Topic: Dual Exhaust/Smithys Benefits - ?


len47merc    -- 04-27-2016 @ 4:03 AM
  Beyond look & sound, have any of you that have converted to dual exhaust and non-stock mufflers such as Smithys realized any performance improvement from the change(s)? If so, what improvements (fuel mileage, power, etc.) and in general how much?

If you converted to duals did you stay with the original size pipe diameter or change? If you changed - to what size?

Are any of you running Smithys or equivalent straight-thru glass packs on single exhaust systems and if so same question about performance.

Lastly, if you are running a single exhaust Smithys or equivalent how does a single Smithys sound to your ear? Too compressed/'spitty', too loud or robust and rich?

Thanks -

Steve

This message was edited by len47merc on 4-27-16 @ 4:15 AM


ken ct.    -- 04-27-2016 @ 6:20 AM
  I removed my mufflers and run straight pipes , used stock size TP,s to rear ,insert motor cycle (2 stroke) short 6" baffels in the ends of pipes. Not loud at all and never been stopped in 5-6 yrs of running that way by the POLice. lol Love um. ken ct. omo


len47merc    -- 04-27-2016 @ 6:31 AM
  Hey Ken - thanks for your reply. I will appreciate your and others' thoughts on the performance questions I posed though.

Steve

This message was edited by len47merc on 4-27-16 @ 6:32 AM


trjford8    -- 04-27-2016 @ 7:00 AM
  I've always used regular glass packs. Inexpensive and a good sound for duals.


len47merc    -- 04-27-2016 @ 7:23 AM
  Guys - I appreciate your sharing what it is that you use, but that does not address any of the questions regarding performance. Please advise in that regard - thanks in advance.

Steve


flathead4rd    -- 04-27-2016 @ 7:43 AM
  I don't think you will any performance improvement just by adding dual exhaust. At least nothing you can feel. It might help a little with cooling but most owners just do it for the sound. I use Brockman glass pack mufflers on mine but I'm running a very modified flathead. Love the sound.


TomO    -- 04-27-2016 @ 7:47 AM
  I did not notice any increase in power after installing headers and Smithys. The engine does run cooler though. The gas mileage seems about the same.

The pipes are 2" all the way back.

Tom


fordv8j    -- 04-27-2016 @ 12:17 PM
  I have Reds headers and dual smittys on both our 38,,,sounds great,but didn't help mileage,still around 15mpg,,no power increase


1934 Ford    -- 04-27-2016 @ 5:35 PM
  I have duals with two cherry bomb glass packs on my 34 Fordor, not loud but nice.
My 35 pickup has single exhaust with one cherry bomb glass pack. Nice sound too.
Our 34 phaeton had original style exhaust single exhaust and muffler. all I heard was the fan.
The original system was correct, but not as much fun to listen to when we were touring. I like to
hear the 221 cubic inches and 85 horses working. As for speed, who cares? The flathead V8 was
quick in it's day and still walks away from other cars of similar vintage on Glidden type tours, with either style exhaust.

1934 Ford's since 1972


len47merc    -- 04-27-2016 @ 6:49 PM
  Thanks 1934 Ford, fordv8j, Tom and flathead4rd - think you guys nailed all the considerations I was looking for.

The original muffler on my '47 is beginning to show some initial external telltale signs after 69 years. I am fortunate to have received a complete NOS original single-exhaust system with the car including a new muffler, all with the original tags still attached. Given the plan is to go for the Rouge Medallion Award (running gear) in Gettysburg I want to stay all original but if the muffler goes I was considering a temporary Smithys or equivalent on the single exhaust until the drive to PA and judging.

Like 1934 ford the '47 with the original muffler is so quiet it is hard to tell the car is running at times or if it cranked or not. The car owns quietest car awards in a couple of local clubs. Just thought for sxxts & grins perhaps it would be interesting to try a glass pack if you guys indicated the sound was rich and robust versus an over-compressed 'spit' on a single exhaust. If performance improvements existed then that would have been a bonus down the road, but this does not sound like it is the case.

Thanks to all -

Steve


rg130    -- 04-28-2016 @ 4:05 PM
  Regarding your question about dual exhausts and is there any subsequent increase in performance/horsepower, Hot Rod magazine ran an article in its June 1953 addition entitled "Dual exhaust systems - What can they do for '53 cars?" The article discussed installing dual exhausts on several (23) different stock new, or near new, cars using a dynamometer to test the vehicles before and after the exhaust changes. The first change included using the stock exhaust manifolds with dual exhausts and steel packed mufflers. The next change and retest involved dual exhausts with headers and steel packed mufflers. Not all of the cars could be tested with headers due to availability, but Ford was tested with them.

The Ford engine was a stock V8. The article indicated that the Ford engine had the highest exhaust back pressure of any car tested. By installing a dual system the back pressure was reduced substantially. The article also indicated that in all cases that back pressure dropped with the dual system, with a resultant increase in road horsepower.

Depending on the car tested the results varied. The installation of headers over stock manifolds differed and in some cases had no horse power increase.

The test indicate that the stock Ford benefited from the installation of duals but not headers. If you have an old copy of Hot Rod Magazine, June 1953, you may want to read the entire article.

This message was edited by rg130 on 4-28-16 @ 4:18 PM


len47merc    -- 04-29-2016 @ 5:08 AM
  Wow - rg130 - great memory in pulling that from your mental hard drive! I do not have the mag but believe you covered the fundamentals very well. Thanks for responding.

Fwiw, have a neighbor whose 'Blanche' nagged him mercilessly to remove his cherry bombs from his modified '56 Cxxxy and install quieter Magnaflows. For the time being prior to Gettysburg I may fit one of his bombs on the '47's stock single exhaust to get a feel for the sound and change back to the original muffler before EFV8 judging. Longer term, and based on all your inputs, collective experience and the objective results in the article rg130 quoted, if the original single exhaust is too 'spitty' and not deep and robust enough for my personal preference, I may convert over to, as Tom notes, 2" duals but still use the original manifolds - more research by me on how to do this most efficiently will be needed down the road before then.

Thanks all -

Steve


ken ct.    -- 04-29-2016 @ 5:27 AM
  Steve remember larger pipes louder sound. Stay with the stock smaller pipes if you want quitter dual system. Ken ct.


ken ct.    -- 04-29-2016 @ 5:29 AM
  Steve remember larger pipes louder sound. Stay with the stock smaller pipes if you want quitter dual system. Ken ct.


len47merc    -- 04-29-2016 @ 6:02 AM
  Thanks Ken - will do!

Steve


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