Alternative to blocking EGR

[John Larkin]

I just got a spare set of heads back from being cleaned and magged. I don't have any experience with Buick heads so I'm learning and reading. Looking at them, I notice the incredibly large EGR ports in the center exhaust runner. Surely these must cause all kinds of turbulence. I am not interested in blocking them off. I am interested in reducing their size. After asking a few questions, a suggestion evolved into driving a piece of "pipe" down the EGR ports so that the hole effectively becomes smaller. This way it would remain functional but at much reduced airflow (hypothetically like the end ports and their small EGR ports). I would assume given the right piece of "pipe", it could be expoxied in there just like a cylinder sleeve and then port blended to the runner. There is a little casting slag that would have to be cleaned up to make it completely cylindrical.

I did a search and didn't come up with anyone ever trying this. Any thoughts? Would it affect chip calibration at cruise?

 

[JeffG]

You could fill it with melted lead. Then blend it into the port and drill a small hole.

 

[John Larkin]

Might not be desirable since lead melts at about 600°.

 

[jastrckl]

interesting. the irc efnet #cars guys were talking about this very same thing today. if that wasn't you, then I might ask them.

 

[Intercooler]

Champion uses aluminum to fill their irons. For us without the means to do this Devcon Epoxy (blue stuff) is what most machine shops use.

 

[FreddieWilliams]

Originally posted by Intercooler
Champion uses aluminum to fill their irons. For us without the means to do this Devcon Epoxy (blue stuff) is what most machine shops use.

Does this stuff hold up to all the exhaust heat?

I was never comfortable with the large EGR passage and wanted to fill it up also. I was more concerned about the filler material breaking down/ falling out and going through the turbo.


Anyone know were I can pick up a few pounds of molten aluminum?

 

[Intercooler]

Yes. Devcon will hold up like metal.

 

[KendallF]

Josh, that was on #buickgn..yes, it was John and I who were talking about it.

Aluminum rod or thickwall tubing, if you want to retain the EGR. I wouldn't put Devcon (or any epoxy) in an exhaust port. I think you'd be seeing it on your turbine blades soon!

 

[Intercooler]

Guess you wouldn't want it in your lifter valley either or your oil pump could be seeing it but the Buick big block guys and 4.1 production block guys use it.

 

[KendallF]

Originally posted by Intercooler
Guess you wouldn't want it in your lifter valley either or your oil pump could be seeing it but the Buick big block guys and 4.1 production block guys use it.

I have nothing against epoxy in the lifter valley, or even in an intake port for that matter. There's a big difference in temperature between those areas and an exhaust port, however. The various types of Devcon, for instance, are only rated to 250 degrees.

My S2 block had epoxy in the lifter valley and on the freeze plugs when I bought it. One trip through the block oven (5-600 degrees?) and that stuff was cracked off and gone.