fast22

Hey guys,
I have a fuel injected 509" running a side mount whipple with about 5lbs. of boost. When i bought the boat it was running without a thermistat and still is. I had some work done recently and my mechanic seems to think that I should be running a thermistat. I have been told different things in the past, Should I be running a thermistat on this motor? It never gets above 110 degrees water temp and the oil runs about 210-215 and gets up to about 230 on hard runs but comes right back down. The motor also has a circulating water pump if it makes a differance. Thanks for any help.
Scott

Anarchy Powerboats

Can't hurt to have a temp gauge or are you talking an internal thermostat? Are you closed cooling?

fast22

I have temp gauges on both water and oil,I'm talking internal thermostat, it is raw water cooled. My mechanic is concerned about the water never getting above 110 but I've been told the whipples need to run cold. Thanks
Scott

Whipple Charged

Depends on computer calibration. But a 140 stat is max. Ideally, no stat is run. Early models went out with stock, but timing had to be retarded. With stat removed, engine running 100deg, stock timing was fine. Calibration is different because mercury used the temp tables to really richen the motor.

Removing stat can cause other issues as well, it drops water block pressure, which is critical. You can run a 120deg stat, that would be a good comprimise, but I would still drill 4 5/16" holes in it to help keep spikes down and more consistent to 120deg F. Again, this depends on cals, anything cooler than 140 adds significant amount of fuel.

Thanks,
Dustin

Elite Marine

Hey Dustin -

What are the largest pulleys you have for the Quads? I'm pushing 1000HP with my large ones. Would like to have less...

Thanks,

Kirk

fast22

Dustin,
Thanks for the info, Just what I was looking for. Ya'll are fullof good info!! Thanks again.
Scott

Whipple Charged

4.75" upper's and we have multiple lowers. 5.5, 6, 6.5., 7, 7.5 and 8.

Whipple Charged

No problem

ezstriper

the problem running that cold for the engine anyway is condensation build up in the oil, unless you can get the temp up and stabilized condensation is going to be a issue as well as engine just not making all the H/P as it would at operating temp. I understand with EFI you thay are just trying to "fool" the ecm to keep the air/fuel closer to where it needs to be, but if they can be mapped to run rich enough at temp you will be far better off...Rob

Whipple Charged

I guarantee a SC motor will make more power at 100deg F than 160deg F. Not talking emissions, but power. With a SC motor, you can add more fuel and timing with lower head temps. Example, the stock 502 mag with stock stat, 160deg F could only run 22deg total timing at 6psi (with side mount kit). At 100deg F, you can run 30deg and 7psi. Difference is 50+hp. You will not get condensation at 100deg F, only 85 and below unless you have a problem with the oil getting really hot and engine cold, but normally, with oil temp below 180deg, it will not cause condensation. When water flow is high, the oil temps maintain 140-160.

Dustin