Engine Air Temp
 

Measured with a scanner the inlet air temp while running. Around 113 degrees inlet. Ambient temp was 80. This was twin 575sci. Is 30 degree difference normal for boat?

You mean inlet, as in the air going into the flame arrestor?

I don't think the 575 runs an intercooler, right? I would say your numbers are normal. I run a 3.3 whipple with IC and my intake temps are low 90's. If I lean on it, I may see 100. Thats with 65 ish water temp (lake)

I'm not in the same class as most with OSO - we have a stock 7.4 mpi (2000)- but I know this for fact the cooler I can without doubt that the cooler I keep the air in the engine compartment the better speed I can get. WOT at 60 F I easily hit 63 mph (GPS) However, when this summer the air temps in the high 90's and warmer water- I was hard pressed to get into the high 50's. Now I'm not a performance boat owner - 226 Cobalt. But I wish there was some cheap easy way to "Really" lower the temps going into the air intake -- too bad dry ice is CO2-- a chunk in engine area for sure would cool the air!!

3pointstar

The IAT sensor is in the flame arrestor in the 575, so it's basically going to be reading the incoming ( to the throttle body)air temp.

Before I built my fresh air system, I measured engine compartment air temperature with a digital thermometer and a probe and it was 20-30* more than ambient air.

2 of these things are emanating 140-150* worth of heat in a confined space.

Before jumping the gun, are you having a problem with your 575's? If so, please explain.

jaay teee got any pics of the fresh air system you made?

no issues with engines. This is measured by the IAT. Just wanted to know what is normal for a performance boat without dual hood scoops in hatch.

yes. reading IAT with a renda scan tool

I don't have many pics, but Eddie took a few when he listed it
http://m.powerboatlistings.com/photographs/44770

great job !! and getting cooler air to the engine is great as they breather the hot air trapped under hatch

Cool !

Are those then sealed to the outside openings on side of boat ?

Here's a pic of JayTee's arrangement for those that did not click on link and scroll thru pics

http://www.powerboatlistings.com/pow...9__Medium_.jpg

Thanks,
they're sealed to the outside for the most part....darned steering hoses, throttle and shift cables and wiring harness's running in the vicinity
prevented it from matching the inside shape of the top cap , but they're notched out where they pass through....after it was done I measured the air temp inside of the box mounted to the hatch and it was the same as outside.

What you don't see is the additional hosing and blowers that I had to add just to turn the engine compartment air, since the engine isn't drawing it in anymore.

Huh. I guess the engine, at its own detriment, is a huge vacuum keeping the air moving.

looks real nice, and well done too,
like the hour meter location as well, that's were mines going

the whole boat looks nice, hard to go up from that