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Edelbrock E-Street heads -- not for use with roller cams

General engine tech -- Drag Racing to Circle Track

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MikeB
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Edelbrock E-Street heads -- not for use with roller cams

Post by MikeB » Fri May 18, 2018 9:14 am

A guy I know is thinking about going to a mild hydraulic roller cam for his Chevy 350 with Edelbrock E-Street heads, but Edelbrock says the heads are not suitable for use with roller cams.

When I asked Edelbrock if that's because of spring pressure, here's the response I received:

"It is because the valve seats are powdered metal, not ductile iron valve seats. The powdered metal valve seats are harder and the valves have a tendency to bounce off the seats, installed spring height is 1.800" with 120 lbs. on seat, with 310 lbs. open at .550" lift."

Does this makes sense? And don't some flat tappet cams set the valves down quicker than some rollers, especially GM rollers? Also, why use powdered metal seats if it limits a customer cam choices?

Thanks.

Walter R. Malik
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Re: Edelbrock E-Street heads -- not for use with roller cams

Post by Walter R. Malik » Fri May 18, 2018 9:30 am

MikeB wrote:
Fri May 18, 2018 9:14 am
A guy I know is thinking about going to a mild hydraulic roller cam for his Chevy 350 with Edelbrock E-Street heads, but Edelbrock says the heads are not suitable for use with roller cams.

When I asked Edelbrock if that's because of spring pressure, here's the response I received:

"It is because the valve seats are powdered metal, not ductile iron valve seats. The powdered metal valve seats are harder and the valves have a tendency to bounce off the seats, installed spring height is 1.800" with 120 lbs. on seat, with 310 lbs. open at .550" lift."

Does this makes sense? And don't some flat tappet cams set the valves down quicker than some rollers, especially GM rollers? Also, why use powdered metal seats if it limits a customer cam choices?

Thanks.
This is absolutely nonsense ... smaller hydraulic roller cams are inherently milder off the seat than a flat tappet cam.
They may have some other reason they are not telling you but, that reasoning is hogwash.

If the valve spring pressures are correct and the valve lift is not to much; I don't envision any problem.
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mag2555
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Re: Edelbrock E-Street heads -- not for use with roller cams

Post by mag2555 » Sat May 19, 2018 7:16 am

That's full on BS!
I will bet that the issue is those powdered seats are not as tall and hence much more likley to get kicked around and drop out from roller Cam spring pressure!

The sad thing is those Model E heads flow nice and make great power for what they are , and I would not think twice about putting better seats in the heads if I already had them !

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