Coolant Crossover Tube; Necessary?

[femurphy77]

As the title states, is the coolant crossover tube on the 92 LT1 engine necessary. I am unable to reuse the banjo bolts on mine after a head swap and the dealer said the tube and bolts are no longer serviced. From reading some other posts in the forum I am under the impression that the crossover tube is primarily a steam vent with little to no coolant flow through it. If is indeed basically optional to reinstall I suppose just plugging the hose that goes to the header tank would be alright also. Ultimately I will reinstall it once I locate new bolts but would really like to get the engine fired up this evening. TIA. Frank, Indy

 

[Ken]

Given that you reside in a state where it gets a little cold in the off-season, the coolant passing through the throttle body will help the drivability of a cold engine. If you lived in a state where the temperatures never dipped too low, you can get away with bypassing the throttle body coolant passages.

By the way, it is definitely coolant passing through the htroittle body, not a steam relief.

 

[jmccloud]

coolant crossover tube

femurphy 77.
Are you speaking of the tube that connects the heads at the rear of the engine or the throttle body tube at the front?

 

[Ken]

That's what I get coming from a former L-98 owner; I forgot about the differences. :duh

femurphy 77.
Are you speaking of the tube that connects the heads at the rear of the engine or the throttle body tube at the front?

My humble apologies.

 

[Hib Halverson]

If you're talking about the x-over that links the two heads at the rear of the engine, you need that.

If you're talking about the coolant running through the throttle body, you can do without that except in areas where atmospheric conditions can be present for throttle body icing.

 

[femurphy77]

I'm talking about the tube at the rear of the heads, the 1/4" tube. FM

 

[Ken]

Hib had your answer.

If you're talking about the x-over that links the two heads at the rear of the engine, you need that.

I wasn't thinking with my response.

 

[femurphy77]

My original post was a little vague, thanks for the replies everyone. Frank.

 

[Hib Halverson]

I'm talking about the tube at the rear of the heads, the 1/4" tube. FM

I'd advise against operating the engine under any load without that tube. The engine has reverse flow cooling and that tube is needed to keep steam pockets or bubbles from being trapped in the cooling jackets near the back of the heads. Without that tube, cooling will be inconsistent.

If the part is no longer serviced, you'd better find a used one or fabricate some other type of plumbing. Perhaps, drill and tap the holes for pipe treads, install pipe-to AN adapters and make an Aeroquip hose to link the two.