Exhaust question. gasket related.

[Xplorer82]

Ok, well i finally got my exhaust bolts off (cats to headers) and dropped the old exhaust system.

now i have never done any exhaust work except welding on tips, ect. I am getting ready to install my magnaflow bolt-on cats and dont know if i need to place a gasket in between the end of the header pipe and the beginning of the cat(s) pipe(s). i am including pictures below because the end of the header is "rounded off" and the beginning of the cats are "flared". i am not sure if i would place a gasket in the middle of the two.


(click to enlarge)
::::Header flange to cat flange:::: (gasket needed?)

i did not see any gaskets in that area when i uninstalled (unless i over looked them)

thanks in advance.

 

[Xplorer82]

one more question, i went out and dry fitted my tailpipe from rockauto and decided to check things out again. there was some red stuff smeared around the rounded part of the header (end of header, seen in photo).

if they didnt use a gasket there, what would that red stuff be? i was thinking maybe some kind of sealant?

 

[Electrohacker]

being flanged i dont think it uses a gasket, the red might be highheat RTV if there was a leak... maybe?

i'm not 100% on this but its a good educated guess

 

[Xplorer82]

being flanged i dont think it uses a gasket, the red might be highheat RTV if there was a leak... maybe?

i'm not 100% on this but its a good educated guess

thanks for the reply.

after thinking about it more last night and this morning i was thinking the same thing. No Gasket and most likely RTV or some type of muffler putty.

Im just going to clean the area good and bolt everything up. if i end up having a leak i'll use some of that RTV.

 

[jremington59]

I'm going to guess there's a small exhaust donut that goes in there. I don't see how thats going to seal tight with no leak.

 

[Turdle]

There is no gasket in a ball and socket flange
just bolt it up and alternate from side to side while tightening to get an even seal. Id go ahead and use some "ultra copper" sealer on the ball before tightening it all up.

 

[Xplorer82]

I'm going to guess there's a small exhaust donut that goes in there. I don't see how thats going to seal tight with no leak.

i went to Federated and auto zone and all the had listed was the gasket in the pics above.

There is no gasket in a ball and socket flange
just bolt it up and alternate from side to side while tightening to get an even seal. Id go ahead and use some "ultra copper" sealer on the ball before tightening it all up.

^^ correct sir. it just bolts up and seals itself. found that out tonight while installing the cats. didnt get to see this till now, but thanks for the info Turdle.




And FYI, anyone that might be getting the magnaflow bolt on cats, Make sure you check to make sure that the o2 sensor locations are off centered to the left(toward the driverside) on the piping(on the pass side cat). the retard that put mine together put the sensor locations straight on top of the piping which lead to problems. that and they could have made the hanger opening a little larger to let it hang down a little more to clear the under-body and sensors. took awhile but i figured out how to make it all work. ugh.


What a PITA all this has been (almost done with the whole exhaust system now)


anyway thanks guys.

 

[Xplorer82]

Oh one more thing.

after i got the cats bolted up i put all the o2's in and fired it up to check for leaks and after i shut her down and crawled back under there i saw some gray'ish liquid right underneath the end of the cat pipes.

is this something to worry about or is that just some kind of "coating" or something in there and that is how it comes out?

if needed i have pics of the puddle. at first i thought it was antifreeze or something cause it was kind of dark in the garage, my heart about dropped till i smelled it and saw it was a gray color.

 

[Xplorer82]

(click to enlarge)

 

[Turdle]

That is probably condensation from the engine.

 

[Xplorer82]

thanks again Turdle. i figured it was a combo between that maybe and/or a coating inside the cats/pipes or something.


doing the last welds on the exhaust tonight. Man that Edelbrock SDT sounds pretty dang good on the 4.0L. have not had any drive time yet but from idling and reving it up, i like the sounds so far

 

[Xplorer82]

Turdle (or anyone else), got another question sorry.


Ok, at the end of the header where the "ball & socket" connections are, the reason they are there is for them to be able to "move around/give & take" with the motor correct?

If yes, then if there is to much "tension" on that ball and socket then that will affect the acceleration right?


the reason i ask that is i had the problem with the o2 sensor location as stated above (location was on top of the piping and the o2 sensor was squished against the underbody) so instead of using the hanger that was on the bolt on cat i just let the cat hang instead of "hanging from hanger location" so the o2 sensor had clearance, well doing that kind of put pressure/tension on the "ball & socket" and piping.


what i noticed on the test drive(s),
-when i would make a left hand turn it got up and went with ease.

-making a right hand turn it seemed a little hesitant. like something was holding it back

-from take off (going straight) it felt a little hesitant again for about 8-10 seconds, but once i hit about 3k rpm she started to move

-while driving down the road about 55mph i noticed when i kicked it down to pass someone or just to get on it sometimes it would scoot and other times it felt like something was holding it back again.


ball & socket flanges to tight im guessing? it never did that before till the test drive today after installing the cats, edelbrock sdt and new tailpipe. idk, maybe it just needs a little more drive time to work everything out? just thought i would ask, it was on my mind.

 

[Xplorer82]

up one time to see if i can get a answer/opinion(s)

 

[Turdle]

It should be tight, and not allow any flex.

 

[Xplorer82]

It should be tight, and not allow any flex.

Ok then, well i guess my little "theory" was wrong Ha.

hmm, i wonder why it is acting like that then. ehh, that is all for now then thanks again turdle

 

[Xplorer82]

Update on Edelbrock SDT

Well after having plenty of drive time w/the edelbrock SDT installed and getting my kinks worked out, it is time to go back to the good 'ole Flowmaster (american thunder) 40 series.

the edelbrock has a awesome idling tone and sounds awesome around 3kRPM and above, it is just to loud for my taste between 2200rpm thru 28-2900rpm. i believe this SDT would be/sound **** on a v8 X, it is just not for the v6 IMO.


so all in all, i should have skipped buying a new muffler and making the dual out work........ my cheap cure for that since i took a hit in the wallet for that SDT, i cut and welded a plug in for the second outlet on the muffler. hopefully getting the flowmaster under there this weekend. Ugh.

 

[Xplorer82]

well i could not wait. i went ahead and threw the flowmaster back on tonight. Man i missed that muffler/sound.

well anyone want a edelbrock SDT now LoL. only used what, a week & a 1/2. (dual in/single out BTW)


Hopefully Magnaflow/car sound will work with me easily because i have a rattle coming from one of my cats (driver side) its not only when driving but if you hit the pipes near the cats laying under the truck w/it off. it is not a heat shield making the sound. there is either something loose inside the cat or somethings stuck in between the cat and heat shield. i believe it is inside though after some time trying to find the rattle. wish me luck with that Ha.