[Roadsters] U20 Head water passages

[Stephen Wan]

Depends where you live and the weather conditions.  If you drive in the 
cold, I'd leave them open. A warmer manifold will help with fuel atomization 
in cold weather.  If you're in perpetual summer like socal, leaving them 
closed won't affect driveability.  The comp manual recommends closing them, 
because a cooler manifold, means cooler intake air temperature and thus more 
air molecules in the cylinder yielding more power.

Steve
70' 1600
just taking up space in the garage.

----- Original Message ----- 
From: "Richard Brown" <reblues at reblues.net>
To: "Datsun Roadsters" <datsun-roadsters at autox.team.net>
Sent: Tuesday, March 11, 2008 4:04 PM
Subject: [Roadsters] U20 Head water passages


>I am cleaning up and assembling a U20 engine. The water passages from the 
>head
> to the manifold have never been opened. I have searched and found
> recommendations for having them open and closed.