Gen IV 454 relocating water temp and adding oil temp?
 

I just put a crossover on my 454 and was curious as to where I can relocate the water temperature to? There was also one other small wire on the thermostat housing when I removed it. Second thing, my boat doesn't have an oil temp gauge on it. I saw somewhere where Eddie Young suggested putting it on the port side above the oil filter block off plate where the oil pressure sender is, but where would you relocate that sensor? Is it even worth having water temp or should I just get rid of it and monitor oil temps instead?

Deffinately don't want to get rid of your water temp gauge. Sender should be on the front of the intake manifold in the cross over section of the manifold near the thermostate housing. Should have a Tan wire.

Where was yours at?

Personally, I think you should have just left your stock engines as stock.
Crossovers can create all kinds of issues and will have no benefit on stock 454's.
You now need to monitor water temps, water pressure and oil temps to make sure all are within acceptable ranges.
One of the senders on the old T Stat housing was for the gauge sender. The other sender with other wire(tan/blue) was for the high water temp alarm.

Griff I contemplated this issue a lot but I really wanted to just clean up the motor area and remove some moving parts. I have read 100's of threads over the years it seems like and it's all probably stuff I should be monitoring regardless.

All of mine was in the thermostat housing which is now gone. So I'm guessing there is some kind of plug I can remove on the intake manifold. The reason I really decided to replace it all was when I removed the tstat housing it was horribly corroded. I looked at just replacing it and decided to just kill to problems at he same time.

There should have been two senders, two wires, going to tstat housing. One for water temp (tan), and one for water temp alarm switch (tan with blue stripe)

In your harness, there may be a brown with white stripe wire. Sometimes they may be taped up and unused. If you have this wire, that would be your oil temp wire. You'd need to add a sender for it, and obviously the gauge.

For sender placement, you should have a plug or two in the front of the intakes, next to the tstat opening. Or, one underneath the tstat hole in front. Any of those will work for water senders. For oil temp, depending on where your oil psi sender is mounted, you may have a 1/8th NPT plug in the filter adapter avail to use. If not, I would mount the oil psi sender along the pan rail on the port side of block. Several 1/8th plugs there you can use. Then mount the temp sender at the filter.

I'm with Griff on the Crossovers can create all kinds of issues.
I run them only because the first set of engines came with them. I have also purchased all the parts to put water pumps back on.
If you run Crossovers the gain in HP is so small you will never see it. Most likely you will run into water pressure problems.
I run pressure relief valves and have water pressure gauges
to monitor it. Also the heat of the engine can fulucate up down up down.
IMO - I would only run them on a blown application.

I've been running a crossover for several years now with a thermostat and my engine temps are solid unless it's extremely cold. I put the boat in Northern Lake Huron when the water temp was 35 degrees, engine never got over 135. Other than that, the only time I see the temp rise is when I drop to an idle after a long hard run, engine will climb to 190 from 160 than drop down in less than a minute. My intake has a port on either side of the thermostat housing that I use for the 2 sending units. as far as the oil temp, I have a remote filter that I mount the oil temp sender in. I run the oil through the remote filter than the cooler.

As mentioned above I am really not looking for HP gains or increase. I am looking for a cleaner bilge and less moving parts. Adding a oil temp gauge and an water pressure guage is not that big of a deal if it cleans up the overall look of the bilge.

You should have two plugs on the remote oil filter where you can put your oil temp sender. Remove one of the plugs, install the sender.

Correction- looks like you only have one plug. Put it here. Looking at your plumbing your oil filter should be before your oil cooler so you would essentially be getting pan temps at this location.

You may be able to remove this plug and put your water temp sender there. I would be surprised if it comes out, most likely you will break the plug as it will be rusted in place with as old as those motors look. My motor is a Gen V and I couldn't get the plug out.

I rebuilt my 420's 3 years ago. Both water pumps were junk and I hated all the clutter on the engines. I bought crossovers from SM. It really cleaned them up and one less pump to go bad. I relocated the senders on the front of the intake manifolds like everyone suggested. Plugs came out of the stock aluminum intakes easily, maybe not so easy on a cast intake. One sender for the gauge, the other for the alarm. I have had no problems with the crossovers.
As for the oil temp,imo, unless the engines are out, i'd use the plug at the remote filter. Maybe not the most accurate reading, but better than no reading. I'm not sure, but I think Merc used that spot on their older engines for oil temp.
Good luck, BC

If your motors are out - why not put the oil temp sender in the oil pan maybe where the oil drain plug is located.

Also I heard but never seen one as of yet that there is a small oil temp sender or probe that can attach to your motor oil dip stick. IMO that would be too easy then would'nt it.

Anyone now where the oil temp wire would be hidden in the harness?

Secondly, my alarm system never has worked...anyon have a pic of what the contraption behind the gauges looks like?

You'll need to do some poking around for the alarm. Some of the alarms looked like mini bells, some were like black plastic round things. Should have a tan with blue striped wire going to it. Find your sensor on the engine with same wire, run a jumper to ground. Turn the key on position. Alarm should buzz. Make sure you have power going to the alarm also. If it buzzes while sensor is grounded, sensor switch on engine may be bad. My guess is the alarm is not hooked up under dash though

There isn't one. You have to run your own sender wire.

on my Gen VI 502, i put my oil temp in the previous oil pressure location. (above filter boss\Pad) that was eddie young's suggestion to me as well. this way you see the oil temp AFTER the cooler.

for my oil pressure gauge, i used the port on the bell housing. there was already a sender there for the oil pressure alarm so i just put a T in it and ran my gauge from there as well.

This is where i put my water temp sender . I used a Keith Eikert thermo housing . The sender used to be in the intake but the temp probe was shrouded because the sender was screwed into a reducer first . This way the entire probe is in the water flow . If you look by the power steering pump you will see the brown/blue stripe alarm wire . I don't use it as i always monitor my gauges .

http://i1243.photobucket.com/albums/...p/100_0348.jpg

deep,that is a goog looking engine,nice job.

Thank you brother Mike . It either needs to grow some cubic inches or a blower , don't know which one yet . :daz:

yes DEEP its clean i like it.