of course you spoke to George back in the day, mike. my point was simply that one needs to be carefoo in that there are a ton of headers available on ebay and such that claim to be geo's when in fact they may not be. im sure you'd know a legit set, but the OP might not and should be aware of the "fakes".

happy holidays #2

To juanbenae's point, there are numerous replicas of George's headers. A giveaway of the replicas is their collector. I know of at least two replicas that use a sheetmetal fabricated collector, Triad West and MSDS

Here's a Triad header

http://forums.pelicanparts.com/uploa...1182734441.jpg

and here's an MSDS header

http://forums.pelicanparts.com/uploa...1432655395.jpg

Both Triad and MSDS are west coast made in USA companies. I'm not faulting them for making their own stuff. Just pointing out how their headers are different.

Then there's the made in China junk like OBX brand (might be called Becker now?) that copied the George's header and their headers are junk

http://forums.pelicanparts.com/uploa...1271094479.jpg

The 3.2L intake tune is for peak torque around 5800RPMs and the correct header to support that RPM point calculates out to 1 5/8" primary at a primary length of 30". No one seems to mention primary lengths when they advertise headers?

My question is: does anyone make 30" primary length headers?

The next best choice would be 15-16" primary length.

I have several exhaust system calculators and they all come up with 30-32" for primary length at 5800RPM.

Thanks for the info Sal.

Does anyone make a system like this for a backdated 3.2? (this is for a 65-73)

https://i.postimg.cc/Dw8XqFZs/EXHAUSTKIT77-LR1.jpg

Reviving this re: George's European Headers.... on a stock 2.7 for mostly street use (and no heat needed)...

So would it be better to stick with the 1.5" OD (35mm ID) set? Or jump up to the 1-5/8" OD set (38mm ID)?


1.5"
https://cdn11.bigcommerce.com/s-hbzr...=2&imbypass=on

1-5/8"
https://cdn11.bigcommerce.com/s-hbzr...=2&imbypass=on

I have considered getting a set of Georges style headers made up, (I have yet to find a header guy to do it) with a pyramid collector as apposed to the triangle collector. Any good info as to a benefit one way or another on the collector? Bob

Bob,

I would talk to William Knight about headers. I am not a fan of the George's headers merge collector design. It is really old school.

Scott

There is no better collector design out there then the Burns/f1 style collector. Waay back when I was invloved with M&k I just copied a Burns collector.. It really is almost easier to manufacture then the splayed collectors and just perform so much nicer.. I am surprised that the big manufacturers are not just use that as the starting point and make a 30-32" primary. Seams to be best of all worlds.

I would not give credit to Burns for the F1 style collector. They are just one of many companies that utilize that type of design. I think SPD has been using that design as long as Burns and they offer several different convergence angles:

Exhaust Components - SPD Home Page B

Yeah I know but the majority of folks identify with the burns collector. Kind of like crescent wrench though its really an adjustable wrench

Header design compromises are inversely proportional to the price. Georges headers are a budget model with a lot of compromises, the Triad version even more so. To optimize performance the headers must be designed specifically for your engine. Merges must be smooth, transitions gradual and primary lengths and diameter tuned for peak horse power. Proper scavenging is essential. For the 3.0L SC engine this would be 30"-32" long 1-1/2"OD primaries with F1 style merge collectors. Our headers follow this formula.


http://forums.pelicanparts.com/uploa...1591883369.JPG


http://forums.pelicanparts.com/uploa...1591883369.JPG

For a completely stock 2.7, a larger than stock header may not be an improvement. There are likely many threads on header sizes in these Forums so I suggest some searching.

And I always suggest getting some input from expert techs and engine builders in your local network-- including if possible PCA members. The stock configuration 2.7 has been around a long time and I am sure that there is a wealth of knowledge for this relatively simple question.

And by the way, I have used (George's) European headers (around $1k thee days I think), SCARGO headers (around $3k or more these days I think), and headers sourced from William Knight (likely around $1k these days I think). My application in all cases has been high performance racing engines. In these applications, the collector design differences are likely more important than for stock 911 engines.

If I were looking for headers for a stock 2.7, I would choose European headers from GT Racing, or I might try some stainless headers from William. But I would not expect any meaningful difference in performance (power, torque and/or any other parameter) based on the collector design.

I might also consider some other aftermarket headers at lower price points.

For a stock 2.7, a large consideration might be muffler and fabrication requirements for the different choices. I think the European header approach might be moist straightforward in terms of fabrication.