heat riser

Unknown

I have all I need to re-install the twin-H on my '53 Hornet. After taking apart the manifolds I find that there is a lot of play on the heat riser shaft, especially on the side with the counter weight. I am sure that it will leak exhaust if installed as is. Is there a bushing or seal that goes there, if so what do I need? I could remove the heat riser completely and close the shaft holes; how would that work? Any advice would be appreciated.



Jim G

Unknown

I don't know if a bushing was originally used there, but one of brass would be prefered in this application. If you were to remove the heat riser altogether, cold starts may suffer a tad. However, if you are in southern CA, that may not be an issue. If the play is marginal, it will probably be audible on start up but should subside as the engine warms.

brnhornet52*

Hi Jim,

If you have substantial play between the heat riser shaft and manifold, you could get a bushing installed by a competent machine shop to take up the play. Replacement heat risers are virtually unobtainable, unless you would get a new manifold with good heat riser. You could also remove the heat riser as you said, and have a machine shop drill and tap the manifold for plugs.

I dont really think that running the car without the heat riser will really affect the performance. Mine has plugs and it runs fine, but requires a little longer warm up time in colder temps.

SuperDave

I drilled out my manifold and installed a pair of bushings from Ace Hardware. Bought a steel dowl to fit the bushings from the same store, cut to length, then reinstalled the flapper. I did have to mig weld the flapper. A hacksaw slotted the end for the spriing. The weight had to be drilled out and repinned.The pin that held the spring was also rusted off, so I drilled and installed a roll pin. Probably took two to three hours with common shop tools with the exception of the welder. The flapper could have been brazed but I chose the welder. Nice and quiet and warmups are quicker...and it's back to original.

Dave W.

dave s

Jim G wrote:

I have all I need to re-install the twin-H on my '53 Hornet. After taking apart the manifolds I find that there is a lot of play on the heat riser shaft, especially on the side with the counter weight. I am sure that it will leak exhaust if installed as is. Is there a bushing or seal that goes there, if so what do I need? I could remove the heat riser completely and close the shaft holes; how would that work? Any advice would be appreciated.



Jim G

I would just drill and plug them. I live in PA, run my cars in the winter and never had warm up problems with any of my 3 hornets, two have 7X manifolds without heat riser and other had Clifford headers.