US1 Fountain I have heard of the freez plug thing on a sbc but havent on the big block.

I would think it would pump thru the water circulator .

The circulating pump is removed and the holes blocked off.

I'd be inclined to think that Merc would be installing crossovers on their engines if they were such a godsend to marine engines. Instead Merc still uses a circulating pump on their supercharged engines.

US1 Fountain - That is a cool idea (no pun intended) to bring in water through centre freeze plug holes. If the water passages in the head are all the same, then doing this and taking water out at both front and back would be the best you could do at equalizing cylinder temperature. Shows you those boys were thinking.

I don't know if any of this is necessary on a stock engine, but supercharged, where detonation is so affected by air temperature and combustion chamber surfaces, it could be the difference.

In a related question, how low can you go with T-stat settings. Some guys on the board swear by 120F on their Procharged stuff. The lower the temp, the higher the water flow the T-stat must be allowing.

In another related question, I remember years ago seeing the temperature gauge sender installed in a certain part of the BBC cylinder head. Why was this done and can we learn anything about where the hottest water is by this?

Pic of B&M 250 in post 5 is now on my boat. I did retain the steam relief tubes but "y'd" them together to reclaim a fitting for the over temp alarm. I have installed the 120 T-stat and I think it helped with oil consumption. Not sure why nor do I care at this point.

Before the 120 stat I would use about a quart to 2-3 hours. With the 120 I use a quart in 5 to 6 hours. Perhaps the flow rate evened out some hot spots and allowed the rings to seal up better. With the original 140 T-stat gauge would read 145 at cruise and climb to 155 at WOT. With the 120 it reads 120 at cruise and 125 at WOT. Starting at a lower temp increases the time to heat soak the block to a point where the cooling system cannot keep up with the T-stat rating. Oil temps were reduced with the 120 T-stat as well.

BadDog,
Do you have problems with moisture in your oil? Does your oil look milky? It seems that the temps are low and that moisture could be present due to not getting the oil over 212F. Just curious.
Russ

Russ,
No signs of milk. I am using the Perma Cool oil T-stat. Temp stays around 210 at cruise with a max temp of 235 to 240 depending upon water temp. I am using the large Eddie Marine oil cooler. These are the temps I had before the SC install. With the SC and a 140 T-stat my oil was getting to 255, that is why I went to the 120. The oil is being cooled by the block somewhat. It seems that the the Eddie Marine cooler is only sufficient up to about 640 HP on 502. My dump valve is on the output side of the oil cooler. I think your setup is similar to mine? B&M 250, 502, headers and Nickerson carb.

What kind of water pressure readings do people get with or without circulating pumps.

I run a crossover with no TSAT and get 10psi at WOT. Both engines are identical.
Gil Exhaust and standard bravo pumps with new impellers.

I would try to bump the pressure up some so you get closer to 20# at WOT. (This is also what you will usually end up with utilizing the stock setup.) Easiest way would be to install a restrictor in the stat housing. I had best results with the middle sized one (3/4" ??). They can be bought from Jegs, Summit or a speed shop for a couple bucks.

You need pressure to assure you are getting a good fill of water in the block and heads.

Tim,
Yeah the loss of the port for the over temp alarm was something I hated when installing those lines. Since I didn't use a bypass hose, I used the port in the stat housing for the over temp sender.
So you tee'd both of the rear lines into the single fitting on the opposite side of the senders?
Get this, the guy that bought my 27' calls me last week and tells me he is thinking about installing a, (drum roll)....................B&M 250 blower with a 1050 Dominator on the boat. I think he is considering RLW's setup for sale.
Better watch out, the US1 may be back in the race! :D