscosity in the dampers.)
>>
>>-- 
>>*Bill Schooler      *Check the MGCC Wash DC Centre Web Page
>>*Woodbridge, VA     *http://members.aol.com/mgccwdcc/
>>*schooler@erols.com 
>>*53 TD
>>*60 MGA 
>>*69 MGB/GT
>
>==================================
>
>>Chris,
> 
>I got rid of a junk 69 MGB-GT a few years ago that went like mad compared
to the 76 B, especially on acceleration,  but had such bad uni-body rust
that you could feel the flex. It had SU's and I probably should have saved
it or at least canabalized parts. However, I was (and still am) on a 500
lbs- out-500 lbs.-in diet so I got as much as I could get for it and let it
go. The saving grace is that it actually had chicken shit all over it,
inside and out and smelled just like an old chicken coop inside  so it had
to go. Not too pleasant, believe me!  I have space to pile up junk of all
kinds. It is a (bad) habit, so I got rid of the GT on that basis.
>
>The 76 B is another matter, however. I am intrigued with the ZS's lack of
performance, which I gather is due to emission requirements. I have been
through mine and tried everything you can imagine to make sure is is
functioning correctly and to  increase performance short of enlarging
internal passages. I still want to see how it does with a properly installed
stock intake/exhaust manifold and exact tuning, just to set a baseline, I
guess. The XKE with dual ZS's isn't great off the line unless you rev it up
and drop the clutch but it DOES GO so the carbs aren't all bad.
>
>In the process of working with the ZS on the B I ran light oil, heavy oil
and no oil in the damper as well as different springs (and no spring).
Nothing improved acceleration (or hurt it either). I am not 100% sure off
the top of my head exactly what happens in a ZS when you open the throttle
butterfly, or what causes the dogginess compared to SU's.
>
>--Jack
>



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