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

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Post Reply
MikeB
Member
Member
Posts: 55
Joined: Wed Mar 22, 2017 10:44 am
Location: North Texas

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

Post by MikeB »

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
Guru
Guru
Posts: 6353
Joined: Tue Jul 24, 2012 11:15 am
Location: Roseville, Michigan (just north of Detroit)
Contact:

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

Post by Walter R. Malik »

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.
http://www.rmcompetition.com
Specialty engine building at its finest.
mag2555
Guru
Guru
Posts: 4584
Joined: Sun Sep 18, 2011 11:31 am
Location: Heading for a bang up with Andromeda as we all are.

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

Post by mag2555 »

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 !
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
Post Reply