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Building-up my rebuilt 455 for my 442. Engine came with the EB Performer Intake with a stainless coolant cross-feed line going to the forward to aft LH side coolant passages.
See picture, is this necessary? It had iron heads now aluminum. I may call EB on this but I know there are folks here that are just as knowledgeable.
Whoever put that bypass on is clueless. For some reason, people think this helps cooling. Unfortunately, these are people who have never actually opened a Chassis Service Manual and looked at the coolant flow diagram. Coolant flows into the water pump, rearward in the block, up into the heads, and forward in the heads before exiting at the T-stat housing. Installing a bypass like this actually REDUCES coolant flow to the heads, which are the hottest part of the engine. Lose it.
Will do, thanks Joe. Car came that way and yeah it has had a lot of clueless done to it.
Based on your explanation the driver side heads would lose some coolant flow- glad I asked.
By the way, this is the other reason why the nipple for the heater hose has a restrictor orifice.
Bingo! Had this problem on one of my builds years ago. Replaced the factory cast iron intake with an aluminum intake and moved the nipple (1966 so no valve), but didn't know about the restrictor. It was so many years ago I forgot, but I think the symptom was it was overheating. Anyway scratched our heads for a while, somehow we figured out to look at the old manifold and found the restrictor, moved it to the new intake and problem was solved. This is so easy to miss!
Whoever put that bypass on is clueless. For some reason, people think this helps cooling. Unfortunately, these are people who have never actually opened a Chassis Service Manual and looked at the coolant flow diagram. Coolant flows into the water pump, rearward in the block, up into the heads, and forward in the heads before exiting at the T-stat housing. Installing a bypass like this actually REDUCES coolant flow to the heads, which are the hottest part of the engine. Lose it.
I've seen on other Olds sites talk about "4-corner cooling". I never lingered on the topic long enough to investigate, but what does that entail, and is it truly effective?
I've seen on other Olds sites talk about "4-corner cooling". I never lingered on the topic long enough to investigate, but what does that entail, and is it truly effective?
Chevy people push this, and as I noted above, it makes ZERO sense. All you are doing is pulling coolant out of the head before it has a chance to cool the head. How does this help?
You wouldn't get any coolant flow through that line what so ever being where it is for 1, nor up that high. Once the system pressurises with coolant it would just remain in the line.
Someone thought it may have done some good when they installed it I suppose.
Does anyone have a dimension for the restriction in the hose nipple?
I have an aftermarket one with no restriction. I would like to put something
in it to restrict flow.
Thanks, Matt
Whoever put that bypass on is clueless. For some reason, people think this helps cooling. Unfortunately, these are people who have never actually opened a Chassis Service Manual and looked at the coolant flow diagram. Coolant flows into the water pump, rearward in the block, up into the heads, and forward in the heads before exiting at the T-stat housing. Installing a bypass like this actually REDUCES coolant flow to the heads, which are the hottest part of the engine. Lose it.
I would bet my last dollar that if the “4 corner cooling” had any benefit whatsoever, the Olds engineers would have designed the engines with a system like that.
After reading this thread, I checked the original heater hose nipple for my non-A/C 69 442. There is, what looks like, a plastic disk sitting in a grove in the nipple. The inner diameter looks to be about the same size as the hose nipple. IIs this the restrictor or does something sit on top of that? It may be hard to see but I added a photo below.
That's it. Easy to miss. When I transferred the nipple from the stock manifold to my new aluminum manifold. Mine was still sitting in the well in the old intake manifold. I don't remember the exact symptoms (35+ years ago) but the cooling system was not working right without that restrictor disk.
March 14th, 2019, 05:46 AM
