Roller rockers and new valve springs

I found a set of old-stock Crane gold rockers (10758-16). They're 1.6 ratio. I'm not clear on if I'm required to use a heavier valve spring or not with these, as with everything I seem to discover mixed results online.

your stock valvesprings are floating with your stock rockers. It will be worse with the cranes. So YES you SHOULD change the springs if you want to benefit from the higher ratio. If your budget is very low, I would just change the springs.

Are you getting a good deal on the rockers ? I have a set of gently used comp pro-magnum SA 1.6 ratio (3/8" stud) and crane iron head valvespring kit I could sell.

jasonlachapelle wrote:

your stock valvesprings are floating with your stock rockers.  It will be worse with the cranes.  So YES you SHOULD change the springs if you want to benefit from the higher ratio.  If your budget is very low, I would just change the springs.

Are you getting a good deal on the rockers ?  I have a set of gently used comp pro-magnum SA 1.6 ratio (3/8" stud) and crane iron head valvespring kit I could sell.

I got a good deal I think, about half what Jegs wants for a set.

Ok, I think I understand, I need springs that are slightly taller since the ratio is higher. Are your springs the right height?

No, you don't understand. You need springs that are the correct installed hight and provide adequate control. Your stock springs were barely adequate to control the valve when new. They are now old and worn out.

Yes, I am sure my springs are correct for this application, but I'm not interested in selling them separately for now. P/N was crane 10309-1.

Set price?

jasonlachapelle wrote:

No, you don't understand. You need springs that are the correct installed hight and provide adequate control.  Your stock springs were barely adequate to control the valve when new.  They are now old and worn out.

Yes, I am sure my springs are correct for this application, but I'm not interested in selling them separately for now.  P/N was crane 10309-1.

Thanks Jason, I was unclear what you meant by 'float'.

Andebe wrote:

Set price?

$375 shipped. PN comp 1618-16 (ultra pro-magnum) and crane 10309-1.

lamune wrote:

I found a set of old-stock Crane gold rockers (10758-16). They're 1.6 ratio. I'm not clear on if I'm required to use a heavier valve spring or not with these, as with everything I seem to discover mixed results online.

while i can appreciate your interest at adding perfomance 1.6 rollers to your bone stock engine,.

It's a bit of a step in the wrong direction INMHO,. as jason has said,. a better investment for performance gain on bone stock engine would be new valvesprings,.

I personally wouldn't even worry about them unless you plan on running the motor over 5500rpm,.

money would be better spent ona tune for your ecm,.

but,. you do what you want,. you're gonna anyway right?

phantom 309 wrote:

but,. you do what you want,. you're gonna anyway right?

I've heard that before someplace.....Oh you said it to me!

Tom

silverfox103 wrote:

I've heard that before someplace.....Oh you said it to me!

Tom

Well, he's right, isn't he?

In this case I totally understand that going to roller rockers offers very little benefit for my use other than slightly lower friction over the stamped ones. It's just something I always thought was cool and always wanted to do.

you'll squeeze around 10hp out of the engine with the 1.6 ratio roller rockers, maybe more if your valvesprings are really tired.

Get a tune if you haven't already! definitely good bang for the buck.

I picked up a spare PCM so I can send it out for a tune one of these days.

The rockers arrived today, and the look fine. The sticker on the side of the package says that LT1 needs spring 10309-1

In a few weeks I'll save up and pick up a set of those and then tackle the stem seals, springs, and rockers. I may pick up a set of pushrods to have on-hand in case I find any that are messed up, though I'm not sure if they are prone to wear or bending under normal circumstances (I'd guess no on that!)

The goal of all this isn't more power, although that's always welcome. I'm curious to see if the engine runs better or not with the new springs and if the oil fouling goes away with the stem seals.

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buying a cam and new chain would have been a better idea,.

but,.. why not do that now?

Even with 164k on the clock?

I did change the chain, but not the cam.

lamune wrote:

I did change the chain, but not the cam.

Ok,.

it'll be waaay faster now,.

Yeah I figure that timing chain should be good for at least +25, maybe 30 HP.

Oh, hey, I almost forgot I need a LT4 knock module. So far my searching comes up with none in stock. Anyone have a lead on one?

Well, since I've been utterly incapable of finding a LT4 knock module I'm kind of stuck with the stock rockers for now.

However the car is laid up with two missing gears in the tranny, so I may as well change the valve springs and oil seals while I have time.

Is there any problem using the Crane springs with the stock rockers?

The Crane springs are noticeably beefier than what's on there now. I'm really curious to see what that does to how the motor runs.

You may need taller valve covers with the roller rockers. Everything I have ever done to my car requires that I do at least one other thing, and spend at least $50 to make it work.

you can do the springs with stock rockers, but you should install the cranes
you can use the stock valve covers with the crane rockers
you don't "need" an LT4 KM. As discussed, get a tune and tell the tuner to tune out the false knock.

Ok, thanks guys. I'll drop the rockers in too and see what happens. I have a spare PCM I can send out for tuning (or perhaps de-tuning in this case)

you will not notice any difference other than the fact the motor will like to rev a little easier over 5500,.
which most folks with stock motors don't do very often,.
but psychologically it will feel much faster i,m sure,..

I don't want it to go faster. I think it goes fast enough. It's all about the experience. Also it looks cool, maybe it's time for some transparent valve covers.

Progress!

Got half of them installed. I'll do the adjustment tomorrow.

I also discovered cylinder #7 leaks air into the crankcase like crazy. That's also the one with the lowest compression and worst fouling. Nothing a rebuild won't fix, I suppose.

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Isnt air in the crankcase a killer? Read recently,Nick said thats a sure sign of a bad ring/rings? Your luck continues my wagon friend...

Andebe wrote:

Isnt air in the crankcase a killer? Read recently,Nick said thats a sure sign of a bad ring/rings? Your luck continues my wagon friend...

He was talking about blowby and pressure in the crankcase. I'm not seeing much of that, the dynamic vs. static pressures are somewhat different things when comparing a running motor to pressurizing a cylinder with shop air.

However it's not a good sign.

silverfox103 wrote:

phantom 309 wrote:

but,. you do what you want,. you're gonna anyway right?

I've heard that before someplace.....Oh you said it to me!

Tom

.... and me upon several occasions... and he's right.

Ok, half way done. Need some more stem seals and I can do the other side.

I had time this weekend to finish the roller rocker install, since the transmission won't be shipping until later this week.

It seems a little smoother at idle, probably more due to the valve lash being adjusted for the first time since 1995 than anything else. It runs the same, though it has this sound to it now that's pretty interesting. It sort of sounds a bit like a bank of sewing machines.

I discovered that #7 and #8 bleed a lot of air into the crankcase. #1 and #2 are less leaky. The 4 center cylinders seem to hold pressure very well. I'm not sure if this wear pattern is typical or points to some problem... but I figure I'd mention it.