How much does it cost to have your base manifold and plenum ported?

I don't care about the runners, I'll just buy new ones.

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1986 Camaro
Carbureted 305
700R4

 

There's not a lot that can be done to the stock manifold. TPIS says with all the work they did on one it only paid off with 4 HP on a stock engine. A highly modified engine saw 14.

You can do the plenum yourself with a high speed grinder - an electric drill will work too but is slower - and a carbide bit.

All you do is remove the two rectangular obstructions in the area just behind where the throttle body bolts to the plenum. You can match the runner openings to the size of the gaskets if you want.

I did my own and it only took a few minutes. Be sure to wash out the plenum when you're done to remove all the aluminum chips.

Aluminum's easy to work on, just don't get carried away.

You'd probably be looking at $150/$200 to have a shop do it, but I'm only guessing.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

Cool. I guess I'll get a new intake.

Ported Plenum, SuperRam intake manifold, and SLP runners should be a good combination right?

 

I think TPIS only saw between 4-14hp so they could sell you one of thier intakes!
I did the intakes on both my 5.7 and 5.0 motor and it made a big difference.
Alot more than 4 hp. My 305 puts 220.5hp to the rear wheels. Only mods are hollow cat, dynomax catback, ported intake plenum runners and tb bypass.
If you have the money, by all means get the aftermarket intake but if you want to stay cheap port your intake. Just the cost of some dremel bits and an intake manifold gasket set.
------------------
Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/relocated MAT/ AdjFPR/IROC frnt@rear swaybar/wonderbar/steeringbox/alum drvshaft/ Alston SFC/3:23posi disc rear/MAC LCA/H.Adams Panhard Rod/KYB struts/ shocks/
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

[This message has been edited by Rob P (edited January 29, 2001).]

 

Check out Dan Burke's site. He does porting on the side. He has good pricing, quick turn around, and I hear he does a good job. He's also a frequent long-time member of this site (ws6transam).
http://www.isthq.com/~dan/fcar.html

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Bob '89 Formula CC350
Last(lost)Member of the Elusive Great Lakes Crew
My car's homepage

 

Hey Rob, I am doing mine right now. How did you reach into the mid passage of the intake? My fingers are even long enough to reach in there.



------------------
1990 Roadster

 

I got the wand attachment to the dremel. Lets you reach deep inside and smooth things out.

------------------
Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/relocated MAT/ AdjFPR/IROC frnt@rear swaybar/wonderbar/steeringbox/alum drvshaft/ Alston SFC/3:23posi disc rear/MAC LCA/H.Adams Panhard Rod/KYB struts/ shocks/
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

Gosh, I must be slow! It takes me about ninety minutes to port a plenum with a high-speed die grinder and carbide cutting bits! ...and an intake is worse! Probably about 12 hours of grinding time.

Of course, I do more than simply "smooth out" the runner passages and knock out the little walls that shroud the EGR passages. I raise the roof of each port in the intake .100" and recontour the area around the injector boss.

See: http://www.isthq.com/~dan/efi.html for a rather stale webpage dedicated to it. I ought to re-do it to add some more information. However, like RCR, I have a somewhat new family that takes up most of my time these days.

Thanks for the referral, Rob!

------------------
Daniel Burk
http://www.isthq.com/~dan/fcar.html
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff. PST suspension, Braided stainless brake lines, Koni struts, 11-inch rear disks,Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Turbine Technologies 2500 stall converter, underdrive pulleys, Crane Hi-6 & more.
1.05g skidpad verified.
New best E/T! 14.039 at 100.82 MPH in 41 degree air at Stanton, Michigan.

 

Ihave quite a few hours in both my intakes. I didn't do as much measuring as you did though! I rely on my military Mark I, Mod Zero Eye Ball! I basically gasket matched all openings, polished/smoothed all casting/flash, cleaned up my runners and worked the plenum really well.

------------------
Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/relocated MAT/ AdjFPR/IROC frnt@rear swaybar/wonderbar/steeringbox/alum drvshaft/ Alston SFC/3:23posi disc rear/MAC LCA/H.Adams Panhard Rod/KYB struts/ shocks/
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!