Darrell Walker wrote:
>I'm still undecided on whether or not to stick with the stock exhaust
>manifold on my 4A, or go to a header. Kaster (in the Comp Prep >Manual)
>says the header is good for a 6 HP increase on a hot street >engine,
>throughout the power range. However I believe he is talking >about the
>pre-4A manifold, and the doesn't say anything either way in >the 4A update
>section. I've heard that the 4A manifold is supposed to >be superior to
>the previous ones, but is the header still better?
The TR4A exhaust manifold is substantially superior to the standard TR4
manifold. I have seen TR4As raced still with the original manifold so it can
be that bad...
>The one downside I've also heard with regards to headers is that they
> >increase the temp under the hood (and being directly under the carbs >and
>intake manifold probably makes it worse). Do ceramic coating >help? I
>don't really like the looks of header wraps, so I probably >wouldn't do
>that.
Yep, I run headers on my TR4. They were custom made for my car in 1966 so I
don't know how comparable they are to moden off the shelf versions. Mine get
hot. As a result I put header wrap on the bottom half of my headers and the
engine temp dropped by about 10 degrees.
AFAIK ceramic coating has two benefits. Firstly, it is supposed to drop
temperatures, but I can't say by how much or if it is more or less effective
than header wrap. Secondly, the headers are coated inside and out. Coating
the insides apparently has the effect of giving smoother exhaust gas flows
and thus a free-er flowing exhaust which should have performance benefits.
I am seriously considering ceramic coating my headers as the header wrap
looks a bit ugly, but I am reluctant to take them off as it requres a
removal of the carbs etc.
Cheers,
Michael
63' TR4
69' 2000
Sydney, Australia
_________________________________________________________________
Join the worlds largest e-mail service with MSN Hotmail.
http://www.hotmail.com
/// triumphs@autox.team.net mailing list
/// To unsubscribe send a plain text message to majordomo@autox.team.net
/// with nothing in it but
///
/// unsubscribe triumphs
///
/// or try http://www.team.net/cgi-bin/majorcool
|