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Old 11-08-2006, 01:15 PM   #1
bowtiebreece
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Intake Manifold Gasket

I have a small Block 400 with a leaky intake manifold gasket. The leak has gotten bigger and I am wondering how much a repair is going to be. I do some work myself but with out much experience with this and no timing light I think it is over my head. what would something like this cost me to get repaired?

Here are pictures of my project, I have taken bumpers, emblems, trim, grill and lights off and am in the middle of taking the bed off
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Old 11-08-2006, 01:41 PM   #2
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Re: INtake Manifold Gasket

for the money it will cost you to take it in I would buy a gasket ($25) and a timing light ($50) and do it yourself. I put a new intake on mine and it's easy. Just be sure to titghten them down equally and take your time. I even installed ARP stainless steel bolts when i did mine...you will need to drain your coolent, remove your dizzy (good time to upgrade to HEI), remove intake, clean all surfaces, replace gasket, replace intake (use sealant on the bolts), replace dizzy, hook it all up and refill coolant. Let it all set up overnight and then start and reset timing. SHould be good..... I am sure that oyu can find detailed pictures on here that will fill in the blanks...
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Old 11-08-2006, 03:07 PM   #3
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Re: INtake Manifold Gasket

I am sure I might start a little controversy on this subject, but definetly worth bringing up and comparing notes. In the past I have used the front and rear rubber lips for sealing the intake front and rear edge. I was careful putting them down and had no leaks. Now I have read and was told by the engine guru, to just lay down a good bead of silicone and forget the front and rear seals and you will be better off.

Any one care to throw out their opinions?????
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Old 11-08-2006, 04:05 PM   #4
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Re: INtake Manifold Gasket

The end seals, imho, might be fine if the block has never been decked, heads have never been shaved, same thickness head gasket as stock and the stock intake manifold is used. If you change any of that, the stock end seals are going to either get squished too much or not enough causing leaks. If the clearance is too small, they will even prevent the intake from sealing to the heads. Even if they do fit right, it is just rubber on iron, and it will weep some oil out anyhow. A bead of Ultra-black rtv silicone is oil proof if done right and allows for any machining and other parts tolerance difference.
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Old 11-08-2006, 04:23 PM   #5
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Re: INtake Manifold Gasket

When i did my intake, i also wasnt sure as to whether or not i was going to put the end seals in.. it had some pretty large gaps, i decided not to put them in, i just ran a good large bead of rtv and thats it. Still seems to be fine.. So no i dont think they are really necessary. I think you should do the intake yourself.. I was pretty fresh to motors and trucks when I did mine, and I decided to do the intake myself and it was easy cheese.. You will also need a torque wrench..
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Old 11-08-2006, 04:27 PM   #6
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Re: INtake Manifold Gasket

I couldn't fit a torgue wrench on my edelbrock...I seem to remember the instructions on Edelbrock webpage saying to use RTV instead of the rubber gasket, so i did. Like I said, let it cure overnight prior to starting your engine or you will have leaks from blowing the rtv out...

Last edited by msgross; 11-08-2006 at 04:28 PM.
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Old 11-08-2006, 04:57 PM   #7
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Re: INtake Manifold Gasket

maybe use a swivel socket+extension? I think thats maybe what i did cant remember
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Old 11-08-2006, 04:58 PM   #8
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Re: INtake Manifold Gasket

they torque low anyway (20-30lbs maybe)? i used the two finger on a little wrench method!
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Old 11-08-2006, 05:17 PM   #9
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Re: INtake Manifold Gasket

i have done 7 or 8 intake swaps and i always use the silicone and ditch the rubber end piece. i have never had a leak.
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Old 11-08-2006, 05:21 PM   #10
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Re: INtake Manifold Gasket

You can do the intake gasket repair yourself without really needing to have a timing light handy. Just put a mark on the distributor where the rotor is pointing and a mark somewhere else to use as a reference - when you reinstall the distributor just make sure you get those marks lined up and you are good to go.

