What PSI and type radiator cap / surge tank?

Xavier · #1 (**permalink**) 08-01-2010, 05:54 PM

I have had no cooling problems ever with my single 16psi radiator cap; but I recently went with a Kirkrham FE style surge tank for my 351w and this calls for a radiator cap, so I am going purchase two new ones of similar make..

- What PSI should I use? I use a 80/20 mixture of radiator and water with water weter.
- Both should be the same PSI?

Clearance is very tight between the surge tank and the hood so I was going to go with a Stant 10371 style as seen here...

http://www.stant.com/brochure.cfm?br...ocation_id=179

Thank you.

Excaliber · #2 (**permalink**) 08-01-2010, 05:59 PM

Quote:

What PSI and type radiator cap / surge tank?

You ask...

Stock metal surge tank on my FE. In September I'm flushing the system, re-filling with Evan's waterless coolant and running a 7 lb cap if I can't find a 4 lb cap. Oh, and make sure whatever cap you use it's a "recovery style" cap and plumb your surge tank overflow to a recovery container.

Water and antifreeze mix? That is SO "yesterday"...

But, if you insist, go with 50/50 mix, not 80/20. Forget the water wetter, with the antifreeze it's a waste of time. Straight water AND water wetter, well OK then.

Rick Parker · #3 (**permalink**) 08-01-2010, 09:23 PM

Be aware that the rubber hoses may be borderline for 18+ pounds.

Xavier · #4 (**permalink**) 08-03-2010, 11:16 AM

Thanks Rick, never thought about that.

Excaliber · #5 (**permalink**) 08-03-2010, 11:40 AM

Thats one reason I'm going with Evans waterless coolant, to reduce the pressure on the entire system to help prolong and prevent future pressure related problems. Not only hoses, but head, intake and other gaskets as well.

Here's the part I don't get. If folks are willing to run up to 80% antifreeze coolant and a mix of water, why not just cut to the chase and run what is essentially 100% antifreeze coolant? Think about it, your 80% there already, the additional 20% (water) now demands that special additives for corrosion are included in the base stock (antifreeze). Those additives will dissipate over a given time frame and have to be replaced or the entire fluid changed out. This is a no brainer, in my opinion, you have three choices.
1. Water and additives like water water wetter, a good mix for maximum coolant heat exchange.
2. Water and antifreeze mix, less heat transfer ability than straight water but it covers you for winter freeze up conditions.
3. Waterless coolant, about the same heat capacity as a mix, no additives so it doesn't need periodic replacement and provides freeze and boil over protection far beyond any pressure capped "mixed coolants" could hope to provide. 370 degree boiling point at ZERO pressure.

patrickt · #6 (**permalink**) 08-03-2010, 02:00 PM

Quote:

Originally Posted by Excaliber

Here's the part I don't get. If folks are willing to run up to 80% antifreeze coolant and a mix of water, why not just cut to the chase and run what is essentially 100% antifreeze coolant?

Because...

Excaliber · #7 (**permalink**) 08-03-2010, 02:11 PM

-70 F or so (varies from NPG to NPG+) freeze point for Evans, but it doesn't actually freeze even then. It becomes a super cooled slush that contracts slightly (rather than expand like water). Your good for Siberia baby!!

patrickt · #8 (**permalink**) 08-03-2010, 02:15 PM

100% ethylene glycol is bad for summer and bad for winter. It's dumb, dumb, dumb. Now I don't know whether it expands or not when frozen. Probably not. I think water is one of the few liquids that expands when frozen. Uhhh, maybe we could try that experiment on your block?

Excaliber · #9 (**permalink**) 08-03-2010, 03:06 PM

I totally agree 100% Pat! ethylene won't cut the mustard. That's why Evan's is propylene...

Tested to 500,000 miles (so far, truck fleet) and was still good to go.

Yes, we are going to try that in my block, stand by for news...

NPG= nonaqueous propylene glycol