Magnum valve springs, again

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nrp3

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I know this has been discussed someplace, but I usually have bad luck searching for threads. I have a P4876348 380hp cam (288/292 and .501/.513) that I want to stick in a magnum. The mopar book recommends the 5249464 spring. I thought I read somewhere in here that their two spring offerings were marginal. Should I step up to the 4876062 heavier spring. Are the retainers recommended for these two springs the stock ones that I already have? I am trying to keep things simple.
 
The two springs that MP offers are rated for .525" lift and the heavier .6" lift. I am running a Comp XE268H which is a .509/.512 flat tappet cam, the .525" lift rated spring controls it just fine.

You can't use the stock retainers. The stock springs are a beehive design where the MP springs are straight wound. The MP retainers for the springs are the same as the 2.2/2.5 4cyl motor retainer. I harvested my retainers from the junk yard. You do need to use the locks from the magnum moter though since the groove arangement is different between the 2.2/2.5 and the magnum motors.
 
Sounds like I'll stick with their recommendation on the springs and the retainers, not sure what luck I'll have finding used retainers here.
 
nrp3 said:
Sounds like I'll stick with their recommendation on the springs and the retainers, not sure what luck I'll have finding used retainers here.
Click to expand...

Don't skimp on retainers! IIRC good moly steel retainers are only about $60 for a set of 16 from Crane.
 
Have a part number for those retainers?
 
That's for a 3/8th valve stem opposed to the 8mm, would that make any difference? I haven't been able to find any other measurements for these springs other than 1.42 od.

I can really see the appeal of the chevy valve springs, etc. Looking at a set of the mopar springs, retainers, and seals, runs about 340.00 or so at mancini and thats about the best price I could find.
 
nrp3 said:
That's for a 3/8th valve stem opposed to the 8mm, would that make any difference? I haven't been able to find any other measurements for these springs other than 1.42 od.

I can really see the appeal of the chevy valve springs, etc. Looking at a set of the mopar springs, retainers, and seals, runs about 340.00 or so at mancini and thats about the best price I could find.
Click to expand...

Just use these these valve locks, they work with all retainers. http://store.summitracing.com/partd...860918+4294860853+4294866446+115&autoview=sku

As far as valve spring reccomendation goes, do you have any specs from MP regarding intalled height and pressure plus pressure at a given lift?

Beehive style springs are really the way to go, but that would require an entirely different retainer too. Call Comp or Crane tell them what your plans are, they are quite helpful if ask nicely and don't stammer on the phone and tell them EXACTLY what your plans are. Sometimes it helps to write it all down before calling. Isky may be able to help too.
 
All I can find is 1.64 installed height.

Monicatti has the prices down to 299.00, still a chunk of change.

What tool do people recommend for on the car valve spring compressors? Must need a chevy one?
 
ramcharger said:
Just use these these valve locks, they work with all retainers. http://store.summitracing.com/partd...860918+4294860853+4294866446+115&autoview=sku
Click to expand...

Can't use those locks with magnum valve stems. The magnum stem has a radiused grove, those locks are for a square groove.

The best bet is to purchase the MP retainers for magnum springs, go to the dealer and purcahse new 2.2/2.5 retainers or go to the junk yard and harvest 2.2/2.5 retainers. They are all the same.

When I got mine the junk yard didn't even charge me for them.
 
Is there a particular year/car that I should look for in the yards or when I am discussing with the counter guy? Part number is probably different too?
 
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