Ok so we all know how stupid the intake bridge/elbow design is on the LLY+ engines. So I figured I would change it for the better when I put my new engine in.
The issue is that the elbow is not attached to the bridge in any way shape or form. It relies on the EGR motor housing (or a custom bracket) to keep it from blowing out of the bridge. The o-rings alone seal it from boost, but dont prevent it from being blown out under high boost.
I just left the EGR motor housing in place previously (took out the EGR cooler though), but I decided to make it cleaner this time around. Also, that flange where the elbow attaches to the intake manifold is a weak spot and always prone to leaks. If you have twins, this area gets stressed even more because as the motor moves around under the torque, it loosens up the flange and elbow.
My solution fixes all of these problems, and provides more give in the post-CAC intake piping system.
I thought about just welding the elbow into the bridge, but if you have to replace the CP3 or anything, it makes it a MUCH bigger job. It makes things a LOT easier if the elbow remains removable.
First I ground off the flange on the elbow, but left a bead to allow a silicone boot to seal without getting blown off. Then I drilled and tapped the intake bridge and elbow to allow two stainless steel screws to be screwed through the elbow and bridge itself. This holds the elbow in place, and keeps it from being blown out under boost, but also allows the elbow to be easily removable for service. When I put the screws in, I had to drill it more near the edge than I would have liked to, but also had to avoid drilling through where the o-rings seat. I also put some thread sealer on the screw threads to seal that up. So far zero boost leaks.
Then on the intake pipe for the twins, I did the same thing. Cut off the flange, and welded a bead around to allow the boot to seal. I upgraded to the LBZ intake manifolds and bridge/elbow at this time as well, so the boot I used needed to be a 2.75" to 2.50" reducer. (the LBZ elbow OD is 2.75", the LLY twins intake pipe is 2.50" OD) I also had to remount the MAP sensor because the LBZ intake manifold does not have the mount/hole for the LLY MAP sensor.
Anyway, just thought I would share. Big thanks to Tacojedbob, he did the MAP sensor relocation bracket, and Madisonjam85 did the drilling/tapping/grinding (I was busy putting the heads and stuff on the motor).
ben
The issue is that the elbow is not attached to the bridge in any way shape or form. It relies on the EGR motor housing (or a custom bracket) to keep it from blowing out of the bridge. The o-rings alone seal it from boost, but dont prevent it from being blown out under high boost.
I just left the EGR motor housing in place previously (took out the EGR cooler though), but I decided to make it cleaner this time around. Also, that flange where the elbow attaches to the intake manifold is a weak spot and always prone to leaks. If you have twins, this area gets stressed even more because as the motor moves around under the torque, it loosens up the flange and elbow.
My solution fixes all of these problems, and provides more give in the post-CAC intake piping system.
I thought about just welding the elbow into the bridge, but if you have to replace the CP3 or anything, it makes it a MUCH bigger job. It makes things a LOT easier if the elbow remains removable.
First I ground off the flange on the elbow, but left a bead to allow a silicone boot to seal without getting blown off. Then I drilled and tapped the intake bridge and elbow to allow two stainless steel screws to be screwed through the elbow and bridge itself. This holds the elbow in place, and keeps it from being blown out under boost, but also allows the elbow to be easily removable for service. When I put the screws in, I had to drill it more near the edge than I would have liked to, but also had to avoid drilling through where the o-rings seat. I also put some thread sealer on the screw threads to seal that up. So far zero boost leaks.
Then on the intake pipe for the twins, I did the same thing. Cut off the flange, and welded a bead around to allow the boot to seal. I upgraded to the LBZ intake manifolds and bridge/elbow at this time as well, so the boot I used needed to be a 2.75" to 2.50" reducer. (the LBZ elbow OD is 2.75", the LLY twins intake pipe is 2.50" OD) I also had to remount the MAP sensor because the LBZ intake manifold does not have the mount/hole for the LLY MAP sensor.
Anyway, just thought I would share. Big thanks to Tacojedbob, he did the MAP sensor relocation bracket, and Madisonjam85 did the drilling/tapping/grinding (I was busy putting the heads and stuff on the motor).
ben
