Sincat_23

Im thinking of rebuilding my heads on my camaro. I was thinking of buying a Crane Cams Powermax cam(summit part # CRN-254122),
Crane performance Springs(CRN-99848-12),Comp Cams Magnum roller tipped rocker arms(CCA-1413-12),and Comp Cams pushrods(CCA-7816-12)for my 3.1. Is there any thing else I should do to the heads or buy for them and how much horsepower do you think I'll get? Thanks. One more question, does anyone have a part number for a duoble roller timing chain? Thanks again..

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92 Camaro 3.1 V6 (Red)
-Hypertech Chip
-Dynomax Exhaust
-Taylor Spiral Spark Plug Wires
-2.5 Harwood Lift-Off Cowl Hood
-B&M Megashifter
-B&M Shift Improver
-15x8 Crager 5-Star Chrome Rims
-Yellow Weapons-R Intake Filter
-Custom Cold Air Intake
-KYB Shocks & Struts
-Borla Exhaust Tips
-MSD Coil
-Air Lift 1000 Load Assist Springs
-EnergySuspension Swaybar Bushings and Links
-ACDelco Rapid Fire Plugs

KED85

Here's what ya do.
Take off head.
Have new valve guides installed.
Valve guides wear out real quick.
Get NEW springs, ready for your 6500RPM attack!
New retainers, TOO!
Back cut valves 30/45/60/90 degrees, into the heads.
Mill/plane heads FLAT! (just a brush on the sand paper machine)
Install new roller tip rockers (1.52 is a great choice) the rockers gotta fit under the valve covers.
Install.
Have fun.
OH, cam.
Crane cam designed the 3.4 cam for GM.
Go get one!
It's the best design out there.
FORGOT THIS
800-831-0884
Northern Auto Parts, Timing chain & Fel Pro gasket is $50.
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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

[This message has been edited by KED85 (edited July 03, 2001).]

x55Cam

You can also unshroud the valve heads. Your machinest should know what to do. The cast iron heads are capable of producing 1.5 HP per cubic-inch with some minor port work.

The intake port entrances should be matched to the intake manifold gasket and casting irregularities should be removed from the port walls. Blend the sharp edges and machined steps in the valve bowl to form a smooth approach to the valve seat. The exhaust valve bowl should be contoured to form a smooth venturi under the valve seat. Don't remove the vanes!

Since you have the intakes off it would be quite advantagous to port those also. The stock configuration is an impediment to the airflow capabilities. You can put all the cam you want in your motor but the real horsepower makers are the heads. Don't overlook them.

KED85

Having just rebuilt my 2.8 heads (same as the 3.4, except for strong springs),
I would strongly suggest just doing as I offered.
These heads are an exceptionaly well designed combustion chamber.
Unlike my Old Chevy Small block heads from 1969 (the 69 Z-28 & 1970 LT-1 heads) and 1972 (the Hi Po 487 X heads) which do require lots of porting and polishing to remove the casting crud. I spent 10 hours porting and polishing one head.
Compared to those 4 SBC heads (2 per engine) these 2.8/3.1/3.4 are a dream of a design, they are that well made, these days.
Computers & casting molds have advanced the final product by light years.
You can talk all ya want (Flame Suit on) but, don't waste the effort. Reassemble everything right, tight, leak free & go have fun.
Spend the saved money on TIRES!!
You'll need them!
You'll never feel any difference by the porting & such with these little engines, UNLESS YOU LIVE AT 6500RPM ALL DAY!
And we don't drive at 6500RPM every second.
Don't waste the effort.
OR
discuss this conversation with your machinist.

I was gonna install 2.02 valves on these SBC heads.
I was talked outta it.
WHY
These heads flow so well (my choice of SBC parts) and I drive on the street.
I will loose so much bottom end torque for the higher upper end, I would not have any fun on the street, where I live.
And drive.

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

x55Cam

Rather than debate KED85's points about what you should or should not do to your heads, here is a quote taken from the "Chevrolet Power Catalog" 6th edition -dated 1988 and the 7th edition - dated 1994. I highlited certain parts that I thought interesting to point out:

"Cast iron cylinder heads were designed for production applications, and extra material was not included in the port walls to allow extensive enlargement of the runners. Nevertheless, competition 2.8-liter engines with production cylinder heads are capable of producing over 1.5 horsepower-per-cubic inch with only minor port work."

If GM themselves are claiming the potential of v6/60 degree can be realized with "minor" port work that would result in a gain of HP to be 1.5 per cubic inch, who am I or anybody else to argue? Mabye this is exagerating a bit, but why not at least explore this possibilty while you have the chance? If your going to sink all your har earned $$ into the valvetrain, shouldn't you utilize the new components to see it's potential?



[This message has been edited by x55Cam (edited July 04, 2001).]

TomP

Here's the part # for a double-roller timing chain set; it's by Cloyes, part #9-3137. It ran me $90 from Summit Racing- the summit part # is CLO-9-3137. As far as I know, it's the only Dual Roller chain for the 2.8/3.1's out there- oh and you won't re-use your timing chain tensioner. The box says not to, and that's because the sprockets hit the tensioner.

I also hear that GM's castings were sloppy, and there's a lot of flash (metal that shouldn't be there) sticking out into the ports. I say if you've got 'em off and apart, then, go for it. You might not want to go wild with $$$ at the machine shop, but a home-port-job might do wonders.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

jaseman2134

iTrader: (1)

i was thinking about porting on a 3.1 that im getting and taking apart to clean out. how spot on does it have to be. i dont want to bite off more than i can chew but would like to have some fun upgrading the teeny weeny bit that i am from the 2.8