Hemi Build

[48Dodger]

Your drawing makes it look clean and straight forward....but it rarely DOESN'T frustrate the hell out of the builder.

Its used a fair amount in racing and is worth the effort in my mind.

 

I have no doubt you make it look easy and fun Bill..lol...no pressure.

 

48D

 

For those who are curious:

180 headers tie the power stroke cylinder to the exhaust clylinder 180 deg from each other to help keep a steady and even exhaust pulse. 

This is different from tieing 4 exhaust ports from one side of the engine together in a single collection tube. The result sounds similar to a Ferrari.

Edited May 8, 2015 by 48dodger

[mrwrstory]

I am anxious to experience the sound.  Hope it doesn't sound like an Import 6   

[48Dodger]

LOL....not a chance!

 

48D

[mrwrstory]

Been starin at this thing waaaay too long!  Awful lot of tubes to stuff into this space,...pretty intimidating.  

I could not see the solution looking at the mockup so decided to bite the bullet and weld up the manifold that

goes beneath the pan in order to make some progress.  Now I've got a "stake in the ground" that's non-negotiable. 

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The coming week will tell  

[mrwrstory]

Slow but satisfying progress.  Made this little die to stretch the primary tubes to match the oval shape of the opening in the header flange.

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Also learnt how to MIG weld 1/16" tube to 3/8"plate, which is..............generous preheating of the plate to assure penetration before burning through the 1/16 stock.  Makes perfect sense.  The tubes are just tacked on the outside.  They will be welded on the whole circumference on the inside and ground smooth.  Finally the outside will be finished by brazing the perimeter.

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I'm livin large!!!!!!!  

Edited May 21, 2015 by mrwrstory

[mrwrstory]

A long way from being done but couldn't contain  myself,...... can't believe how cool this looks and I just needed to share it.

I got this far before I ran outta tubing bends.  Iii'lllll be baaack in a few days   

[LODI3QTR]

Very nice work....

[Niel Hoback]

   Wow! do you have an assistant named Igor?

[40plyrod]

Awesome!

[mrwrstory]

On another forum I got several "smarty pants" comments about the swoopy primary pipes,....as in, straighter would be more efficient and the level of difficulty.  Welllll, my reasoning is that I'm trying to use up length to get 34" equal length primaries.  Note the 36" welding rod as my guide.  Also, the 180 concept adds to the complexity.

Now, before there are comments and/or the obvious question of "why",...it's because I can (with some challenges) and because I think it looks cool,...not to mention a little ego massaging.   

 

 

[Don Coatney]

Pay no attention to the comments on that other forum. In the end you will have the best sound.

[40plyrod]

Those "smarty pants" comments can't be from another car forum, because if they're questioning practicality, having anything to do with an old car shouldn't even be considered. If you just want to drive around and play it safe get a new car. My wife's Subaru gets great gas mileage and gets her to the store with no issues. . . and very little fun. Keep going Bill.

Edited May 30, 2015 by 40plyrod

[deathbound]

Looking good.....hope you checked the torque on those hose clamps!

[Niel Hoback]

Hi-temp hose clamps, no doubt.

[mrwrstory]

​I am totally enamored with the colors.  Hope to preserve as much as I can.  This is silicon bronze brazing done with a TIG welder by my good friend Mike.

[Ulu]

Wow! nice fab work!

 

As for the basket o' snakes design, well IMHO there is no cooler looking exhaust system in all of motordom (unless maybe you can plant dual turbos on top?   )

 

A complex, twisty, entwined style is almost more important than mere fluid dynamics theory though.

 

Style, and clean fab too (which you got both in spades there bud.)

 

(edited, because there is no e in motordom)

Edited June 6, 2015 by Ulu

[Todd B]

On another forum I got several "smarty pants" comments about the swoopy primary pipes,....as in, straighter would be more efficient and the level of difficulty.  Welllll, my reasoning is that I'm trying to use up length to get 34" equal length primaries.  Note the 36" welding rod as my guide.  Also, the 180 concept adds to the complexity.

Now, before there are comments and/or the obvious question of "why",...it's because I can (with some challenges) and because I think it looks cool,...not to mention a little ego massaging.   

 

 

I think what you are doing is awesome!!  But I do have a question.  When we build houses I was told for dryer venting every 90 degree elbow adds 6' of pipe.  Would the same theory apply here?  You said you want to maintain the 34", do elbows mess with that? 

 

Again, very cool

[Todd B]

I should of made myself more clear.  What if some pipes have 3 elbows and the others have 4 elbows. 

[mrwrstory]

This is really fun stuff!  And to remind,..... most, if not all is for the enjoyment of the task and the satisfaction of accomplishment.  Kinda like why do folks climb mountains.  I've taken on this particular response to see if I can pen a succinct, respectful and relatively objective   reply.  

