original vs modified exhaust manifolds

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66CustomCab
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original vs modified exhaust manifolds

Post by 66CustomCab »

So I'm thrilled to have this new toy, but finding some of the modifications made by previous owners annoying. Needed to change the starter on this 352 today, and found the "long pipe" manifolds that had been put on made that impossible. Sure, they look cool and I suppose they would improve flow over the flat single tube original manifolds, but are they really necessary? :?

After several hours I found the solution... my sawzall. I now have a new starter, but also a really loud truck :doh: Now the decision needs to be made. Buy another set of fancy pipes, or back to original equipment? :hmm:

I'm never going to race this truck, not seeing the point of all the "upgrades". Any thoughts? :help:
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Re: original vs modified exhaust manifolds

Post by DuckRyder »

On a bump you simply have to remove the header and reinstall.

FE exhaust manifolds are VERY restrictive, headers would be the number one thing to do to increase power. You’ll also have to replace/reconfigure the exhaust to match the manifolds should you choose to go back with them.

But it is pretty much a choice based on your preferences
Robert
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Re: original vs modified exhaust manifolds

Post by Bill Ramsey »

why the heck would you cut the header when you can simply unbolt them? you ruined them.
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Re: original vs modified exhaust manifolds

Post by 66CustomCab »

First, the headers were already ruined, rusted thru in several spots. It would have to happen anyway, just not planning on doing it so soon. Second, they were bent so badly I couldn't remove two of the bottom bolts at all.

As for restrictive, (and yes, having to reconfigure) that's my conundrum. Certainly easier to just buy the same thing, but in the future if (when) I need to get at a hat starter again, the same problem will arise. Nobody has given a strong reason not to go back to original, so I will leave that option on the table for now.

thanks for your thoughts...
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Re: original vs modified exhaust manifolds

Post by jzjames »

With my old truck (69 F100) I had the bolts on the headers set up to easily loosen, slightly move the header to get clearance to get to the starter and pull it out.
Then just re-tighten the header bolts. Voila :D

I think this is a pretty common fact with those folks who use headers.

My header bolts were actually allen-head bolts, again, kept in condition to be easily loosened.

I’d say go with another set of quality headers = :2cents:
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Re: original vs modified exhaust manifolds

Post by sargentrs »

You could always go with shorties or block huggers https://www.summitracing.com/parts/hed- ... odel/f-100 Wouldn't give you the same boost as the long tube but they'd beat the OEM and give you more clearance for the starter problem. You'll probably have a difficult time finding some original manifolds in good condition and the price wouldn't be that far off.
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Re: original vs modified exhaust manifolds

Post by 1972hiboy »

I purposely went back to stock manifolds to eliminate the access problems. For me, I did not feel like I needed headers. Never been sorry about it. :2cents:
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Re: original vs modified exhaust manifolds

Post by FLASH 1 »

HERE Over the years I have found and this going back 30 years + Headers run so hot that eats starters up... I have many times had to replace on the side of the road in hot weather a starter,, once we threw those junk headers off Got the stock manifolds had them coated, run the stock pipes with a crossover pipe < H-Pipe > and truck ran real fine WITH NO STATER ISSUES .. Now if you want to run headers I would cut each tube separate that bolts to the head so you would get a better fit,, Never-Sieze on all the bolts.. Oh yes you can buy those fancy starters but what if you go on a trip starter fails, you will then have to find a source to get you going so stuck getting a starter from the parts house unless your broke down in front of Summit or Jegs or the little brown truck is going to deliver it to you on the side of the road :lol: :lol: :lol: :lol: :lol: :lol:
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You're getting good advice on factory manifolds here

Post by farmallmta »

:yt:
Bias alert: when I was younger, I loved headers. As I've gotten older and more experienced, I've taken them off everything I own and will never put any back on, unless they're the rare factory Ford cast iron headers. I do have a 406 with those on it.

Headers help the evacuation of spent combustion gasses from the cylinder. They also reduce the backpulses from the cylinder into the intake manifold as the intake valve opens, resulting in a more even flow (but still not entirely smooth, by any means) of fresh air and fuel vapor into the cylinder. Think of the combination effect as a bit extra air and fuel entering the cylinder, like free supercharging.

However, this effect is minimal at low to moderate loads and RPMs of under 5000. Where you see the greatest positive effect from headers is under heavy load at higher RPMs, the tube lengths and overall design affecting where in the RPM range the effect is greatest. This could be flat-out racing or extended hill climbing with a heavy load. If you are not engaged in either of those two, you're going to find headers to be a way more expensive and headache proposition than any possible benefit you'll get from them.

