455 Plumbing Help Needed

[rssfla]

Ok, well I have read enough of these threads to know 455olds are not the in thing, but before you start busting ba**$ I must say I have 2 BBC 454's in my NOVA.
So back to the 455 question. I bought a jet boat project boat a few months back ( always wanted one to plat with on the lake ).
I'm hoping someone can help with some plumbing issues. OK, the waterpump plate had its 2 holes blocked off, the housing on the intake also not in use, and the heads had the water ports leading to the intake welded shut. If i remember correctly, the hoses came from the pump and straight to the heads - nipples plumbed into the front. Also nipples out the back with valves to adjust water flow to the headers.
Can someone tell me the proper plumbing setup?
Is it common on the 455 to block off the ports to the intake ( Ive seen lead inserts to do this ) Also, should i install a dump valve (popoff valve) ?
Any help is much appreciated.

[Wet Dream]

Not sure if mine is right, but this is how mine is :
From the pump, through the oil cooler, to the water pump plate, and out the T-stat housing to the transom dumps.
How the hell does your cool if you have everything blocked off??
I better read that again.;)

[Ken F]

Boy, that sounds way different than anything I've ever seen, but have never messed with an olds either.
Be patient, someone will come along and answer your questions.
The usual way is to come off the pump to a T, then to the back of each log, water flows forward through the log to preheat, then into the thermostat housing. From the waterpump cover it exits to the snail and into the exaust.
I can definatly tell you however that you definatly need a pressure regualtor w/an overboard dump. You can see block pressure way in excess of 100 lbs coming straight off the pump.
Ken F

[Wet Dream]

Ok, the more and more I read your post, the more my face gets twisted in a big ol' confused frown. If everything is welded shut but you have lines tapped into the heads, where does it exit? Pics sure would help.
Pop off valve (pressure relief valve) helps, but you can get away with a gate valve too. Mixed emotions from all the guys on here about that. Are you sure the "lead inserts" are not blocking the crossover exhaust ports?

[moneysucker]

This sounds odd to me too, I don't know that I would want the cold water going strait to the heads. If you have log exhaust I would flow from A gate valve at the pump to a T that goes to the transom exhaust, from the front of the exhaust to the front of the heads, then exit out the rear of the heads.
I have a feeling you have OT headers from the post, In which case I would re tap the water pump plate and ron in there to pre heat the water to the heads. Olds motors are notorious for cracking heads. I think some Pix would help you to get a better answer. But that is tha best I can come up with without Knowing for sure. You may want to pull the screw in plugs at the bottom of the block and flush out all the sand in the block also. With the water entering and exiting so high it will accumulate in the bottom of the block and can cause bottom end dammage. It is a good practice to do this at least once a season.
Cy

[sidewound]

Not sure if you got logs or headers. Maybe this will help. I've got one for headers too. Lemme know.
Peace Man!:cool:
CESAR
http://www.***boat.com/image_center/data/500/114logs.jpg

[sidewound]

My 455 is plumbed just like the log diagram.
http://www.***boat.com/image_center/data/500/114MILL_IN_010-med.jpg
Here's the one for headers.
http://www.***boat.com/image_center/data/500/114HEADERS-med.jpg
Hope this helps.
Peace Man!:cool:
CESAR

[Wet Dream]

Sidewound, thats the Performer intake, right?

[sidewound]

Originally posted by Wet Dream
Sidewound, thats the Performer intake, right?
Yup it's the performer WD!
Peace Man!:cool:
CESAR

[rssfla]

THANKS FOR ALL THE GREAT RESPONCES.
OK This may better explain it, and i have a few pics if i can post them. The water comes from the jet pump to a fitting on the front of the motor right behind/along side of the waterpump cover. from there i guess it circulates through the motor and exits thru a fitting on the front of the heads to the dump ports on the back of the boat. At the rear of the head there is another fitting that sends water to the headers ( Reward OT ) and small valve adjusts the water flow. Both water ports in the heads to the intake have been welded shut ( why? Have not freaking idea ).
So what do you think?

[rssfla]

this is where the water comes in, the other pic is where it comes out and goes to the headers. And what the heack is that green thing?

[rssfla]

one more

[sidewound]

Some kinda hybrid setup ya got there. I got no Idea Bro.
The little green thing looks kinda like an asco valve but I've never seen one used like that before.
Peace Man!
CESAR

[rssfla]

what the heck is a asco valve?

[Hal]

Normally the water would circulate thru the block, then the heads and discharge out the front of the manifold. Does'nt seem like you would get very good circulation thru the heads the way it is.

[Hal]

Never mind I looked at the pictures again. It should work. Just different than the norm.

[rssfla]

Well from reading many many of these posts over the last few nights since i found the site, I realize that i need to ad a pressure relief valve ( i was getting some serious water in the oil ). I also realize I have much to learn. I will post some pics of this projets in hopes of getting some input from you guys. Thanks for the help thus far.
Roger

[TahitiBoss21]

a lot of people have the plumbing issue right on. I have the logs too, and here's mine:
From the pump, through the logs to preheat, then to the waterpump plate *which leaks from behind, monello has new ones* then out the intake manifold to the dumps.
mondello says to run a line from one or both of the manifold ports in the rear out of the back of the boat to make a constant stream, and to regulate it via guage to 8lbs! He said the trick is to leave the gate valve on the jet as open as possible. I don't really see what the difference is other than that you're totally filling the motor with water that way and resisting it on the way out. They do know their stuff there, plus i always have moisture in the oil problems.
I just run the gate valve almost all the way closed, idle temp at around 150 and cruises at about 120, anything other than that and the motor gets way too hot too quick! hope this helps

[TahitiBoss21]

Originally posted by rssfla
THANKS FOR ALL THE GREAT RESPONCES.
. Both water ports in the heads to the intake have been welded shut ( why? Have not freaking idea ).
So what do you think?
Okay, if you're running an aftermarket manifold on these stock heads, you want to try to eliminate the heat risers on each side of the intake. Mondello guys weld it shut or use a JB weld type material so the head doesn't hit the aluminum, also could cause the fuel in the bowls to boil over. Mine are not welded shut, and the manifold gets glowing red hot. these ports are between the two middle cylinders. The water only enters/exits from the four corners.

[GlastronGuy]

Originally posted by TahitiBoss21
Okay, if you're running an aftermarket manifold on these stock heads, you want to try to eliminate the heat risers on each side of the intake. Mondello guys weld it shut or use a JB weld type material so the head doesn't hit the aluminum, also could cause the fuel in the bowls to boil over. Mine are not welded shut, and the manifold gets glowing red hot. these ports are between the two middle cylinders. The water only enters/exits from the four corners.
http://home.comcast.net/~glastron_carlson/wsb/media/93515/site1030.jpg