3.7 engine swap

[oilydogg]

just got done swapping a newish motor into my lund boat. hooked everyting up turned on the hose and everything seems to be working as it should except.....i have no gauges now. they are all backlit on the dash but none of them are giving any readings. ive been right through checking all the connections. i gotta be missing something simple. any ideas?

 

[Eric 3.7LX Alpha 1]

Re: 3.7 engine swap

They all should move slightly when the ignition is turned on, even before cranking the engine. Are they getting power?
What was the engine before the swap?

 

[oilydogg]

Re: 3.7 engine swap

its the same engine. well it was a mercruiser 165 but i put the intake and 4 barrel from the 180 on it. they dont move when the key gets turned on. they were all working before i swapped motors. im about to pack it in for the day working on this and my multimeter is at home anyway. i was just wondering if i was missing something. i did not hook the hour meter back up so i have a loose wire that is scothlocked onto the resistor wire from the coil. would that do it. i havent found a good place to mount it yet because it used to be mounted where the power steering pump is. should i try to hook it up and just leave it hanging. would that cause the problem i have?

 

[Eric 3.7LX Alpha 1]

Re: 3.7 engine swap

That power wire for the hour meter might also be feeding the gauge cluster.

The gauges have a switched power wire, separate power from nav lights to be backlit, and wire from each sending unit. Also a ground on there somewhere for backlight. That switched power wire is usually jumped from one gauge to the next. so If no power at one same on all.

 

[Bt Doctur]

Re: 3.7 engine swap

You should put it under the dash wired to the ign. lead for the 12V

 

[oilydogg]

Re: 3.7 engine swap

the other thing that was different about the engine i put in was that its still runnung the original charging system. i am having a hard time getting the pulley lined up to run the alternator conversion so im still running it with the original charging system. i tried hooking up the hour meter and no change in the gauges.

 

[oilydogg]

Re: 3.7 engine swap

so i noticed this morning that when i have my battery switch on both one of my batteries starts to make noise like its boiling and then smokes at the terminal. the positive terminal. and my battery switch seems broken to. sparks inside when i switch it and something is rattling. almost everything is closed today around here except walmart. think i can find a quality battery switch there? and still no changes with the gauges. i think its got something to do with running the old charging system vs. alt. conversion. cant put my finger on it.

 

[Eric 3.7LX Alpha 1]

Re: 3.7 engine swap

Hey Dog, check your PM.

 

[zbnutcase]

Re: 3.7 engine swap

You have a direct short somewhere

 

[oilydogg]

Re: 3.7 engine swap

ya i guess i had a direct short somewheres.......right between my friggin ears. turns out i had a battery connected backwards. i guess i just had to take a step away for a day. it was right there staring me in the face. thanks for the tips. i hope to be on the water by midweek. just gotta neaten up the engine compartment, mount the hour meter, put the interior back together around the doghouse and register it. fingers crossed.

 

[oilydogg]

Re: 3.7 engine swap

okay i took the boat out and ran it and everything was good until i let it cool down enough to check the coolant. and it has oil in the coolant again. one of the problems i had before i took out the other motor. so its gotta be a oil cooler crack or the power steering cooler right? i put a new head gasket intake gasket and new exhaust and gaskets on this motor before i put it in.

 

[solar7647]

Re: 3.7 engine swap

okay i took the boat out and ran it and everything was good until i let it cool down enough to check the coolant. and it has oil in the coolant again. one of the problems i had before i took out the other motor. so its gotta be a oil cooler crack or the power steering cooler right? i put a new head gasket intake gasket and new exhaust and gaskets on this motor before i put it in.

The power steering cooler has water running through it not antifreeze so that out of the question. Its the last thing water runs through before the water leaves the engine.

It is the intake manifold. It is most likely cracked. If you had the issue with the old engine and you put that intake on this engine then thats most likely it.

I would remove the intake and remove the cover for the oil cooler and inspect it. Or if you have the equipment pressure test it.

 

[Doernuth]

Re: 3.7 engine swap

When you put the new Head gasket in did you have the head machined/checked. You could have a cracked head. Does the flow go the other way as well? is there water in the oil also?

