Al Gietzen wrote:
I got a hold of some coolant pump flow data from a dyno run on a 13B with
the stock pump; with a thermostat.
The high power runs resulted in coolant temps high enough to maintain wide
open thermostat. The flows are encouraging. The data goes up to 5000 RPM,
and is basically linear with engine speed. The good news is that at 5000
the measured flow was 34.6 gpm. Charting and extrapolating to 6000 gives 42
gpm. Should be enough to handle powers up close to 250 hp.
On the other hand; the oil flow is marginally low; from the standpoint of
oil cooler design.
Coolant Oil
1500 rpm - - - - - - 10.3 gpm 3.5 gpm
1800 - - - -- - 12.5 4.1
2500 - - - - - - 17.4 5.6
3000 - - - - - - 21.0 6.5
3600 - - - - - - 25.3 7.3
4000 - - - - - - 28.2 7.8
4500 - - - - - - 31.5 8.1
5000 - - - - - - 34.6 8.1
I know nothing of the pressure drops in the external loops, but presume they
are quite low in the cooling loop.
I have a 20B (with a 12A front cover) and a 13B pump. The engine internal
pressure drops would be expected to be about 1 1/3 times the 13B, which
results in some flow reduction. Question: Other than the double thermostat;
is the stock 20B pump the same as the 13B pump?
After seeing Bulent's 13B Cosmo water pump I would not be a bit surprised if the
20B pumps were not quite different than the 13B pumps. The 13B Cosmo pump
is much better than the 13B 87 turbo and the 88 NA water pumps.
With this oil flow, the delta T gets large. At 5000 rpm and 135 hp, the oil
in was 177 F, and the oil out was 225 F. For sustained higher powers, an
oil-air cooler is going to get LARGE.
I have what Atkins calls a "high output" oil pump. I don't know what that
means; but the data he gave me was about 4 gpm per 1000 rpm up to about 4000
rpm, and then flattening out.
Al
Al, do you have a Racing Beat rotary engine catalog? There is a lot of
info in there on oil pumps.
Paul Lamar
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