heres my problem, i have some people telling me leave the circ pump on some say go with a crossover,,,,,,,,,,members solve my problem 700 hoarse na 540....

Everyone I talk to says take the pump off,it robs horsepower(I've heard as much as 10-15 hp) and the potential for the stupid thing to seize up on you is there also (although I've never seen it happen).I would like to put crossovers on my motors but I don't want to lose the serpentine setup.CP Performance has a setup so you can run the serpentine belt but it would run around $450 per motor,I don't feel like coughing that up right now.Your setup looks like it would be easy to change over.I would do it. .02

Nocig -

Maybe I don't understand the art of good water temperature regulation and crossover setups, but I think they are a PITA. I run a crossover because the recirc pump needed to go to make room for a supercharger setup. I miss the days of firing up my 502 and watching the water temp go right to a solid 140° (or was it 170°?) and stay there with the stock merc setup.
Do a search on crossovers on this forum. I think you will find many opinions.
Good luck.

Greg

if a crossover is done right, it frees up a few hp and dumps about 30lbs of weight, and in my case gives better access to the front of the motor.

A crossover with a bypass, merc pressure relief valve, 140 t-stat with 2 or 3 3/16" holes and a sea strainer works very well for me. (2 years). My motor runs about 160F and warms right up.

Sea strainer is to keep crap out of the t-stat and relief valve.

Looks a lot neater also.

Wobble -

Sounds like you have a good recipe. How does the bypass work and how is the pressure relief plumbed in? Do you know what your WOT water pressure is?

I would like to change my water crossover experience from bad to good with the right setup. I am a little concerned about what the T-stat does to water flow to the back of the heads.

Nocig - Hope it is OK that I chime in with related questions. Thanks.

Greg

If you run a t-stat which I would recommend, the bypass allows water to pass around it when the t-stat is closed.

The holes in the t-stat are to bleed any air out of the space under the t-stat when it is closed.

The relief valve bleeds off any excess pressure, anything more than about 27psi. This is best mounted after the oil and PS cooler and bleeds the excess overboard through a dump

thanks guys always instant knowlegable responses..........does any one have a pic of a motor with a crossover setup so i can see how it differs from mine and ideas on how to plumb it...............

oh yeah thanks to wobble..................fuel stuff from a couple weeks ago

I have two 540na motors in my scarab and had waterpressure issues. I then put 2 meziere electric water pumps on. 9lbs. at idle 15lbs at 5800. Ive had these pumps six years with no problems. Brian

Thanks Scarab 30 Due Ya Have A Engine Pic............................I GOT A OIL ISSUE WITH MY BREATHERS TOO