gt40 valve spring info needed

[Brown_Muscle]

Hey I'm having a set of GT-40 heads out of a 97 explorer rebuilt by a friends tech school shop and i was wondering if anyone had any specs on the valve springs, such as the correct tested pressure out of a haynes or chilton manual. I have them for our cars but i wasnt sure if they were the same. this is an example of what i need:

Valve spring pressure:
intake (first check) ..... 74 to 82 lbs @ 1.78 in
intake (second check).....190 to 210 @ 1.36 in

also Valve spring free length info would also helpful.

Thanks in advance!!!

[1987cp]

Never run used valvesprings of unknown age or mileage. Always install new valvesprings suitable for your camshaft and intended usage.

Anything else?

[Pirate]

Hey I'm having a set of GT-40 heads out of a 97 explorer rebuilt by a friends tech school shop and i was wondering if anyone had any specs on the valve springs, such as the correct tested pressure out of a haynes or chilton manual. I have them for our cars but i wasnt sure if they were the same. this is an example of what i need:

Valve spring pressure:
intake (first check) ..... 74 to 82 lbs @ 1.78 in
intake (second check).....190 to 210 @ 1.36 in

also Valve spring free length info would also helpful.

Thanks in advance!!!

To save you some trouble....the Exploder valve springs are junk.

[Brown_Muscle]

thanks guys, we got the correct specs and they all tested within the correct range. and no way im spending 160-200 bux if the springs are good...

[P72Ford]

You're going to be Captain Valvefloat if you use anything more aggressive than a stock cam.

[Brown_Muscle]

hahaha captain valvefloat..... that was what I was just about to ask...why the springs are crap. Don't worry though, I'm going to use a stock cam, and I will definitely install better springs when i upgrade my cam, which will not be for a while...

[gadget73]

The springs might test in spec, but the specs are shit. They're too soft and won't keep the valves under control with any sort of RPM. Stock Explorer cam at 4800 rpm and they float so bad you think the motor is going to explode. Multiple people have tried this, and had the same results. Not good, and it could potentially allow piston to valve contact. Also, you don't want to change the springs with the heads on the car. Do yourself a really big favor and upgrade them now while its easy, rather then later when its a pain in the ass.

[Brown_Muscle]

I gotcha, thanks for the info, If i choose to use the heads I will most definitely upgrade the springs then.

[Brown_Muscle]

One more quick question, is it possible to use E7 valve springs or even lopo head springs instead of the stock explorer ones? I have access to a Mark VII with a H O in it.

[1987cp]

You can use any replacement spring suitable for the cam you intend to use, but I'm thinking the same Piratey concerns will apply for any used valvespring, and possibly even more so for something that's probably approaching or even past 20 years old.

When I had my stock E7 heads rebuilt, I obtained a set of stock replacement Mustang GT springs and had the guy install those, since the stock HO cam was the biggest I intended to run with them (factory Exploder cam currently installed). Cost me about $67 from the dealer parts department.

[Brown_Muscle]

Really $67 dollars from a stealership for all 32 springs?? thats not bad at all.. In that case I'll look into getting some new E7 springs for mustang GT...

How many years ago was this you got the springs, online the cheapest i can get is 110 for all of them, but the dealership parts store is probably different.

[1987cp]

Well, 16, but yeah. I bought mine in late 2006, I think ... got them from a dealer called Courtesy Ford in Okemos, MI. I've dealt with some rather annoying parts departments, but those guys were pretty cool. I thought they would have been more than that, but AutoZone wanted about the same price for what they had listed, and (at least at the time) I didn't have any info on the suitability of those springs, so I got the stock ones.

[Brown_Muscle]

wow what was i thinking...yeah 16 valves haha. I can get some "sealed power" springs for a 95 mustang GT for around 60 bux shipped from rockauto... so i may go that way. How much better would an explorer cam be compared to my current 82 351? a decent amount i would imagine...Thanks though!

[1987cp]

Sealed Power from Federal-Mogul should be good stuff.

My personal best info on your stock cam from '82 is listed here: http://www.grandmarq.net/vb/showthread.php?t=30232 .... IF this compilation of replacement-supplier info means anything, it could be either the very-tiny cam (195/195 .050 duration) listed for use with the first 351W for '69 or a rather more respectable bumpstick (206/221 @ .050) introduced for '81. No idea yet on whether those data mean anything, though, as that particular compilation has already proven completely meaningless as an indication of what OE parts were used for at least a few applications ('85 Mustang 4V, SEFI 5.0 Panther, 5.0 Explorer, to name a few) ....

Are you ready to buy linkbar-style roller lifters to run the Exploder cam in your pre-'94 block? I saw a used set on the Corral for $250 once, which isn't that bad if you get the cam cheap. Might want something bigger for a 351, though, in which case the Comp "Retrofit" lineup is worth having a look at.

[gadget73]

well, the cam question is somewhat moot since I don't think you're going to be able to put a roller cam in a flat tappet block without some sort of retrofit thingy.

I've seen these suggested as a good valve spring for GT40 heads to replace the Explorer ones:

http://www.summitracing.com/parts/TFS-31400414?autofilter=1&part=TFS-31400414&N=700+115&autoview=sku

http://www.grandmarq.net/vb/showthread.php?p=385074&highlight=valve+springs#post385074