Once again I need to replace the exhaust packings on my daily driver 61 80hp. This is the third time in fours years. The exhaust system is the stock logs and single exhaust crossover with a repro muffler. The hanger is stock. Nothing is moving around as far as I can tell. I've always retightened the exhasut after few hours of run in time just like their directiosn say to.

IMO these packings are too darn soft to last any length of time. I've been very pleased with most of my purchases from Clark's, but these donuts are not one (or 6) of them. Page 7A of their catalog really talks them up as the bees knees. I'm not impressed with them one bit.

I've got some other ones from another vendor that appear to be made from a more dense material. I'm going to try them this time.

Has anyone else had problems with these packings breaking down prematurely?

Andrew,

Unfortunately, none of my engines ever stay in the car long enough to find out. I like the way they seal, but they do tend to come apart whenever I pull the engine out.

Cliff Tibbitts
Nicholasville, KY
CORSA, CKCE, Derby City Corvairs
66 Monza, 140/4sp

I would say that I have had good service with those Clark's packings but with perfect surfaces. If you have rust scale on your logs or on your tubes, I would expect them to disintegrate after compression. I would point out that the asbestos ones would fail, too, under similar circumstances. Some that might hold up better are the original ones with the steel band on the outside. Anyway, try grinding your logs clean of any scalus and getting any debris out of your tubes so whichever you choose to use seat properly.
Crawford

I've never had one fail but there's always a first time. FWIW, when I install a log, I tighten the clamps then tap the retainers with a hammer to seat the donuts then retighten the clamps. I keep doing this dance until the nuts stay tight after tapping the brackets - this tells me the donuts are full seated and yes I clean everything until the surfaces are smooth. Works for me

Craig N. Coeur d'Alene ID.
66 Black Monza 4dr, 4.2L V8 49k
61 Seamist Jade Rampside 140 PG
65 Canadian Monza 4dr 110/PG 40k
66 Sprint Corsa convt - First car! Re-purchased 43 years later
2+2 gnatsuM 5691

+17 Tons of parts

I got my last ones at a FLAPS. But if I were you, I'd be really tired of having to replace them so much. Why not go for the aluminum ones that some of the vendors have?

Kurt
1966 Monza convertible
140 - 4 speed

Pittsburgh,Pa.
CORSA MEMBER
WPCC - Western Pennsylvania Corvair Club - 2018 National Convention

With headers they dont last long,,they seem to disinigrate very easy,,I like stock ones alot better and they last alot longer.

davemotohead Wrote:
-------------------------------------------------------
> With headers they dont last long,,they seem to
> disinigrate very easy,,I like stock ones alot
> better and they last alot longer.

I used Clark's aluminum packings for the header on my '66. Been sealed tight since 2007.

David Clamp


1965 Corsa convertible - 140 4spd/3.55/AM-FM

2013 Mustang GT convertible - 5.0, 6spd auto, Procharger i-1

2003 Miata SE - 6spd manual (wife's toy)

"Victory is mine!" - SG

Norman, OK

No problems here with the graphites either. I've actually re-used them before, even tho you are not supposed to....

Are you over-tightening the exhaust? Surfaces clean as mentioned?

--------------------------------
Ronnie
Southern Maine.
www.dirigocorvairs.net
66 Corsa Convertible, 140, 4sp.
65 Monza Convertible, 110, PG.




It doesn't leak, it's marking it's territory.

A mirror is a reflection of the miles travelled.

Never had a problem with them. Just put 135,000 on my 95hp Van engine before tear down. I don't know what conditions others have, but I have found engines where the exh. tube from the head can be burnt away. This is the part the exh packing slips on.
I still have quite a few sets of new OEM packings. Kinda went crazy buying them years ago. However I like using the asbestos free Clarks these days.

corventure Dave Wrote:
-------------------------------------------------------
I don't know
> what conditions others have, but I have found
> engines where the exh. tube from the head can be
> burnt away. This is the part the exh packing slips
> on.

I agree, you'll notice shortened life if the part of the tube that extends into the manifold isn't in good shape. Same at the crossover or u-tubes.

I use a block of wood/hammer to seat the manifold before tightening and then after run-in, I do it again.

Dan Kling
1961 Greenbrier Deluxe, 110 HP, 4spd, 3.89 stump puller
1963 Spyder Coupe, restored, converted to 4spd Saginaw
1967 UltraVan #299, The migration has begun, we're on the road again......Save the Whales!

Photos of our Greenbrier, UltraVan and work-in-progress @

[www.flickr.com]

I think that I have 1 or 2 sets of NOS ones....

That being said - never a problem with the Clarks ones on my Van or Convertible. Ran headers on the Corsa, so it had aluminum packings.


Eric P.
DeWitt, IA

While the exhaust was off the first time I had to drill out the studs and retap. One of the ears broke off and I had to build it back up with weld. After grinding, drilling and tapping it you can't tell that it's been modified. I even belt sanded the flange flat, and used a 1.25" drum sander to smooth out the pits in the bevel. I don't think the surface condition of the parts is to blame.

I won't have apart until much later tonight after work...have to wait for it to cool down after the drive home. I expect that it's just the 2 larger pipe packings and not the 6 tube packings, just like the last couple of times. I'm glad that I used stainless studs with double brass nuts. After the first time, I made sure I always have at least one set of packings in my stash at all times.

In the assembly manual, I remember seeing a short pair of tubes that sleeved inside the donut between the pipe and the logs. I've seen these on a few engines that I've torn apart....most of them rusted into bits. Is there a reason that none of the vendors have these? Are they not needed? Something tells me that these loose sleeves were needed on factory pipes to center the packing but are already welded in the reproduction pipes. Any ideas?

Yes, those are necesssary, but they don't extend past the packing.
Crawford

My exhaust packing loss was due to a poorly shaped x-over, the two 90 degree bends weren't pointing in the same direction. The result was I had to struggle bolting it onto the logs. After i used a torch and adjusted one side, it worked alright.
The cross-over had no road damage. It just came that way as near as I can figure.

Noah
Milwaukee

Andrew, I had the same experience with my Greenbrier. It seemed to be related driving it year round. I had to replace them in the spring two years in a row before I sold it.

Sam Russell
Durham NC
1962 Monza Wagon Ted Brown EFI Gen II
1964 Spyder coupe