Physics /Math and an Alpine 4 into 1 header

[jdoclogan]

As I reflect on my overall calculations and read more of David Vizard's writings I came up with the following:

"Assuming no flow losses, a piston traveling down the bore will pull in one eighth of" 1592cc. That is 199cc for a stock Alpine Series II bore. With a compression of 10:1 the volume above TDC will be approximately 19.9 cc. "If a negative pressure wave sucks out the residual exhaust gases remaining in the combustion chamber at TDC, then the cylinder, when the piston reached BDC, will contain not just 398cc but 398 + 19.9cc = 417.9cc. Thus, the engine runs like a 1671.6cc engine instead of a 1592cc. That scavenging process is, in effect, a fifth cycle contributing to total output. Understand with poor flow the engine performs closer to just a 1592cc engine. Obviously the same math can be applied to the 1725 engine. The results would be a stock 1725 performing like an 1811.4cc engine. Using the same math on those that are boring out a 1725 to 2000cc and the results would be 2100cc.

Note: While the tube and length sizing for the header is important to get max gas flow, the collector system is the more important part to the scavenging (pressure difference) process. Ceramic coating and or heat wrap can help with the gas flow and protecting surrounding components.

 

[jdoclogan]

Update:
Here are three intake manifolds that work with the Logan header. All stock intake manifolds work. In addition, we don't need the clamp for the collector. There is so much clearance with this configuration that it easily snakes down through the steering arm/generator/starter.


Jerome's intake for the downdraft Weber.



Redline's side draft Weber intake.



Straight side draft Weber intake. This required a slight mod at the tip of the Weber attachment ears (1 & 4) nearest the header tubing.

I'm getting the 1592 engines completed and will do a comparison dyno-test with stock header.

 

[alpine_64]

Great work Jerry, on the final manifold is that a holbay h120 manifold that has been cut and shut level?

Im wondering how a TWM dcoe manifold might work... Might be better than a modified holbay

 

[jdoclogan]

The h120 has the modification for a slight upward stance. I have a TWM on the Promotional Harrington Le Man. Alas, I'm not going to take it off and test it at this time. I will replace the Atalla header on the PHLM. Atalla's header did not have proper clearances and needed hammer alterations to work. In addition, it was made from 1.5" tubing.

If all goes well with this prototype 2.0. I may have a request Michael. To better process the replication of this header I would like to see if you could source a fabricator in China that could do the mandrel bends for each tube. Then put on chrome ceramic coating. Thus, the final product would have superior fit, function, and look spectacular.

 

[alpine_64]

The h120 has the modification for a slight upward stance. I have a TWM on the Promotional Harrington Le Man. Alas, I'm not going to take it off and test it at this time. I will replace the Atalla header on the PHLM. Atalla's header did not have proper clearances and needed hammer alterations to work. In addition, it was made from 1.5" tubing.

If all goes well with this prototype 2.0. I may have a request Michael. To better process the replication of this header I would like to see if you could source a fabricator in China that could do the mandrel bends for each tube. Then put on chrome ceramic coating. Thus, the final product would have superior fit, function, and look spectacular.

Can see what i can do, i have the contacts of some guys that do high end customs exhausts and mufflers.... All stainless systems with operable mufflers... Not sure they make headers... But they'd be a decent place to start asking.

 

[jdoclogan]

Sounds good Michael.