Short Stroke 408

[71RS/SS396]

Screaming short stroke 408 we just finished for a customer. It still has hydraulic lifters and runs on pump gas, took it all the way to 8700 and the valvetrain remained stable. We modified a set of LS3 Fast short runners to work with the LS7 heads. We kept the timing at 25 degrees with the pump gas. It made 688 hp@7,600 but the torque didn't peak until 6,600 so I think this might be easier to race on street tires. I think with higher octane fuel and more timing it would go to 700 hp. This is going into a C5 vette so intake height is an issue but with a better intake it should get above 700 hp.

http://i1009.photobucket.com/albums/af219/tmackg71/IMG_3193.jpg (http://s1009.photobucket.com/user/tmackg71/media/IMG_3193.jpg.html)

http://i1009.photobucket.com/albums/af219/tmackg71/Destroked%20ls71.jpg (http://s1009.photobucket.com/user/tmackg71/media/Destroked%20ls71.jpg.html)

[Jay Hilliard]

Awesome Tim. Did you use stock rocker with trunion upgrade or something else?

[71RS/SS396]

Awesome Tim. Did you use stock rocker with trunion upgrade or something else?
Stock LS7 rockers with the CHE Precision bushing style trunion upgrade. This is the lightest rocker combination out there.

[Flash68]

Very cool Tim.

Can I assume you did not start any of the dyno runs lower than that 4600 rpm?

[Che70velle]

Wow, hydraulic lifters at 8700. That's cool!
What is bore/stroke?

[71RS/SS396]

Very cool Tim.

Can I assume you did not start any of the dyno runs lower than that 4600 rpm?

We knew the peak torque was going to be pretty far up in the rpm range so that's where we decided to start the pull.


Wow, hydraulic lifters at 8700. That's cool!
What is bore/stroke?

4.165X3.75

[Jr]

Iron block?

[71RS/SS396]

Iron block?

RHS aluminum.

[71RS/SS396]

For those that prefer graphs, red is hp and blue is torque.


http://i1009.photobucket.com/albums/af219/tmackg71/FB_IMG_1494023370894.jpg (http://s1009.photobucket.com/user/tmackg71/media/FB_IMG_1494023370894.jpg.html)

[GregWeld]

When the 65 Mustang motor is finally rebuilt to it's last legs - I'm going to have to call and talk about switching to an LS motor in a Ford. I'd do it just to piss people off.

[SSLance]

That torque curve... **drool**

[Flash68]

When the 65 Mustang motor is finally rebuilt to it's last legs - I'm going to have to call and talk about switching to an LS motor in a Ford. I'd do it just to piss people off.

Please do! :action-smiley-027: