Stock Exhaust Manifold or Header (1 Viewer)

[Wildabeast60]

I haven't replaced my exhaust manifold yet-Can't decide if I want to go with a header or stay stock. I know many of you have gone to a header and want your opinion! Either way, it'll be only a few $$ more to go to a header, and 10-20 hp's would be nice! Auuuggghhhh! I just want my Cruiser to run right!

 

[Rice]

The only way you would get 20 HP from putting on a header (on an F or 2F engine) is if the manifold you're taking off is clogged shut. I'm not against headers and run them myself but do it with the realization they require extra care and will not give you a "new" motor. On a stock motor you can expect a little extra torque and a couple HP ... not until making internal engine mods will any true gains be realized.

Keep in mind also, even though the header itself may not cost that much the added cost of exhaust work drives up the $$.

Rice

 

[Degnol]

Tough call. I just installed a SOR 2 piece header on my '40, but I haven't fired it up yet. Some say the 2 piece allows for some flex and may be less likely to have leak problems. I like the SOR because the flange on it is the same thickness as the intake manifold, so no half washers or milling of the intake.
Another important thing to do is retorque after it gets to operating temp, then check and retorque until it doesn't change.
I wasn't having any problems with my stock exhaust, so I may be borrowing trouble, the main reason I changed was so I could run a 2F intake and it wouldn't mate with the F exhaust manifold.
I have not disposed of the stock setup...just in case.
Ed

 

[Romer]

I run a header with two pipes connecting to the exhaust. I like it, but remember that you need to include exhaust hook up in the cost when you are trading. If you do piping and welding your self this will be no big deal.

 

[swank60]

Just to pile on another question (or two)

First - doesn't header intallation take kind of a fine touch and a little modification? I've never done it, but I am considering it.

Second - is there a possibilty you could damage a high milage engine by running a header (I'm assuming that the change in back pressure could have a reaction) - it seems like I've heard someone at some point in my life mention this...I'm not sure though.

 

[IDave]

Having done it both ways on the same rig, I'll weigh in here. [glow=red,2,300]IF[/glow] you live in a cold climate (by that I mean it gets below 0, not just below freezing a few days a year), and your stock exhaust has a functioning heatriser, you will appreciate the stock heatriser. No question the stock exhaust is easier to fit and get a good seal.

The one-piece headers like MAF 6>1 can be very difficult, but not impossible to get a good fit and gasket seal. Takes double gasketing and permatex high-temp copper to do it for some, not to mention retorquing and so forth.

The two-piece SOR (I owned the one Degnol has now) was a pleasure relative to the MAF. It sealed well, easily and was virtually maintainance free. Too bad it doesn't fit with a PTO setup.

As for back pressure, I would guess that with other engines Swank60 is right: the change in back pressure might bother some other old chevy engine or something. With these tractor F and 2F engines, I don't thing it matters a whiff.

As for power, I think maybe, just maybe there was a small difference in [glow=red,2,300]feel[/glow] when I went back from headers to stock exhaust. I would err on the low side of the horsepower change on my guess. Far more important to get the timing correct.

As for gas milage improvement: maybe 1 mpg. Again, get the carb and timing correct and you will have far more of an impact.

 

[Wildabeast60]

Well, the lack of hp gain is reason enough NOT to get it! That's the whole reason I was interested in one in the 1st place. According to MAF, they could give you up to 20 hp gain. So, so much for that! I think I'll go back to stock. Thanks for all the replys!

 

[osteology]

I add my 2 cents - I put on a 6-1 ceramic header on when I had a cracked manifold. Not much performance gain - maybe a bit at higher RPMs (highway passing, etc) but barely noticeable. Almost no change at lower RPMs where you would want it on the trail. My biggest complaint would be poor running while warming up - I would keep the stock manifold just to keep the heat riser(even living in north texas)

 

[fsusteve]

Same here, bling factor when you look under the hood, but very little else.

 

[Degnol]

Well, not much to really report here, but I did fab a 3/8" aluminum plate and tapped it for a fluid heat riser, got to be better than nothing. Takes water right from the head and circulates through the bottom of the intake, then on to the heater core.
Haven't tested it yet. I live in Missouri, so onlu occaisional need. Letcha know how it works out in the fall. Spring has sprung here.
Ed

 

[IDave]

I agree, the fluid heat risers are substantially better better than no heat riser. But the exhaust heats up faster than the engine coolant. So there you are.

 

[dd113]

If you have a good IN/EX do not put on a header. Buy an intake and sell your old as a set.

If your EX is cracked buy a cermanic coated header not new OEM or one part of a used OEM.

They will all leak eventually

 

[RBHME]

any opinions on the MAF ceramic headers.???
Need help on this as my 40 is in shop and has MAF 6<1 and they leak bad.... so shop recommends ceramic . Going back to stock aisisn carb and stock intake.

 

[Cruiserdrew]

I dislike headers. Actually, I hate headers. I have the smog legal header on my 40 and had to reseal it 3 times to finally get it to stop leaking. Plus it is loud and very hot. I also assume that it will rust out in 4-5 years. 20 horsepower gain is a joke, I can't tell any difference at all. When OEM stuff works, it is usually better than any alternative. Stick with the stock exhaust manifold if you are lucky enough to have one in good shape.

 

[70LCruiser]

im in the process of a frame off resto, and was thinking about putting a header on, just because the bodys off soo its easy enough to do it. who has the best setup, Im pretty sure I want a full exhaust (header, muffler, and pipes)? also I AM running a factory PTO winch. will this get in the way at all?

 

[IDave]

If you want to keep your PTO winch AND have headers, the MAF 6>1 is the only one you can make fit that I know of that is widely available. I think GreenWeenie on this board has a different brand, but I don't recall the name off hand.