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JD
what kind of a gauge are you using to monitor the O2 sensor?

Hi Fritz-
At this point, I don't have any O2 sensors or gauges. I'm "thinking out loud"... But when I figure out what I'm actually gonna do, I'll be sure to post info in my build log.

JDK

Chuck said:


In the immortal words of Ray Charles- "You lyin' ta me, Honey!"
Not really... And it is tempting, you Silver Tongue'd Devil, you ...

But at this point, with one set of headers purchased already... I'm leaning more toward modifying the huggers (i.e. "the already paid for set") or if that won't work, buying a set of Mustang "Shorty" headers from Summit or somebody. Background info: James has a set of the Shorties on his pickup. The driver's side has a crack in the collector. He offered to go halves on buying a set, I get passngr side, he gets drvr side, everybody happy. With that scenario, the headers are 140 bucks plus shipping, my half would equal about $75. And I could bolt it up and go.

I haven't priced the cost of tubing to build one header (or a set) but I'd guess it'd be close to that, and then I'd have to build the darn thing. Which is to say there's no guarantee it'd get done right with only ONE purchase of tubing, ya know?!?!? I'm gonna take one more long look at modifying what I've got, probably Saturday. Plan B is to purchase the Shorties, but that Plan B is getting closer and closer to being Plan A.

I'd love to build a set of headers, mostly just to say I'd done it, but not right this moment...
Now, when I add the turbo(s)...

Thanks for the encouragement, Chuck, honestly.
Take Care-
JD Kemp

Hey Tom-
You're spot-on, I think... Most folks I've talked to are in line w/ your thinking, that neither mis-matched or modding the one side won't do much harm if any to HP production, and I can always build a set of headers later if I need to. You can check the long-winded version of this answer just up the page...

Thanks for the input!

JD Kemp

I thought the staggered can-am ram tubes were b/c BBCs have 4 long and 4 short intake ports on the heads. That was just an assumption, not based on any facts...

You will be fine with mismatched headers. Most OEM systems are mismatched, just front to rear, rather than side to side.

Good point, Sean...

OK, just for reference, here's pictures of A) Block Hugger header that I have- And B) typical "Shorty" header, like I would use on passngr side- Both have 1 5/8 primary tubes and 2 1/2 collectors. Main difference I can see is the front three primaries on the Shorty are longer than the companion pieces on the Hugger and the reverse is true of #4.

When this idea first came up, I was totally and adamantly opposed to it. No engineering reason, just having mis-matched headers seemed "wrong". It seemed the flow rates, back pressures, scavenging would all be different, and the motor would never be quite "right" somehow. So far, the assembled brains of this group say not so. The more I look at it, the more trivial it seems.

Maybe I'm just an Old Worry Wart or something. (Nobody has addressed that concern I expressed that all my babies would be born naked... And the Allies might lose the war... And that we'd never know what Billy Joe threw off the Tallahatchee Bridge...)


JDK

Visually the differences are minor. The length of tubes is about the same between them so no net difference. I would run them without giving them a second thought. IMO!!

JMR

Yo, JMR-
Thanks, Man, I 'preciate your input! I'll keep y'all posted on how things turn out!

JDK

You are welcome but you know how much you paid for the advice - right?

Sean, you raise a good point about the BBC heads. I hadn't thought about the intake port differences, I just assumed the staggered ram tubes were to stretch the power band. You may very well be right

JD, I'd post my opinion on this subject, but I'm smart enough to know that no one, not even me, is interested in my opinion on this subject.

Bill

Bill, you're being much too modest. But you did remind me of a song...

So, in the words of my favorite philosopher, Jimmy Buffett:
"Is it ignorance or apathy? ... I don't know and I don't care!"

But then again, we have severly beaten this particular horse... If you want to save your intellect for more weighty matters in the future, no one could fault you for it.

JDK

I think these match better than a lot of oem systems (which has been said), but you might consider using both Ford oem shortys and selling the block huggers on Craigs or Ebay.

You might also consider building the car to accept the exhaust. The oem shortys will last longer. They aren't pretty but do have some stainless blended into them, like most exhaust systems since about 1990.

I used 66 GT350 tri-Ys on my ranger. They are long tube and are not equal from side to side, but work well.

If you were going with oem injection and trying to use oem tuning, placement of the O2 sensors would be critical.

Hi MV8-
Thanks for looking in on this... Only problem with "building the car to accept the exhaust" is that it would be "Re-building" the car. It is a viable solution, but the truth is I'm not willing to expend that much time, money and/or energy at this point.

That's an interesting point about the long-tube headers off the 350. If they're not equal and as we all know (well, those of us old enough) the GT-350 was no slouch in the performance department. So, the conclusion I keep comin' round to is that I been worrying about a non-issue... Which is, in itself, a good answer.

Educate me a bit on the placement of O2 sensors, please Sir... I will be using the oem injection and tuning, at least to start with. I'd guess the sensors need to be equidistant from the cylinder heads. But I'm guessing... What did you mean by that 'placement is critical' part?

Thanks!
JDK

I will assume your going to run the heated o2s (ie, not 1-wire o2s), so distance from the head is not as important for getting up to temp and in closed loop in a timely manner.

You need a good average sample of all the cylinders in a bank to provide feedback to the computer which will affect all the cylinders of the bank. The Ford computer may change the mixture of all cylinders based on the o2 feedback on one side, even though there are two o2 sensors. I'd look into that before deciding on bung placement. It's better to be a little rich on the poorer flowing side than too lean on the better flowing side.