Quote:
Originally Posted by PTAddict
Thanks Mark! I wouldn't have thought a system would work without some room for thermal expansion, but obviously you've proven that wrong.
I did find this kit to add a dry break and high point for bleeding LT4 systems. Kinda spendy but probably worth it when you read about how tricky these systems are to bleed and get all the air out. |
GM has done the reservoirless intercoolers on several cars now, my ATS-V being one of them. I think the LT4s are the same way. Haven't worked on an LT5.
My hunch is the lengths of rubber hoses and the hoses being flexible is enough allowance for thermal expansion. It's not a huge volume and not a large delta T, at least compared to the engine coolant.
And yes, bleeding the reservoirless systems is a bit of a pain.
The "riser funnel" method like the kit you posted works pretty well, in my experience you can get about 90% of the air out by filling the funnel and toggling the pump on an off many times to "burp" the system-- you'll get enough air out, at least enough so it won't trip the ECM's pump cavitation monitoring on a factory car. The cavitation monitoring on the factory cars will shut the intercooler pump down if it detects cavitation from air in the system (I'm guessing it monitors the pump current for excessive ripple which would indicate air in the system, or low current which would indicate no coolant and no load on the pump.)
However, if I first bleed the system by the "riser funnel" and pump cycling method, then hook up the factory filling/bleeding method of a Kent Moore quick connect fitting and a Vac-N-Fill, it will pull a little more air out of the system that the "riser funnel" method left in. The factory intakes have the fill points located a bit lower than the tops of the intercooler bricks in the intake, so air will always want to collect in the bricks at the highest point. Only way to get 100% of the air out of the system is to use a Vac-N-Fill or similar and run it through a couple of vacuum and draw cycles until it only pulls a steady stream of coolant out.