Valve Springs, 200, Comp Cams 260

[dmsmith55]

I bought some 73-75 302 Ford springs that test about 80 @ 1.59 and 180 @ 1.25 (and 220 @ 1.15). I want to use a Comp Cams 260 in my 200, 0.440" lift. The 302 valve springs are quite a bit stronger than Comp Cams' recommended spring which is 48 @ 1.60 and 148 @ 1.25. I checked also for coil bind at max lift (1.15") and I can get a 0.030 feeler gauge between the coils. Does anyone have thoughts or experience with this setup and have you had excessive cam wear?? Is 0.030 OK for coil bind clearance??

 

[Anonymous]

Hello dmsmith,

.030 "safety margin" is a little close. Comp themselves recommend
.100" but contradict that quite often with their spring recommend-
ations for various cams. The stock 200 spring is very good and
has a higher spring rate and more seat pressure than the Comp
spring for that cam. I used new stock springs with that cam in
my '61(described at bottom) and with the porting and header
that engine went from "begging for mercy" at about 4500 rpm
to "screaming happily" to 6000 R's and never experienced
valve float. It's my opinion that new stock springs are more than
adequate for that cam and the 302 springs may be un-necessary
and possibly shorten the life of the cam. MY $.02

Ron.

 

[dmsmith55]

Thanks, bus station. I have some slightly used stock springs; I will check them and see if they all come up to spec and use them if they do.

 

[80Stang]

Comp's own recommended springs float at around 5300rpm, stock 200 springs obviously hold on better. But that 260H cam will end way sooner so you can run with Comp or stock springs as it is not practical to rev it much higher than the cam lasts anyway. Got a dyno sheet of a 260H in a 200 block. Also dynoed a setup with beefier cam and Comp springs and found where they float.

 

[powerband]

I had the machinist I know rebuild a D7xx head with 302 springs adn I bought rebuilt adjustable rocker setup from RAS (Rocker Arm Specialists). I was concerned about coil bind since the head was milled .070 and the milling effectively lengthened the pushrods. RAS cautioned that .060 at maximum lift was a safe minimum clearance. The machinist cut the valve spring seats on the head and installed hardened-shouldered valve spring seats to spec'd spring height with the later valves/springs.
http://www.rockerarms.com/

Powerband

 

[MustangSix]

While .030" may seem close (it is), keep in mind that that is the distance between two coils. You should have several times that distance because you have multiple coils to compress.

A 260 is a fairly mild cam. It doesn't take a lot of sprng pressure to control the small valves we have, so don't go too heavy. It's not necessary.

 

[Anonymous]

Hello All,

I,d like to post a correction to my previous statement. I checked
the Comp catalog last night and found that the springs for the
260H cam are virtually identical to stock springs as far as seat
pressure, open pressure and spring rate. The only real difference
is that the Comp spring coil binds earlier( has less available travel).
Comp's spring coil binds at 1.125" where as stock springs coil bind
at 1.065". The coil bind spec. in the catalog could be a misprint
(I hope so!) because that would only give you .020" to.035"
extra depending on installed height .
Here's the stock spring specs: 1.828" free length, 1.355"O.D.,
1.006"I.D., .177" wire diameter. 52# @ 1.585"--154# @ 1.220--
coil bind @ 1.065. Spring rate: 279lb/in.
Comp's is 280lb/in. Thank you, Ron.