I've read a lot of old threads regarding the sound difference with and without a factory crossover and off road mufflers, most agree with a crossover and original factory mufflers it is noticably quieter. The consensus is that new repro off road mufflers don't sound the same - louder and "raspier". Does the crossover make a noticable difference with the new off road muffler?

 

I think it makes a difference----------------AND I DO NOT LIKE THE CROSS OVER!
The last year was 62, then all cars, regardless of engine option, had dual exhaust WITHOUT a cross over, which I think sounds better.
MANY people add an H or X pipe when having a new exhaust system installed. Once you have to pull a transmission, and fight the X/H pipe, you will remove it and throw it in the river!

 

I know you're asking about a C1 but this C2 install may help ==> Click Here

 

I'm curious about the stock setup for '57 with the current off road mufflers available. I've heard the difference with and without the intake manifold block off and there's a difference

 

Nice clean looking installation. Was there a performance difference that was noticeable?
John

 

Mine is unique, but may answer some questions asked.

On my 62, I have full length headers, then bolted to them are short ~6" reducers, and then another flange to the 2-1/4" exhaust pipes. After about 5 years driving it with this configuration, I decided to reduce the rap from the unknown brand turbo mufflers, and install a "H" pipe. I put it in connecting from one reducer to the other, with a 2" pipe bent to clear the Muncie trans in-between the 2 reducers.

I immediately felt an increase in mid range torque, and a welcomed decrease in harshness of the tone from the exhaust, and a slight reduction in overall exhaust "noise".

I can remove the 12 bolts (3 per the 4 flanges, 2 flanges per exhaust side), with the welded in H pipe assembly, for R & R of the trans.

I subsequently (in 2006) installed a different trans (MY6 - 4 speed OD), which forced me to relocate the H pipe forward of the trans main case, so the crossover pipe setup was revised (see above picture).

Since then, this past Dec., I had the old unknown mufflers replaced with the same size Dynomax Turbo mufflers, which then resulted in a slightly louder tone, until they were "seasoned in" after a month or so. A slight increase in top end power was felt (old mufflers after removal, had some significant rust coming out of them, so it was past "time") .

Hope this helps,
Plasticman

 

Correct-------------------------- for carbureted engines. BUT, FI engines DO NOT HAVE an exhaust crossover in the intake manifold. Thus, for FI engines there is no way to make a comparison with and without the manifold block off plates.

Now, one more of my oppositions for the 57-62 exhaust cross over pipe. If it is ever necessary to drop the pan, that cross over pipe has to be removed. If it has been on for an extended period, and the joints have become seized, it can be a challenge to remove the cross over. No thanks!

 

There is a factory built in cross-over via the intake manifold.

 

Yes, but if it has been blocked (as on FI engines from the factory), or due to heat (carb percolation) issues, then a H-pipe is definitely a plus.

Besides, it is far more effective anyway, due to the larger volume of gases it handles (much larger diameter).
I installed one on a SBC that still had the crossover passage, and it still showed mid-range torgue gains, and reduced harshness in the exhaust note.

Plasticman

 

That was for heating the carb base, right? About a 1" square port.

Not like a 2" down pipe connecting pressure from 8 cylinders.











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Tom, FYI, a few years back I had to remove the oil pan from my FI '60 which has the cross over pipe (customer FI which had been rock tumbled caused my engine to swallow a pebble... long unpleasant story....). Anyway, main point is that I didn't have to remove the cross over pipe. Unbolting the head pipes from both exhaust manifolds was all I had to do to gain removal clearance.

Jim

 

Yep, that is correct, but the crossover still has to be moved out of the way to drop the pan.

 

It really wasn't a big deal to drop the pan . The crossover pipe wasn't a factor.

 

The exhaust note sounds good using the crossover pipe. Better mid range performance a plus.....what I was looking for. Thinking it's time to head over to the muffler shop to have this done on my car.
John

 

I didn't notice any difference in performance but sound was what I was looking for and made a world of difference (to me anyway)