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Intake Manifold Gasket Leak - New Build

RedWings69

Contributor
Jr. Member
Joined
Jul 21, 2016
Messages
59
Need some feedback given i do not want to do this for a third time. I believe i am ordering the wrong gasket for my re-man motor for the intake manifold. Twice i have had a coolant leak and each time it is in the driver side rear where the intake meets the head. Either the gasket is wrong or it keeps shifting.

Question - should i be using high temp RTV in this area or can someone suggest the proper intake gasket based on the picture attached. Any help would be appreciated.

PS- The intake manifold is new and the first gasket i used was supplied buy engine builder. The second was from local auto parts store based on year of engine.
 

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bronconut73

Bronco Guru
Joined
Aug 7, 2012
Messages
9,916
First,

Use RTV at the China rails.
Those seals tend to leak or blow out.

I have used a little RTV around the intake manifold gasket at the water passages in the past with good results, but its not always advised....
 

DJs74

Bronco Guru
Joined
Apr 1, 2014
Messages
1,135
Looks like you are using the cork end gaskets - I would get rid of those and use a bead of RTV on the front and rear rails. It's possible that the end gaskets are preventing the seal between the intake and cylinder head.
Next - I always use RTV on the coolant passages - not gobs, just a decent layer all the way around the port.
Last - I also use Edelbrock Gasgacinch 9300 on the cylinder head & intake side of the gasket, just a complete thin coat.

Edit:
For 302... Felpro 1250 gasket https://www.summitracing.com/parts/fel-1250



DJs74
 

B RON CO

Contributor
Bronco Guru
Joined
Jun 29, 2016
Messages
2,412
Loc.
Statesville, NC
Hi, I use threaded rods in the corners to guide the intake straight down home. After the inner bolts are started the threaded rods come out. I've had the intake push the gasket and ended up with oil seepage into the intake port without the threaded rod guides. As mentioned, use sealer sparingly. Some guys swear by a big bead of silicone only on the front and back rails. I think some gasket sets don't even give the front and back seals. I also let the sealer set up overnight before adding coolant and running the engine. Good luck
 

Skiddy

Bronco Guru
Joined
Oct 8, 2003
Messages
11,557
Hi, I use threaded rods in the corners to guide the intake straight down home. After the inner bolts are started the threaded rods come out. I've had the intake push the gasket and ended up with oil seepage into the intake port without the threaded rod guides. As mentioned, use sealer sparingly. Some guys swear by a big bead of silicone only on the front and back rails. I think some gasket sets don't even give the front and back seals. I also let the sealer set up overnight before adding coolant and running the engine. Good luck
X2 making studs to slide the intake down makes a world of difference
 

tirewater

Contributor
Sr. Member
Joined
Jan 28, 2011
Messages
1,040
Loc.
San Francisco Bay Area
Carburetor studs work well as guides for the intake manifold.

Your intake manifold coolant port is too big for that gasket. Use a different intake manifold gasket. You can try the fel-pro 1250 gasket which has multiple cut out options on it. Be sure to follow installation instructions carefully in regards to torque and cleanliness.

Check to see that the intake manifold sealing surface is flat with the cylinder head. If the cylinder head was resurfaced at an angle it could affect sealing.
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
Need some feedback given i do not want to do this for a third time. I believe i am ordering the wrong gasket for my re-man motor for the intake manifold. Twice i have had a coolant leak and each time it is in the driver side rear where the intake meets the head. Either the gasket is wrong or it keeps shifting.

Question - should i be using high temp RTV in this area or can someone suggest the proper intake gasket based on the picture attached. Any help would be appreciated.

PS- The intake manifold is new and the first gasket i used was supplied buy engine builder. The second was from local auto parts store based on year of engine.

Could you include the Gasket manufacturer and part number?
 
OP
OP
RedWings69

RedWings69

Contributor
Jr. Member
Joined
Jul 21, 2016
Messages
59
MR Gasket 203G from O'Rielly's and Victor Reins Mahle 95-1462VR which is a master set that came with long block re-man.
 

73azbronco

Contributor
Bronco Guru
Joined
Nov 11, 2007
Messages
7,796
New build? I'd clean all surfaces, use the studs as noted above, and carefully dry install the intake with no gasket and check for square/plumb/gaps. wiggle it a little and use a really thin feeler gage to see if one side or end or top or bottom is or has a larger or smaller gap. Do the planes of the head and intake match? Gap is OK, you just don't want one end to be tight and the other really lose (the side that leaks), with one half of the intake squared up, and the other half all wonky.

Also, gut feeling and experience, using the cork/rubber galley end seals instead of just RTV is causing intake to sit to high.
 
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