Oil issues with 454

[Nanu/Nanu]

So... Bear with me please I know I have probably left out some key information here but if you need it ask and I will do my best to get it to you.

I have a 454 engine not sure on the generation I have know idea how to confirm it. It's carbureted runs good.

First issue I have been trying to evacuate the oil and have only been able to get half of the oil out. My dip stick is attached to the pan not the block. I am thinking I'm going to pull the dipstick and try to evacuate it from there. But why or what would be putting my evac hose in a bind or keep it from getting to the sump of the pan?

Second issue oil pressure is good at idle and good at full throttle. But when Cruising on my last trip the gauge would show the pressure dropping for no reason and then it would just shoot right back up. I feel this is a oil pressure sender issue. I just got a mechanical gauge to check this but I have to go to a lake as it only happens underload with no rhyme or reason. Does anyone have other thoughts about this?


Thank you for your $.02 in advance.

 

[azsunfun]

pump oil out dipstick, you wont get it all unless you have oil pan drain, have you checked? what is you should have lower pressure at idle than wot, do you know what pump you have, low pressure high volume?

 

[oldschool]

Best way to get the most (not all) oil out is with a drain on the pan. Baffles in the pan can impact this as well.
With regard to the oil pressure, I’d check it with the mechanical gauge to see if you have the same issue.

 

[Nanu/Nanu]

pump oil out dipstick, you wont get it all unless you have oil pan drain, have you checked? what is you should have lower pressure at idle than wot, do you know what pump you have, low pressure high volume?

I have yet to find a plug in the oil pan by feel or sight. But I'm only pumping out about 4 quarts and I'm still showing oil on my dip stick that's how I know I'm not getting it all out. When my extractor tube is fully inserted about 4" shy of bottoming out on the dipstick tube. (Story of my life haha)

I know nothing about the oil pump. Idle pressure is about 40psi open throttle is about 50-55psi.

 

[azsunfun]

I have yet to find a plug in the oil pan by feel or sight. But I'm only pumping out about 4 quarts and I'm still showing oil on my dip stick that's how I know I'm not getting it all out. When my extractor tube is fully inserted about 4" shy of bottoming out on the dipstick tube. (Story of my life haha)

I know nothing about the oil pump. Idle pressure is about 40psi open throttle is about 50-55psi.

u b fine on oil!!! shops i do beleive have better pumps and can do better than our garage tools, i think your fine unless we're missing something

 

[MK1MOD0]

When pumping out, it seems ya never get all the Old oil out. Just change oil a bit more frequently. Also, make sure your not overfilling the sump. If it’s overfilled, the crank wI’ll whip the oil and cause aeration and frothing which will show as inconsistent oil pressure.

 

[oldschool]

Is this a stock Mercruiser engine or a custom build?

 

[Nanu/Nanu]

Is this a stock Mercruiser engine or a custom build?

Both... So I bought it used previous owner said it was fresh rebuild 454 it has a lumpy cam and roller rockers. Going by my knowledge of mercury 454 it's like 310-330hp and the cam and roller rockers I'm guessing I'm close to 400hp.

New development

Took a look at the oil sender today when I got home and the issue k believe was the electrical connector was supper loose. Changed it out anyway as it looked old. Tightened up the connection and we will see if this fixes the mystery oil pressure drop.

So the old dipstick tube ran to the front of the motor and pointed directly at the back of my bench seat. Only had an inch or two to pull it out to check the oil. Got a new flex line one that attaches to the header. Check my oil on old dip stick one last time before I pull it and confirm engine is full so I can establish a baseline reading if new dipstick is different.

Pull the old dipstick out first thing that's different is the tube ran 6.5" into my pan and was just rtv. So it looks like someone shoved it down in the pan rtved it.

New dipstick is only about 1.5-2" where it meets the pan. No biggie just different. Test fit reveals absolutely no oil on the dip stick.

So now I'm thinking I fucked up ordered the wrong part. But to confirm this I get my evacuator out and pull the oil out. Now with my dipstick out I can hear my evacuator hose hit the bottom of the oil pan. I'm golden kick it on and I pull out 4 quarts And I'm sucking air. WTF!

So here I've been checking my oil thinking I'm full or pulled oil out thinking I actually over filled my oil when low and behold my dip stick has been fucked up and completely inaccurate from the get go.

Soo... Yeah Ive been running this motor on 4 quarts when it needs 8. This isn't the first issue I have come across with finding fucked up shit on this motor. But if you want to hear that you'll need a lot of beer and time. The previous owner is aware of most of these issues and to his credit he was stand up and offered me money actually tracked me down and gave me a prop. When I wouldn't take money. I just told him I work on all my own stuff I just want you to know what you mechanics are charging you for.

Thanks to all of you who replied you guys rock and I think I've resolved my issues. I'll post soon if things aren't fixed.