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MHS / PAC RPM Series Street / Strip Valve Springs for GEN 3 5.0L, 5.2L Voodoo and Predator Cylinder Heads

MHS-702623-32
True Drop in Design. Fits Stock Retainers, VCT Friendly, .625" Lift Capable
Pricing: $599.00

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Description

MHS / PAC RPM Series Street / Strip VCT Friendly Valve Spring Kit 
for GEN 3 Coyote, 5.2L Voodoo and Predator Engines 

  • Manufactured in the U.S.A. by PAC Racing for Modular Head Shop
  • Designed for N/A and Moderate Forced Induction Applications up to 25lbs of boost
  • VCT Friendly for use with Factory Phasers 
  • Endurance Heat Treatment and Surface Finishing for additional strength and reliability 
  • Lighter than any other spring offered for this application
  • True Drop-in design. Fits Stock retainers and Spring Seat / Seal 
  • 12.5g weight savings over the Factory Spring / Retainer Combo
    when paired with MHS Titanium Retainers - 20% lighter!
  • ID Chamfer Top and Bottom for consistent Retainer and Valve Seal / Seat fitment 
  • 88lbs Seat Pressure @ 1.800" Installed Height, 221 lbs/in. Rate, 1.100" Coil Bind
  • .625" Recommended Max Lift 
Finally a Drop In, VCT Friendly Valve Spring for the GEN 3 Coyote, 5.2L Voodoo and Predator Engines that can handle more than stock lift. These Springs are designed to be used with both stock and aftermarket camshafts. The main focus of these springs is to be able to support both higher than stock RPM and boost pressures, without beating up the phasers or needing to lockout the camshafts. 
We recommend these valve springs for street / strip applications running no more than 25lbs of boost and a max lift of .625". 
 
For Full Spring Specs, please see the Specs tab above. 
 
 

Spring Specs

Part Number  MHS-702623-32
Application GEN 3 5.0L Coyote, 5.2L Voodoo / Predator 
Seat Pressure   88lbs @ 1.800" Installed Height 
Open Pressure   221lbs @ 1.200" - .600" Lift 
Spring Rate   221 lbs / in 
Coil Bind   1.100" 
Max Recommended Lift   .625" 
Spring ID Top   .538" 
Spring ID Bottom   .700" 
Spring Weight (g)   46.2g - Stock is 55.8g 
Features   PAC RPM Processing, ID / OD Chamfer 
Optional Steel Retainers   4130 Chrome Moly - 7.3g 
Optional Titanium Retainers   6AL-4V Titanium - 4.4g 

 

Comparison Chart

MHS 702623-32, PAC-1281X and OEM Spring all tested and weighed on the same day with the same equipment. 

Ferrea S10168 and Comp Cams 26001-32 based on published data.

No spring is exactly the same. Pressures and weights will vary +/- 2%. Chart based on averages. 

   MHS 702623-32                 PAC-1281X        Ferrea S10168     Comp Cams 26001-32   OEM Gen 3 Spring  
Spring Style   Beehive   Beehive   Dual   Beehive   Beehive
Drop-In Design ?   Yes   Yes   No   No   Duh...
VCT Friendly   Yes   Yes   No  No   Yes of course 
Seat Pressure   88 lbs @ 1.800"   85 lbs @ 1.800"  85 lbs @ 1.800"     105 lbs @ 1.765"  65 lbs @ 1.800" 
Spring Rate   221 lbs / inch   234 lbs / inch   315 lbs / inch  291 lbs / inch   241 lbs / inch 
Open Pressures   210 lbs @ .550" Lift 
 221 lbs @ .600" Lift 
 214 lbs @ .550" Lift   258 lbs @ .550" Lift 
 274 lbs @ .600" Lift 
 265 lbs @ .550" Lift 
 280 lbs @ .600" Lift 
198lbs @ .550" Lift 
Max Recommended Lift   .625"   .551"  .700"   .615"  .550" 
Coil Bind   1.100"   1.190"   1.060"   1.090"   1.185" 
Spring Weight (g)   46.2g - Spring Only 
 50.3g w/ Ti Retainer 
 53.1g w/ 4130 Retainer
 53.3 w/ Stock Retainer 

 51.7g - Spring Only 
 55.8g w/ Ti Retainer
 58.6 w/ 4130 Retainer 

 58.8g w/ Stock Retainer

 Weight N/A 
 Dual Spring = Heavy 

 Weight N/A   55.8g - Spring Only 
 62.9g w/ Stock Retainer 

Both the Ferrea and Comp Cams Valve Spring Kits require different valve spring retainers, valve seals, valve spring locators and have too much spring rate for the factory VCT Phasers. Both of these kits use ID locators which require a standard metal clad valve seal (import style, non top-hat) and larger than stock retainers which just adds weight. 

The MHS-702623-32 and the PAC-1281X have similar pressures, both with a slightly lower spring rate than the stock spring. 
The MHS Spring is lighter and capable of more valve lift, while having very similar pressures. In fact, these springs have the exact same nose pressure at .200" lift. Both are a drop in design and VCT friendly.

Weights: There is much more to valve train stability than seat and spring pressures. When adding any type of variable valve timing in the mix, it gets even more complicated. When spring pressures are limited, the next step is to lighten the valve train up. 
Our spring is 5.5g lighter than the PAC-1281X and 9.6g lighter than the OEM GEN 3 Spring. 
When comparing the MHS Springs with our 6AL-4V Titanium Retainer to the OEM Spring / Retainer combo, there is an average total weight savings of 12.6g - Thats 50.4g of valve train weight savings per cylinder!

Details

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  • Item Requires Shipping
  • 6.0 lbs.
  • W8.0000” x H8.0000” x L8.0000”
  • Free Shipping!

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