porting/polishing exhaust manifold, removing carbon buildup? - Toyota Nation Forum : Toyota Car and Truck Forums

crazy_camry · 12-02-2003, 03:11 AM

i've got a 3s-gte twin entry exhaust manifold lying around, waiting for my turbo conversion, and i'm wondering if i could do any porting/polishing to it. any pointers?

also there is a great deal of carbon buildup inside the tubes, and i've read it's better to have it smooth and shiny. any ideas on how to remove the carbon? Thanks.

da_horse · 12-02-2003, 07:36 AM

when the fvck did you buy that???

and how much? u my friend are a nut...and i'm mean that in a good way

ahhahaha, seriously mate i can't wait for you to finish the car, might even fly up to check it out myself lol....

carbon wise i'm not sure, but polishing it you can use a dremel, ask Harmer, he's experienced with that stuff.

all the best mate...

Huy

luisitol · 12-02-2003, 09:59 AM

Yea i have a 3sgte exhaust manifold lying around for my turbo conversion as well and i would like to do some porting/polishing before i send it out to be ceramic coated and then slap it on, so any tips and/or guidleines would be much appreciated.

5Sfte · 12-02-2003, 10:45 AM

Send it to Extrude Hone for polishing!

luisitol · 12-02-2003, 11:14 AM

Extrude Hone is way too much $$$$$. Its a great process and really improves flow, but $3-400 is way too much.

5Sfte · 12-02-2003, 11:18 AM

Just a suggestion.

luisitol · 12-02-2003, 11:39 AM

yea i had considered it, but i figured some home porting/polishing and then some 1500 deg ceramic coating would have to do.

crazy_camry · 12-03-2003, 04:06 AM

Quote:

Originally posted by Da_HoRsE
when the fvck did you buy that??? and how much?
Huy

lol thats the manifold i've always had, i got it when i got the turbo, like 6 months ago

its was $50

da_horse · 12-03-2003, 10:02 AM

wait just re-read it, exhaust manifold....somehow i got it in my brain that you wrote intake manifold.....kekekeke must...get...sleep

Huy

arcasmachineracing · 12-03-2003, 06:53 PM

Hahaha... this thead is jokes. I am over tired also. ACID THAT SUCKER UP! HAHAHA!

alltrac165 · 12-05-2003, 01:58 AM

Smooth and shiny on the exhaust is a good thing. If you don't have a good hand with the dremel tool, use sand paper rolls, no cutter. Less margin for error. Just smooth it out, removing protrusions, casting flash, etc. Then go to finer paper until it's nice and shiny smooth. Don't try to hog it out unless you are a pro. You can have it cleaned first at any automotive machine shop. Then send it out for the HIGH temp coating if you're running a turbo. The standard stuff will not hold up to turbo heat. There IS a difference in composition.

crazy_camry · 12-05-2003, 08:15 PM

can i just sand away the carbon? as for making it shiny (the inside) i've polished up an intercooler, would it be similar to that? also should i use a metal polishing compound (autosol) on the tubes?

alltrac165 · 12-06-2003, 11:43 AM

Yeah, if you like you can use polishing compound on the last step. Cast iron is pretty freakin hard so use sanding rolls first to get it as smooth as possible, then go to finer rolls and finally polish. If you feel brave, you can gasket match the exhaust manifold entry runners. Line up the exhaust gasket on the manifold, scribe around the gasket at each runner. Blend the runner back about 1-1.5 inches. Make sure the gasket lines up evenly on the head as well, but don't mess with the head. You do not under any circumstances want the runner on the head to be bigger than the runner on the manifold as that hurts flow badly. However, if the runners on the manifold are a smidge bigger than the runners on the head, it helps reduce reversion back into the cylinder of the exhaust gasses. That is good for power.

crazy_camry · 02-22-2004, 03:28 AM

sorry to bring back my old thread, but how much bigger should the exhaust runners be compared to the head? are we talking 0.5mm or 1 or 2mm or what? thanks.

alltrac165 · 02-23-2004, 01:44 AM

.5 to 1mm or so would be fine. It varies head to head and manifold to manifold, so there's no set number for everything. Some packages work better with all the mismatch at the top, some better with it at the bottom, some with it all the way around. I don't know for your set-up, never seen it tested. Most seem to like the mismatch according to several expert sources though, so a safe bet would be all the way around in the neighborhood of 1mm give or take.