tom3

Anyone know of a 7 psi cap for our cars? Brand and PN? Looked all over but no listings that I could find. See some for the 50s and early 60s vehicles, nothing for newer stuff.

Lurbie

iTrader: (3)

I'm sorry, but I don't. I have to ask why though. The point of higher pressure is to reduce boiling point of your coolant. So, and this might be a stupid question so don't flame me, why do you want to reduce the boiling point?

sofakingdom

iTrader: (1)

Can't think of very many worse ideas for an "improvement"... that's gotta rank right up there with "cleaning up the engine bay".

What makes you think you need to make it easier for your coolant to spew?

tom3

You're going in the wrong direction. Have a lower temp thermostat, fan switch to turn on both fans at a bit under 200 degrees. Nothing but nightmares with coolant leaks on this old machine. Not too uncommon with all the hose connections and gasket mating surfaces getting rough and warped. Low pressure cap and some GM sealer might get me out of this constant mess? The cap would still have enough pressure to keep the coolant in liquid state (aeration/cavitation) but maybe reduce the tendency to leak. I hate antifreeze with a passion anyway, can't be without it though. Plain water starts to boil at about 250 deg. at 15 psi or so, 230 at 7 psi. Mix some antifreeze in with it and those temps go way higher, should be no problem there. Thanks for the replies though.

GeneralDisorder

iTrader: (1)

Replace the gaskets and hoses. It's not hard. There isn't that many. The hardest ones will be the intake manifold gaskets. You will probably find pitting on the lower manifold around the rear coolant ports. I handled this with bead blasting of the manifold and filling the pits with JB weld then block sanding it smooth. Worked excellent.

You can't "get out of" a leaky cooling system with less pressure. That isn't going to work.

GD

sofakingdom

iTrader: (1)

Zackly...

NO.

FIX THE REAL PROBLEM(S) rather than trying to half-a$$ alternate-ethnically engineer around a busted car.

YOU're going in the wrong direction.

Replace the hose fittings with brass (all of like $10 at HD or the like for BOTH of em), replace/repair mating surfaces as necessary (which ones ACTUALLY LEAK???), and otherwise just do it right. You'll be MUCH happier in the long run. ("long" in this case being, next week at the longest) Use antifreeze of course... not sure where this "I hate antifreeze" idea came from, but it'd be a great plan to learn how to use it to your advantage rather than "hate" on it.

Precisely where does it leak from? What have you done lately to fix it?

tom3

Well, I guess this thread has run its course. Thanks for the replies but I'm pretty sure I was wrenching on small blocks before you guys were born. One thing I have found out though is that worm gear clamps don't work on the plastic fittings on that heat control valve, best to use the full circle spring type clamp so as not to collapse the bibs. Most people don't like those clamps but GM used them for a reason. That was three or four leaks that finally got fixed. I'm guessing there is no low pressure cap that fits the later radiators? Oh well, thanks again.

sofakingdom

iTrader: (1)

I have my doubts.

Yes you're right about the worm gear clamps. Or at least, I agree. Those spring ones keep a constant tension trying to compress the hose around the fitting; a worm gear clamp, no matter how hard you tighten it, the rubber eventually compresses and the tension is lost. Unless of course, you go back and re-tighten them a bit on a regular basis, which is kinda .... nahhhh. I seek the spring ones out and use them whenever possible rather than worm-gear ones.

No, no lower-pressure cap that fits a high-pressure system, that I know of, fortunately.

GeneralDisorder

iTrader: (1)

I really like the Oetiker ear clamps. Especially for really small hoses.

It makes no difference how long you have been wrenching - there's always something to learn. Running low pressure WILL cause cavitation in the water pump which will erode the pump housing and impeller. Among other things. It was not designed to be run without the pressure.

GD

jmd

iTrader: (4)

The flat band clamps with screw are available aftermarket. For silicon hose apps. IIRC.

While better than worm gear crap, they have no advantage over the constant tension style, which maintain pressure despite temp. changes / expansion and contraction.

Regarding low temp radiator caps, they exist. Old parts catalogs (Napa used to be a source of lookup) used to be more helpful. Now, everyone is stupid. You, me, especially the guy behind the counter. No modern company is going to put effort in helping others buy "wrong" parts. Not only is the market of incorrect app. parts low-volume;

The liability of a dingnut wanting his engine replaced 'cause the cap "didn't work" isn't to the corporate benefit. At the same time, they do try and sell junk that has no benefit, as long as it sells to dingnuts that believe they're helping their car. Solid transmission mounts, solid engine mounts, pacesetter headers, chromed parts that retain heat, poly bushing that don't function right, the list is long.

Ironically, they sell lots of thermostats in a wrong temperature to persons who think setting a lower minimum temp. helps prevent overheating, or otherwise improves their car (it doesn't.)

The other reality check on your pipe dream of fixing the problem by not fixing the problem is this: years back, you could get at least 6 different thermostats temps. from 160 on up that would all fit a SBC. When you try and order some of the part numbers, the stupid gets weeded out. Because, the old PN just refers / orders the new PN that they still feel like selling due to profitability. No need to have 6 different ones. 3 will do.

It gets over 120 F ambient temp. here and I run 195deg thermostats. When you figure out why, you'll have somethin.

tom3

Getting interesting here. Camaro started leaking everything from everywhere several years ago. Pulled engine and trans, replaced every gasket, seal, o-ring, did some head work. Put back in with a set of those blue Hi-miler hoses using regular hose clamps. Bad idea there. Car has really given some service for the money, still looks and runs great. Couple pictures just for fun, engine just before install, and my old 302 (used to call it a 301, bored 283) that outran some mean Fords back in the day.