The Stovebolt Site Forums The Shop Area Engine Shop Splitting exhaust on a 235

I decided I'm going to split the exhaust on my 235 while the trucks basically apart for restoration. I can get Fentons for around $250 but saw tube type selling for $132. Weigh in guys....pros/cons?

Thanks

Fentons are reproduced castings, but work as originals. Tubes are fine too. Just depends on if you want the period look or not.

Tube headers burn out, and/or leak at the gasket area where they meet the head. They also increase under hood temperture and noise. The cast iron ones should work better and last longer.
Jerry

What is the advantage of splitting the exhaust without going dual carbs?

I am sure there is some but what percentage power increase is associated with the dual exhaust as opposed to dual carb and dual exhaust

The firing order on a inline six is 1-5-3-6-2-4. With a split exhaust, there is 240 degrees of crankshaft rotation between each exhaust pulse in the manifolds and pipes. The exhaust pulses in the manifolds go front-rear-front-rear, etc. There's no crowding of exhaust pulses, and plenty of room in each pipe for the flow from individual cylinders. Spliting exhaust on an I-6 actually makes some sense. Dual carburetion is just eye candy unless a great deal of engineering and tuning goes into the process.
Jerry

They sound real nice, too.

Here is old HRM test on Stovebolts:
1955 HRM tests on a 261

And some dyno test results from Leon:
Leon' dyno test resulus

Hoyt

Thanks Jerry
As always, the detail of your knowledge is impressive.

I would like to go with a dual exhaust at some point. The thought that I would have to go dual carb as well to get the benefit always turned me off
(tuning one carb is enough work for me)

I would still need to get or build a set up to warm the intake though right. As I would lose my heat riser

Rich

If you can find an original Corvette 235 dual manifold, it's got the same heat riser system the single-pipe manifold uses. They're scarce and pricey, however. A good welder can build a split exhaust setup from a single, but it's not as effective as a factory or aftermarket dual system.
Jerry

For this reason I believe the ones I have made would show little or no difference in performance compared to Fenton’s and/or the Corvette version and probably have better cold start driveability than the former. D.I.Y. info here.