1959 big block engine swap, corvette exhaust

[grumpyvette]

OK, since the topic here is exhaust systems, I have a question for the any of the exhaust experts. I have a ’59 Corvette with a 572/620 crate motor. I could not find any ‘D’ port headers, much less ones that would fit in this car, so I built a set of equal length (32”) 2” diameter primary headers that dump into a 3” exhaust. The mufflers that I currently have are perforated tube type and offer very little in the way of noise reduction. I would like to have something quieter, but none of the commercial “box” type chambered mufflers that I have found will fit in the limited space. The current mufflers are 4” in diameter, but I could probably fit something like a 5” x 7” oval shape in the available space. Anyone have a suggestion on what type of muffler I could buy (or build) to make this beast quieter?

first congratulations on what looks like a very nice custom built car frame, for what is obviously a car you put a good deal of time and effort into building.


your limited room is obviously a problem, distance and volume to expand and cool the exhaust helps dissipate its strength, you might want to measure very carefully to find exactly what the largest muffler size could be , because in this case size and distance do mater
the NOISE you hear is the result of repetitive high pressure pulsed exhaust,as the cylinders, release high pressure exhaust gases into a confined space the headers and tail pipes, you MUFFLE the sound by destroying the individual PULSE STRENGTH, and velocity and spreading out the exhaust pressure to an even flow as it exits,
installing an (X) pipe will effectively blend alternate pulses, there are (X) PIPE DESIGN MUFFLERS

allowing the pulse to expand and loose energy in a muffler after an (x)- pipe blending and smoothing the exhaust pulse also helps, as it effectively increases the area the exhaust pulse can expand into,

viewtopic.php?f=56&t=1503&p=37131&hilit=mufflers#p37131

viewtopic.php?f=56&t=495&p=15640&hilit=mufflers#p15640

viewtopic.php?f=56&t=2916&p=10987&hilit=mufflers#p10987

viewtopic.php?f=56&t=45&hilit=coke+can

viewtopic.php?f=56&t=1166

 

[philly]

looks like an american shifter, good choice, this looks like a really well thought out setup. about the exhaust, there are lots of oval and round mufflers thatll fit back there, in fact spin tech has some of the nicest sounding mufflers in the industry... if you cant find what you're looking for out of their varied selection, call them and they will make mufflers just for you exactly the size you need with the type of sound resonance you want for not too much more than a regular muffler would cost from them.

http://www.spintechmufflers.com/muffler ... at_14.html

888*550*7746 or 951*360*2474

 

[grumpyvette]

Grumpy:
Thanks for the information.
I really don't have room for a true 'X' pipe, but I could fit a crossover 'H' pipe in the location shown in red below. I would be about 7" in length. Do you think that would help?

yes a properly installed full diam. (H) pipe should make some improvement Id imagine if you record the exhaust sound before and after the (H) pipe install youll be able to measure the difference and reduction in sound with a BD meter but you may only notice a change in tone with your ears

I would think that careful measurement and an (X) would fit

and yes, swapping out the current, smaller tubular mufflers that resemble old style glass pack won,t hurt