Stronger valve springs?

[MiniCJJ64]

If I was to get stronger valve springs for my 200 compared to stock springs. What would to do? Also if I was, could I just use the same valves I already been using.

 

[Patrick66]

im using 302 springs, you can also use 289 springs. classicinlines.com has them, along with some performance ones. you can use stock valves and retainers.

 

[wallaka]

289/302 exhaust springs only, mind you. The 302/289 intake springs are too big.

 

[CZLN6]

Howdy Back James and all:

I'm just curious why you need stronger valve? Anymore spring pressure then you need to control valve float and/or flutter just accelerates wear.

If you're doing a valve job, consider back cutting the intake valves for less weight and shimming the stock springs up with .030" shims. This suggestion comes from one of Ak Miller's articles from back in the '60s. That's what I did when I did my '78 head. With a 260 Comp cam and ocassional bursts to 5,500 I have no valve float.

I do have a set of 4.0 V6 valve spring retainers that are 6 grams lighter then the stock, 2 piece 200 retainers, that will go in next time the head is off.

Adios, David

 

[MiniCJJ64]

Well I just have stock cam and springs and my rpm only goes to 4000 rpm and I would like to bring that up alittle if I could.

 

[wallaka]

Probably need a better cam, then.

 

[Harte3]

Probably running out of "breath" and stiffer springs won't help that.

 

[gary6768]

If I was to get stronger valve springs for my 200 compared to stock springs. What would to do? Also if I was, could I just use the same valves I already been using.

I have a set of from classic inlines i didn't use. i put in some with more pressure than they had. $10 for the shipping and you can have them Gary

 

[MiniCJJ64]

what set did you get from classic inlines. I will buy them from you.

 

[AzCoupe]

Stock springs float around 4500rpm and are barely able to do their job. Old worn out springs, are going to float much sooner.

I believe spring pressure is totally dependant on the type of driving you do. If you have a daily driver and are more concerned with reliability and longevity, rather than burst of high revs, then a light spring is suitable.

However if you take it to the track on weekends, as many of our members do, then a heavier spring is called for. When you rev the motor into the higher ranges, the one thing you don't want is for the valves to float. This causes the valve to bounce off the seat because the lifter doesn't follow the cam lobe as intended. This is much harder on the valve train, than a bit of extra pressure. And its definitely not condusive to winning races.

 

[addo]

I usually see the springs in a street driven motor as the "safety valve". A little valve float will let you know that the engine is past its peak operating condition. Being a non-interference motor that turns lower RPMs, the risks of damage are minimal.

From that perspective, I'd spend money first on a new timing set, then a cam/lifters. Valve springs would come third!

 

[MiniCJJ64]

I guess I will have to get a bigger cam in the future.

 

[Anonymous]

I'm assuming this is for your new head?

If so definitely upgrade your springs from the stock ones!

Later,

Doug

 

[60s Refugee]

My thought is that if you can't rev above 4000 with no load then you have some other problem, not valve springs. I can only guess what that might be, and there can be a hundred guesses. Start with a tune up, checking the timing, checking the compression, replacing the fuel filter. Check the carb linkage for full open throttle. That kind of stuff might save you some time and $$$.

Harry

 

[MiniCJJ64]

I have seen it with no load rev to 5000 to 5500, but with load it revs only to 4000. I really need to get a bigger cam, but it looks like alot of work.

 

[60s Refugee]

How many miles are on your engine? Is it ready for an overhaul?

Harry

 

[MiniCJJ64]

My head has about 26,000 miles and my engine has 16,000 miles since the rebuild

 

[Bort62]

FWIW, my stockish motor is pretty much outta breath @ 4000 RPM, even with the turbo.

 

[CZLN6]

Howdy Back James and All:

James, I believe there is something out of whack, other then your valve springs, which is holding your engine back. A stock '78 200, with OEM Holley #1946 carb and DS II ignition should easily rev to 4,500 rpms.

Verify for me what ignition you are using with your H/W carb? Have you set the initial advance with a timing light? Vacuum guage? Have you verified that your timing mark on the damper is accurate?

Have you verified that your throttle is opening completely by flooring the gas pedal from inside the car? What do your spark plugs look like?

Could your exhaust be plugged in any way? What is your exhaust system?

I'd sure encourage you to look deeper into this puzzle. Keep us posted on what you find.

Adios, David