The Ford Barn

daoust · 12-01-2011, 02:34 PM

My '47 Ford has dual exhaust. I'm considering going back to the original single exhaust configuration. Is there any disadvantage to doing so? Any performance differences to expect?

Thanks.

Dutchtreat · 12-01-2011, 02:38 PM

I would think that you would get better mileage with the dual exhaust,as it allows the engine to breath better. You do need to keep your foot out of it to pickup mileage,but a good way to do that is to use a Vac. gauge to drive by.

Vic Piano · 12-01-2011, 02:52 PM

Any performance loss would most likely be negligible however, dual exhaust do let the Flathead breath better and run a little cooler. Your biggest loss (in my opinion) would be the sound created by the duals, especially if you’re running steel packed mufflers or no mufflers at all.

Clem Clement · 12-01-2011, 02:52 PM

Can you talk more about driving by vacuum gauge. I had on on my Model A, but I don't think it changed my driving habits. Clem

Ol' Ron · 12-01-2011, 04:37 PM

If you were to read JWL's book you'd find that dual exhaust don't add much if anyt5hing to performance. Best book on the market today.

daoust · 12-01-2011, 04:42 PM

Sponsored Links (Register now to hide all advertisements)

Ron, educate me please...I'm new to this. Who is JWL and where do I find his book?

Thanks.

4dFord/SC · 12-01-2011, 04:42 PM

Probably no noticeable loss of performance, but a definite decrease in coolness and your status as a car guy

daoust · 12-01-2011, 05:01 PM

Loss of engine coolness would be bad. Loss of personal coolness is mathematically impossible because I dont have any which is the same as my status as a car guy. The truth hurts.

jdl · 12-01-2011, 05:09 PM

Quote:

Originally Posted by daoust

Ron, educate me please...I'm new to this. Who is JWL and where do I find his book?

Thanks.

Here's the link.. (excelent info book)

http://www.flatheadv8.org/jwlfacts.htm

bobH · 12-01-2011, 05:12 PM

Do as Ron says... There is no 'technical' advantage to duals on a 'normal' street-driven car. Pretty hard to dispute the data published by JWL. As for sound, I've tried ONE smitty (single exhaust) on my two cars, just as someone else posted here awhile back. It gives a definite flathead sound - not real loud. JMO

daoust · 12-01-2011, 05:43 PM

jdl: thanks for the link.

Clem Clement · 12-01-2011, 07:31 PM

Facts is not necessarily helpful. When we were doing my son's 64 1/2 Mustang we wanted duals. He sold the idea to his Mom based on my saying it saved gas money. When we were working on his modern Chevy truck the arguement still carried the day (That took a little more imagination as Virgina doesn't allow us to fix exhaust systems. My bud worked for Speedy muffler and he was able to find an obscure truck model offered only in Callifornia where duals were factory installed.

Ol' Ron · 12-01-2011, 08:53 PM

I love the sound of duals, a set of glass packs and an L-100 cam. Brings a smile to my face.

Shadetree · 12-01-2011, 09:56 PM

You can always tell the guys that grew up with these cars. The first thing I did when I got my `35 running was to install dual Smitty's with pennies in the heat risers. Wasn't concerned about horsepower or efficiency. Just wanted that sound...

Shadetree

12-01-2011, 02:34 PM	#1
daoust Member Join Date: Nov 2011 Location: Stratham, NH Posts: 66	Dual Exhaust My '47 Ford has dual exhaust. I'm considering going back to the original single exhaust configuration. Is there any disadvantage to doing so? Any performance differences to expect? Thanks.

12-01-2011, 02:38 PM	#2
Dutchtreat Senior Member Join Date: May 2010 Location: DeKalb, Illinois Posts: 103	Re: Dual Exhaust I would think that you would get better mileage with the dual exhaust,as it allows the engine to breath better. You do need to keep your foot out of it to pickup mileage,but a good way to do that is to use a Vac. gauge to drive by. __________________ 1st. Cav Trooper Operation Garry Owen F Troop 9th Cav'71-'72

12-01-2011, 02:52 PM	#3
Vic Piano Senior Member Join Date: May 2010 Location: Odessa, FL Posts: 7,611	Re: Dual Exhaust Any performance loss would most likely be negligible however, dual exhaust do let the Flathead breath better and run a little cooler. Your biggest loss (in my opinion) would be the sound created by the duals, especially if you’re running steel packed mufflers or no mufflers at all. __________________ Imagination is more important than knowledge.

12-01-2011, 02:52 PM	#4
Clem Clement Senior Member Join Date: May 2010 Location: Fairfax, VA Posts: 3,393	Re: Dual Exhaust Can you talk more about driving by vacuum gauge. I had on on my Model A, but I don't think it changed my driving habits. Clem

12-01-2011, 04:37 PM	#5
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,862	Re: Dual Exhaust If you were to read JWL's book you'd find that dual exhaust don't add much if anyt5hing to performance. Best book on the market today.

12-01-2011, 04:42 PM	#6
daoust Member Join Date: Nov 2011 Location: Stratham, NH Posts: 66	Re: Dual Exhaust Sponsored Links (Register now to hide all advertisements) Ron, educate me please...I'm new to this. Who is JWL and where do I find his book? Thanks.

12-01-2011, 04:42 PM	#7
4dFord/SC Senior Member Join Date: May 2010 Location: Columbia, SC Posts: 1,579	Re: Dual Exhaust Probably no noticeable loss of performance, but a definite decrease in coolness and your status as a car guy

12-01-2011, 05:01 PM	#8
daoust Member Join Date: Nov 2011 Location: Stratham, NH Posts: 66	Re: Dual Exhaust Loss of engine coolness would be bad. Loss of personal coolness is mathematically impossible because I dont have any which is the same as my status as a car guy. The truth hurts.

12-01-2011, 05:12 PM	#10
bobH Senior Member Join Date: May 2010 Location: so cal, placerville, vegas Posts: 1,394	Re: Dual Exhaust Do as Ron says... There is no 'technical' advantage to duals on a 'normal' street-driven car. Pretty hard to dispute the data published by JWL. As for sound, I've tried ONE smitty (single exhaust) on my two cars, just as someone else posted here awhile back. It gives a definite flathead sound - not real loud. JMO

12-01-2011, 05:43 PM	#11
daoust Member Join Date: Nov 2011 Location: Stratham, NH Posts: 66	Re: Dual Exhaust jdl: thanks for the link.

12-01-2011, 07:31 PM	#12
Clem Clement Senior Member Join Date: May 2010 Location: Fairfax, VA Posts: 3,393	Re: Dual Exhaust Facts is not necessarily helpful. When we were doing my son's 64 1/2 Mustang we wanted duals. He sold the idea to his Mom based on my saying it saved gas money. When we were working on his modern Chevy truck the arguement still carried the day (That took a little more imagination as Virgina doesn't allow us to fix exhaust systems. My bud worked for Speedy muffler and he was able to find an obscure truck model offered only in Callifornia where duals were factory installed.

12-01-2011, 08:53 PM	#13
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,862	Re: Dual Exhaust I love the sound of duals, a set of glass packs and an L-100 cam. Brings a smile to my face.

12-01-2011, 09:56 PM	#14
Shadetree Senior Member Join Date: May 2010 Location: Cottageville, WV Posts: 1,535	Re: Dual Exhaust You can always tell the guys that grew up with these cars. The first thing I did when I got my `35 running was to install dual Smitty's with pennies in the heat risers. Wasn't concerned about horsepower or efficiency. Just wanted that sound... Shadetree __________________ Son, you will never blow an engine up in high gear.