Eliminating the secondaries

[Perry Mitchell]

This is how I keep my secondaries open at all times after removing the vacuum actuators.

[Paul Workman]

Originally Posted by Perry Mitchell

This is how I keep my secondaries open at all times after removing the vacuum actuators.

Sooo... It appears you removed the actuator(s) and replaced them with a flat tab bolt, yes? Nice. Oh, but to be safe, it might be worth considering to dab some BLUE lOCKTITE on the threads under the nuts to prevent them from vibrating loose, resulting in the secondaries (possibly) creeping closed insidiously.

[Perry Mitchell]

I used a 1/4'' threaded rod and flattened one end using a hammer then drilled a hole in it for the linkage pin to slip into. Loctite on the inboard nut might be a good idea. I used a nylon lock nut on the outside.

[grahambehan]

Paul, et al
Engine made 528 hp
Ken owns the car that this engine was installed in.
I will put more info on the fb page, including video

Graham

[XfireZ51]

Originally Posted by grahambehan

Paul, et al
Engine made 528 hp
Ken owns the car that this engine was installed in.
I will put more info on the fb page, including video

Graham

And this makes me shake my head when I read stupid comments on the C8 forum about how DOHC motors need to spun like a sewing machine to make any power. 528chp from a 5.7L NA motor. And one designed 30years ago.

Graham, what cams did u use for this?

[grahambehan]

Originally Posted by XfireZ51

And this makes me shake my head when I read stupid comments on the C8 forum about how DOHC motors need to spun like a sewing machine to make any power. 528chp from a 5.7L NA motor. And one designed 30years ago.

Graham, what cams did u use for this?

Power peak was at 7200 rpm.
Cam profiles were Lotus prototype.
Around 12mm lift, I think the duration was around 280 total.
I will dig out the info to confirm, don't have it with me at the shop.

Graham

[Paul Workman]

Originally Posted by grahambehan

Paul, et al
Engine made 528 hp
Ken owns the car that this engine was installed in.
I will put more info on the fb page, including video

Graham

Thanks for the clarifications, Graham. Much appreciated. And, if there are any dyno graphs available on that beast that you might have, I'll happily add them to my LT5 gen-III reference folder.

Paul.

[Paul Workman]

Just to add...

With regard to coking on the valves, I should mention too that in addition to secondaries delete, the installation of an OIL CATCH CAN was a notable contributor to the reduction of valve coking.