Unbelievable
#1
Drifting
Thread Starter
Member Since: Mar 2001
Location: St. Louis, Missouri
Posts: 1,411
Likes: 0
Received 2 Likes
on
2 Posts
Unbelievable
I was there when it happened and I still don’t believe it:
This started out as a leaking rear Y-pipe. I bought a used rear Y-pipe from a local vendor (supposedly from another ’79 model) which ended up being an aftermarket pipe that didn’t fit. So, “while I was at it”, I figured “why not just go with a dual exhaust?” I couldn’t find a muffler shop that would do it locally so I ordered a kit from a reputable dealer that fabricates their own kits. Shouldn’t be much of a problem for a competent shade tree wrencher like myself, I thought.
Last Saturday, I was attaching the first exhaust section to the passenger side exhaust manifold. I was tightening the last stud when I noticed “hey, this thing’s getting’ kinda wobbly…”
Well, I guess all things happen for a reason. It’s better to discover this problem while the car is up on jack stands, as opposed to later on down the road. The only cause I can think of is that maybe the heat riser, which is normally installed between the manifold and exhaust, wasn’t opening fully and the manifold got hot, then cooled again, again and again.
For most of us, we would see this as an opportunity to slap on a pair of headers. However at around $300 for a good pair plus having to cut up the new exhaust to accept a collector and a flange, this is getting beyond my budget. I have $300, I just don’t have $300 in mad (Corvette) money.
Most will just roll their eyes and consider this a trivial setback. If this were an early ‘70s shark, I’d be more dedicated to it but I no longer have the time and money to pour into this hobby. After I get this job done (hopefully, someday) I need to sell this car and move on to a cheaper hobby – maybe handmade toothpicks.
This started out as a leaking rear Y-pipe. I bought a used rear Y-pipe from a local vendor (supposedly from another ’79 model) which ended up being an aftermarket pipe that didn’t fit. So, “while I was at it”, I figured “why not just go with a dual exhaust?” I couldn’t find a muffler shop that would do it locally so I ordered a kit from a reputable dealer that fabricates their own kits. Shouldn’t be much of a problem for a competent shade tree wrencher like myself, I thought.
Last Saturday, I was attaching the first exhaust section to the passenger side exhaust manifold. I was tightening the last stud when I noticed “hey, this thing’s getting’ kinda wobbly…”
Well, I guess all things happen for a reason. It’s better to discover this problem while the car is up on jack stands, as opposed to later on down the road. The only cause I can think of is that maybe the heat riser, which is normally installed between the manifold and exhaust, wasn’t opening fully and the manifold got hot, then cooled again, again and again.
For most of us, we would see this as an opportunity to slap on a pair of headers. However at around $300 for a good pair plus having to cut up the new exhaust to accept a collector and a flange, this is getting beyond my budget. I have $300, I just don’t have $300 in mad (Corvette) money.
Most will just roll their eyes and consider this a trivial setback. If this were an early ‘70s shark, I’d be more dedicated to it but I no longer have the time and money to pour into this hobby. After I get this job done (hopefully, someday) I need to sell this car and move on to a cheaper hobby – maybe handmade toothpicks.
#2
Le Mans Master
You can get shorty style headers that will bolt right in place of the stock manifolds
Should be around $80-$100, check Summit and Jegs.
Should be around $80-$100, check Summit and Jegs.
#3
Melting Slicks
Member Since: Oct 2004
Location: Knoxville Tennessee
Posts: 2,662
Likes: 0
Received 6 Likes
on
5 Posts
Sorry you had this problem. Looks like it had been cracked for awhile You could probably pick up a used manifold somewhere cheap. Get rid of the heat riser altogether; they cause more problems than the are worth. I love my '79; it has been a lot of labor, but a labor of love.
Bernie
Bernie
#4
Drifting
Thread Starter
Member Since: Mar 2001
Location: St. Louis, Missouri
Posts: 1,411
Likes: 0
Received 2 Likes
on
2 Posts
Yes but I assume that the shorties won't attach to my existing pipes.
Originally Posted by RedBad1979
You can get shorty style headers that will bolt right in place of the stock manifolds
Should be around $80-$100, check Summit and Jegs.
Should be around $80-$100, check Summit and Jegs.
#5
Drifting
Thread Starter
Member Since: Mar 2001
Location: St. Louis, Missouri
Posts: 1,411
Likes: 0
Received 2 Likes
on
2 Posts
Well, the heat riser has been a point of contention. Corvette Central says the passenger side pipe is cut shorter to compensate for the heat riser but I couldn’t get the pipe to align with the cross member when the heat riser was in place, so I removed it, as shown in the photos.
Pretty crude way of getting the car warmed up quicker to reduce emissions. I think it took Detroit a decade or so to learn how to make cars burn clean without using all of these horsepower-robbing band-aid approaches.
Pretty crude way of getting the car warmed up quicker to reduce emissions. I think it took Detroit a decade or so to learn how to make cars burn clean without using all of these horsepower-robbing band-aid approaches.
Originally Posted by BerniesVette
Sorry you had this problem. Looks like it had been cracked for awhile You could probably pick up a used manifold somewhere cheap. Get rid of the heat riser altogether; they cause more problems than the are worth. I love my '79; it has been a lot of labor, but a labor of love.
Bernie
Bernie
#8
Le Mans Master
Originally Posted by Neo Fender
Yes but I assume that the shorties won't attach to my existing pipes.
#9
Drifting
Thread Starter
Member Since: Mar 2001
Location: St. Louis, Missouri
Posts: 1,411
Likes: 0
Received 2 Likes
on
2 Posts
OK, thanks - I'm just concerned about the flange location being different than the OEM manifolds. Unless they're pretty close, the pipes may not align.
Originally Posted by RedBad1979
The shorties should bolt in - they have the same 3-bolt flange as the manifold.
#10
Le Mans Master
Originally Posted by Neo Fender
OK, thanks - I'm just concerned about the flange location being different than the OEM manifolds. Unless they're pretty close, the pipes may not align.
#11
Burning Brakes
Now you have seen firsthand why airplanes sometimes just drop out of the sky, or a race car will slam into a will for no obvious reason...or worst yet mysteries highway accidents with big rigs...etc.
Metal fatiques and will fail. This is why aircraft parts are tested, inspected, and replaced after a certain cycle period even if the part looks good to the naked eye.
Good think it happened at home on the jackstands. Imagine if that pipe snapped and dropped down at 75 mph!
Metal fatiques and will fail. This is why aircraft parts are tested, inspected, and replaced after a certain cycle period even if the part looks good to the naked eye.
Good think it happened at home on the jackstands. Imagine if that pipe snapped and dropped down at 75 mph!
#12
Advanced
Member Since: Oct 2005
Location: Gummersbach/Germany NRW
Posts: 83
Likes: 0
Received 0 Likes
on
0 Posts
I have shorties in my cobra. You might need a special socket when removing your sparkplugs. If they don’t match correctly, I recommend using a stainless flex adapter tube, worked great for me. Other than that, they’re fine.
As far as your old manifold goes, you must of had some serious spitting or hissing noises, no?
As far as your old manifold goes, you must of had some serious spitting or hissing noises, no?
#13
Drifting
Thread Starter
Member Since: Mar 2001
Location: St. Louis, Missouri
Posts: 1,411
Likes: 0
Received 2 Likes
on
2 Posts
Amazingly, no. I’ve had exhaust leaks on other cars and could always hear them. This was a surprise.
Originally Posted by wayne64
As far as your old manifold goes, you must of had some serious spitting or hissing noises, no?
#16
Drifting
If you replace the exhaust manifold with a new/used one and you're worried about the extra space that's left after you remove the heat riser you can have someone just braze the heat riser butterfly so it stays open, or remove the butterfly from the assembly completely.