Lateral-g Forums

Lateral-g Forums (https://www.lateral-g.net/forums/index.php)
-   LSX Conversions (https://www.lateral-g.net/forums/forumdisplay.php?f=70)
-   -   Short Stroke 408 (https://www.lateral-g.net/forums/showthread.php?t=54888)

71RS/SS396 05-03-2017 05:28 AM

Short Stroke 408
 
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/...1/IMG_3193.jpg

http://i1009.photobucket.com/albums/...ked%20ls71.jpg

Jay Hilliard 05-03-2017 09:21 AM

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

71RS/SS396 05-03-2017 09:55 AM

Quote:

Originally Posted by Jay Hilliard (Post 658312)
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 05-03-2017 11:31 AM

Very cool Tim.

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

Che70velle 05-03-2017 02:05 PM

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

71RS/SS396 05-03-2017 02:39 PM

Quote:

Originally Posted by Flash68 (Post 658317)
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.


Quote:

Originally Posted by Che70velle (Post 658321)
Wow, hydraulic lifters at 8700. That's cool!
What is bore/stroke?

4.165X3.75

Jr 05-03-2017 03:16 PM

Iron block?

71RS/SS396 05-03-2017 03:49 PM

Quote:

Originally Posted by Jr (Post 658325)
Iron block?

RHS aluminum.

71RS/SS396 05-07-2017 04:40 AM

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


http://i1009.photobucket.com/albums/...4023370894.jpg

GregWeld 05-07-2017 08:02 AM

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.


All times are GMT -7. The time now is 02:53 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2026, vBulletin Solutions Inc.
Copyright Lateral-g.net