Baja226sport

iTrader: (28)

I just ended up getting the 140 degree high flow stats. I figured since mercruiser uses a 140 in their 502 mag and hp 500 apps then what the hell. Worst I can do is buy a 160 if it is not getting to temp.

Clustergear

I run Merc. 140 t-stats, drilled four 3/16 holes. Runs a steady temp, with out holes temp runs up and down. I am using a crossover, plenty of water for exhaust.

zeke

youre running a cross over with out a bypass and the 4 holes are enough?
Im getting too low of water temps and dont have a bypass on my crossover, and just wondering if the 4 holes drilled in it is enough

Clustergear

I do have a by pass hose on my crossovers. I had t-stats with holes in the tops, the new ones I put in look like regular t-stats. The temp would go up & down. I drilled the holes and how temp stays steady at 140

MILD THUNDER

iTrader: (3)

The difference of 30, 40, or 50 degrees of water, flowing around the cylinders, in my opinion, will not have a detrimental effect on PTW clearance. You want to have piston to wall clearance changes, run the engine on the lean side with a supercharger. The heat put into the piston from combustion temps will have a much greater effect on how much the piston grows. Not 30 or 40 degree water temperature change.

Now, a car, say on a cold winter day, when its 10 degrees outside, and coolant temp is at 10 degrees, and eventually warms up to 200*, might change the bore size slightly.

We've been running no water stats for many years on blown marine stuff. The key is running oil stats to help control oil temp. The idea behind a cold running engine, is to prevent detonation. If the head can be kept cooler, this helps cool the valves. The only cooling a valve gets is when it comes in contact with the seat. This is why narrow seat widths are no good in the marine world, and why we need inconel valves to be able to stand up to the extreme heat. If the valves stay cool, the chamber stays cool, the proper afr and timing, the engine lives a long happy life. Heat, is the worst enemy here.

Tell me when was the last time a BBC marine engine blew to pieces because it was ran on the cold side, water temp wise? Then tell me how many blew to pieces, because a valve cracked, piston melted, dropped a seat, torched a head gasket, cracked a head, or pounded the rod bearings out of it.

With all that being said, in a N/A marine engine, I WOULD run a water thermostat, 140 or 150*. The main reason that I would, is that if carb'd, the little extra heat, will help it idle better. These are just my opinions, and I'm not a Metallurgical Engineer.

I would not lose sleep over having some magical ideal water temp. There is nothing wrong with 140*, 150*. Don't think that somehow by getting your engine to 180* its gonna thank you by tucking you in at night and all your problems are solved.

For those of you who remember the old smog non computer controlled car's of the 70's, and the crappy fuel back in the day......Any of you remember those hot summer days, when the coolant temp would creep up, and all of a sudden the engine would spark knock (ping)lose power and run like $hit??? funny they didnt do that till things got hot. Those old cast iron intakes, heads, and exhaust manifolds were huge heat soakers. Guys ran the biggest radiators you can buy, big electric fans, and anything they can do to keep the engine cool. We have a unlimited supply of cooling water, and some of you guys are trying to get that heat into your boat engines, why....I just dont get it.

You may look at your cars water temps at 190*, and think, they run them at 190*, because it must be best for the engine. Theres more too it than that.

Most cars, trucks, etc, do not have separate oil coolers. The engine oil temp is reflected by the water temp of the engine. So, in order to have a good oil temp, the coolant temp must be controlled. Also, with a automatic transmission, there is a reason the transmission cooler is built into the radiator. Not for keeping it cool only, but to keep it warm. When its 10* out and going down the road, if the trans wasnt plumbed into the radiator, the trans oil may not ever reach operating temperature. Of course then there is the whole EFI closed loop emissions stuff, directly controlled by the coolant temp sensor.

For a carbed hi perf marine engine, I see no gains being had by "heating" things up. If your oil temp is too low, install a oil thermostat.