Valve Spring Choice for Solid Roller Street/Strip

[Turbobuick6]

If you are looking for a small diameter spring to run street/strip with, I would recommend the PAC-1530 (1.284" OD) setup @ 1.950".

185 seat and 575 open @ .060" from bind.

I emailed PAC about this spring, but they have stopped making them. Looked like a nice street/strip valve spring for the .700 lift range.

They have not stopped making them, who ever you spoke with was miss-informed.

[Orr89rocz]

I emailed PAC about this spring, but they have stopped making them. Looked like a nice street/strip valve spring for the .700 lift range.

They have not stopped making them, who ever you spoke with was miss-informed.

Its listed as special order item on the website. Not a stocked item

[Turbobuick6]

I emailed PAC about this spring, but they have stopped making them. Looked like a nice street/strip valve spring for the .700 lift range.

They have not stopped making them, who ever you spoke with was miss-informed.

Its listed as special order item on the website. Not a stocked item

Yes they are usually built to order (1-2 week lead times)

[F-BIRD'88]

With your valvespring play you are going to end up spending more money than any money needed to do maintainance on the lifter bearings. Again, with running nitrous you do not want to short the valvetrain of spring force and control.
The roller cam you have may be of short duration but is way beyond a street strip street roller cam lobe design.
Bouncing the valves and thus the lifters st high rpm is much harder on everything than the spring pressure of those springs.

[n2omike]

With your valvespring play you are going to end up spending more money than any money needed to do maintainance on the lifter bearings. Again, with running nitrous you do not want to short the valvetrain of spring force and control.
The roller cam you have may be of short duration but is way beyond a street strip street roller cam lobe design.
Bouncing the valves and thus the lifters st high rpm is much harder on everything than the spring pressure of those springs.

So you think the specs are a little 'fast' for street/strip car that comes out on nice weekends, and goes to the track a few times per year? I am looking for longevity... hence the bushing lifters, good pushrods and crower stainless shaft rockers. I do expect to be able to take it out and go 25-50 miles down the road if I want to... with a few 7500 rpm blasts mixed in. Will likely tighten the lash down 0.006" from what is listed in order to make life easier on everything.

(solid roller)
279/291 @ 0.020"
249/258 @ 0.050"
172/177 @ 0.200"
0.4120"/0.4315" lobe lift
0.700"/0.690" lift with 1.7/1.6 rockers
110º Lobe Separation
0.018"/0.022" lash

Unrelated to this tangent, but here is the intake that's going on it. Ported Super Victor.
Carb is an AED.

[F-BIRD'88]

If the springs are not up to controling this valvetrain then the first time you buzz it up to 7500 rpm you will start damaging all this expensive stuff..
It does not matter how much you drive it.
Consult the cam grinder for spring requirements.

You have a false sense of economy, when it comes to mechanical systems and durability.

Again that cam is not a "street roller".
Weak springs can allow bounce etc at 7500 rpm.

The valvetrain does not self heal.
The intake looks beauti.

[n2omike]

If the springs are not up to controling this valvetrain then the first time you buzz it up to 7500 rpm you will start damaging all this expensive stuff..
It does not matter how much you drive it.
Consult the cam grinder for spring requirements.

You have a false sense of economy, when it comes to mechanical systems and durability.

Again that cam is not a "street roller".
Weak springs can allow bounce etc at 7500 rpm.

The valvetrain does not self heal.

I read how a lot of the higher end guys are getting more rpm with less spring pressure... by using smaller diameter, lighter weight springs/retainers, etc... and wondered how it would apply to a 0.700" lift, fairly fast 'street/strip' cam... hence this post to inquire about it.
I did call Bullet... which is who ground the cam... I believe I talked to Chris, and he advised me to use the existing springs that came with the TFS High Port 225 heads... the Isky 9385, which is a 1.56" diameter unit a 500 lb/in rate and 245 lbs on the seat. He said I should get 3-4 years out of a set.

'Could' a person get away with the smaller, lighter PAC spring? Possibly. Is someone reputable going to step out and actually recommend it? Probably not. Better safe than sorry... and as long as Bullet liked the springs that are already on the heads, it's money in the bank. I'm not dead set on being a guinea pig. lol The post was an inquiry to see if significant power/reliability could be gained with the lighter parts.

My main concern is power WITH durability. I've been acquiring these parts for a long time. The receipt on the heads is from 3/11/2011... and some of the parts came before that. I'm okay with waiting to be able to afford the RIGHT parts. Do you think the camshaft is going to prematurely beat up the valvetrain? Is it THAT fast?

