7.4 running hot?

[ericcarr2000]

I've been trying to figure out what's going on with my fresh 454. I took it to a supposed mechanic at Michigan motor exchange to have the final adjustments done on it like the timing set... Etc.... They knew it was a fresh motor and decided to do the camshaft breakin procedure on muffs... They had told me that the thing got so hot that they stated they heard cracking noises coming from the bell housing and burnt rubber smell. I brought it home and found out that of course the impeller was **** along with the exhaust flappers. I replaced them, decided to start it up on my muffs and let it idle in the driveway. Of course I tore through that impeller also, so I put another one in, took the boat to the boat launch started her up and I noticed she bag an to get hot yet again. Now at this time while at the dock, there was no thermostat in her and all I pretty much did was idle and maybe a tad bit at around 1200 rpms. I shut her down when I seen the temp gauge get to around 200. Brought her home, checked the impeller and it was still good at this time.
So I guess I'm asking if I'm just being paranoid of it overheating or is there something else I need to check?

 

[Bondo]

Ayuh,..... Pull some hose ends, 'n see if ya got water flow,....

Are ya seein' water flow,..??

There should be a t-stat in the housin' to direct the water,....

 

[thumpar]

There is probably old impeller pieces in the power steering or oil cooler blocking the flow. You need the thermostat in there, otherwise you will have hotspots in the engine.

 

[ericcarr2000]

Well I just got in from checking the oil in the oil is quite a ways past the dipstick where it was before I'm assuming I'm getting water in there?

 

[thumpar]

If it was water it would look like a milkshake. Does it smell like fuel?

 

[ericcarr2000]

Also for the short period of time that I had it In the water I noticed there is water in the bilge already. And yes actually it did smell like fuel

 

[ericcarr2000]

Here's the thing I didnt notice there being too much oil on the dipstick until I knew sufficiently the motor was getting water when I put it in the water at the dock.

 

[ericcarr2000]

OK here's the weird thing I just got done checking oil again and now I don't see it registering way up the dipstick.
Weird so I decided to do a compression test on it myself this is what I came up with.


8-100 slowly dropping.
6-125 slowly dropping
4-122 slowly dropping
2-130 slowly dropping
7-120 slowly dropping
5-130 slowly dropping
3-125 slowly dropping
1-125 slowly dropping

 

[alldodge]

My nickels worth, you have a 1990 model 454 which (unless it's been changed) has an engine mounted fuel pump. If this is the case your fuel pump is dumping fuel in your motor and gas is mixing. This is why your oil level is going up and there is no milk.

As for the your compression numbers IMO there all lower then they should be

 

[ericcarr2000]

Well I guess I must have been having a bad morning. I checked the oil dipstick after doing the compression test and it was right where it should be... Weird..

 

[flipbro]

OK here's the weird thing I just got done checking oil again and now I don't see it registering way up the dipstick.
Weird so I decided to do a compression test on it myself this is what I came up with.


8-100 slowly dropping.
6-125 slowly dropping
4-122 slowly dropping
2-130 slowly dropping
7-120 slowly dropping
5-130 slowly dropping
3-125 slowly dropping
1-125 slowly dropping

Those are low numbers for a fresh motor! My guess the Rings haven't seated yet. Did you go with cast rings or molly?

 

[ericcarr2000]

To be honest I'm really not sure.

 

[NHGuy]

I'd get the cooling figured out, put in a new fill of break in oil and filter and run the engine on a hose not muffs.
Immediately after start up go to 2000 rpm. No wait for warm up! It has to rev immediately to keep oil on the cam & lifters during the break in run! For 20 minutes. you want to rev it between 1700 & 2500 to complete the cam break in and continue the ring break in.
I'd use that Joe Gibbs Driven oil. 10-30 is fine for break in. The engine won't be loaded, just turning.
Then since you have a flat tappet cam you ought to run some oil that has some zddp or zinc in it. Failing that, buy some zinc additive and put it into whatever oil you choose to run.

 

[flipbro]

A fresh engine run so hot it crackles when shut off on its first run.. The excessive heat causes that film of oil on your cylinder walls to glaze over thus preventing the Rings from seating . I'd be paying that tech a visit.

 

[flipbro]

I'd get the cooling figured out, put in a new fill of break in oil and filter and run the engine on a hose not muffs.
Immediately after start up go to 2000 rpm. No wait for warm up! It has to rev immediately to keep oil on the cam & lifters during the break in run! For 20 minutes. you want to rev it between 1700 & 2500 to complete the cam break in and continue the ring break in.
I'd use that Joe Gibbs Driven oil. 10-30 is fine for break in. The engine won't be loaded, just turning.
Then since you have a flat tappet cam you ought to run some oil that has some zddp or zinc in it. Failing that, buy some zinc additive and put it into whatever oil you choose to run.

I couldn't agree more!

 

[ericcarr2000]

Update... Well I took in to a reputable marine mechanic yesterday and told him the issues I'm having with it. He called today and suggested to me to take it to another mechanic who specializes in dynoing marine motors... The problem I have now is I have to pull the motor out again and take it to him.. Is it worth it in your guys opinion?

 

[flipbro]

I would get the cooling issue figured out as NH Guy said the do the break in. If you used cast rings ya may get lucky. Keep an eye on the temp.

 

[alldodge]

Update... Well I took in to a reputable marine mechanic yesterday and told him the issues I'm having with it. He called today and suggested to me to take it to another mechanic who specializes in dynoing marine motors... The problem I have now is I have to pull the motor out again and take it to him.. Is it worth it in your guys opinion?

Don't know what a dyno is going to tell you about it running hot, if that is still the issue. What is the reasoning behind the dyno comment?

 

[ericcarr2000]

That's what the guy at andersons marine center suggested due to not knowing much about the motor. I guess guessing the wrong jet sizes for the carb can be pretty much catastrophic.

 

[alldodge]

the wrong jet sizes for the carb can be pretty much catastrophic.

Agree, if it's to small your running lean and it will burn a piston. That said, your using a rebuilt motor of the same size and hp of your old one I thought. So using everything from the old one should not be an issue, and your motor is getting hot at fast idle. This is not a lean condition yet, this is a cooling problem.

The mechanic probably just doesn't know enough or doesn't want to mess with it.

I will say this, you pay for dyno time, and if the shop has to find out what's clogging the motor they will, but it will cost