Bigger Cam in 5.0 TPI without machining heads?
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Car: 1991 Pontiac Trans Am GTA
Engine: 305 TPI
Transmission: 700 R4 slushbox
Axle/Gears: 2.73 Posi
Bigger Cam in 5.0 TPI without machining heads?
Is there any way to run a bigger cam, say about .500 lift with 1.5 rockers with just a valve spring swap, or is there a hand tool to let you ream the spring pocket for bigger diameter valve springs? Any help would be appreciated, as I really don't wanna machine stock 305 TPI heads, until after I port them...
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Car: 87 Iroc Z
Engine: 305 TPI
Transmission: 700R4
Re: Bigger Cam in 5.0 TPI without machining heads?
.500 lift is a little too much to ask out of stock LB9 heads. I would keep it in the .470 range at most from what I have read from most people's experience. The spring pockets are not what need to be machined, its the valve guides. They make stock diameter valve springs to handle a pretty good bit of lift.
#3
Re: Bigger Cam in 5.0 TPI without machining heads?
you COULD try offset locks. .050" offset valve locks raises the installed height .050"
With the proper spring specs, you could effectively run around .500-.510 lift on stock heads. Just measure the stock installed heights and add .050" to them. Then find a spring that will keep spring seat pressure around 110-120lbs for most mild to medium hydraulic rollers.
Crane however makes a powermax 2032 cam that specs out at 214/220 and just under .470 lift for stock heads with 1.5 rockers.
that be a good cam for a 305
With the proper spring specs, you could effectively run around .500-.510 lift on stock heads. Just measure the stock installed heights and add .050" to them. Then find a spring that will keep spring seat pressure around 110-120lbs for most mild to medium hydraulic rollers.
Crane however makes a powermax 2032 cam that specs out at 214/220 and just under .470 lift for stock heads with 1.5 rockers.
that be a good cam for a 305
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Car: Red 1987 IROC Convertible
Engine: 305 LB9 TPI
Transmission: T5 5-Speed
Axle/Gears: 9-Bolt 3.45
Re: Bigger Cam in 5.0 TPI without machining heads?
It sounds like he doesn't want to pull the heads off the engine. Screw-in studs would mean machine work. (Which brings up the issue of using press-in studs with high lift cams. Not a good idea....)
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Car: Red 1987 IROC Convertible
Engine: 305 LB9 TPI
Transmission: T5 5-Speed
Axle/Gears: 9-Bolt 3.45
Re: Bigger Cam in 5.0 TPI without machining heads?
I also have the same cam with World heads, etc. It kicks butt for a 305!
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Car: 1991 Pontiac Trans Am GTA
Engine: 305 TPI
Transmission: 700 R4 slushbox
Axle/Gears: 2.73 Posi
Re: Bigger Cam in 5.0 TPI without machining heads?
Thanks everyone, you've been helpful. I wonder how much power the Crane Powermax 2032 would add, by itself(before I install the Jet-Hot Hedman Tork-Step shorties, do a custom exhaust, and reburn my computer), and how much it could support if I were to do supporting mods, like port and polish heads and intake. I was looking at the XFI series of cams for it, but the problem with putting one of them in, is the fact they're so high lift.
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#8
Re: Bigger Cam in 5.0 TPI without machining heads?
eh it should add some power..its a step up from stock thats for sure. i'd expect near 15whp over stock TPI with full exhaust and tuned. not a bad gain at all. with some TPI mods, you'll pick up more as that cam could use some help breathing. head mods will see the biggest gains. probly see 10whp there on a stock car, let alone that cam and TPI mods
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