Roller tip rocker question...

[sir loin]

Newbie here, cool forum.

Question: My current stock rockers are 1.52:1. I'm using a 'Phase 2' cam and I want to got to a roller tip rocker. Should I stick to that stock ratio or can I go to 1.6:1?

I have a 3.1L '94.

Thanks

[19Cutlass94]

'94 the 3100 should be 1.6:1 but if they are not, yes you can go to this ratio.

[sharkey]

just a hunch, but im going to guess he has a 3.1l, not a 3100. the stock rockers on it are 1.5:1 non roller tips, 1.6:1 roller tips will wake the motor up a little bit.

[19Cutlass94]

'93 they introduced the 3100 and by '94 I though it was pretty much all 3100's....

[sir loin]

Damn, I thought y'all would be experts on this engine. This is a 1994 3.1L with 1.52:1 ratio stock, starter on the driver's side, iron heads. I currently have the stock rockers and want to go to the roller tips but don't know if the 1.6:1 with a fatter cam would cause problems with the valves coming too close to the pistons.

Thanks.

[sharkey]

yup, but j-bodies still had the 3.1l in them through 94.

[geoffinbc]

Damn, I thought y'all would be experts on this engine. This is a 1994 3.1L with 1.52:1 ratio stock, starter on the driver's side, iron heads. I currently have the stock rockers and want to go to the roller tips but don't know if the 1.6:1 with a fatter cam would cause problems with the valves coming too close to the pistons.

Thanks.

Starter on the drivers side but iron heads? Makes no sense unless it is an Isuzu application.

But in any case there was NEVER a 1.52 ratio that came stock on any of these motors. They are 1.5 stock for everything gen I and II which includes your iron head engine. Anything gen III came with 1.6 rockers.

But in any case you can usually go to 1.6 ratio rockers on just about any after market hydraulic cam. But the words "Phase 2 cam" don't mean anything to anybody. You need to tell us the specs on that cam so we know what to tell you.

[bszopi]

Knowing what vehicle the engine is in will also help determine which engine it is.

[Superdave]

Knowing what vehicle the engine is in will also help determine which engine it is.

Exactly....


we're only experts IF we have all the information

[sir loin]

Starter on the drivers side but iron heads? Makes no sense unless it is an Isuzu application.

But in any case there was NEVER a 1.52 ratio that came stock on any of these motors.

You need to tell us the specs on that cam so we know what to tell you.

Yes, it is an Isuzu. 1.52:1 IS the ratio as spec'd by GM parts catalogue, Isuzu/Helm service manual, and check out any Jeg's catalogue in the rocker arm section.

As for the cam, I got it from ARI. It came in a plain box, brand name? Who knows. I guess I could call them. Here are the specs:

Type: Phase 2

Manifold Vacuum: 16-18

Duration @ .050": Intake204 Exhaust214

Adv. Duration: Intake270 Exhaust280

Lift: Intake.420 Exhaust.443

Lobe Center: Intake107 Exhaust117

Best power band from 1500 to 4000 rpm. Excellent low to mid-range torque from 1500 to 3500 rpm.
No computer or component modifications necessary. Stock or slightly modified cylinder heads.
Stock compression, stock carb or FI. Smooth idle.

[geoffinbc]

That cam will perform similar to the Crane 260-2 cam. You can easily run a 1.6 ratio rocker with it.

And sorry the rocker arm ratio is 1.5:1. I have the OEM manuals published by Helm INC and also have access to GM's Online Service Information. All the specs you see listed on this site are a copy of that information. Along with the OEM service manuals I have "How to rebuild your 60 degree V6" and the Chevrolet Power Manual. All of them list a 1.5 ratio for all Gen I and II motors.

[torq455]

yeah, the only way you'd have 1.52 is with crane roller tip rockers.

[86euro]

yup, but j-bodies still had the 3.1l in them through 94.

As did the Luminas (cars, gen II).

[Turtle]

HI Im new here and i have a 94 grand prix with the 3100 and want to know what rockers i can upgrade to , ive been looking around at roller rockers but i dont have an idea what i can switch too

[SappySE107]

You can either got with crane gold race rockers that are 1.6:1, but you will have to modify 4 of them to clear the lower intake manifold. You could also upgrade to the newer heads that have roller rockers stock. Your stock rockers are 1.6 stamped steel ball fulcrum. The only higher ratio that works are the harland sharp 1.65:1 narrow body SBC rocker arms.