Water pressure with crossovers/t-stat
 

How many still have too much WP by just using the standard crossovers with the bypass hose and a t-stat?

I did:cool:

Well hell, I know you did! :D I'm just looking for a starting point as far as what size plug to install in my brass tee and wether to go with heavier springs in the tee for my crossover design. With weather being uncooperatiing this past weekend, I couldn't do any dailing in. Looks like I will be playing with it this weekend in Kentucky. :rolleyes:

I did also with a 3/4" hose hooked directly to the port that goes back to the crossover, and the CMI's were getting starved in the process. I think you need to get rid of the pressure before the T-stat.;)

I ran mine last night 15psi at 3K 20 at 5K IMCO exh 5/8 restrictor in tstat housing no bypass eng temp 110 oil temp 150. I hit 6psi boost 4 or 5 times for 5 to 10 sec at a time so the temps will come up a little.

US1 Fountain,
I'd take a look at Gary Grime’s setup. If not to buy it just to get some ideas. The system removes the pressure before the crossover or circulating pump and dumps it out the transom. It is plumbed with 1 1/4" hose. If there is a momentary spike it can handle it. His system allows you to use a thermostat. I'll post some pictures next week.

Dan

Dan,

That would be great! Pictures work wonders for me. Does he have a web site or are you buying it?

Been following that topic by MIKEHTM (?) and thought he said it was around $600. I agree that the ideal system is as you say, control pressure before motor. This way it also keeps all cold lake water away from t-stat, which is what all standard crossover and bypasses unfortunately do. I'm still in the designing stages with the brass tee used on the crossover. I'm down to spring pressure and bypass hole sizing. Just need some lake time to work it out. No plan to drill any dumps in the transom, so I am dumping excess thru the exhaust. My exhaust flows enough to handle what ever I can give it.

I'll look forward to the picture!

Thanks,
Jerry

US1;

You need to touch base with Wette Vette. I run the exact same set-up he designed, no pressure problems, no starvation of headers, and I run a thermostat. If your pressure is high simply twist the Deltrol valve to dump more water. Its much cheaper than the Grimes set-up and I know it works. There are pictures on a previous thread. If you would like to see the set-up look for me at Cumberland. 26 Carrera cat, white hull with purple/yellow/black graphics, KEEP R WET is the name.

One thing I like about a pressure sensitive
 

valve is it opens and closes as pressure goes up or down. When you have to open a valve manually for the top end then you don't have pressure in the engine for the low end. ????

I'm not knocking anybodys systems. Whatever skins the cat. Just don't cut yourself doing it.
My engine temps will get to about 170 at idle when I first start up and then the stat will open up and settle around 150 . When running hard temps are about 140. Head temps are equal. Be sure to check you head temps with a digital gun. Mine was about 40* different if I recall correctly. Grimes has a cure for that too.
I basically did the same thing Grimes did but couldn't get a stat to work properly. I gave up and used a reducer washer. That was just a bandaid. It took Grimes awhile to find or design a stat that the bypass hose would not shock it and keep it closed all of the time. That was my problem with my system. I spent bucks and then gave up and let Gary put his system in.
Good luck to all.

Mike;

Your point is well taken about low end pressure...it was a concern of mine as well. At idle I have about 4-5 psi, with barely a trickle coming out the dump, at 70 mph pressure is about 15 with a good stream out the dump, and at 100+ pressure is 20. I'm sure water is screaming out the dump there but I've never looked.:D I do know from before I had the dump my idle pressure was exacly the same as now, at 70 I had about 25 psi, and @100+ the guage was buried (I estimate 45psi+) :eek: My water temp is 150 all the time, idle..6700rpm, doesn't matter. I run a thermostat in the system as well.