<VV> Turbo Carb

jvhroberts at aol.com jvhroberts at aol.com
Sat May 23 14:34:17 EDT 2009

 The YH can be made to work well, and I had no trouble doing so. However, if the goal is to get a buttload more air through the carb and make more boost, the YH has serious limitations. I've bored a couple, with some luck, but the SU is a major step out of the box in this respect. No way will a YH flow what a 2" SU flows. 

And as far as the hole through a YH, it's pretty small for a 150-180HP engine. But then again, GM intended that small venturi to be the boost limiter. I remember measuring as much as 12" Hg vacuum between the YH and compressor inlet, and that's pretty damn restrictive. 



-----Original Message-----
From: Tony Underwood <tony.underwood at cox.net>
To: virtualvairs at corvair.org
Sent: Sat, 23 May 2009 12:57 pm
Subject: Re: <VV> Turbo Carb

At 11:15 PM 5/21/2009, Smitty Smith wrote:

>To say the YH carb is a POS or that it can't be made to work right 
>is defeatest and misleading at the least.

Kinda makes me wonder why Carter made the things for decades if they 
don't work right.

>Sure there are several better carbs.  Get a yh right and it will 
>allow your low compression turbo to idle with the best 95 twin carb 
>for a half hr at a stretch without loading up.  Open the throttle 
>and it will pass a surprising amouut of controled fuel air mixture 
>for the size of its venturi.  Educated tinkering with its metering 
>rods can give a smooth flow of power from idle to over 5000 rpm with 
>no problem.  The fact that it limits ultimate engine output was 
>planned by the engineers to save the engine from destruction by the 
>owner.  The 150 carb is more conservative than the bigger 180 of 
>course.  Even a high output turbo can't pull enough air through a 
>180 carb to make a beast out of the engine.  Good performance is 
>about all you can hope for, with emphisis on "good", not exceptional.

There's that old magazine article that managed to extract well over 
200hp from a turbo engine using that YH... and mostly stock GM 
parts.   I thought that was pretty good, using 1960s tech.

By the way:   That YH is not a very small 1xbbl carb.   There's a 
respectable size hole through it.

>I am defensive about the Generals economical choice of a carb for 
>the turbo.  It does a good job for what he spent for it.  If you say 
>it is a POS then you better come armed with some facts.  I mean 
>other than you aren't mechanic enough to make it work as designed.

I always managed to get them to work, by hook or by crook, one way or 
the other.   Thus, I never felt the need to change out a YH for 
something else.

...except another YH.

"Everybody gots one..."

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