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ho cam 4 degrees advance & gt40 springs

yakelys69

Sr. Member
Joined
Nov 20, 2006
Messages
732
89 5.0 H.O. with about (70,000), 96 explorer gt40 heads (rebuilt). NV3550, Dana 20, 4:56 gears, 35" tires.

Is advancing the ho cam 4 degrees with a Timing Chain and Gear Set still considered the preferred setup? If so any recommendations on what brand/set to get? https://www.summitracing.com/search/year/1989/make/ford/model/mustang/department/engines-components/part-type/timing-chain-and-gear-sets/maximum-advance-retard-at-camshaft/4-degree?N=4294949512%2B4294950041%2B4294951343%2B4294951333%2B4294899544%2B4294887740&SortBy=DisplayPrice&SortOrder=Ascending

Also I understand the GT40P springs are not good but are the GT40 springs ok with this setup? if not any recomendations?


References:
http://classicbroncos.com/forums/showthread.php?t=248404
 
OP
OP
yakelys69

yakelys69

Sr. Member
Joined
Nov 20, 2006
Messages
732
Comp cams... Springs, chain, or both?

Also considering we aren’t usually running high rpms how necessary are valve springs? A few other ways I would prefer to spend $188 although alexsparts has som for less that I think would work. I’m not planning on 1.6 or 1.7 rockers. Admittedly I have little to no real experience with this.
 

broncnaz

Bronco Guru
Joined
May 22, 2003
Messages
24,341
Its not really high RPMs that affect the valve springs. Its the amount of lift involved and if said springs will accept the lift of the cam without the coils touching each other. But high RPMs if you have weak springs then you will have valve float where at low RPM's you may never have a issue with weak springs. I think youd be fine with the explorer springs. But may want to check coil clearances at max lift. Usually you want at least .080 before coil bind.
4 degree advance on the HO cam may bring it down to the explorer RPM range which may be a good thing when in OD
 

sykanr0ng

Bronco Guru
Joined
Aug 11, 2014
Messages
5,363
Comp cams... Springs, chain, or both?

Also considering we aren’t usually running high rpms how necessary are valve springs? A few other ways I would prefer to spend $188 although alexsparts has som for less that I think would work. I’m not planning on 1.6 or 1.7 rockers. Admittedly I have little to no real experience with this.

On small block Fords 1.6 rockers are the stock ratio.
 
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