Aftermarket Header available for the L20B?

[Mike Phillips]

Going to try to remove the broken studs out the exhaust manifold but if I run into problems, are there any aftermarket headers available for the L20B?

 

Or anyone in the SoCal area with a good stock exhaust manifold?

 

 

:)

[]2eDeYe]

Headers are available, but the L16 mannny is the best flowing of the L series exhaust manifolds. Flows at least as well as a good header.

[hang_510]

the studs are in the head...

 

Or anyone in the SoCal area with a good stock exhaust manifold?

 

:sneaky: yep!

[Phlebmaster]

I agree...my exhaust flows freely :eek: I have the finned L-16 mani, and I am happy with it. Do you have round port or square port head?

[Mike Phillips]

the studs are in the head...

 

I thought the threaded stock coming out of the bottom of the exhaust manifold were referred to as studs because they don't have heads like a bolt?

 

How about Exhaust Flange Bolts?

 

:)

 

I agree...my exhaust flows freely :eek: I have the finned L-16 mani, and I am happy with it. Do you have round port or square port head?

 

 

The one I have has square exhaust ports as does the head. Here it is,

 

 

 

And here's the upcoming project...

 

 

 

 

:)

[]2eDeYe]

That's the best manifold you can get for an L. L16 manny with no smog ports.

 

I drilled mine out and heli-coiled it. Bought some brand new Grade 8 studs and grade 5 nuts with lock washers.

[datzenmike]

Heat them up around the stud to orange hot and use vice grips. They will squeal, but they will come out much much easier. Heating makes the metal swell and the hole becomes bigger. I use SS nuts and they always come off easy later. You may be able to get the studs in metric SS too.

[hang_510]

2eDeYe;86784'']That's the best manifold you can get for an L. L16 manny with no smog ports.

 

those are studs, i thought you were refering to where it mounts on the head not at the collector.

 

get em out and use that one!

 

 

 

 

thats a different pipe too. havent seen that one. none of mine have it???

mini-turbo??? :lol:

[datzenmike]

That's the EGR tube. First L16/18 Manifold I've seen with it on. The '74 620 with the L18 had EGR. First year EGR, last year for L18 in the truck. Also there are no air injection nozzles on the exhaust ports. '75 and up L20Bs had air pumps and earlier cars did, but trucks were often exempt from some smog stuff where cars of that year were not. That might be a truck L18 exhaust manifold.

Edited October 8, 2008 by datzenmike

[Llittle_Llama]

damnit i need one of those....

[datzenmike]

If that is a truck exhaust it only came on the '74. L18s were used on the '73'5 trucks and wouldn't have had the EGR tube is my guess.

[dat521gatherer]

vice grips have never worked for me but then again i never heat it up. a trick that has worked for me is pounding on a 12 point socket on the stud. you may be sacrificing a socket but in my opinion thats all a 12 point is good for. whoever came up with a 12 point should be shot. i've removed exhaust studs and a head bolt doing this. and when all else fail drill it out and tap it. no need to heli coil it unless you drill the hole too big.

 

i've got one of those finned square manifolds but it doesn't have the pollution pipe. my l20b had that pipe and i took it off and put a plug in it.

[dat521gatherer]

sometimes a good pipe wrench will work but you have to have some good meat to grab onto.

[phatdave]

but you have to have some good meat to grab onto.

 

Leaves me out!

[Mike Phillips]

Heat them up around the stud to orange hot and use vice grips.

 

Tried this method yesterday... no luck...

 

when all else fail drill it out and tap it. no need to heli coil it unless you drill the hole too big.

 

Have two holes drilled and broke a drill bit off inside the third stud...

 

Now I'm trying to drill out a drill Carbon Drill bit...

 

Ugh...

 

Hook, nook or crook we'll getter done...

 

 

:)

[]2eDeYe]

no need to heli coil it unless you drill the hole too big.

 

When I finally got to the 'clean' threads they were so pitted and rusty, I wouldn't have trusted them to hold my pant's up, and I don't wear a belt. :D

[hang_510]

Now I'm trying to drill out a drill Carbon Drill bit...

 

theyre never EZ-out :cursing:

 

 

 

lemme know what else you break trying :lol: (my list is long...)

[mike]

Are you guys saying a square port L16 mani will flow as good/better as a header on a round port L18/20 head? If so do you use the round or square port exhaust gaskets?

I had a non smog L16 mani and I doubt that Ive got it anymore... Somebody helped themselves to anything that wasnt bolted onto my truck:mad: They left all the EGR shit that I ripped off though, that was nice of them.(sorry for bitching)

 

As for the stuck studs if there is not a broken bit in there try grinding them flat and use metal punch to get a good center/guide for the bit and start with a small bit and work up to the proper size. go slow and use lots of lube (I usually just use PB blaster or WD 40 because its what Ive got. Make sure the bit is sharp too, if its not go to harbor freight and buy a couple cheap metal bits of each size that you need. Ive tried sharpening bits before but it seems that once they loose the factory tip the only thing theyre good for is wood.

 

Is there enough room to fit a bolt down from the top on those studs, maybe use one that doesnt fit tight, might have to shape the head a bit with a grinder to make sure that it sits flush and square... That way if you have to remove the exhaust again worst case scenario is that youd have to buy 3 new nuts and bolts.

[datzenmike]

You can run a round or square port head on a square exhaust manifold. A round exhaust manifold is only good on a round port head. Use the square gasket.

[Mike Phillips]

lemme know what else you break trying :lol: (my list is long...)

 

 

 

One knuckle

 

The good news is the old broken studs have now been removed. The bad news is the flange isn't as pretty as it use to be but it will work.

 

:)

[]2eDeYe]

You could always get the flange machined flat again.

[Mike Phillips]

2eDeYe;87241']

You could always get the flange machined flat again.

 

 

It's plenty flat, it's just now I'll be using bolts to hold the two flanges together instead of studs. No big deal, just want a quiet exhaust.

 

Just a comment that maybe someone has some insight into?

 

Seems like a poor design not having any lower holes designed into both the intake and the exhaust to hold these to flat and tight to the head?

 

:confused:

[The Birdman]

You can run a round or square port head on a square exhaust manifold. A round exhaust manifold is only good on a round port head. Use the square gasket.

 

Just found this thread, but are you sure it's ok to run a square header-manifold on a round port head?

[wayno]

Just found this thread, but are you sure it's ok to run a square header-manifold on a round port head?

 

Only short term, you need a proper exhaust manifold long term.

I did it for 3 or 4 months, but you will start going threw intake/exhaust gaskets eventually, and everytime you have to put a new one on, you will try to tighten it tighter, and tighter till you strip and/or break head studs/bolts/threads, just do it right, buy a proper exhaust manifold.

[Skib]

Iv run square port mani with square port gasket on a round port head. never had any problems.

but thats just my personal experience with it.