I did the intake on my BBC a while back and I was nervous that I would screw something up but really as long as you get the RTV laid down and set the intake down slowly so you don't have to move it - you should have no problems.
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Last edited by Yukon Jack; 11-08-2006 at 05:22 PM.
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Old 11-08-2006, 05:29 PM   #11
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Re: INtake Manifold Gasket

Make sure you get the proper intake gasket. Dont use the stock style fel-pro on an aluminum intake as it may cause leaks. I beleive the part# is 1256 Fel-pro is what you want to use. And you dont really need a torque wrench if youre careful. Start in the middle and work your way out. Yes use the ultra black rtv on the ends without the end seals. Lay approx. a 1/4" bead on each end of the block,run it up the side of the head about 3/8" on both sides front and back. Then with a little blue silicon put a small amount around each water passage then lay your intake gasket ont the heads. then GENTLY lay your intake in place. Make sure you get it the right spot so you dont have to move it around too much and pull out the RTV.start the intake bolts by finger first. Use a little rtv on the threads to seal the bolts, and use a small (AN) style washer with the bolts tighten them in order starting in the middle and working your way to the ends. Let the truck set overnight so the RTV cures. As long as you mark the location of the rotor tip on your distributor and put the dist. back in the same way you can tune it by ear to get you by or you can purchase a timing light and set it right. change your oil when youre done cause you will get some antifreeze/water in the lifter valley when you pull the intake off.-Sorry SOOO long!
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Old 11-08-2006, 05:43 PM   #12
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Re: INtake Manifold Gasket

20 years as a mechanic and I have always used silicone for the ends of the intake. Another tip for distributor removal/install. As said earlier, mark the distributor housing and rotor position. As you lift the distributor out, the rotor will spin. mark where it stops turning and use that mark as a reference when re installing the distributor.
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Old 11-08-2006, 07:59 PM   #13
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Re: INtake Manifold Gasket

Quote:
Originally Posted by msgross View Post
for the money it will cost you to take it in I would buy a gasket ($25) and a timing light ($50) and do it yourself. I put a new intake on mine and it's easy. Just be sure to titghten them down equally and take your time. I even installed ARP stainless steel bolts when i did mine...you will need to drain your coolent, remove your dizzy (good time to upgrade to HEI), remove intake, clean all surfaces, replace gasket, replace intake (use sealant on the bolts), replace dizzy, hook it all up and refill coolant. Let it all set up overnight and then start and reset timing. SHould be good..... I am sure that oyu can find detailed pictures on here that will fill in the blanks...
you can ABSOLUTELY do this yourself very well for less than a shop would charge, and get to keep the tools to boot. Happy to help you walk through it, or there are some great books for this if you want to go that route. It's about a 2 hour job on a good day and if you take some shortcuts - like having the engine on TDC compression on #1 before pulling the distributor.
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Old 11-08-2006, 08:02 PM   #14
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Re: INtake Manifold Gasket

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Originally Posted by wolfthing2000 View Post
I am sure I might start a little controversy on this subject, but definetly worth bringing up and comparing notes. In the past I have used the front and rear rubber lips for sealing the intake front and rear edge. I was careful putting them down and had no leaks. Now I have read and was told by the engine guru, to just lay down a good bead of silicone and forget the front and rear seals and you will be better off.

Any one care to throw out their opinions?????
What, opinions? On this board? :-D

I've never had a problem when I've used the seals, but I don't do it any more. The reason you've had good luck is because you're being very careful about placing the intake....it only takes a little shift to move it out of position. The 1/4" bead of RTV is just easier and more tolerant of a little "adjustment" if required. So I agree with both of you...but I've found the RTV bead to be a better solution.
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Old 11-08-2006, 08:04 PM   #15
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Re: INtake Manifold Gasket

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Originally Posted by Green Machine View Post
Even if they do fit right, it is just rubber on iron, and it will weep some oil out anyhow.
Agree overall, but just wanted to note that the install instructions for the rubber seals note that a little RTV is required in the corners. If you put the seals on completely dry, they're for sure not going to seal - not the vacuum, let alone the oil
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Old 11-08-2006, 08:37 PM   #16
7387chevys
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Re: Intake Manifold Gasket

rtv front and rear started it up right after we got it put on ........no leaks
Shane
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Old 11-08-2006, 11:23 PM   #17
wolfthing2000
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Re: Intake Manifold Gasket

Reminds me of a bad experience my friend had with a local shop who did a manifold change for him. He drove it home, maybe 10 miles and to work the next day, maybe another 10 miles , and a rod was a knockin with a good sound motor with maybe 60k on it.
The shop refused to have anything to do with it. He took it to the GM boys and they found anti freeze in the crankcase!! Turns out the first shop must have not changed the oil after they spewed Prestone in the guys engine!!!! Be Sure to drain the coolant out. And change the oil too!!!!
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Old 11-08-2006, 11:26 PM   #18
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Re: Intake Manifold Gasket

I forgot to tie it together here, but I have read that if coolant gets in the crankcase and it runs it through the lube system, the only cure is a teardown and new bearings since the anti freeze eats the bearing material fast!!!!
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