1.255" outer .870" inner H-11 Tool Steel
Seat pressure: 115# @ 1.750 350# @ 1.175

the cam is a flat tappet 234/244 .488/.510 114ls
.510/.544 with the 1.6RR's I'll be using

They are stock diameter, so I wouldn't need any head machining. But, I'm concerned about the seat pressure being too high and wiping lobes off my cam. What do you think?

Also, if no on these, do you have any other recommendations (the cheaper, the better)? Thanks.

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
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Jester,

The pressure is a little higher than stock, and will only produce more valve train stress with 1.6:1 rockers. A roller cam will accept the pressure better than a flat-tappet cam, but the push rods and rockers had better be stronger than stock.

Some springs start at nearly 200 lbs. seat pressure, so the 115# rating is not completely radical. If you're using aluminum heads, you should probably consider seat washers to keep the heads from getting worn by the springs, in which case you might want to machine for depth, anyway. You can reduce the seat pressure slightly by installing the springs at a little taller initial height.

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Later,
Vader
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"Make Me Bad"
Adobe Acrobat Reader 4.0

 

Thanks for the input Vader. It's a flat tppet cam (roller is not an option), iron heads, and the rockers and pushrods will be aftermarket.

 

Jester,
I have a similar situation and Im trying to figure out whether or not I should change my valve springs. The camshaft Im going to be running has the same specs as yours except for the LSA (112 vs 114).
Valve spring installed height is 1.750 with 100 lbs pressure and 310 lbs at 1.250. Coil bind at 1.190. The coil bind # is what concerns me. If Im doing the math correctly (and not leaving out any variables) this leaves .050-inch clearance before coil bind.
Later

 

Any other opinions?

 

Jester,

Hummm......ye ole Edelbrock performer RPM cam ay? Those H-11 tool steel springs will work fine....but ditto on Vaders' caveats.

Comp cams lists wear notes on non-billet cams as having a low-threshold of wear at 130# seat and 310# open. I'd guess the springs you have will run 70,000+ miles before they wear the cam appreciably. Make sure to use a good synthetic oil, and you can probably double that 70,000 figure.

FOR MATT - on to clearances.........

I'm not too enthusiastic about that .050 number - yeah, it will probably be okay, but Lord help you if you ever put this motor into valve float......it would not take very much harmonic backlash to bind. End result?

1)Retainer breaks
2)Lock disintegrates
3)Valve becomes "free-spirited"
4)Valve meets piston.
5)Insuing violent meeting between stainless-steel valve and forged piston = grenade.

Shoot for .100" clearance before bind on the exhaust side and .080" on the intake side.

Going under .070 and .050 makes my sphincter pucker.....it's just too risky.

I know you didn't want to hear this ('cause it means more $$), but....it be de truth.

BOR



[This message has been edited by Box of Rocks (edited November 10, 2000).]

 

oh GOD no. I refuse to use anything with the name Edelcrock on it its an SSI cam,..from PAW $45

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
Jesters's Page of Sick Pleasure
Florida Thirdgenners Message Board
ICON Motorsports

 

BOR,
please email me i have a question.
i lost your email address and phone #.
btw, hows the vette running?
later