Whos running with these?
I put them on this winter and got to run the boat today. They are drilled and tapped into the rear waterjackets on the intake, and tie into the front intake water jackets. My water temp sending unit is right next to one of these lines on the one side. When running at 4000rpm and up, my water temp stayed around 145*. As soon as I come back to an idle speed, the temp gauge instantly jumps to over 230* for approx. 10 seconds, then comes back down to 145. Just curious if the tube next to the sender is somehow causing this.
Thanks

US1

I have those holes plugged in my intake. could I tee my bypass line from the water pump to the intake and run lines into the back of the intake? Would that give me proper flow? How are they hooked up in a car?



Running closed cooling I have my temp probe on my bypass line, the overtemp probe in the front of the intake and my Pressure guage reading pressure at the top of the t-stat housing. My temp has been really steady. I thought I would see an increase in block pressure on shutdown but it hasn't happened yet. My pressure and temp seem to increase slightly with rpm over 4K. Pressure goes from 5 lbs to about 7lbs and temp 160 to about 170. With a 160 t-stat.

FlyFast, I don't know enough about this yet to say one way or the other when you throw a water pump in on the equation. Sorry

I did remove both of the intake steam pocket bypass tubes to see if it would eliminate the sudden heat spike . Ran boat again today and still had the same problem. So the tubes were not the cause of this. While cruising, my temp shot up to 230* again. I immediatly stopped to an idle and felt the intake at the sender unit, it was hot. Then felt the t-stat housing and the water lines going to the exhaust, they were warm. So I just removed the t-stat. Problem solved, but wouldn't build up any heat. Need to work on my crossover/bypass design. It must be bypassing too much water and not flowing it through the motor. I think my problem is that I put the bypass tee in the direct flow path of the water, vs offsetting it to one side, out of the direct flow path. Back to the drawing board.

US1 Fountain,
Did you try to drill the thermostat? I never thought water could be such a problem. You may want to take another look at what MIKEHTMSR24 is running.

Did your heads seal up?
Dan

I called edelbrock tech line 800 416 8628. You are right they are to release the steam. Edelbrock said to run lines to the front of the intake manifold. If you cannot do that the next best thing would be to connect the two rear water jackets.

I have yet to figure out whether or not to use the rear water jackets. Getting the steam out sounds good but it is another hose that might leak and it might take some of the flow away from the heads.

I too, would like to hear what other members are doing with the rear water outlets.

Candyman,

Yes the t-stat is drilled. It also was open when I removed it, so it wasn't stuck closed. It has to be that the balls in the brass tee are not able to stay closed and force the water thru the motor with the tee being in the direct flow path. I imagine just the pressure from the water flow is enough to override the spring pressure in the tee. I have tighten the tension on the balls to see if it helps, but then it causes the water pressure to be around 25-28. I'm looking for around 18lb max. Like I said, if I would have offset the tee to one side, it may have worked. I also have thought of just installing a pressure regulator in the supply hose, but don't want to drill boat for a separate dump. Trying to be able to dump the exccess water equally on both sides in the exhaust. Just a little more tinkering. I'll get something.

And NO, the weeping is still there. Decided to let the little bastard leak for now and deck the block later. As long as my oil stays clean of water, I'm going to run it.

Flyfast,

I'm going to reinstall the 2 steam lines. Not sure they are doing any good, but guess they can't hurt. Plus, now I have holes drilled and tapped in my intake. Don't know how you can check for steam pockets. The motor has ran the last 5 yrs w/o the lines with no problems, should have left it as was. I don't think you need but small lines there. You aren't trying to flow water thru them, just rid any pockets. I used 3/8" SS lines. Should have went smaller just so that I am getting as much flow tru the heads as possible and not bypassing them by going thru the lines. Thinking will install some plugs insided the fittings and drill 1/8" holes for some flow.

Jerry

I have run the steam lines for a couple of years. From the rear to the front std merc hsg under the Tstat portion of t stat hsg.. one side connects to where temp sending unit was and tapped hole basicly opposite side same location for other side and relocated temp sensor to the rear of the hsg. I used 3/8 Areoquip lines and have taped them for pipe plugs and have tried different size holes in them seems to make little differance. What I do know is that to get some serious power ot of BBC on a dyno if these lines werent installed the engine damage would often be the result. I have run them on my Ford engines also. Biggest differance on carb engines seemed to be a more uniform plug readings ie no more stagger jetting. Also in the automotive world the engines / heads were designed to opperate with a higher water pressure to help over come hot spots with out the cirulation pump and using just the marine pump I dont know if there is enough pressue to accomplish the task. There shure is enough water to supply it.... although here in the Great Lakes the supply seems to be diminishing

I will also state upon removing the heads # 7,#8 and #2 valves looked the hotest. They are not all connected to the same runners leading me to believe jetting might not be the problem. Also noted (this is an 88 engine) that water transfer holes in the block on #2and #7 do not line up as the rest of the cylinders do.. so I matched them to the gasket which matched the heads but not the cylinder block. the engine at low speed runs hotter than high speed but never reachs temps hotter than before... plugs all look good . Will be pulling the heads soon to look at the valves to see if there is evidence of more even temps in these cylinders

The way that we have bee doing it is to connect the two outlets on the rear of the manifold to a tee and run the tee to a dump in the transom and empty over board. You can put a valve on after the tee to control your flow if you want. Also a friend used this method, devconned his 3/8 dunps and redrilled his with an 1/8 inch drill bit to cut down on the flow out the dump without using a valve. Works great and if needed he can drill bigger. Sure gets rid of all the steam.