Installed new engine today, think that I might have an Exhaust Leak.

[Reziel_1983]

Hey guys, I put my 377 in today and when we fired up the engine to do the break in I heard a sort of high pitch ticking type noise coming from what seems to be the passenger's side of the engine. I didn't notice until we had the engine at about 2k rpms but one of the pipes or whatever on the header was red hot. Whenever we were putting the headers back on we accidentally bent one of the gaskets. Could this be an exhaust leak?

[INSIDIOUS '86]

if you bent it you may have cracked it and it simply blew out

another posibility is if you dont have a notched pan the crank on 377's hits the side of the pan for some odd reason

[Reziel_1983]

That could be it too... we just used the stock 400 sbc oil pan that came with the block...

[Reziel_1983]

Do you have the link of the oil pan I would need? I'm gonna change the header gasket tomorrow to see if it's fixed, but if not I guess I'll order a new pan. But the noise did sound like it was coming from the header.

[68GMCCustom]

did I understand you to say that one of the eight header tubes was red hot? and the other 7 weren't?

If so I'd be pulling that valve cover too to check everything for that cylinder.

[Reziel_1983]

Yes, that's correct, one tube. What should I be checking for when I pull the valve cover?
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[Reziel_1983]

Seems like the spark plug wire for #6 has been burned through. This is the same cylinder that was red hot on the header tube. Put a new gasket on, noise still there... I think you're right about the pan cause it sounds like its coming from the bottom.
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[Reziel_1983]

New wire on, tube still getting red.
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[68GMCCustom]

pull the valve cover....and check your p-rods/rocker arm for proper installation/movement and make sure your intake and exhaust valves are opening all the way.

[Reziel_1983]

Alright, I will do that tomorrow. Thanks.

[stroker87]

I had to change oil pans on my 383 stroker dont remember what was hitting it (rod bolt I think) one of the shops tried to bang on it to get the clearance needed since it was just barely hitting it but that didnt work out to good so i installed a moroso #20182 pan worked out well

[INSIDIOUS '86]

you can see dents in the bottom from where the rods made thier own clearance lol

i used hamburgers 1088 oil pan. comes with gasket and pickup, but it wont tell you that on summit

[rs72z]

Is this a destroked 400 or is it a std bore 350 with 3.75 400 crank?

[Reziel_1983]

Originally Posted by rs72z

Is this a destroked 400 or is it a std bore 350 with 3.75 400 crank?

Destroked 400.

[rs72z]

No need wording about the rods hitting the pan then. Make sure you don't have any vacuum leaks also. Pull the header back off and check the gasket.
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[INSIDIOUS '86]

mine is a destroked 400 as well, maybe you have a valve not closing on the exhaust and that ticking is the combustion exiting the valve into the exhaust causing it to glow

[csb#356]

Yeah your exhaust valve is probly not closing all the way, and that could burn that valve really quickly.

[Reziel_1983]

Thanks, I will try and figure out if it's not closing and how to make it close if it's not, lol.

[68GMCCustom]

new motor.....not surprising to have the valve lash adjustment or something else be off somewhere...easy to do.

[Reziel_1983]

readjusted valves, noise still there. Didn't test the header though because we want to get the noise resolved before that. But there's also a lower pitch kind of knocking sometimes... usually when the engine is revved a little. We don't know for sure but think it could possibly be a main bearing... going to have someone come look at it tomorrow...

[INSIDIOUS '86]

check the pan near the pan bolts by the flywheel if you see notches that werent there its the rod smacking the pan

idk why mine did considering these motors are shorter stroke so one would think there wouldnt be a clearance issue? oh well i like my hamburgers pan alot lol

[Reziel_1983]

I'll check that tomorrow. There are two distinct noises though that we're hearing, and then there's the header tube glowing. We think that we're most likely gonna have to pull the engine again...

[Reziel_1983]

Another weird thing is, the higher pitch noise isn't always there, only sometimes... and whenever we changed the timing, it would sometimes get worse.

[INSIDIOUS '86]

sounds like something isnt right in the valvetrain, did you use break in oil for the engine?

[Reziel_1983]

Originally Posted by INSIDIOUS '86

sounds like something isnt right in the valvetrain, did you use break in oil for the engine?

We used Delo 15w-40 for it. That is what our machinist told us to use.
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