Stock 440 valve springs?

[jg68]

Has anyone ever run a small performance cam with them? just wondering how far you can push them I was looking at one of the summit cam kits, do you think i could get away with it, any feed back would be appreciated.

Thanks

[jg68]

Anybody 

[firefighter3931]

I did years ago on my first cam swap but the engine was an HP 383 with low miles (56K) and the cam was pretty mild....old Crane "Fireball" grind. It ran pretty good and pulled hard to 5500 rpm and i don't recall any issues with valve float. I suppose if the cam had slow ramps and the lift was within the parameters of the valvespring then it would work fine. If it were me....i'd pull a couple of springs and test them for seat/open pressure and coilbind to make sure they match up with the new cam....cheap insurance.

The Comp 911 is a good spring that works with most hydraulic grinds and some moderately agressive solid cams as well. At $90.00 a set, they're pretty cheap. 

Fwiw, some of the 2bbl engines had very mild valvesprings designed for low lift (.430) cams. I'm not so sure i'd run those even if they checked out. 



Ron

[jg68]

Thanks Ron, the reason for keeping the stock springs is #1, the engine was completely rebuilt not to long ago, #2, i really don't want to be yanking the heads off neither, were i have it stored theres limited space & no elec.

If i do this, i'm going to stay conservative, i was looking at one of the summit cams, i think the smaller one would be fine, but don't know about its power potential over the stock one, its 442/465 with 214/224 @ 50. rpm range is 2000-4500

The bigger one i'm sure would work great, 465/488 with 224/234 @ 50, this one is 2200-5000.

i'm pretty sure there the 4bbl springs, it came stock with a TQ, so what do you think of these cams, would it be worth it, or should i just leave it alone

[firefighter3931]

The Summit cams are pretty descent. I recommended the larger 465/488 to a member here for his smogger 400 that was mildly reworked (head mill/valve job, headers,SD intake, holley750) and he really liked it. Mike said it would boil the tires in all 4 gears....lol. Those profiles are pretty slow on the ramp speed so a fresh rebuild head with descent replacement springs would work fine.

Whats the rest of the combo ? Gears, engine size, converter, etc...


Ron

[jg68]

Its a rebuilt 446 with headers, perf intake, 750 holley & stock converter, the cyl. pressure is decent, 148-152 on all, the gears are 355s SG, the heads are 452s, So do you think the larger summit cam will be ok with the stock springs or should i go with something smaller?

[firefighter3931]

I'd probably go with something a little smaller....the stock converter will hurt it. That cam comes alive ~2400rpm. The smaller stick might be better suited for this application. How heavy is the vehicle ? The build seems geared towards bottom end power from the parts you've listed. The "performer" is all done at 5000 rpm but it makes lots of bottom end power. Something along the lines of a Comp XE grind would work nice.....either the 262 or the 268.


Ron

[jg68]

The weight is around 3700, this is on my 77 D100 SW 1/2 ton, it has 31" tirers, but i'm planning on some 28" to give me more gearing, i'll look into the XE cams, i just liked the price of the summits, if i decide to leave it stock, i'll just plum in a better fuel system & run some nitrous, i have a brand new powershot 125 system looking for a home

[firefighter3931]

At that weight and with the 3.55's and stock converter + taller tires the XE262 would be my choice.

218/224@.050
110* lsa
.462/.470 lift


Ron