Polishing aluminium manifold

[chez00]

Hello ozhondies,
I am swapping a GTi6 engine into my Peugeot 205, kind of the equivalent of a b20 into a CRX. The manifold sits front and centre and is quite a large unit so I thought I'd polish it to tart it up a bit. You may wonder why the hell I'm posting here, but the question is fairly general and would apply to any honda. Basically what I want to know from someone who has undertaken the arduous task of polishing an ally manifold, is what the method is of getting a clean transition where the runners meet the plenum. I will post photos tomorrow to show what I mean but it should be fairly clear. Cheers!

[chez00]

This is the part I'm talking about. I want it to look as clean as possible and am not sure how to get into the joint to make it come up smooth and even. Any tips?

http://i1276.photobucket.com/albums/y471/neatgearboxes/IMG_3271_zps99c1f04f.jpg (http://s1276.photobucket.com/user/neatgearboxes/media/IMG_3271_zps99c1f04f.jpg.html)

Where it's at after a couple hours. "Shaved" and just starting to remove the rough casting.
http://i1276.photobucket.com/albums/y471/neatgearboxes/IMG_3272_zpsbf6f4a8d.jpg (http://s1276.photobucket.com/user/neatgearboxes/media/IMG_3272_zpsbf6f4a8d.jpg.html)

[markismaximus]

have you considered having it hydrablasted (glass bead slurry) before giving it a final polish? It won't give you a mirror finish, but will get it relatively close. It gives the surface more of a polished finish as apposed to dry blasting which leaves it matt.
Although it appears you have heavily sanded it, so not sure if this is an option now.
this is a guy who does it here in QLD. There are some pics on his site, I had my gearbox done and turned out great

http://www.suncoasthydrablast.com.au/html/not_bikes.html

[curtis265]

PM TbM. He polishes everything

[dougie_504]

I had this issue when polishing my rocker cover with the grooves.

Tried a combination of using my fingers and sandpaper, and also using those sanding sponges to get into the nooks.

Otherwise maybe try a sanding/polishing drill-bit. It's going to take a lot of elbow grease either way. Good luck!

[chez00]

Thanks guys, yeah it seems like it's pretty much elbow grease. I'll try a drill bit one though.

[.Dave]

Nice swap! A mate had the same thing and it hammered!

[Limbo]

wire brush on a drill?

[TbM]

This is the part I'm talking about. I want it to look as clean as possible and am not sure how to get into the joint to make it come up smooth and even. Any tips?

http://i1276.photobucket.com/albums/y471/neatgearboxes/IMG_3271_zps99c1f04f.jpg (http://s1276.photobucket.com/user/neatgearboxes/media/IMG_3271_zps99c1f04f.jpg.html)

To shave i use flap wheels, hand sand with a soft block on curved surfaces or you can use things like this dremal attachment (http://www.amazon.com/Dremel-511E-Coarse-Finishing-Abrasive/dp/B000FBF3OM/ref=sr_1_1?s=hi&ie=UTF8&qid=1396903388&sr=1-1&keywords=Dremel+511E) for small curves and blemishes like the one in your pic.

PM TbM. He polishes everything
http://www.ozhonda.com/forum/customavatars/avatar24136_24.gif

[mocchi]

fuk m8

make a build thread pols

[chez00]

Just nicked my dad's Dremel, I'll give that a go, cheers TBM.

Build thread? Better not, doesn't quite fit on ozhondie.

Some specs:
1988 series 1 205 gti

XU10J4 (iron block)
Forged bottom end (11.2:1 CR) 86.5mm
Balanced
Lightened flywheel
0.000" piston protrusion (zero deck height)
Baffled sump
Port and polished head
stage 1 inlet cam (260* advertised)
#3 inlet pulley (2* advance over standard)
Gti6 inlet manifold and throttle body
4xLS1 coils
ViPEC ECU running full sequential ignition and injection
Custom 2.25" exhaust (yet to be built) with 8-4-2-1 Mi16 manifold

Quaife LSD
4.43 FD

Lowered radiator
Custom CAI funnel over top of radiator (yet to be built)
Battery relocation to rear (I want to change this to rear passenger footwell)

24mm rear ARB
rear disc brake conversion
"big brake" front swap (306)
Front strut brace
stock (new) suspension
Standard ride height
standard 14" pepper pot wheels
Dunlop Direzza Sport Z1 star spec 185/60/R14

Standard interior including original tape deck
wideband lamda gauge tucked in fan outlet.

Aiming for somewhere around 100kw at wheels, don't really care, just want torque and response. In <900kg kerb weight it should move. I've built this as a daily and to compete in the very tight and twisty Collingrove hill climb in the street registered under 2.0L class.