NSW Corvettes

Technical Tips => Engines - Carbies - Exhausts - Dissys => Topic started by: reserved on June 25, 2006, 09:04:46 PM

Title: EXHAUST MANIFOLD
Post by: reserved on June 25, 2006, 09:04:46 PM: :b2:an:mmm:grr

I removed my old exhust manifold to fit a new one, went to remove the gasket, but could not find one fitted anywhere, looked in the assembly manual and found that there was no gasket fitted on the 454 motor. I purchased a gasket with the new manifold, my question to the other home mechanics is should I fit a gasket or not.
All sugestion listened to and then possibly ignored.
;41
:P
Title: EXHAUST MANIFOLD
Post by: Cameron 77C3 on June 25, 2006, 09:26:26 PM: Dammm. No gasket. Hmmmmm. It goes against my grain not to fit one but they must of had a reason for leaving them out. I have not worked on a big block.

Rat Pack. Here is a chance for you to finally make your selves usefull.;41

Cam
Title: EXHAUST MANIFOLD
Post by: SC on June 25, 2006, 10:47:17 PM: you can use a smear of black silcone it works well as long as the mating surfaces are in perfect condition if not use a gasket, holden 4.2 and 5.0 engines never had gaskets fitted to them either
Title: EXHAUST MANIFOLD
Post by: Cameron 77C3 on June 26, 2006, 10:12:50 PM: So reserved, what are you going to do?

Cam
Title: EXHAUST MANIFOLD
Post by: reserved on June 26, 2006, 10:26:41 PM: :evil:b2:evil

I am waiting for more input from my fellow big block experts befor I ignore them and probably use the gasket as it can't hurt.

;27;27;27
Title: EXHAUST MANIFOLD
Post by: MADLT1 on June 26, 2006, 11:50:58 PM: i have had big blocks in the past and allways used a gasket;42
Title: EXHAUST MANIFOLD
Post by: smokem on July 16, 2006, 08:16:21 PM: Using silicon is fine as SC says . Use good quality to handle heat . Guy I know in Melb. builds high dollar headers never uses gaskets.
Title: EXHAUST MANIFOLD
Post by: 69 DIRTY RAT on July 16, 2006, 11:40:14 PM: I havent got gaskets on mine either! just that silicon stuff!
Title: EXHAUST MANIFOLD
Post by: Vette Obsessed on July 17, 2006, 09:00:32 PM: No big block here but I don't have any gaskets on my extractors. They were installed using silicon alone by the place that made the pipes and I've since reinstalled them myself with silicon with no leaking issues.
Title: EXHAUST MANIFOLD
Post by: reserved on July 17, 2006, 09:14:00 PM: :mmm :grr :mmm

Thanks for the feedback guys, OK then how do you use it?
A thin coat (1mm or so) and let it dry befor fitting the manifold, or apply it and try to get the manifold on and correctly tensioned befor the silicon dries

;eek ;40 ;eek
Title: EXHAUST MANIFOLD
Post by: SC on July 17, 2006, 09:31:39 PM: just like you said a thin coat and do it wet you have plenty of time before it skins over tension bolts and your done black silicon 712 is what we use all the time we have never had a failure
Title: EXHAUST MANIFOLD
Post by: reserved on July 17, 2006, 09:54:00 PM: ;) ;) ;)

Thanks SC will try it.

;laugh ;43 ;laugh
Title: EXHAUST MANIFOLD
Post by: reserved on July 18, 2006, 08:35:35 PM: ;30 :flower :flower ;30

Today I went to
Bunnings, Auto parts, Repco, Luckey exhausts and SBC
Looking for black solicon 712, with no luck
Best I could find was one rated at 320 degrees C
and not recommended for exhausts.
WHERE DO YOU GET IT!

;48
Title: EXHAUST MANIFOLD
Post by: Cameron 77C3 on July 18, 2006, 08:39:00 PM: Try CBC Consolidated Bearing Company. Do you want me to see if I can get some tomorrow and bring it to Hooters. Assuming that your going of course.

Cam
Title: EXHAUST MANIFOLD
Post by: reserved on July 18, 2006, 08:55:34 PM: Cam :luv

Yes please.

;42;43;42
Title: EXHAUST MANIFOLD
Post by: Cameron 77C3 on July 18, 2006, 09:11:24 PM: I'll call in and see them on the way to work tomorrow.
Title: EXHAUST MANIFOLD
Post by: Cameron 77C3 on July 19, 2006, 10:21:46 AM: Reserved, no luck squire. They think that the 712 is a Dow Corning product and they only stock Loctite. Their high temp only goes to 316 Deg C.

We need to find what the temp rating of the 712 is.

I'll make some calls and see what I come up with.

Cam

edietd:-
No, dow corning don't have a 712 either. You should have got a small block.;39
Title: EXHAUST MANIFOLD
Post by: Cameron 77C3 on July 19, 2006, 11:18:11 AM: Ok I'm just waiting for some faxs to come in of the data sheets on some of these products.

I also made a call to Scott at Corvette Alterations.

He informed me that with his infrared thermometer gun pointed onto the exhaust manifold his gun goes off the scale and it goes to 500 deg C.

He informed me that if the surfaces are completely flat and smooth with no pits that the "no gasket" is the better option and if they are not flat, the gasket option is the way to go. He also said to be sure that it is the metal type gasket.

This is only information that I am supplying for your consideration, it is not a recomendation. It is in no way to say that any other information offerd in this thread is incorrect.

Once the data sheets on the silicones (silastics) come in I'll let you know what they have published.

Cam
Title: EXHAUST MANIFOLD
Post by: Cameron 77C3 on July 19, 2006, 03:17:05 PM: Mr Reserved. I have the data sheets on these products. To much for me to put up here. I'll bring them with me tonight.

Cam
Title: EXHAUST MANIFOLD
Post by: Cameron 77C3 on July 20, 2006, 01:58:59 PM: Hey SC. You said last night that you were going to check if that was 712 or 732. Come on get your act together. ;48;43
Title: EXHAUST MANIFOLD
Post by: SC on July 20, 2006, 04:43:35 PM: sorry cam i didnt have you phone number with me at work
ooooops it was 732
i was close
lol
Title: EXHAUST MANIFOLD
Post by: Cameron 77C3 on July 20, 2006, 05:35:08 PM: Quote
Originally posted by SC
sorry cam i didnt have you phone number with me at work
ooooops it was 732
i was close
lol

You sod. Do you know how long I was chasing 712. ;30 Wait till I see you next time. ;53

OK, Reserved one of the data sheets I gave you last night is on the the silastic that SC spoke of.

Cam