water restrictor question

[kslle]

steel block alum. head limited late model motor. on 10 lap runs car runs 220. but on longer runs starts to creep up towards 230 but caution came and temp dropped to 200-210. coming off the track heats up again but cools quick. oil temp. 200 all the time. running afco double pas that was check and boiled out, stewert stage 3 pump, 4 blade fan mounted with in 1 inch of radiator, have fan shroud and plastic along sides of nose to funnel air. 3/4 restrictor in it now. so two line of thought am i not moving enough water so go bigger or none, or am i not allowing the water in the radiator to cool enough so using smaller restrictor would slow it down to cool, thought i would rather error on the more volume then less. any thoughts?

[perfconn]

Throw the restrictor away.Make sure your fan is the high pitch 4 blade not the Afco one.Make sure the timing isn't too high.Make sure the carburetor isn't too lean.Make sure the mud is washed out of the radiator.Make sure your water pump pulleys are not worn out.

[TheJet-09]

Are you also pulling the water off the back of the heads/intake? Assuming its a Chevy you should. Water temp should generally increase under caution as you're not moving as much air. How clean are the fins of the radiator?

[kslle]

timing is good. running a tad rich on jets,new belts, how can pulleys can be checked, radiator washed every week. running water too heads but not manifold

[perfconn]

If your turning over 8000 use the 25-30% reduction pulleys.Grab the fan and see if you can turn it by hand.Don't run over 36* timing if it's 23* heads

[Ralphy]

We had the same problem. We replaced pulleys and fixed the overheating.

[LM14]

We tried a few different sizes of water pump pulleys before we were satisfied with our temps. We could keep our engines at 190-205* no matter what the outside temps and we always ran a single pass radiator and shroud with duct work in front and a GM (#442) 19" fan.

That being said, we always ran a 7/8" or 1" restrictor. We tried without one but we always had better luck with a restrictor in place.

We also made sure all air to the radiator came from in front of the radiator. If we left the top open in front of the radiator it would make temps go up 10-20* every time. Even duct tape was better than nothing there.

For us, the high pitch (not a cheapo) 19" fan, shroud, duct work in front and on top of the radiator and a restrictor was a must.

Sometimes you just need to do what works best for your situation.

SPark

[Wheelman33]

The GM fan is a must. But we always ran restrictor on gas with no probs.