 

[oilydogg]

Re: 3.7 engine swap

when i put the head gasket in i did not have the head checked for anything. it was on the newish motor i put in. i only changed the head gasket because i had everything off except the head so i went ahead and did the head gasket anyway. there is no water in the oil. i think i may put the 2 barrel carb and intake that i took off and put that on. i ran the wellcraft boat that this donor motor came from a bunch. for about two weeks. 6 or 7 pretty good trips. and it ran like a champ. will try to test/ inspect the intake when it comes off to see if its the culprit.

 

[solar7647]

Re: 3.7 engine swap

when i put the head gasket in i did not have the head checked for anything. it was on the newish motor i put in. i only changed the head gasket because i had everything off except the head so i went ahead and did the head gasket anyway. there is no water in the oil. i think i may put the 2 barrel carb and intake that i took off and put that on. i ran the wellcraft boat that this donor motor came from a bunch. for about two weeks. 6 or 7 pretty good trips. and it ran like a champ. will try to test/ inspect the intake when it comes off to see if its the culprit.

I think that will solve your problem. If you find the intake is cracked a good aluminum welder should be able to fix it.

 

[oilydogg]

Re: 3.7 engine swap

i got the intake off and opened up the oil cooler part and it looks like its been repaired before. anyone ever seen the inside of one of these? is there supposed to be a glob of weld right in the middle? and is the fuel pump the same in the 165 as the 180? i put the pump from the 180 onto the 165 because the arm that sticks into the side of the block looked a little different. i thought it might be to pump more fuel to the 4 barrel. should i put the other fuel pump back on?

 

[solar7647]

Re: 3.7 engine swap

There are differant kinds of pumps for the engine but I am not sure if it matters witch one you have. You would have to look up the specs. I know there are two differant arms and one the goes upside down as well, but beleive all forms of this engine require the same fuel pressure.


Mine has that same glob, but i see it through the top side under the carb, it may have something to do with the casting. I know when I worked in a foundry we had castings that would leave holes on them and I would have to weld them to close it. Thats my thought of it any way.

It will be hard to find a crack if its small, you will need a die that is sold that you cot the area with and it will seep into the crack so you can see it.

Throw that other manifold on and let us know what you get.

 

[oilydogg]

Re: 3.7 engine swap

i put on the two barrel and intake and ran it on the muffs for about an hour while wicking up the floating oil in the exhaust riser/ reservoir with paper towels. must have been a little left in the system cuz it doesnt seem to be getting any more oil into the coolant. ill take it to the lake tomorrow to run it for a while and see. i had a hard time rigging my throttle cable to work on that two barrel. it comes over the top of the valve cover with the four barrel but runs down stbd side of intake on two barrel. puts an extra curve in my cable but should work. that weld spot in my oil cooler sounds just like the one you are describing. visible through carb. so i dunno if its cracked or not. if i can run for an hour tomorrow with no additional oil in coolant i guess i got that part of her licked.

 

[solar7647]

Re: 3.7 engine swap

good to hear. I would think you got it if you ran it on muffs no problem. It would still have a lot of pressure in the oil so I think it would have got more oil in it if it was still leaking. Before you take it out on the lake i would drain the coolant and flush the system then re fill it. That way you know 100% that it stoped. You dont want to be looking at oil and not know if its new or old. It should be a pretty easy job.

You could use a standard flush kit from an auto store that intersects with a hose.
Just my thoughts. Happy to see your making progress.

 

[oilydogg]

Re: 3.7 engine swap

2 pretty long days of fishing at a couple different lakes. no more oil in the coolant. everything seems to be good. doesnt seem to be any lack of power. maybe ill see a difference once i load on a few buddies. any pointers on getting the pulley for the alternator conversion lined up? lots of wiggle room in the bolt holes and i cant get the thing anywhere near straight. makes the shakes. not a problem till the original charging system craps out i guess...... where can i buy some of that crack finding dye? i think i would eventually like to go back to that 4 barrel. will the lack of the oil cooler on the 2 barrel intake affect anything?