Discussion Forum - Northstar Chevelle Club

Yes, a washer is what I used. I found one that fit tight in the hose with a 3/8 hole, I think a 1/4 would be better however.

Also I found this which I thought was interesting. https://webstore.spalusa.com/content/files/content/PDF/30102130_SPEC.pdf       Look at the voltage chart. With just 1in. of restriction on the water column the air flow through the radiator is cut to almost 1/3 and amperage goes up. This is inches of water not mercury. I takes approximately 14" water to equal 1" mercury. Inches of mercury is what we use to measure engine vacuum. So, if he has a 4 row with a high fin count rad., he might do better with a 7 blade engine driven with a clutch and over drive pulleys to overcome the higher restriction as opposed  to he 1 1/4" tube two row aluminum rads are not as restrictive, so the high flow electric fans should be good.

We talked about drilling the stat at the show, won't do much for reducing coolant temp but never a problem bleeding air from the system.

I've read about using the Ford fan assembly, I would think the OEM fan motors pull air better as they are designed to cool the truck with A/C and auto trans. I was suppressed to see how much air flow performance degraded with very little restriction on the low buck fans, the high end not so much.

Why is he changing the pump? Is it leaking or going to a high flow? I would also recommend overdrive water pump pulleys, the more turns the water makes the hotter the radiator runs so the air across the core will pull than pull more BTUs.

Has he wired the fans to the alternator yet or are they still at the battery?

Update---He changed some things and now it's holding no higher than 185 degrees idling in the garage with the AC on:

High flow water pump

Holes drilled in thermostat

Restrictor washer in the bypass hose

The real test will be in traffic, so that's next on the list but it's much better all ready compared to before.

This brings up the question of why is that hose there to begin with ? I see many people blocking the ports and eliminating the hose completely and claiming the engine stays cool just fine. If restricting that hose down to nearly nothing helps low speed cooling, why not just remove it ?

On A/C cars there is a vacuum controlled water shut off valve in the heater line, and, with the stat closed, no bypass line the water pump can't move coolant. Due to the lack of coolant flow, the stat may not see enough temp to open in time, engine could then develop hot spots . Some say the water pump will cavitate and aerate the coolant, maybe. In a non A/C car there is flow through the heating system so shouldn't be any problem as long as one heater hose is routed near the stat. The holes in the stat also helps, but with no heater or bypass hose I would drill larger and more holes in the stat. On small blocks there is an internal passage in the block that runs from the water pump mounting surface to the cyl head.

I have also heard that if the water flows through the engine to fast it will not absorb the heat. I don't believe it. The faster the water moves through engine/cooling system the more BTUs are pulled out of the engine and moved to the radiator, the hotter the rad runs the more efficient it is, then more BTUs are removed.

As for the timing       As long as the engine starts good, (no kickback) and doesn't ping, I would add another 4 to 8degs initial, see how the engine responds.

Talked to Brian last night and he had called the rad company and they're going to replace his rad and upgrade the fan capacity.  There is only a 10 degree drop between the inlet and outlet of the rad and they said it should be 30-40 degrees difference, so they think there could be a restriction (pinched tubes?).  It's been acting this way since day 1, so he suspects the rad was bad from the get go when he installed it a year ago.

 

Lost in the 60s wrote:

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Good of them to stand behind their product..

I hope this will take care of the issue for him.

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Yeah, the only painful part is he needs to ship it back first before they'll replace it, but at this point he's willing to do anything to fix the issue.   

Bobs_Place wrote:

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So the rad company thinks there are restricted tubes? They must know something. With a good radiator, the drop in temp will be less with higher coolant flow. Assuming his temp readings were taken with the coolant temp well above the opened stat temp and his rad was not compromised with restricted tubes, than the air flow across the core is inadequate.

Good to here that they are supporting him, sounds like they are covering all the basses with the new rad and upgraded fan assembly. Is the rad upgraded or is it the same capacity?

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Yeah Bob, he said after describing all the things he's tried, they were pretty quick to say they would send a replacement rad.

 

Same size rad for the replacement, but higher output fans than what he has now.