Sanderson headers

[Vshofel]

I'm I stalling a New ford performance crate engine.302 Hoping I can reuse the old Sanderson headers. The primary is 1 1/2 Inches. Will I have an issue? Or do I need the 1 5/8?

 

[Madgyver]

it's a 302, you'll be fine with 1.5" primary tubes.

 

[Vshofel]

The mechanic is pushing the 1 5/8, I thought the same. Bit the guilt I'm feeling if I mess up.. It's a 350hp motor. And I know I'll never see thelode specs, but still nervous

 

[Broncobowsher]

1½" will be fine. 350 isn't that much HP. You are not making a max effort engine. You will have a good driver. So you leave 3HP behind, who cares? You will never notice.

 

[Vshofel]

I know., I am. Pretty sure it will be fine but, he's saying
I can run the old headers It will choke the exhaust flow out of the cylinder heads.
I really don't want to make a mistake. But the headers I have are only 6 months old and less than 40 hrs they are brand new. And to waste $700 obviously I don't want issues or to downgrade performance. I'm nervous to make a mistake

 

[lars]

You aren’t making a mistake. 1.5” is fine for 350HP.

 

[DirtDonk]

As the others have said, you are not making a mistake. But you are over worrying it.
After all, it’s just exhaust. It’s not a permanent part of the engine.
And even if you were making a mistake, it doesn’t qualify as an ultimate mistake, because you can easily replace headers down the road if you feel that at 6000 RPM, you’re not seeing your maximum performance potential.
What are your plans for the entire exhaust system?
Are you looking for bragging rights, or are you going to be driving it like a racer?

After all, that’s where the larger tubes really make the most difference. From idle to 2500/3000 RPM, the headers are probably fairly equal.
From 3500 to 6500 you really see a difference on a dyno with the slightly larger header.
Notice, I said dyno. There is certainly a difference, and the more power the engine develops, the bigger the difference between the two. But most people would never feel it on their “butt dyno” versus a real dynamometer.

But how are you going to be driving the vehicle and how is the engine built?

Also, is it a flat tappet cam or a roller? Assuming a roller, but I had to ask because breaking in a flat tappet cam is dangerous to headers with coatings on them.

 

[bronco italiano]

Sanderson's are premium quality headers!!

 

[ntsqd]

1-5/8" would be the mistake. Not everything is better when it's bigger, and this is a prime example of that.

 

[DirtDonk]

With shorties, I don’t believe the larger size is as big a mistake as it would be with long tube headers. But the fact still remains, you have an almost new set of 1.5’s so the mistake would be spending the extra money in my opinion.

 

[ntsqd]

It may not matter like it does with longer, tuned (sic) length primaries, but it's still too big for most 302's.

 

[DirtDonk]

Agreed.
Wonder which 302 is being installed?

 

[Vshofel]

As the others have said, you are not making a mistake. But you are over worrying it.
After all, it’s just exhaust. It’s not a permanent part of the engine.
And even if you were making a mistake, it doesn’t qualify as an ultimate mistake, because you can easily replace headers down the road if you feel that at 6000 RPM, you’re not seeing your maximum performance potential.
What are your plans for the entire exhaust system?
Are you looking for bragging rights, or are you going to be driving it like a racer?

After all, that’s where the larger tubes really make the most difference. From idle to 2500/3000 RPM, the headers are probably fairly equal.
From 3500 to 6500 you really see a difference on a dyno with the slightly larger header.
Notice, I said dyno. There is certainly a difference, and the more power the engine develops, the bigger the difference between the two. But most people would never feel it on their “butt dyno” versus a real dynamometer.

But how are you going to be driving the vehicle and how is the engine built?

Also, is it a flat tappet cam or a roller? Assuming a roller, but I had to ask because breaking in a flat tappet cam is dangerous to headers with coatings on them.

Hydraulic roller camshaft

 

[Vshofel]

Agreed.
Wonder which 302 is being installed?

