Back fire through intake when floored

[Sean Buick 76]

You have made enough changes to the emgine that it will require a different fuel curve vs stock. It I’ll need a tune of some sort.

 

[Connorpod]

Hey everyone, I thought I’d give an update: This miss was due to fuel pooling in the intake manifold. Since vortec heads do not have an exhaust cross over, a passage has been added into to some intakes that help warm the hole in with coolant. The Edelbrock intake manifold that I bought did not have a coolant passage in it to warm the plenum. Will need to purchase one that had that passage. Unfortunately it looks like the GMPP intake is the only one that has it. It’s funny, I was so focused on timing, and camshaft issues that I never considered the heads. Thanks for the help everyone!

 

[tayto]

the vortec Edelbrock Performer RPM intake has a passage under the plenum. I routed coolant through it and ran TBI. seemed to work good...

 

[L31MaxExpress]

the vortec Edelbrock Performer RPM intake has a passage under the plenum. I routed coolant through it and ran TBI. seemed to work good...

Was that the marine version? The ordinary Vortec RPM I still have does not have that passageway. That specific manifold is like 20 years old though.

 

[tayto]

Was that the marine version? The ordinary Vortec RPM I still have does not have that passageway. That specific manifold is like 20 years old though.

No it wasn't the marine version. The manifold I used (7116) was probably bought around late 2012 or early 2013. I recall rbob recommending it because of these passages that you could plumb coolant too. Too bad they don't do that on their other vortec manifolds.

 

[Connorpod]

Lucky! I have the spread bore edition of the performer. Unfortunately, the lack of injector shrouding came at the price of no coolant plenum passage.