Accepting that modifying cars doesn't make much sense anyway, why do this stuff?  Answer, because we can.  We enjoy the challenge and the task and hopefully the results.  Isn't that the same concept as painting a picture, hitting the perfect drive, building a piece of furniture, catching the biggest fish or climbing a mountain.  It's different strokes for,.....ya know!  

So yes, straight pipes would be more efficient,...but how long should they be?  Long ones are better for torque, short ones for horse power.  Short ones are easier to stuff into an engine compartment but torque (long pipes) is what you feel in your butt.  Equal length primaries and the merging of pipes to affect pulse timing (scavenging) are other factors that contribute to efficiency and power.  There is no one best solution that answers all needs unless you select "best at 3000 RPM", as an example.

For some reason that defies rational thinking, I decided to attempt 180 headers.  That concept alone is difficult to explain.  In short, it's the timing of exhaust pulses that yield the most consistent frequency of events in the exhaust system.  American V8s have their inherent "thump" due to crankshaft configuration and the resultant ignition/exhaust timing.  The "thump" is due to inconsistent timing of exhaust pulses in the system, particularly with dual exhausts.  The remedy, in the case of American V8s, is to route exhaust from two cylinders, from each side, to the opposite side, yielding two exhaust systems. essentially servicing two 4 cylinder engines.  That's what you saw in Ford's Indy and GT40 cars, i.e "the basket of snakes".

The goal was set at 34" long primaries (low end torque).  That length also facilitates routing two of the primary pipes from each side,...to the opposite side.  All of the bends you see are to "use up length" in the two pipes on each side that do not transition across.  The goal of this project too is to get the job done within the frame rails and in the neighborhood of the firewall.

At the moment, I'm barely half way, 'tho I think I can see the light,...etc.  Kinda like getting half way across the creek on stepping stones that you've discovered en route and believing you'll find enough more to complete the journey.

Wish me luck!  

Edited June 5, 2015 by mrwrstory

[DonaldSmith]

I just wanted to say, good luck, we're all counting on you. 

[Todd B]

After reading your response I figured the way you answered my question you must have been my old high school teacher or a politician.  So I read your profile and I see you are 97 years old.  That makes this build even more amazing.  But my question still is not answered  

[mrwrstory]

I should of made myself more clear.  What if some pipes have 3 elbows and the others have 4 elbows. 

Yes Todd, 4 elbows would be less efficient than 3,.....but what's an elbow, 90 degrees?  I got some that are 100 degrees and some that are 80 degrees and I wouldn't call a 180 degrees an elbow and, and,.....  number of bends, elbows or otherwise were secondary in my quest,...whatever ever that was!  I forget,....forgot    first time I've been "called" for being 97   and I am neither a science teacher or politician   

Edited June 5, 2015 by mrwrstory

[Don Coatney]

A couple of years ago I spent a night in a Georgia hotel where a Lamborghini convention just happened to be in progress. Sitting outside the Hotel room I had the pleasure of listening to the sweet exhaust sound all evening as there were hundreds of them cruising the streets. The hammer of the exhaust when they shifted gears was like a symphony to my ears. If your exhaust design sounds anything like what I heard your efforts will be self rewarding. Carry on!

[48Dodger]

Not sure what people were saying about your design exactly....but from what you wrote, they were missing the point.

HP and Torque don't live without each other. Exhaust systems affect engines that have wide power bands and routinely operate below peak torque. Torque is what most people feel...not HP. If you race your vehicle at a high speeds (rpm) and can hold it there...now you're feeling HP. The harmony of HP and Torque for most vehicles relies on the gears, the power to weight ratio and what the vehicle is suppose to do. I am getting to a point...really...lol.

 

Bill's vehicle is not going to race at 9000 rpms in competition on a circle track, he is not going to set a new land speed record of 400 plus MPH, he is not reinventing the wheel or rethinking physics. For me, Bill is testing, and challenging the HP and Torque of his mind! He is building the thoughts from the creative side and sharing it. If he was only interested in going fast, his vehicle would be ugly like mine, he'd have more electronics and roll bars. If he was only interested in show, he'd have less interest in what makes him happy. Honestly, I don't care what his "Dyno'd numbered - ET- time slip thingy- dragon coefficient - scooby doo" is.......This guy is turning the volume up to eleven and having a great time!

 

You're doing a fine job Bill.....thanks for this awesome thread and rock-on brother!

 

Tim aka 48Dodger           

[Ulu]

Clearly Bill is a man who likes to build things. I have the same disease & so it's easy to recognize.

 

With that regard, no other justification is necessary.