Intake porting
Thread Starter
Instructor
Joined: Sep 2009
Posts: 110
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From: seabrook tx
Intake porting
Well finally got around to putting in my camshaft last weekend,Got the intake off an got a good look at it. There is quite a bit of porting you can due to this intake,a very pore casting. I thought the intake restriction would be in the runners or upper plentum. After looking at it all I would say its the lower intake that is restrictive.So i am going to due a port an gasket match job on the lower. It has to help. 1986 cp.
Safety Car
Joined: Nov 2008
Posts: 4,328
Likes: 15
From: Jacksonville FL
Be extremely careful with your intake as some of the walls are thinner than you think. This topic has been done many many times. Search out and read a lot before you start and see where folks have screwed up. Gasket matching isnt too risky but when you start into the walls you may run into trouble. The crappy molding on the inside is on the other side as well so you wont know its too thin until its too late. Have a buddy who does aluminum welding standing by!
http://forums.corvetteforum.com/c4-t...or-torque.html
http://forums.corvetteforum.com/c4-t...ke-plenum.html
http://forums.corvetteforum.com/c4-t...-manifold.html
http://forums.corvetteforum.com/c4-t...ng-intake.html
Just for a few. You can also go to thirdgen.org I think for lots more.
Good Luck!!
http://forums.corvetteforum.com/c4-t...or-torque.html
http://forums.corvetteforum.com/c4-t...ke-plenum.html
http://forums.corvetteforum.com/c4-t...-manifold.html
http://forums.corvetteforum.com/c4-t...ng-intake.html
Just for a few. You can also go to thirdgen.org I think for lots more.
Good Luck!!
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Stock runners should be tossed in the trash or reuse them til you can upgrade they are a hindrance also, find yourself some used Accels or maybe some SLPs.
Or just do your portmatch put it back together and call it a day
Get yourself some dyekem and a scribe
Aftermarket pieces can be ported just not quite as much but they are already worlds better than the stock piece, siamesing the dividing wall down a few inches helps, too.
The base can be fuilly ported there is plenty of material that can be removed but youll need to go ALL the way through to make it really effective , it will take you quite some time.
Or just do your portmatch put it back together and call it a day
Get yourself some dyekem and a scribe
Aftermarket pieces can be ported just not quite as much but they are already worlds better than the stock piece, siamesing the dividing wall down a few inches helps, too.
The base can be fuilly ported there is plenty of material that can be removed but youll need to go ALL the way through to make it really effective , it will take you quite some time.
Last edited by cv67; Jan 4, 2011 at 08:22 PM.
Racer
Joined: Oct 2007
Posts: 478
Likes: 1
There is work that can be done at the entrance area on the stock runners. It is not exactly a smooth transition from the casting portion to the runner tube itself. Best bet is aftermarket runners as said above.
Some of the plenums I have seen need work where the runners bolt on. Not exactly a smooth entrance to the runners. Should be a nice bellmouth shape. Also make sure the runners have at least the same if not larger opening at the plenum. You don't want a ledge in that area.
Again depending on your goals maybe an aftermarket base and runners would work better for you.
Some of the plenums I have seen need work where the runners bolt on. Not exactly a smooth entrance to the runners. Should be a nice bellmouth shape. Also make sure the runners have at least the same if not larger opening at the plenum. You don't want a ledge in that area.
Again depending on your goals maybe an aftermarket base and runners would work better for you.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
You can do lots of stuff (porting/grinding) to the top end of a TPI. Here is some of my ported L98 stuff:
Modified '89 plenum:
Modified SLP runners:
Plenum to runner transition:
Ported aftermarket intake:
Modified '89 plenum:
Modified SLP runners:
Plenum to runner transition:
Ported aftermarket intake:
Race Director
Joined: Nov 2003
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From: Overland Park Kansas
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Drifting
Joined: Aug 2010
Posts: 1,880
Likes: 4
From: Montgomery Texas
I just finished doing this job two weeks ago. I hammered those 1.5" steel ***** through my runners to stretch them out. Everything was gasket matched and opened up. I them closed off all of the Exhaust passages and plated off the EGR. When I was all done grinding I took it to S&S and had Allen tumble all of it for several hours. It all came out polished up like a new penny, I am talking slick as chrome. You could feel a diffrence for sure, it was not like hitting a 100 shot of N2O but you could tell a diffrence.
Race Director
Joined: Nov 2003
Posts: 12,221
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
It's' definitely worth it. For my 383, my goal was to convert a set of SLPs to near superram configuration. By removing most of the divider and concentrating on the short-side radius, I think you can see how the effective runner tube gets very near superram length.
A 5200-5300 shift point is about right with this setup (probably higher with a 350).
A 5200-5300 shift point is about right with this setup (probably higher with a 350).
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Below are a few pics of my work.
http://forums.corvetteforum.com/c4-t...-far-pics.html
Last pic is his, different base.
engle, your work looks very nice.
Last edited by cv67; Mar 18, 2011 at 01:58 AM.
Melting Slicks
Joined: Mar 2002
Posts: 3,108
Likes: 126
From: S.L.C. UT
[QUOTE=3859c1;1576994305]Awesome work! Below are a few pics of my work.
Someone mentioned the stock base being thin. In my opinion it's not as thin as it seems. I have ported quite a few stock GM TPI bases and there is plenty of material to be removed to make for major improvements! I just got done porting one for use with AFR 190cc L98 heads and I must say it's a monster!!! It's as good as any aftermarket TPI base, if not better. I will have pics of it soon.
Who ported those? You or Ron (Cuisineartvette)?
Someone mentioned the stock base being thin. In my opinion it's not as thin as it seems. I have ported quite a few stock GM TPI bases and there is plenty of material to be removed to make for major improvements! I just got done porting one for use with AFR 190cc L98 heads and I must say it's a monster!!! It's as good as any aftermarket TPI base, if not better. I will have pics of it soon.
Who ported those? You or Ron (Cuisineartvette)?
Last edited by tpi 421 vette; Mar 18, 2011 at 12:17 PM.
Burning Brakes
Joined: Nov 2008
Posts: 995
Likes: 1
From: Naples Campania
One could be extremely lazy and have someone else do it.
http://www.corvetteplenum.com/
Send them yours, and they send you one back, as far as i know.
If your not confident, something like this might be an option. I really don't know about this site, so I'm not advertising. I've never bought anything from them, but I've heard of them. Do research before you buy.
http://www.corvetteplenum.com/
Send them yours, and they send you one back, as far as i know.
If your not confident, something like this might be an option. I really don't know about this site, so I'm not advertising. I've never bought anything from them, but I've heard of them. Do research before you buy.
Burning Brakes
Joined: Nov 2010
Posts: 1,006
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From: Spartanburg South Carolina
