CNC Machined 1GR-FE Exhaust Cam Gears (3° Retard)

Soo has anyone confirmed they received an Actual 3° gear as advertised? Just finishe my @Roostfactor pulley wrap and am ready to see what these gears will do for My Supercharger

 

All the gears were effected.

The last of the parts I needed to machine a new keyway in these gears comes in today. Will keep y'all posted.

 

You’re the man!

 

I'm glad you're on this. You've pointed out a number of things I did not know and had not considered. I'm curious now if machining a new keyway and leaving the old keyway empty will affect life of the gear. I wouldn't think so, but it's spinning pretty fast.

Can we buy gears with no keyway?

 

Race lightened with the additional key-way

The harmonics will change though.

 

Spoke with my fellow fabricators and my machinist regarding the additional keyway changing the balance of the gear. They laughed at me. They mentioned how the key isn't exactly the same size as the keyway and being that the gear is so small it won't be a problem.
My machine has been tied up making parts for a local galvanizing plant. After I finish machining out this hole for a press fit bearing, I can start building a jig to do our keyways consistently/accurately.

 

Very exciting @mightytacoman !

The harmonics changing is true, but until what RPM will it be noticed is most likely far beyond the realm which these engines will ever reach. A statement of truth with little relevance in the scope of play.

Don't forget to add the reference dot for proper orientation. This forum is like the field of dreams. If you ask they will build it.

 

You can add me to the list of the next batch as well.

 

This is exactly what I was thinking of doing with a spare set of stock gears I have. At a quick glance it seems 180° would put you at the tip of another tooth. I haven't put a compass on it to be certain.

 

You are correct in your assessment.

 

Just need to go 183 degrees!

 

Or to simplify, 3° off center of a tooth.

 

183? Or not 177° if you're wanting 3° retard? I guess that depends on the direction the cam turns during operation. I haven't even looked into that. I assumed clockwise rotation.

 

Just flip it over.

 

Lol good point.

 

So I was successful in machining out the gear and will be able to replicate my results. Bottom picture has the gear upside down (notice lack of timing mark) to show the teeth are exactly 3 degrees off. Accuracy to within 1 minute of a degree (1/60th). If time allows- will install next weekend for further proof of concept.

 

Bravo @mightytacoman

 

Waiting upon Install.

 

Would rather install new gears then new stock gears.

 

So, I have a question that’ll likely cause a shitstorm.

This quote that is probably off the urd site: "The exhaust cam gears retard the exhaust gear timing by 3° in relation to crank angle. Allowing the cylinders to empty more completely on the exhaust stroke. On the intake stroke the cylinders will fill with more air and fuel increasing the overall volumetric efficiency of the engine. There will also be less hot exhaust gas left heating the incoming air and fuel and reducing it's knock potential. This is very advantageous with forced induction conversions."

I’d like to know wtf. First of all, if we are retarding the exhaust cam by 3° Of crank angle, then our cam gears should only be machined for -1.5° of cam angle.

Secondly, by retarding the cam we are increasing valve overlap. Which, doesn’t sound to me like the correct way to go with a supercharged motor.