exhaust manifold

[lm48]

I am restoring a 2000 with a 2.0 L engine with 1800 head on and a carb setup. Is time to install the exhaust manifold and I notice a crack between the #2 and 3 cylinder. See picture. Appears to be stress releases crack so I do not think will be an issue in the future. The manifold is from a 79. Is this a common issue?

[124JOE]

mine had that crack also

[lm48]

Look to me as a cast pre tension release with out any future complication. So am good to go and start the engine on Saturday. Keep my fingers X due to electrical. This is the reason I like carbs.

[tartan18]

My 1975 1800 exhaust manifold has the same "crack." It appears to be intentional.

[WYSpider]

They are designed that way. What kind of down pipe are you using? Does yours sweep under the passanger's side to where a CAT is?

[lm48]

I am using a 79 down pipe, there is no more cat but the pipe follow the old line. I just start the engine for the first time after rebuild. A bottle resonator replaced the cat few years back, done by PO. All the pipes are 2” all the way back. Looks like the internal hole of the resonator is only 1” dia. so I order one with 2 ¼” which was the smallest size what I can buy. I try to run with out but the sound is terrible. Can’t wait to hear the new sound.

[IndyMark]

I have the 79 2000 Carb setup also. My manifold had same crack. I was also trying to track down exhaust fume issue for a while and noticed a leak where the exhaust manifold connects into the down pipe. It is normally a dry fit with no gaskets and prone to leak, plus the 4 studs on the manifold are easy to snap off. I had to drill and re-tap 3 of the 4 studs.

When I put it all back together I cut my own gasket out of metallic exhaust gasket material (Autozone $10 a sheet) and used RTV on both sides. The result is a good tight non-leaking fit and helped to solve most of my fume issues.

[lm48]

To remove the broken studs from the manifold I welded a nut on the top of what was left from the stud and was relatively easy to remove with out the need to drill or retread. As for gasket I had to make myself one to, but I was not able to get just plain material so I got one for Chevy and cut some round pieces out, set them temporarily with gasket sealant until the bolts where tide.

[BEEK]

as someone said above, that is not a crack, it is a designed expansion joint , to keep the manifold from cracking.