Headers 3" exhaust system

[frank folkmann]

Netters.
At Iowa Rally I meet Jerry Jardine a drag racer from the 60s. He had a set
of Thorley Headers and mandrel bent 3" exhaust system. The list on headers
and muffler tail pipe was $899.00 Plus shipping. Muffler and tail pipe only
$444.00 plush shipping.We can purchase this Header and muffler kit for
$764.00 and Muffler kit only for $382.00. He pays 1/2 the shipping if
ordered by Nov 1, 1999. The reduced price expires DEC 31, 1999
Any one interested can place their order by calling 1-800-934-3569. Jerry
was the person who designed the Thorley Headers.

 

[roger black]

Question time on the headers. I've been wondering why no one has installed
dual exhaust along with the headers to move that exhaust out faster.
Haven't understood why go to the expense of headers without the two exhaust
pipes. Any ideas why or why not? Wouldn't it make the engine breathe or at
least exhaust more efficiently adding torque and HP?

Roger
7? ????

 

[chuck blanford]

Roger

It would be difficult to dual the GMC, as the exhaust pipe is routed through
the frame cross members on the passenger side, and the fuel lines run
through the comparable openings on the opposing side. Max diameter through
the frame is 3". To extend duals to the rear would require an exhaust
system underhung the low slung frame. Not a feasible alternative for this
chassis, IMO.

Chuck
77 Kingsley w/ Thorley Headers & 3" System
North Idaho

- -----Original Message-----
From: rblack
To: gmcmotorhome
Date: Monday, October 04, 1999 7:39 PM
Subject: Re: GMC: Headers 3" exhaust system

>Question time on the headers. I've been wondering why no one has installed
>dual exhaust along with the headers to move that exhaust out faster.
>Haven't understood why go to the expense of headers without the two exhaust
>pipes. Any ideas why or why not? Wouldn't it make the engine breathe or
at
>least exhaust more efficiently adding torque and HP?
>
>Roger
>7? ????
>
>

 

[wayne newland]

Arch

At Marion, NC, I saw several coaches come in with exhaust pipes coming out right
in front of the bogies, and I wondered about the heat on the tires. Maybe it
isn't a problem, but I'm not buying their tires, either.

Wayne Newland F9300 75 Palm Beach Columbia, (raining) Md

> In a message dated 10/4/99 9:42:53 PM Central Daylight Time,

>
> > understood why go to the expense of headers without the two exhaust
> > pipes. Any ideas why or why not? Wouldn't it make the engine breathe or
> at
> > least exhaust more efficiently adding torque and HP?
> >
> Roger
>
> What I am about to say is my own myth----nothing more. I have run
> headers on my race cars---they do help there. You do have to retune
> after you put on headers. I good set will clear out more of the exhaust
> and bring in more new fuel and air. Now on the street I dont know if you
> need to retune or not. The difference is the muffler. The myth I have is
> that you are not going to get a big difference with headers and a muffler.
> If you do get much I sure would have a look at the plugs to see if you are
> running lean or not. Now for your next question twin pipes. Well, you would
> have to go below the frame---a little close. Coming down the drivers side
> the fuel lines would be right above them-----not cool. I will admit to more
> than one vision of a GMC with Twin Chrome Lake Pipes exiting just in front of
> the bogies. Darn it Roger it will take me 2 days to get that out of my head
> now.
>
> Take Care
> Arch

 

[wayne newland]

Arch

I wouldn't sware to pipes coming out on the driver's side. From where I was, I
was mostly seeing the passenger side.

Wayne

> In a message dated 10/4/99 10:39:27 PM Central Daylight Time, wayne

>
> > At Marion, NC, I saw several coaches come in with exhaust pipes coming out
> > right
> > in front of the bogies, and I wondered about the heat on the tires. Maybe
> > it
> > isn't a problem, but I'm not buying their tires, either.
> >
> Wayne
>
> OMG you have just added 2 days to the time it will take me to get
> the Lake Pipes out of my head. Seriously were there any with
> pipes coming out on the drivers side? This would scare the He** out
> of me. I dont know if it is stock or not but mine has all sorts of stuff
> wire tied to the metal fuel filler pipe. Wires, fuel lines and vent lines.
> If the turn out tips on the exhausts are done right heat should not be a
> big problem. ( my myth) Thanks for the info.
>
> Take Care
> Arch

 

[timothy brown]

Roger wrote:

 

[steven d. ferguson]

Roger,
Interesting question. I experimented with that with my long-haired
messcook's '55 Chevy. With 4 into 1 headers, a balance tube behind the
collectors, and a pair of 2.5 inch tailpipes, the car would turn the 1/4
mile at 12.29 at 106 mph. Switching to a single 3" exhaust netted the
exact 1/4 mile times & mph. I dropped the exhaust at the collectors
(open headers) and made a few passes & the results were the same. All
withing a tenth of a second or so. The real benefits lie in using
headers. A good rule of thumb is that any header is better than most
cast iron manifolds period. The volume of exhaust our low rpm vehicles
generate at their operating range is easily handled by a 2 1/2 in system
using free-flowing mufflers. The original hemi & Corvair turbo types
set a standard that is still in use today. As exhaust cools it takes up
less volume (c'mon you engineer types, help me out here) and the cooling
process starts the instant the exhaust valve opens.
Headers do have some drawbacks. The engine compartment is hotter, (it
seems the ceramic coatings address this), they typically have a noise
referred to as header "ting", and usually you have to richen the mixture
some to maintain the same air to fuel ratio.
Would've liked to meet Jardine. He's a legend!
By the way, here in San Diego we have Ed Hanson's Muffler Shop. His
Dad used to work with Doug & Betty Thorley in LA. Ed is the king of
performance exhaust systems and his prices and follow up can't be beat.
He has done quite a few 3" systems on GMC's and knows all the tricks.
(To date he has done 14 exhaust systems on my cars.)
HTH
Steve Ferguson
San Diego

 

[john szalay]

>snip>>>> I will admit to more
>than one vision of a GMC with Twin Chrome Lake Pipes exiting just in front of
>the bogies. Darn it Roger it will take me 2 days to get that out of my head
>now. Arch
>

your not going to believe this, but last year, we saw white one in Alabama
looked just like that, had a pair of short lakers coming out just under
the side windows. did,nt get to talk to the owners, they pulled out right
after sunrise... Sounded fab......
John & Brenda Szalay
73 PD

 

[roger black]

Arch,
Sure would look good with a couple of those chrome 70's style Corvette side
pipes on each side. Just have to make a three inch hole in the frame to get
it to the outside. Leave em straight, to hell with mufflers. If need be,
stuff them with steel wool when you have to.{:>)

Roger

 

[ritch hwang]

There was a couple from SoCal towing a pristine "covered headlight" VW bug
at the last year's Marion rally. They were running a highly modified
Cadillac engine with exhausts exiting behind the the cab area. Hey, just
a thought.

As always, best regards.

~ Ritch & Betty Hwang ~ Clarkston, MI ~ mailto:rhwang
Visit our home page ~ http://www.concentric.net/~rhwang/
~ =^..^= Trinket ~ the shy Persian kitty ~
~ 76 GMC Birchaven ~ FMCA F249339 ~ RVClub 00930 ~ ICQ# 6408591~
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