Valve springs?

[Doug_Guilds]

I am looking to get new valve springs for my 89 3.1. Its a stock grind cam with the comp cams 1.6 ratio rockers, but seems to fall off pretty bad after about 3500 rpm. What company has a good set of springs?

[richtazz]

There is no reason to go to performance valve springs unless you have a high-lift cam. Higher spring pressures equal more friction which equals less horsepower. GM stock springs are good for 6,000 rpm, and I doubt you'll be taking that old style, zero lash 3.1 any higher than that.

[maxwedge]

Originally Posted by richtazz

There is no reason to go to performance valve springs unless you have a high-lift cam. Higher spring pressures equal more friction which equals less horsepower. GM stock springs are good for 6,000 rpm, and I doubt you'll be taking that old style, zero lash 3.1 any higher than that.

Agree with Rich, a stock 3.1 170k miles pulled good to 5k, something else is going on here. I cannot see 1.6 rockers on a stock cam causing valve float.

[Doug_Guilds]

Well this thing is stock except the rockers, but the engine does have 224,000 on it. I definately don't want it to go over 5500 rpm, so a new set of stockers from GM should do nicely then.

Thanks guys.

[maxwedge]

Originally Posted by Doug_Guilds

Well this thing is stock except the rockers, but the engine does have 224,000 on it. I definately don't want it to go over 5500 rpm, so a new set of stockers from GM should do nicely then.

Thanks guys.

The pcm will limit the engine rpms here, is this what is happening, if so valve springs, again will not help. How did we go from 3,500 to 5500? You are modifying a 224k engine, relax , you are flirting with disaster trying to squeeze more rpms here.

[Doug_Guilds]

Oh it has rpm, it just doesn't seem to pull hard after 3500.

[maxwedge]

Originally Posted by Doug_Guilds

Oh it has rpm, it just doesn't seem to pull hard after 3500.

Did it before you worked on it when did this change? Power is down on any engine with that mileage, how is the fuel pressure under load.

[Doug_Guilds]

No, it felt pretty much the same. It has an inline fuel pump, cause it has a fuel cell in it, so unless it's a regulator problem that shouldn't be an issue. It's a MiniStock dirt car that I race at the local dirt track.

I am going to redo the engine after the season is over, but would like to get what i can out of it the next 4 races, that's when our points end.

[maxwedge]

Originally Posted by Doug_Guilds

No, it felt pretty much the same. It has an inline fuel pump, cause it has a fuel cell in it, so unless it's a regulator problem that shouldn't be an issue. It's a MiniStock dirt car that I race at the local dirt track.

I am going to redo the engine after the season is over, but would like to get what i can out of it the next 4 races, that's when our points end.

So after all this, you now tell us what the real deal is here, nice curve ball for trying to help you based on the lack of definitive info!! Check the fuel pressure at the rail under load!

[Doug_Guilds]

Originally Posted by maxwedge

So after all this, you now tell us what the real deal is here, nice curve ball for trying to help you based on the lack of definitive info!! Check the fuel pressure at the rail under load!

What the heck are you talking about? The real deal was I wanted info on valve springs, and Rich answered my question very well. Then you mentioned another potential problem. Ok cool, but if you needed all kinds of application info, fuel system specs, and exact mods done why didn't you say so?

Thank you for the advice.

[maxwedge]

Originally Posted by Doug_Guilds

What the heck are you talking about? The real deal was I wanted info on valve springs, and Rich answered my question very well. Then you mentioned another potential problem. Ok cool, but if you needed all kinds of application info, fuel system specs, and exact mods done why didn't you say so?

Thank you for the advice.

You are trying to connect your performance issue with the supposed weak valve springs, without " all" the info related to your issue we are second guessing as condition that can be related to the general configuration of the engine, remember we are sitting at a desk trying to visualize what is happening.

[Doug_Guilds]

PM sent Max.