Another noob exh. manifold porting thread...

[daytonajesse]

Hey guys,
Im a total noob to porting/polishing anything, dont know anybody that does it or knows about it really so my knowledge about it ends around the common sense area, what I have read, and what few pictures are on these boards I have found, blah blah blah.

Anyway I have been poking around with a stock T1/T2 exhaust manifold and my dremel. I just got a flexible shaft attachment for it yesterday

I was able to completely remove those to big bumps without busting through anywhere so I was happy about that. Other than that I have been smoothing the insides that I can reach, eliminating all of the ridge I can get at, and trying to open it up evenly on the insides.

Is that basically what the goal is here? Is there a way to get in between the first 3 runners? I'll post pics in a bit if I can get my %$%$ camera working!

[tryingbe]

You want to smooth it out.

[mpgmike]

It sounds like you're porting an exhaust manifold. You can't get between the runners, don't worry about it. What you'll find is the biggest restriction will be cylinder #3 where the wall protrudes 1/4 of the way into the port. Different manifolds have different amounts of core shift. Remove as much of that wall as you can without getting too thin. By matching the ports to the gasket and taking that size straight in as far as your tool will reach, you'll be far ahead. You seem to have found the 2 bumps in cyls#3 & 4. Also, radius around the turbo inlet area. There are some sharp bends in there. If you open the turbo inlet to about 1/16" smaller than the turbo's hole, that will help too.

Mike
www.PowreHaus.com

[daytonajesse]

yep exhaust manifold
I took a piece of cardboard and made an imprint of my new turbo's flange, cut it out, mounted it on my exhaust manifold and made the markings where necessary and opened it up to just about what you said already so that was a nice fluke! I figured there is a small amount of play on exactly where the turbo sits when bolted and I did not want a flat edge poking through for the exhaust to get all turbulent on.
I've been working on it off and on for about 6 months now I guess, not very often but I have probably in total 10 dremel hours and maybe 2hrs more working with my hands, into it already. I've removed handfulls of stuff from it just smoothing and getting those 2 bolt bumps and ridge.

What kind of gains can be had from a ported/polished exhaust manifold?
I know you have no idea how mine might perform, I mean in general.


This is just another part for my collection of parts that hopefully someday will turn into a working engine to replace my leaky tired stock (mostly) 88 T1 motor.
Rebuilt .42/.48 T2 S60 Clipped turbine, ported exhaust manifold, 2.4 lifters and conical springs, Forged rods, T2 pistons (Im most likely going to buy new forged ones), 2.5 SV, I have a high vol oil pump but i dont think im going to use it.

[86Shelby]

A carbide bit is your friend. A very good friend. Otherwise Mike covered it pretty well.

[mpgmike]

A sand blaster and some Tech Line coatings and they look like this...

Mike
www.PowreHaus.com

[crazymadbastard]

Quote:

Originally Posted by mpgmike A sand blaster and some Tech Line coatings and they look like this... Mike www.PowreHaus.com

I used that techline stuff on the manifold and hotside of the turbine and wastegate, I though it would be a good idea, underhood temps seem pretty low now.

[mpgmike]

Consenses is that it lowers manifold surface temps about 400* F.

Mike

[bfarroo]

Quote:

Originally Posted by 86Shelby A carbide bit is your friend. A very good friend. Otherwise Mike covered it pretty well.

Yep after using a carbide bit on a Die grinder the dremel is just about useless. The carbide bit and a die grinder would have cut your work time down to an hour I bet. I have a tendency if getting carried away with mine.

Benji

[86Tona]

Quote:

Originally Posted by mpgmike A sand blaster and some Tech Line coatings and they look like this... Mike www.PowreHaus.com

Mike what is that threaded hole in the side of the manifold? Is that for the O2 sensor?

[86Tona]

Quote:

Originally Posted by mpgmike Consenses is that it lowers manifold surface temps about 400* F. Mike

If I may add to what Mike has said, it would then also lower the engine compartment temps a great deal which means the intake manifold as well. This has to be a good thing when trying to lower incoming air temps.

[daytonajesse]

my guess is egt bung

[88_Pacifica]

^ yep.. It's for the EGT sensor... should be required equip on these I've found out...

[tkelly27]

+1 for EGT. Wideband too! but that goes after the turbo.

[86Tona]

Does anyone know of a DIY EGT circuit drawing? I'm building an A/F gauge and would love to build into it an EGT gauge.