Summit 1102 cam compatible with stock vortec 906 head/valve springs
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1979 Chevrolet Malibu 496-TH400-9" (cruiser). 1992 Chevrolet S10 355-700r4-7.625" (daily driver).
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Yes. One of my buddies is a 3rd generation automotive machinist. No idea how many Vortec heads he has seen. With all of the talk about valve lift limits on the factory Vortec, he maintains never having seen one of those heads in his shop unsafe for .450 valve lift. That covers the 1102 cam. The springs on the 906 heads will work great. Run it.
Do you already have the 1102 cam? If this engine isn't going above 3,500 RPM......the 1101 might be worth your consideration.
Not that it matters, but I think the 8 in your casting number is a 9 if you look a little closer. It is worth mentioning that the 906 heads will require a different intake manifold than the cracked heads would have used.
Do you already have the 1102 cam? If this engine isn't going above 3,500 RPM......the 1101 might be worth your consideration.
Not that it matters, but I think the 8 in your casting number is a 9 if you look a little closer. It is worth mentioning that the 906 heads will require a different intake manifold than the cracked heads would have used.
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thanks. Yes i already have the 1102 on the shelf.
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Works fine with factory L30/31 Vortec springs and 1.5 rockers.
Yes the L31 head is pretty good through .45 inch lift. But this is heading to the border at .47. If your given to winging the engine out you want to check this clearance especially with production springs as spring action can get rather wonky when you’re pushing beyond 5000 RPM. This is especially true if reusing old springs, like people they loose strength as they age. Unlike people working out with weights doesn’t push back on wear and tear.
Bogie
Yes the L31 head is pretty good through .45 inch lift. But this is heading to the border at .47. If your given to winging the engine out you want to check this clearance especially with production springs as spring action can get rather wonky when you’re pushing beyond 5000 RPM. This is especially true if reusing old springs, like people they loose strength as they age. Unlike people working out with weights doesn’t push back on wear and tear.
Bogie
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ok. Another option then. I have a set of replacement (non vortec) springs SBC Stock Valve Spring Set Chevy 283, 327, 350, 383, 400, .450 Max Lift RV880X | eBay .450 Max Lift RV880X
Would those work on these stock 906 heads?
The retainers are different, and the new springs are double springs.
Would those work on these stock 906 heads?
The retainers are different, and the new springs are double springs.
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No reason to do that. Last thing you need is dual valve springs from eBay, assuming they would even fit! There are much better ways to go if you had a higher lift cam.
However, for your 1102 cam's low lift and slow ramps there is NOTHING wrong with stock Vortec springs. GMPP even uses them on crate engines with .431"/.451" valve lift.
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That's not what is considered a dual spring.....that is a single spring with a flat wound damper inside it.
Actual Dual springs have two round wire coil springs, one inside the other.....and may or may not also include a flat wound damper between the coil springs depending on brand and spec.
What you've got is just a basic stock replacement spring for the pre-Vortec engine.....i don't know if they will for sure fit the Vortec head....I've heard you have to remove and discard the damper to use them on Vortec??
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Good catch. I didn't even click on the link! No need to even evaluate them for use with his cam.
And yes, there is at least one potential issue using pre-Vortec springs, but I don't remember it.
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