magnum r/t springs

[needsaresto]

K guys,I did my research here and otherwise.

Magnum R/T spring part #: P5249464

This is the lighter one.

This part comes up at Summit as being over $17 each! Emailed them about this as they are supposed to beat any price.

Moparts racing it's about $9 each.

Mancini is about $11 each.

Big difference.Does anyone know the part # for the comparable Comp spring? Price?

Any other springs that will work?

I wont be going over .450 lift. Do I really need to get different springs? I'll probably never see 5500 rpm. Very mild Lunati Voodoo hydraulic cam and stock valvetrain. Mild porting using templates.

The heads have brand new magnum springs (single wound without dampner) meant for a factory roller cam. I dont have a spring checker so I cant tell you anything about installed height or spring rate. Heads are freshly machined. I may need to post pics of the stock ports as I stuck my finger in and cant seem to find that lump for the rocker bolt that everyone bitches about.

Which brings me to another point. Can someone recommend an accurate and economical spring rate checker ?

Also,where (and what)is the factory magnum casting # as opposed to the EQ head?

thanks all!

 

[dgc333]

There is no Comp Cam spring that is comparable to the R/T spring. The stock spring is a beehive spring and the retainers for those springs won't work with the R/T spring, the 2.2/2.5 4cyl retainer is the correct size. Comp Cams has a beehive that fits the magnum head without machining but it will require new retainers too.

I would say you do need new springs.

The factory springs are barely adequate for the stock magnum engine cam shafts. The smallest Voodoo cam has .454 lift with 1.5 rockers. The magnum head uses 1.6 ratio rockers so you will wind up with .484 lift. Plus the Voodoo series cams has very fast ramps which requires a stronger spring to control compared to a more typical ramp design with the same lift and the 1.6 ratio rockers makes the issue worse.

 

[needsaresto]

Thanks!

Summit says they will beat the moparts racing price.
Probably by 1 cent,lol!

 

[POLISH AVIATOR]

the guy from comp that i spoke to at the gatornationals said comp is not
interested in researching springs for that head because nobody uses them(!)
bad attitude racing engines in morriston,FL found a crane spring PN-96803-16
that works with the mopar perf.retainer for magnum/2.2.my problem now is
that the pushrods barely clear the dinky holes in the heads,so i gotta pull them and grind 'em bigger.

 

[Coyote Jack]

the guy from comp that i spoke to at the gatornationals said comp is not
interested in researching springs for that head because nobody uses them(!)
bad attitude racing engines in morriston,FL found a crane spring PN-96803-16
that works with the mopar perf.retainer for magnum/2.2.my problem now is
that the pushrods barely clear the dinky holes in the heads,so i gotta pull them and grind 'em bigger.

Having to grind the pushrod hole a little bigger is common on these heads.

If I remember right, Patrick over at Moparts has all of the part numbers for cheap stuff to get the proper spring setup. You might want to read about the magnum heads here as well. www.bigblockranger.com

Jack

 

[needsaresto]

Thanks all!

Actually contacted Lunati and they said for my application the stock springs would be just fine. Im planning for a 401.

 

[edbux]

Remember, the Magnum uses 1.6 rocker arms; not the 1.5 of the LA motors.
.454/.475 on an LA would be .484/.506 on the Magnum. My Comp Cam measured out at .501. I didn't get coil bind with the stock springs but I wouldn't use them for anything more than break in and cruising.