Porting my header openings (SLP 1-5/8)
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Porting my header openings (SLP 1-5/8)
SLP 1-5/8" header openings...
http://f2.pg.photos.yahoo.com/ph/gta...c=ph%26.view=t
http://f2.pg.photos.yahoo.com/ph/gta....jpg%26.src=ph
My ported SLP 1-5/8" header openings...to be installed along with my L98 cast iron heads also self ported. Hope to have some track time improvements soon...
http://f2.pg.photos.yahoo.com/ph/gta....jpg%26.src=ph
http://f2.pg.photos.yahoo.com/ph/gta....jpg%26.src=ph
http://f2.pg.photos.yahoo.com/ph/gta...c=ph%26.view=t
http://f2.pg.photos.yahoo.com/ph/gta....jpg%26.src=ph
My ported SLP 1-5/8" header openings...to be installed along with my L98 cast iron heads also self ported. Hope to have some track time improvements soon...
http://f2.pg.photos.yahoo.com/ph/gta....jpg%26.src=ph
http://f2.pg.photos.yahoo.com/ph/gta....jpg%26.src=ph
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An easily removed restriction in exhaust flow that also helps the transition into the header from my ported heads.
As cast the header measured 1.2" width and a 1.5" height. After porting it measures 1.3" and 1.6"...which is the actual area for a 1-5/8" header in terms of the diameter.
1.3*1.6=2.08 square inches. Basically the same as 1.625 squared times pi divided by 4.
Nobody ever really mentions this, and it was something I didn't consider until port matching my head to my header. No reason not to do it before bolting on headers.
As cast the header measured 1.2" width and a 1.5" height. After porting it measures 1.3" and 1.6"...which is the actual area for a 1-5/8" header in terms of the diameter.
1.3*1.6=2.08 square inches. Basically the same as 1.625 squared times pi divided by 4.
Nobody ever really mentions this, and it was something I didn't consider until port matching my head to my header. No reason not to do it before bolting on headers.
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Car: 91 Camaro Vert
Engine: 02 LS1, HX40
Transmission: 2002 LS1 M6
Originally posted by smithtc
An easily removed restriction in exhaust flow that also helps the transition into the header from my ported heads.
As cast the header measured 1.2" width and a 1.5" height. After porting it measures 1.3" and 1.6"...which is the actual area for a 1-5/8" header in terms of the diameter.
1.3*1.6=2.08 square inches. Basically the same as 1.625 squared times pi divided by 4.
Nobody ever really mentions this, and it was something I didn't consider until port matching my head to my header. No reason not to do it before bolting on headers.
An easily removed restriction in exhaust flow that also helps the transition into the header from my ported heads.
As cast the header measured 1.2" width and a 1.5" height. After porting it measures 1.3" and 1.6"...which is the actual area for a 1-5/8" header in terms of the diameter.
1.3*1.6=2.08 square inches. Basically the same as 1.625 squared times pi divided by 4.
Nobody ever really mentions this, and it was something I didn't consider until port matching my head to my header. No reason not to do it before bolting on headers.
*shrug*
doesnt sound like too bad of idea as long as theres enough meat on the header to hold everything together still.... just match a copper gasket to the ports, then lay the gasket over the header... hmm.....
i may just do this for no reason other then the fact that i can...
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#5
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
If your header flanges hang into the port flow path, it's a very good idea to clean them up. That abrupt obstruction creates all sorts of undesireable turbulence, which is a flow killer.
Okay, may not be a big deal for the mild car cruising down the street, but if performance mods have been made, especially towards higher RPMs, it's a good idea to provide a smooth path.
If there isn't enough material to clean up the flange, weld around the tube on the outside first. That's what I did with my 396 headers this past spring (posted pics back in Mar/April).
Okay, may not be a big deal for the mild car cruising down the street, but if performance mods have been made, especially towards higher RPMs, it's a good idea to provide a smooth path.
If there isn't enough material to clean up the flange, weld around the tube on the outside first. That's what I did with my 396 headers this past spring (posted pics back in Mar/April).
#7
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Found it. Didn't find anythong on searches before.
https://www.thirdgen.org/techbb2/sho...ghlight=flange
I don't think my headers needed anything that drastic.
https://www.thirdgen.org/techbb2/sho...ghlight=flange
I don't think my headers needed anything that drastic.
Last edited by smithtc; 11-17-2003 at 01:36 PM.
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#8
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
I had been running those headers since 1997. I never realized how bad they really were until I took them off this spring for the port work.
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Car: 1988 pontiac Trans Am GTA
Engine: DFI,Single Plane,200cc Dart I.E,355
Transmission: Th400 PTC converter
Axle/Gears: Stock Ausie 9 bolt w/3.45 gears
hey, im porting (gasket matching) everything too and i already ported my manifold now i am going to start the heads, but the only bits i can find are for soft metal(dremel). now i kno the cast iron heads arent soft metal but will these bits still be good to use or do i need to go and buy dye grinders?(spelling sux..sry)lol????
thanks for the help
dave
thanks for the help
dave
Last edited by 88GTAbandit; 10-05-2004 at 12:41 AM.
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