7X Exhaust Split removes heat riser

ratwasp

I picked up a repro 7X exhaust split manifold (wasn't cheap) and now that I look at the set up, it eliminates the heat riser I believe? Is this right?

Glowplug

Correct /// no heat riser

Lee ODell

Wrong. The repo 7X exhaust split manifold does not eliminate the heat riser. The heat riser can still work with it.

The original 7X exhaust split manifold will not bolt up to a stock exhaust manifold. The real 7X exhaust manifold does not have heat riser and the exhaust begins splitting in the exhaust manifold. The split divider in manifold and splitter extension meet. The repo 7X splitter divider is further into the repo to allow the the heat riser butterfly to open.

The picture you show has heat riser. The 7X manifold exit flange is shorter about where the butterfly pivot pin location is on stock maniforld.

I sold my original 7X manifold and splitter about a year or two ago.

Lee O'Dell

PAULARGETYPE

I STILL HAVE A HEAT RISER IN MINE AND IT WORKS FINE I HAVE INSTALLED 4 OR 5 OF THEM WHEN DANNY BARIER MADE THEM ALL OF THE ONES I INSTALLED HAD THE HEAT RISER STILL IN THE MANIFOLD 

StillOutThere

Why would anyone want to keep the heat riser when adding a 7X-style splitter casting?   The whole idea here is to eliminate restrictions.  Spending money to gain no advantage while at the same time adding the additional expense of a twice-pipes exhaust system doesn't make any sense.   You might as well weld a phony second chrome exhaust tip to the left side of the rear bumper.   Much cheaper and same performance.

Chris Smith

If a factory look is not important, tube type headers will outflow the best log type factory manifold by a bunch. There has to be at least 30 horsepower waiting to be unleashed with aftermarket headers and mufflers even over the rare 7x system. I am in California so there is zero reason to have a heat riser in any case. I have two 54 Hornet Coupes, one with a factory 7x engine and exhaust and the other car has a 7x modified 308 with long tube headers that I had ceramic coated for long life and heat containment. They are both good looking systems. If a factory look is important and so is performance, you could have the stock manifold extrudehone ported and nobody will know but you and your wallet.  

Glowplug

Correct /// no heat riser

My BAD!!!! --- the original 7X adapters did not have the heat riser. Quite a few years back I visited the fellow who was the mold maker for this part.  At that time the original castings were being evaluated. The examples I saw DID NOT have the heat riser installed per factory pieces... so, I assume since the original mold maker sold the molds, the folks who purchased the molds them added the heat-riser?  No foul, agree with Wayne and Chris' comments ... falls into the category of adding fox tails to an antenna... if a under hood visual is what you are paying for vis a vis a performance pop ...

Ol racer

FYI
I removed the whole heat rise baffle in mine since I Dont drive the Car in the Winter.  The modern 7x Adapter is a very nice way to install duals but as mentioned above, the 7X Exh manifold was larger flowing inside than stock with no heat riser, so the Adapter alone will provide only marginal performance. It is real nice to see Duals on Hudson's like the other Cars of the 50's though ....

ratwasp

Here are some pics of my split manifold. The gent who sold it to me said IT BOLTS TO THE BASE OF A STANDARD HUDSON (48 TO 54) MANIFOLD and I WILL HAVE TO REMOVE THE HEAT RISER AS IT WILL HIT THE NEW EXTENSION?

Lee ODell

ratwasp
Thanks for the photos.
Take a look at the inside of the flange that bolts to the exhaust manifold. You will see the divider starts about an inch below the flange. This undivided area is there to allow the heat riser butterfly to open. Please post a picture showing the entrance to the split manifold to show what I am trying to explain. That will help clear up concerns.
You can still remove the heat riser if you like. Some just tie the butterfly open. Others remove it completely drill, tap and plug the butterfly shaft holes. I tried hammering in plugs but they eventually blew out with heat expansion and contraction.
I have tried to copy and paste photos to this post of the pictures I have without success.

Lee O'Dell

RL Chilton

ANy pics you want posted, Lee, you can send them to me and I will be happy to post.  

ratwasp

Lee, here is a photo of the manifold flange:

lostmind

ANy pics you want posted, Lee, you can send them to me and I will be happy to post.  

I also cannot cut and paste to this forum. I asked about it before, but no comments on it.

Are the moderators the only ones that can cut and paste , or is there something in my browser or firewall.

I gave up trying to share things.

Lee ODell

ratwasp
You do not have to worry. The divider is below the flange surface. Thanks for sharing the picture. The real 7X has the divider even with the flange surface with a special gasket that not only seals the flange but also seals the divider.

Have fun with it. The repo also is closer to the oil pump than the 7X.

Thanks for the offer Russell and lostmind. I think something is wrong with the computer because I used to be able to send pictures. I know the pictures of the manifolds in my folder were posted in as previous message showing the differences between 7X and repo as well as the 7X exhaust manifold some time ago. I wouldn't know how to find them.
Lee O'Dell

dwardo99

I just wired the heat riser open on my Hornet because it was not assembled property (not by me) and it wasn't opening fully. I do find the car is a little doggy before it gets some heat in it but it isn't anything major. In summertime it would probably not be noticeable. If I ever have the need to pull the manifolds off I will eliminate it entirely because I'm convinced it presents a significant restriction.