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

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SKU: MHS-702623-32

True Drop in Design. Fits Stock Retainers, VCT Friendly, .625" Lift Capable

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Description
Spring Specs
Comparison Chart
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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!