When I installed my new cam over x-mas, I got a new set of springs. I got the TPIS 700-132 springs used for the ZZ9 cam. They are 1.270" diameter and good to .540" lift. So what RPM will they hold up to without swallowing?

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End with 2.77:1 Gears.

Current Mods: LT4 HOT Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Catco 3" High-Flow Catalytic Converter, Hooker 3" Aerochamber Cat-Back System, Transgo Shift Kit, Performance Resource Chip, Accel Ignition, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET: 14.32 @ 97.7mph
(corrected for elevation)

 

Kind of a tough question. Those are pretty small springs. Are they dual or single with a dampener?

The cam is what determines the rpm range. The springs should be matched for the cam. If the cam is good to 5500 and the springs are for a cam that's good to 7000 then the springs are too heavy. Even though they're designed to do to 7000, the cam won't go that high.

On the other end of the scale, if the cam can go to 7000 and the springs are for a smaller cam of 5500 then the springs will start to float at 5500.

There's a lot more to springs than just diameter and maximum lift. Are the valve guides cut to allow that much lift? What's the spring rate. How much pressure is on the springs when closed at installed height and when the valve is open.

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87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block

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First off, I must state I am not a moron when it comes to auto tech. Secondly, the cam is the LT4 HOT Cam and yes, the guides have been cut and all that is good. I am just curious as to what RPM the springs can take. I mean, I know if I could feed the engine, the cam could probably be good to 6500 or so. Anyway, thanks.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End with 2.77:1 Gears.

Current Mods: LT4 HOT Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Catco 3" High-Flow Catalytic Converter, Hooker 3" Aerochamber Cat-Back System, Transgo Shift Kit, Performance Resource Chip, Accel Ignition, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET: 14.32 @ 97.7mph
(corrected for elevation)

 

I would not trust any stock diameter springs like those to any lift greater than .500", no matter what the sales pitch is. Of all the places in an engine that saving a couple of coins can cause major expensive damage, that has to at the top of the list.

Like Stephen (an experienced racer) said, valve springs don't have a RPM rating as such. That depends on the cam profile under them, and the mass of all the parts they're having to push around. However, nearly any stock diameter valve springs like those will cause the valves to follow the cam profile so poorly that the motor's output will fall off pretty drastically by about 6000 RPM. Plus, with your TPI still on there, the intake tract is done by 5000 RPM anyway, so there's little point in twisting it a whole lot higher than that.

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