the hose from the sea pump attaches directly accross from the hose that feeds the crossover ...there is a baffle in the housing . But basicly they share the same area .... a circ pump might fis the situation but I really dont want to do that ....

I thought about this a little more and it's definitely the plumbing. You either have to run raw water to the exhaust to pre-heat it and then through the engine with no thermostat or run it straight to the crossover with no stat and then to the exhaust. You have the raw water supplying the thermostat and the crossover in parallel. You can solve the problem very simply by re-routing the raw water line directly to the crossover, cap the big ports on the front of the thermostat housing and get rid of the thermostat. It would be best to get rid of that thermostat housing alltogether and go with one that only have two hoses connected that go to the exhaust. Don't run the engine the way it is anymore because you are running a significant risk of heat damage. With no circulation, you can boil water in the heads really quick. With no load, that engine hasn't even started to make heat, even at 1000-2000 rpm. Just 2 more cents. Good luck,

Rene

I'm in the middle of the same project... only I can't figure out how to get mine warmed up! My routing is like what is being described above. I have a restrictor plate (big washer) in where the T-Stat should go giving me about 25lbs @3000rpm's.

Do you have water pressure in the block?

http://www.youtube.com/watch?v=D7VkBzso3xk

nm, I see you have a pressure guage in the manifold... what kind of pressures are you seeing?

25lbs is too much ...esp at 3K .. I see about 4-5lbs up to 2500 or so ...if you blip the throttle it will spike about 10 ..
I'm going to move the gauge to the block ...
Also I think I will add a circ pump on one motor and plumb as suggested on the other and see what I get ...

Jackhammer... I did plumb them like you have yours ...same issue they would not come up to temp and too much pressure ... I added the bypass from the manifold to the crossover and it helped the pressure ...m

Without the restrictor I was seeing 5-7lbs but it never got past 100*. With the restrictor I'm getting 115-120*. Oil stays right there with it. I was going to put a pressure relief valve on it for 25lbs... I could probably drill the restrictor out some to lower the pressure. I was going to see how it acted with a load (dyno) before going too far.

Are these the same motors you couldn't warm up?

yup ... I am ..or was determined to run a thermostat ...

I'd try pulling out the t stats first. It's the easiest and the cheapest way to find if that's the problem, which I think it is. I don't run t stats in either of my Formula engines, or in the Donzi engine.

I was thinking on trying a thermostat and drilling three 1/8" holes in it. I've read some people have had success doing that. I don't have a bypass on the crossover.