Crack in Headers

[cyberpine]

It appears I have one on the front passenger side.

How does this happen and what are are the side effects of running this way? Also, does this imply other possible issues ?

Can this be fixed?

The truck drives with full power and I've otherwise not noticed anything relating to this. I was cleaning them up (in place) and removing that metal wrapper around them when to my surprise and disgust (just purchased the truck 4 months ago) there is was.

Unrelated, but Yesterday fueled up with super unleaded and a slight pinging noise seems to be gone.




Thanks for any help or information

[LONGHAIR]

First of all, that is not a "header" it is a cast iron exhaust manifold. Can it be fixed?.....Yes, cast iron can be welded, but not by just anyone. If you live in a big enough city, there should be someone that can do it for you....but it is usually more cost effective to just replace it.
I wouldn't run it that way any longer than you have to, it will just get worse.

[rockn30809]

Is it broken all the way around? From the pic it appears the crack runs all the way around. If it is busted in two chunck it, if you weld it like that it will draw and you will prob never get it back on. It's no big deal to weld it, any decent welding shop can do it. All you need is a special rod for cast iron, then preheat the manafold, weld then bury it in sand till it cools. Sand helps to slow the cooling and prevent cracks. Some tap the piece with a small ballpeen hammer.

[N2TRUX]

It may not be leaking yet, but it will eventually. Removing the heat shield might actually make matters worse as it will allow water to hit the manifold easier.

Plan on replacing it soon.

[cyberpine]

Originally Posted by LONGHAIR

that is not a "header" it is a cast iron exhaust manifold.

Let me ask you, do headers usually replace the exhaust Manifold?

I just checked and it's about $58 + seals for the replacement.

No mechanic here (clearly), but what would my truck (305 v8) like with open headers. Maybe something like this:

http://cgi.ebay.com/ebaymotors/Hedma...Q5fAccessories


Thanks.

[3r!c84]

yes header replace manifolds but the ones you found are not for this year of truck

[GMC Guy]

just go down to a scrap yard and pull one out of another truck. they're everywhere!

[N2TRUX]

Headers will replace the exhaust manifold, but they won't just bolt right up. Many times headers require spacers for brackets, different plug wires, and new exhaust to be made.

There is nothing wrong with replacing your cast manifold with set of quality headers, in fact it will improve performance. Just know going in it's not just the cost of the header that your looking at.

[Tater]

Headers replace exhaust manifolds.I had the same problem.I had a terrible exhaust leak that I could'nt find,and then one day,and I don't know why but I took the heat shield off.To my surprise the exhaust manifold was cracked all the way around.It was bad timing for me,I was saving up for a set of ceramic coated headers,but because of the timing and money issues I had to get painted headers.

[cyberpine]

What's the big difference between ceramic and painted? Not looking to spend too much on exhuast. Just looking for deeper/louder sound.

I'm thinking of this combination.


Summit G9006 Headers, Full-Length, Steel, Painted, Chevy/GMC, SUV/Pickup, Small Block, Pair

With true dual exhaust to Thrush 16956 high flow muflers. No cats.

With shipping and taxes I'm looking at around $160 for the hardware.






Can anybody comment on fit, performance, installation and sound? I have an 87 c10 305 TBI

I'm not sure if these products are basically knockoffs of Hedman and Flowmaster.

One questions about this setup. Planning to hang the headers myself. Once installed, do I have everything need so that muffler shop can weld rigth off of? Also, any special instructions or adhesives needed. Any clean or prep work to consider? I read I should tighten from the center out.

I'm looking underneith my truck and don't see anything that looks like Cat. but everthing looks stock. Is it a long tube before the mufler?






Thanks.

[Damien]

If all you want to do is change the tone of your exhaust, I would get a replacement manifold to replace the cracked one and change your muffler.

So I just looked at your pictures. Your truck is fuel injected and your cat has been removed. The cracked manifold will diffidently effect the way your truck runs. Your O2 sensor will read the extra O2 coming in through the crack and add fuel thinking your engine is lean.

If you want to add headers and duel exhaust you are going to need more parts like;
O2 sensor bungs or headers with them welded in already $10 ea.
Should have a heated O2 sensor so it still reads correct. $60 ea.
Plus $200- $300 at the exhaust shop assuming they will do work on it without cats.

[pcwillsie]

if you do decide to go with used manifolds go to a good tool store and you some a set of manifold spreaders. Used manifolds have a tendency to draw anyway. these spreaders will make installation of used manifolds much easier.

[shrtbx]

If you are really on a budget just replace the maniflold. If you go the header route i would suggest ceramic or send off the painted ones to get blasted and coated. The paint will burn off quick and you will be left will dull rusty looking headers.

I would think you would loose some low end torque with headers on a 305 but i could be wrong.

I think you can get a nice powerful sound with a set of original 40s series mufflers and stock manifolds. Trust me loud exhausts arent for the faint of heart. Sometimes i love it some times i hate.

[3r!c84]

i got 40s with stock manifolds i love the sound,nice and loud,(sets car alarms off at the highschool )

[ironroad9c1]

The manifolds are not whats holding back your power , its those crappy tbi swirl port heads ,i wouldn't waste the money on headers till you are ready to swap heads, and far as mufflers, AVOID flowcrappers, they flow the worst of any muffler, go with a good dynomax or magnaflow. Much better mufflers for the money.
here is a flow after about 2 years.


and we don't even salt the roads.