who has ported/polished their tpi heads? how hard is it to do this? what do i need to watch out for? i would like to do this to get some extra hp without spending money the best mods are free mods
thanks
Andrew

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Andrew Peery
1987 IROC, 305 TPI, T5
Flowmaster, Ported Plenum, Accell plugs, Wires, Cap, and Rotor
All smog equipment gone and no cat
192hp and 265tq (at rear wheels SAE corrected)
15.20 @ 92.5 mph with a 2.4 60ft

 

I did last summer.It's not very hard just time consuming.There are lots of archives on how to do it and what to watch for.I gained quite a bit of top end.

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Fast as a shark~~~~~~~~~~~~~~~~~ SAVE NAPSTER!!!

 

87,

Yo'll want openings about like this when you're finished:



While you are performing the port work, it's a really good time to install larger valves, enlarge the valve bowls, install screwed rocker studs, and machine the spring seats for larger valve springs. You can install the original springs with spring cups if you wish, or change to better springs right away. The screwed studs are about $15.00 for a set, so it's almost ridiculous not to do it while the heads are off and being dirtied anyway.

Try to smooth the transition of the valve bowls to the short side radius of the ports as much as possible. Make some templates from old playing cards or heavy paper to act as gauges to guide you in getting all the ports the same size and shape. Just reverse the templates for the ports that are opposites. Try to clean up the valve stem bosses in the valve bowls to minimize the intrusion into the bowl areas without shortening the guides (bevel the faces of the guides).

A typical change should look something like this:



Rough polish the intake ports, exhaust ports, and chambers with paper rolls or ScothBrite cones and disks. Finish polish the chambers and exhausts with wire cups and wire wheels, then final polish with rouge and a cotton burr. Don't waste time on polishing the intake ports to a mirror finish. There is no gain in this, and there may actually be some detriment to performance since the fuel droplets may cling to the smooth port walls.

I would also suggest installing improved valve seals when you assemble the heads.

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Later,
Vader
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"What a Day..."
Adobe Acrobat Reader

 

Vader,

How about the combustion chamber? Should that be smoothed out, or left alone? Thanks for the awesome reply, I'm in the process of polishing my set of heads as well.

 

Andrew Whenever you decide to do this give me a call and I will pull my heads too. BTW are you going to mod day??



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91 Z28 5.7l Camaro
T-56,McLeod Street Clutch, Cross Drilled Brakes, KYB's,AFPR, 3.73 Gears, Borla Adjustable Cat Back, Hypertech Chip, Hooker Headers.
more to come....
My 91 Z28

 

hey guys thanks for the great posts

chris
yes i am going to mod day sorry i haven't replied in a bit i've been busy with finals

once again thanks guys