The FE engines in our trucks almost all face ordinary driving conditions under low to moderate load and engine speeds. Header benefits under such conditions include:
1) increase of ordinary torque of about 10-20 ft-lbs under 3500 RPM
2) horsepower increase of about 5-10 under 3500 RPM
3) fuel economy increase of about 1/2 to 2/3 MPG

Header drawbacks under such conditions include:

1) Cost of headers, decent ones in excess of $300 plus high quality gaskets
2) Ceramic or other temperature control coating to extend life in order to reduce heat radiating to starter $200
3) Installation of headers, including new exhaust system to fully take advantage of them, about $800
4) Recommend smaller starter to accommodate heat shielding, about $300
5) Occasional/frequent gasket failure, requiring reinstall
6) Heat soaked starter problems, occasional outright failure requiring starter replacement, troublesome with headers in the way
7) In-cab noise increase of headers is often noticeable, to some ears highly annoying
Cost of headers done right, approximately $1,600

What you get for $1,600 is mostly noise, ongoing maintenance issues and bragging rights, the glow that comes from having performance parts that other people think are impressive, but really aren't for daily driving. What you don't get is much improvement in performance or fuel economy under ordinary use conditions.

If you're pulling heavy loads at higher RPM's, or if you're racing your truck, then there is a much better case to be made for steel tube headers. Or if you just "want to".

Here's some additional good information to soak up on headers if you're truly interested in the subject http://www.hotrod.com/articles/header-basics/

Hope this helps. :2cents:
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Re: original vs modified exhaust manifolds

Post by Ohiotinkerer »

:yt:

That's why I had my stock manifolds milled and put them back on - the cost vs return for what I'm gonna be using my bump for. It would have made no sense for me to spend the money for the headers alone since all I'm doing is using it for when I need a truck or occasionally taking it to a show. Now if I was doing the engine and going with a cam, carb, higher compression etc then I would have done it. Just comes down to what you are gonna be doing with it whether or not its worth it...........my :2cents: on it....... :D
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Re: original vs modified exhaust manifolds

Post by Jacksdad »

I have stock manifolds and front pipes on a 352, and I've always had starter heat soak bad enough to stop my bump being a daily driver. Even a heatshield around the (third) starter hasn't helped. I'm thinking of wrapping the first section of exhaust next.

And change the FE for a Windsor...
:yt:
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Re: original vs modified exhaust manifolds

Post by cep62 »

Jacksdad wrote: I've always had starter heat soak bad enough to stop my bump being a daily driver. Even a heatshield around the (third) starter hasn't helped. I'm thinking of wrapping the first section of exhaust next.
First , I mean no offence.
Where are you getting your starters ? I've never burned up a starter on a stocker F E ,
But I've learned my lesson , and use bigger than stock battery and starter cables with good ends . (not the clamp on style)
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Re: original vs modified exhaust manifolds

Post by Jacksdad »

Not sure about the original, but the last two were O'Reilly's. I changed and upgraded the cables too, and checked all the connections and grounds. I finally went with the lifetime warranty starter, even though it didn't solve the problem. That's okay - collecting parts for my 351 build, so it'll get fixed one way or another.
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Re: original vs modified exhaust manifolds

Post by DuckRyder »

You can also get around the issue of removing the header to change the starter by running one of the mini starters.

Some thing else to look into might be if factory “cast iron headers” will fit.
Robert
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Re: original vs modified exhaust manifolds

Post by farmallmta »

Jacksdad wrote:I have stock manifolds and front pipes on a 352, and I've always had starter heat soak bad enough to stop my bump being a daily driver. Even a heatshield around the (third) starter hasn't helped. I'm thinking of wrapping the first section of exhaust next.

And change the FE for a Windsor...
There is no way you're getting heat soak from stock manifolds and exhaust pipes correctly routed sufficient to cause quality starters to cease working. It just never happens unless you're getting that system glowing red hot... then it's not the exhaust system or the starter, it's timing, ignition, fuel, etc.

My personal extensive experience is that the starters coming from O'Reilly and Autozone for FE motors are complete garbage. The snouts break, the bendix ceases to acctuate, the motor doesn't turn. It's one thing after another with them. I no longer buy starters from those companies. Instead, get a good rebuildable core and have a local automotive battery and electric shop rebuild the starter. Once I started doing that, no more starter problems.
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