302 CI 340 HP BOSS CRATE ENGINE WITH "E" CAM, not trying to go crazy with it - just the old motor was old, and smoking , and i'm sure i could have made it work, i just decided to upgrade it​

 

[DirtDonk]

Well, depending on the year of your original engine, that’s as much as 200 hp more than it came with from the factory.
You might not be going crazy with it, but that’s certainly a big upgrade!

It can certainly benefit from larger headers, especially with the E Cam, which is geared a little more towards performance and lighter vehicles, but it’s not exactly gonna be choked off by the 1.5 primaries at lower rpm.
At least not at that same RPM range mentioned earlier, of between idle and 2500 RPM.
In fact, it’ll probably improve the street manners.

Leaving some power on the table? Certainly.
Enough to notice or be disappointed in? Probably not.
Did you say manual or automatic transmission? And you did say fuel injection versus carbureted?
With the manual transmission, and especially carbureted, you might actually appreciate the slightly higher, low speed scavenging of the smaller primaries.

And I know the subject was broached, but just exactly how much time do you intend to spend between 3500 and 6000 RPM?
And have you read all of the reports of Bronco owners using the E303 cams over the years?
Don’t want to scare you away from the engine, because it’s probably a good one. And maybe the issues others have had with it are all about the overall tune, rather than any shortcomings of the camshaft.
But don’t be surprised if, a few years from now, you decide you want a cam with better street manners. Or maybe just more vacuum production or fuel economy.

Then again, maybe this is all moot and you’re still young and love a lopey idle and that sound that a performance engine makes when it’s revving up!
Planning dual exhaust, or single?
What gear ratio tire size?

 

[Vshofel]

dirt, i honestly never ride that high, its mostly back roads summer driving by the beach,
i know about the cam, worst case i can always upgrade the cam later on,
i have efi (sniper), i actually don't like it, i like seeing the dial and performance, but hate when something goes wrong , no one knows how to mess with that EFI
its an automatic (70, but auto), running 35s on the original gear ratios, i wanted to upgrade the gears , but the mechanic told me to wait to see how i like the performance - i am also installing the James Duff T-Rex, so excited to see how it handles everything

 

[DirtDonk]

Excited to hear all the results too. And I’m a big fan of waiting to do any re-gearing until after everything is done and you’re driving it. A big fan!
You’re more likely to make the correct gear choices once you know how everything plays together.
The automatic will help with certain aspects of this.

 

[rcmbronc]

The only thing you may want to look at is if the connection to the head and header pipe is way off. May need to port match the headers. Other than that I see no issue with the 1 1/2" headers.

 

[rheiser]

Headers and exhaust are a topic I'm going to have to make a decision on before too long. I have a BluePrint 347 going in, and my crusty old headers are definitely not coming along for the ride, let alone the exhaust, which may be original (2" dual exhaust). This conversation is interesting to me, because trying to do the research can be confusing. I've been to the online exhaust size calculators, which recommend a 3" exhaust for the engine size and approximate hp output. I'm sure they're attempting to maximize horsepower, not necessarily low end torque. I don't see a lot of choices for headers that end in a 3" collector sold by the Bronco houses, anyway. Even so, the next decision is whether to go with shorty headers or not. My impression right now is shorty headers plus a smaller diameter exhaust is the choice for low-end torque, while long tube headers with a 3" exhaust it more about a big hp number at high RPMs. I'm sure this has been discussed to death over the years -- has a consensus been reached?

 

[ntsqd]

Without having to dig too deep you should be able to find info on the sizing of the primary tubes and collectors for long tube headers. Somebody out there somewhere probably has a calculator online. I think that the engine dyno simulator also does these calculations.
From memory, the longer and the smaller that the primary tubes are, coupled with shorter collectors, the better the headers are for low end. Large OD, short primaries and longer collectors are more where you want to go for top end.
Those are generalities, and they are displacement specific. What is a large OD primary for a 302 isn't all that large for a stroked 351. If you're going to have custom headers built, then all of this is info your header builder is going to figure out or want to know.
If you're going to buy off the shelf headers, then knowing the generalities will help in making an informed decision.

From a pure performance perspective I'm not convinced that shortie headers are all that much better than an iron exhaust manifold. They likely are better, but not by a huge amount.