28Q29U Plymouth Forum

General Category => General Discussion => Topic started by: Rusty on August 01, 2016, 11:49:57 PM

Title: Manifold gasket
Post by: Rusty on August 01, 2016, 11:49:57 PM
I have a leaking exhaust gasket.  I bought a new old from BEST and it looks like it has some type of graphite coating.  This goes on dry, correct?
Title: Re: Manifold gasket
Post by: Des28Qau on August 02, 2016, 08:20:04 AM
That is correct , sealers,puttys etc will not stick to the graphite. The graphite allows expantion movement (a little slip) with out tearing the gasket.
Cheers Des.
Title: Re: Manifold gasket
Post by: Rusty on August 02, 2016, 11:42:47 PM
It looks like there is machined recess in the block and manifold for alinement rings/sleeve.  Did the 29 come with them?  I have them in my 41 Chevy 216 straight 6. 
Title: Re: Manifold gasket
Post by: frankp on August 03, 2016, 08:46:45 AM
Rusty,

Yes, according to the parts book.  It is called a ferrule (use with production manifold)  Q, U, 30-U, PA, PN 5113.

frank
Title: Re: Manifold gasket
Post by: Gary 30U on August 12, 2016, 02:31:49 PM
Be careful, I bought a set of the exhaust manifold rings (ferrules) for my 30U off of Ebay. I set them aside as I was rebuilding the engine, and when I went to use them they were way to big, but advertised as for the 29-32 Plymouth. I didn't have them before and still don't have them. Just used a good one piece gasket from Olson's Gaskets and works fine.

Happy Motoring, Gary R.
Title: Re: Manifold gasket
Post by: racertb on August 14, 2016, 03:53:52 PM
I don't have them either.  Check with Tom Hannaford at Then and Now as well for gaskets.
Title: Re: Manifold gasket
Post by: imoore on August 16, 2016, 04:59:20 AM
Reason for these locating ring is the original gaskets were copper/asbestos gasket rings. Which fitted over the locating rings and held them in place when manifold was secured.
If you were to picture the engine porting as EIEEIE. The 2 ports(EI and IE) on each side had these gaskets which the centre exhaust pair had a conventional gasket.
The exhaust gasket you buy now whether in kit or singular form may not seal properly. Well on mine they didnt. I tried 3 gaskets before further investigation was in place.
You will find that the one piece gasket would not evenly clamp the manifolds to either block or exhaust manifold. Eventually blowing the gasket.

I had to machine my exhaust and intake manifolds to accommodate the One piece gasket.

I first set up the inlet manifold in a mill using the carby flange face as my holder. i faced the manifold until it was true and square.
I then machined the surface that seals the exhaust and intake together.  I then helicoiled the 2 holes in the centre on exhaust manifold so i could clamp the 2 manifold together with a gasket between.
Using the carby flange again i then faced the entire assembly true and flat. 

After doing this i can run the one piece gasket and have not blown since.

Hope this all makes sense and is of some use

Ian
Title: Re: Manifold gasket
Post by: Des28Qau on August 17, 2016, 04:49:15 AM
I expect that another design consideration of the exhaust manifold rings (ferrules) was to take the downward weight of the manifolds leaving the studs primarily for clamping. Still normal today for machine parts to be pined & heads and intake manifolds to have small ferrules for locating.
If possible I would use the rings , if a bit oversize in diameter you may be able to cut a bit out and close the ends together.

Just my few cents for consideration.
Des.