.454 lift too much for stock valve springs?

-
E

eviper21

Well-Known Member
Joined
Oct 20, 2011
Messages
312
Reaction score
7
Location
SoCal
its a stock 318 with an aftermarket cam, don't wanna spend $200 for new springs
 
probably, need to know recommended seat pressure. might work but pop on top end
 
I agree with green1, I've run mopar .484 cam and stock 915 heads/springs with no problems.See if you can get a set from someone that upgraded.
 
it will run fine
mine did would pop tho if i spun it up to high
but the stock heads did not make power up there anyway
 
eviper21 said:
don't wanna spend $200 for new springs
Click to expand...

You're gonna spend a lot more than that when you stuff a valve through a piston

There's a lot more to it than "coil bind."

Spring pressure --which can be measured. If you have a drill press and a halfway decent scale you can "jig up" a measuring device

Installed height --'s why they make shims

and of course someone mentioned coil bind.

The springs on my 360, which are unknown and used, are not good for more than 5500 with the little mild mechanical cam that's in there

The very same cam in the old Landcruiser engine would turn over 7K
 
I have a .455" lift cam with stock '81 318 springs. It runs great but I am afraid to rev it very high. I just found a set of comp single springs with dampeners, retainers and locks for$60 that another member used for break in springs. Can't wait to get them installed.
 
67Dart273 said:
You're gonna spend a lot more than that when you stuff a valve through a piston

There's a lot more to it than "coil bind."

Spring pressure --which can be measured. If you have a drill press and a halfway decent scale you can "jig up" a measuring device

Installed height --'s why they make shims

and of course someone mentioned coil bind.

The springs on my 360, which are unknown and used, are not good for more than 5500 with the little mild mechanical cam that's in there

The very same cam in the old Landcruiser engine would turn over 7K
Click to expand...

And this answered the op question?
 
i agree a $200 investment in springs would be worth it.

springs lose their temper/pressure with age & use

dropping a valve is no joke, and not something to fight about either

the cam is pretty mild, and stock springs are probably fine. however it depends on the condition of his current springs. the good news is they can be checked at a machine shop and they probably wouldnt charge much of anything to check them for you
 
My new Comp cam has about the same lift. Recommended springs are Comp 901-16.
I've found 60 to 80 dollar price range on those.
Someone sad Comp wouldn't warranty the cam if their recommended springs weren't used with it.
 
Spend the money on new springs. It is a safer bet than dropping a valve. I've dropped several valves and they can take out rods, pistons, and blocks...

unless you need a new anchor for your boat...
 
I got a new set of Comp 901-16 I'll let you have for $40 + shipping. Just throwing it out there so you don't go spending $200 on a set :toothy8:
 
Agree with Stroker on this one. Fresh 340 springs will be nice, up till about .480 to. 490 lift.Use stock retainers,don't sweat it.Check out Competition Products for pricing.
 
$200 for springs??!!! Shopping in the wrong place I guess.

Stock springs will work,but new springs will wake it upand your 340 will realise more performance with new springs,lifters and a cam. Ya kinda have to think on this;Those springs do an awefull amount of work,and see many heat cycles.New springs= cheap insurance against failure.
 
Well thats the thing, the heads are brand new rebuilt 973 heads. New valves, retainers, seats AND springs. As for what springs are on there?? idk but they have Zero miles on them. And since everyone is telling me to use stock 340 springs do I really need to change my new stock springs? Id just hate to waste new parts if i don't need to. Plus the few bucks to get em installed. Thanks for the links and info on the other springs tho, i definitely wasn't looking hard enough...then again i didn't know 340 springs were different / better than stock 318 springs
 
You must log in or register to reply here.
-

Back
Top