[cab0154]

i know for a fact that a good set of 1.55 PSI/PACs with mid 200s for seat and low 700s for open will be fine in the low .700 lift area with a decently aggressive ramp. But I have been talking to PAC and PSI also about some bullet lobes and their recommendations for the lobe (and it was a pretty aggressive ramp) was a lot lower than I was used to, and they said it was due to the smaller lighter springs not needing as much pressure to control the valvetrain and would be easier on parts. I think if you are going to run old school big springs then you might need to stick with extra pressure. but ive also talked to some who say too much pressure for a lobe is common also. the engineers at PSI/PAC are the ones who designed the new springs, so if they say the newer springs with less pressure will support what the older, heavier stuff will; i would be willing to bet they know what they are talking about and you will likely get more life out of your valvetrain as well.

what is the wall thickness on those 3/8" pushrods you are running?

[bob460]

I emailed PAC about this spring, but they have stopped making them. Looked like a nice street/strip valve spring for the .700 lift range.

They have not stopped making them, who ever you spoke with was miss-informed.

Those jack asses, man it's tough to get the right info these days.

They have not stopped making them, who ever you spoke with was miss-informed.

Its listed as special order item on the website. Not a stocked item

I don't see as special order item...............i just see "1500 Series Circle Track Endurance Duals "

[F-BIRD'88]

I agree with Chris at Bullet Cams.
Use what he recomends.

[bob460]

If the springs are not up to controling this valvetrain then the first time you buzz it up to 7500 rpm you will start damaging all this expensive stuff..
It does not matter how much you drive it.
Consult the cam grinder for spring requirements.

You have a false sense of economy, when it comes to mechanical systems and durability.

Again that cam is not a "street roller".
Weak springs can allow bounce etc at 7500 rpm.

The valvetrain does not self heal.

I read how a lot of the higher end guys are getting more rpm with less spring pressure... by using smaller diameter, lighter weight springs/retainers, etc... and wondered how it would apply to a 0.700" lift, fairly fast 'street/strip' cam... hence this post to inquire about it.
I did call Bullet... which is who ground the cam... I believe I talked to Chris, and he advised me to use the existing springs that came with the TFS High Port 225 heads... the Isky 9385, which is a 1.56" diameter unit a 500 lb/in rate and 245 lbs on the seat. He said I should get 3-4 years out of a set.

'Could' a person get away with the smaller, lighter PAC spring? Possibly. Is someone reputable going to step out and actually recommend it? Probably not. Better safe than sorry... and as long as Bullet liked the springs that are already on the heads, it's money in the bank. I'm not dead set on being a guinea pig. lol The post was an inquiry to see if significant power/reliability could be gained with the lighter parts.

My main concern is power WITH durability. I've been acquiring these parts for a long time. The receipt on the heads is from 3/11/2011... and some of the parts came before that. I'm okay with waiting to be able to afford the RIGHT parts. Do you think the camshaft is going to prematurely beat up the valvetrain? Is it THAT fast?

Why don't you call psi or pac and tell them which is the best valve spring that COULD replace the "Isky 9385" in a smaller, lighter spring!

[F-BIRD'88]

It would be a very leading question without specific information about the rest of the valvetrain.
Its about context.

[bob460]

It would be a very leading question without specific information about the rest of the valvetrain.
Its about context.

Well i'm sure the OP would tell them the full specs of engine and intended use...........

[Orr89rocz]

Cam looks very similar to a comp cams RT lobe which is pretty aggressive but searching here bigjoe said he used them in limited street use deals before.

Found this posted but no idea what specific lobe it was

“Currently on dyno with a small block RT intake with a 1.65:1 rocker and 128g valve(i know its heavy) and with a PAC 1385 set at 275lb seated and 660open. This thing is out of control by 7700...”

[n2omike]

Again that cam is not a "street roller".

Thanks for your input, Mr. F-BIRD

Out of curiosity, I looked up the specs on Comp's Xtreme Energy Street Rollers. It looks like the 0.050" and 0.200" are very similar... so similar intensity, but around 0.040" less max lift. As for 'advertised' duration, the Comp lobes are measured at 0.015" and the Bullet at 0.020", so no apples to apples.

First my numbers, and then the Comp Screen Shot. Curious to know what you guys think. Will likely end up keeping the big, old tech Isky 9385 springs for now... but have concerns about the service life of the drivetrain from the 'not any kind of a street roller' statement. Will definitely tighten up the lash... that's for sure. Probably 0.012" and 0.014" hot to avoid beating things up, or something along those lines. Thanks.

(solid roller)
279/291 @ 0.020"
249/258 @ 0.050"
172/177 @ 0.200"
0.4120"/0.4315" lobe lift
0.700"/0.690" lift with 1.7/1.6 rockers
110º Lobe Separation
0.018"/0.022" lash