Welcome to the Corvette Forums at the Corvette Action Center!

65 under car exhaust

brumbach

Well-known member
Joined
Mar 6, 2004
Messages
330
Location
Middleboro, KY
Corvette
1965 convertible
I recently bought the allen aluminized 2 1/2" exhaust system for my vette. I also purchased the spacer (from paragon) in lieu of the heat riser valve for the installation on the passenger's side. Donuts come already assembled with header pipe. Looking at a diagram of my exhaust system, there appears to be an extension section of pipe that goes between the header pipe and exhaust manifold on the driver's side. How critical is this? What happens if I don't install one?

Thanks,

Bill
 
Joined
Jan 1, 2002
Messages
7,246
Location
Washington, Michigan
Corvette
'67 Marina Blue Convertible
That stepped "extension" is necessary to position and reinforce the inside diameter of the composite donut; without it, the donut will disintegrate, the joint will loosen up, and you'll have a major exhaust leak. Some replacement pipes come with the extension already welded to the manifold end of the downpipe - if yours are like that, you don't need the separate extensions.

Don't forget the gasket between the spacer and the passenger side exhaust manifold, and install the spacer correctly - the flat side of the spacer goes to the manifold, and the beveled side goes to the donut.

:beer
 

brumbach

Well-known member
Joined
Mar 6, 2004
Messages
330
Location
Middleboro, KY
Corvette
1965 convertible
That stepped "extension" is necessary to position and reinforce the inside diameter of the composite donut; without it, the donut will disintegrate, the joint will loosen up, and you'll have a major exhaust leak. Some replacement pipes come with the extension already welded to the manifold end of the downpipe - if yours are like that, you don't need the separate extensions.

Don't forget the gasket between the spacer and the passenger side exhaust manifold, and install the spacer correctly - the flat side of the spacer goes to the manifold, and the beveled side goes to the donut.

:beer

Sounds like I'm okay. The allen pipes comes with the donut as you described. Couldn't wait for your response. Luckily I completed the project corrected and took it out for a run. Sunds great. I purchased the off road mufflers from them as well. Not sure the wife's gonna like to loudness as much as I but what the heck. Bill
 

LVMYVT76

Well-known member
Joined
Apr 21, 2006
Messages
664
Location
springfield, mo
Corvette
1976 medium blue
I hope you exhaust fits better than mine did. Drivers side fit ok, passenger side did not fit where it goes through the cross member. Called them up and no help. And they would not take it back.
 

LVMYVT76

Well-known member
Joined
Apr 21, 2006
Messages
664
Location
springfield, mo
Corvette
1976 medium blue
I also took the car and pipes to an exhaust company to have them put on, and maybe they could bend them to fit, they called and said it was not possible to fit them without hacking them up, something they don't want to do.
 

brumbach

Well-known member
Joined
Mar 6, 2004
Messages
330
Location
Middleboro, KY
Corvette
1965 convertible
I also took the car and pipes to an exhaust company to have them put on, and maybe they could bend them to fit, they called and said it was not possible to fit them without hacking them up, something they don't want to do.
Well mind didn't fit right either. My problem was on the driver's side. Passenger side fit like a glove. On the driver's side the rear pipe is too short. I tried to skimp on the union at both the muffler and the front pipe to make it fit. Boy was that a mistake. Seemed to work but came apart while I was driving it and the muffler went into the side of my rear tire and destroyed it. Didn't have a spare. $40 for the tow and $65 for a tire replacement. And the car is deadlined until I solve the problem. Allen is working with me at the time. I've sent pictures of the offending pipe and measurements, etc. Hope they'll be cooperative with me. I'm suppose to drive my daughter's friend in the homecoming parade at her college this Saturday. She's one of the candidate queens.

I'll let everyone know how things turn out.
 

brumbach

Well-known member
Joined
Mar 6, 2004
Messages
330
Location
Middleboro, KY
Corvette
1965 convertible
I also took the car and pipes to an exhaust company to have them put on, and maybe they could bend them to fit, they called and said it was not possible to fit them without hacking them up, something they don't want to do.
How did you finally get it fixed?
 

brumbach

Well-known member
Joined
Mar 6, 2004
Messages
330
Location
Middleboro, KY
Corvette
1965 convertible
Hope someone will help on this one. I've managed to get the driver's side hooked up. Everything is rock solid but I'm worried about the clearance between the inside of the tire and the muffler. Lost one tire to this project. Sure don't want to sacrifice another. I have less than 1" between the end side edge of the tire and edge of the muffler. I'm running 205 70 15R tires. Is this about right spacing or should there be more? Thanks -- Bill
 

LVMYVT76

Well-known member
Joined
Apr 21, 2006
Messages
664
Location
springfield, mo
Corvette
1976 medium blue
i HAVE THE ALLEN EXHAUST SYSYEM FOR SALE: 21/2 409SS, FITS 74 WITH DUAL EXHAUST AND HEADDERS. i had to have my exhaust man make a new exhaust system, called allen exhaust and they would not do anything, said they have made thousands and none had any problems!!
 
Joined
Jan 1, 2002
Messages
7,246
Location
Washington, Michigan
Corvette
'67 Marina Blue Convertible
Hope someone will help on this one. I've managed to get the driver's side hooked up. Everything is rock solid but I'm worried about the clearance between the inside of the tire and the muffler. Lost one tire to this project. Sure don't want to sacrifice another. I have less than 1" between the end side edge of the tire and edge of the muffler. I'm running 205 70 15R tires. Is this about right spacing or should there be more? Thanks -- Bill

I have 1" to 1-1/4" on both sides from the tire to the muffler with 205/75-15's on stock 6" rims on my '67; that's normal.

:beer
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Win Both Corvettes!

Win Both Corvettes and Get Extra Bonus Tickets Now!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Parts/Accessories:

Dead Center Foundation

Vetteskins

Advertise with the Corvette Action Center!

Partners

Top Bottom