Friend of mine keeps telling me that a water temp of 150 is just TOO cold :| (Saying I'll get reduced gas mileage by two dense of a charge )

I've got a Ron Davis w/ Dual SPAL Electric fans, a 350 putting out roughly 400hp (give or take 20hp) Edelbrock Victor Jr. Long Water Pump,

The other night it was about 65, I was cruising at 45mph for 5 minutes, and my water temp gauge read 150-160, The sender is on the passanger side of the thermostat housing, I just recently removed my Heater bypass hose, so I drilled two 1/8" Holes into my thermostat to avoid hotspots.

what'ya guys think? Hope I didnt miss something. (@ idle she sits at about 165-180 depending on how long I sit for, when the SPAL's kick in Im @ a consant 175)

I cant really heat my damn radiator up, so whats the deal ?

I've always heard hot oil and cool coolant make horsepower. However, too cool of an engine also causes increased cylinder wear, which is why an engine should heat up quickly. Having said that, I don't think the engine is too cool. But I also don't think you need extra holes in your thermostat, because the fans will keep the engine at whatever the set point is for the fans to come on. 175-180 is beautiful- most older systems I've seen have trouble keeping that range. Sounds like I'm contradicting myself, huh? If you're concerned about it, I would just try a new thermostat (sans extra holes). The best thing that would come from that is the engine would heat up a little quicker which would help with the aforementioned bore wear. Cylinder wear is on the order of 1000% greater during warm-up (my memory is a little fuzzy on the number because it's been along time since I read that, but it's in the ballpark). Good luck.

The optimum temperature for all conditions is 175 to 180F.

The graph at the bottom illustrates the importance of how critical optimum coolant temperature is to the longevity and performance of an engine. As pointed out above...cool water makes good horsepower if it affects incoming charge temperatures..but only to a point. Warm water minimizes engine cylinder wear but if it adversely affects incoming charge it could rob you of a small amount of power.

http://performanceunlimited.com/illustrations/img215.gif

However, experts agree optimum performance as well as minimal wear CAN share similar temperature characteristics in the 175-180 degree range, which requires a 180 degree thermostat if your cooling system is up to snuff.

The 160 degree thermostat is way too low to be considered for performance or engine longevity. As the chart illustrates, engine wear increased by double at 160, than at 185 degrees. The 160's were commonly used in older, open loop cooling systems where only 6 pound radiator caps were used and low (only water) 212 degree boiling points were experienced in the cooling systems. This low temperature kept the operating temps low in all conditions to prevent gassing at bay.

Also, the correct water temperature is required for the cylinders to achieve a minimum specific temperature in order to allow a fully homogenized A/F mixture to combust efficiently which is 180 degrees.

Another salient point is working with the oil. Manufactures design their lubricants for temperatures over 175 degree (cooling jacket) temps. This assures that working oil temps are sufficient to work properly and moisture in the crankcase is expelled properly. This is a very important point to fully "boil off" the the moisture whereas moisture left behind commonly mix with combustion by-products to form acids as well as cause corrosion.

So, for street applications....180 or above is optimum.

Hope this helps.

well, I'm runnin' a 180 degree thermostat, its just that I noticed my water temps dip into the 150-160 range shortly after startup (perhaps the coolant wasnt fully heated up yet?) Was driving around 45-50mph, the Ron Davis is a pretty beefy radiator, I got it mainly b/c Santa Ana winds are becoming more predominant in the summer here, giving us 2 or 3 week time periods where its 90-100degrees everyday.

So I suppose I should look into whether or not my temps are really @ 150 when I am crusing, with a definate good warm up period.

It's the holes in your thermostat causing inadequate temperature results. You don't need them unless you are running a water pump without a by-pass internal or externally.

Dump it for a high flowing Mr Gasket from Summit. Then it will regulate itself to the correct thermostat cycling points.

I also agree on the hi flow t-stat. I use a BeCool hi flow with an OEM 3 core radiator and it works perfect. Also, keep in mind, that at initial start up your temp will go to around 190-195 until the t-stat opens, then will drop below the t-stat rating for just a few minutes. That is the cool water coming out of the radiator. It should level around 185-190 or in your set up with the sending unit in the intake, around 180-185. Even if the air temp outside is around 90-100 water temps in the 190-200 range will not be a concern. Be sure to run a 15-16 pound cap to keep the boiling temps a bit higher just in case it does rise over 200. That is common in stop and go traffic like parades and cruises where the air flow through the radiator is only from the fan.

Originally posted by HOTRODSRJ:
It's the holes in your thermostat causing inadequate temperature results. You don't need them unless you are running a water pump without a by-pass internal or externally.

Dump it for a high flowing Mr Gasket from Summit. Then it will regulate itself to the correct thermostat cycling points. bingo, not runnin' a bypass, was advised by several people to drill hose in the thermostat, will go with the mr. gasket when I have the cash, things are kind've tight right now :-\ (ah the life of a college student) redface.gif

If your not running a bypass as you stated above, where is the water pump flow supposed to go until the t-stat opens? Restriction to flow is pressure. Without a bypass or path for the coolant to go until the t-stat opens, pressure could build up enough to knock hoses off, or blow gaskets out, especially with a hi-flow pump.

wayner, that's why I advised him (in a different post, a couple weeks ago) to drill those holes. normally, coolant curculates thru the heater core all the time, but he has no heater and no bypass. A couple small holes in the thermorstat will allow a little coolant to circulate even when the stat is closed, which will prevent hot spots or excessive pressure buildup.

I think u r ok, Aonghos. Your temp guage is jus reading a lil lower than it would with the sender in the head.

Wait...wait...wait...wait..!

As far as I know the Edelbrock Victor series has an internal by-pass unless something has changed of late.

So, no holes needed!