Hi everyone. I have searched the forum but cant find a tread about this. I am considering swaping my OEM camshaft with a isky E-4. Can i run OEM springs ? 272 engine, cant remember the head casting numbers, but it was nothing special. I have seen several of you are running this cam 😊

If you've got the heads off and you buy one of the valve spring internal mics you can learn a lot. Once you have the installed height by using the mic, retainer, and keepers a good reference is the internet and I like Competition Parts catalog for finding springs at the pressure you want at installed height..
270 hp Corvettes in the late 50's could turn 6000 rpm with springs rated at 69 psi installed height. I agree with the idea that stock springs may work but I would test what you have, My old Motors manuals shows 56-57 Ford V-8's 161 psi at 1.39" which sounds like what ever over the nose or at partial lift might be.  I'm sure  Ted knows what the stock spring read at installed height.
Also a call to Isky is always a good bet. Let them know your plans.
Best of Luck...

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Robin, I bought the police package springs from Schumann’s. I never run above 5000 rpm’s anyway. Maybe stock would be ok.

  Dennis in Lititz PA

This car would not see 5000rpm either. And i need som better heads further down the road. This is my first "performence" cam swap. I am in the curve of learning right now. Is there a rule to follow here. If you have this much lift, you need that much pressure on the valve ? And the higher the valves are, the more pressure i guess.

I have one of those spring pressure devices you can use on a drill press or vice which has a pressure gauge. With a valve spring in hand you can easily check a spring at installed height and the stock spring height by knowing the valve lift of the stock cam times the rocker arm ratio (simple math) then do it again with the Isky E-4 specs.
The extra lift at the cam will add to the spring pressure over the nose of the cam; I would guess not enough to cause wear on either the cam or lifters. 
On a GM product with a cast cam and Isky lifters we run 140 psi on the seat and .600" lift at the valve and have never hurt a cam or lifter turning the engine 7000 on a 1/2 mile dirt rack.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

The stock springs will handle the additional lift of the Isky E-4 camshaft.  The real question here is if the springs themselves are fatigued to the point that they will go into harmonics or valve float too early thus bringing to the forefront the possibility of a dropped valve or at the very least, dislodged push rods.  I always upgrade the springs with any kind of camshaft upgrade and also check for retainer to guide clearance problems which really comes to the forefront with any kind of increase in lift at the valve.

Lorena, Texas (South of Waco)

I read that Ford recommended max 5400 rpm on their stock valve trains. Their Police service valve train parts were designed to go beyond that. As mentioned, Schumann's Sales used to sell those kits. At John Mummert's site (a link from here) his 265-S cam kit, which is a little beyond the 1957 Ford std camshaft, but good with stock auto transmissions, I believe uses 95 lb seat pressure springs...     


Paul

Thanks for the info. Nice to see you guys still taking care of the younger generation yblockers with tech answers 👍👍