Mercruiser or standard automotive oil pump?

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filafella

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I've got a rebuilt 7.4L engine from US Engines that I'm going to drop in my boat, but I was told that I should get a new oil pump for the new engine. My question, can I use a normal automotive oil pump (which costs only around $40) or do I need to use the Mercruiser #827643 one (which is $200 or more)? Do I even need to put a new oil pump in the engine, or really, do these parts generally fail? Thanks
 
Alpheus

Alpheus

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Re: Mercruiser or standard automotive oil pump?

Yes you should install a new oil pump. The standard automotive one will work fine. I personally have always used Melling pumps and have never had any problems. You don't need high pressure or high volume just stick with stock and you will be fine...
 
Bondo

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Re: Mercruiser or standard automotive oil pump?

I've got a rebuilt 7.4L engine from US Engines that I'm going to drop in my boat,
Click to expand...

Ayuh,... Are you sayin' it came Without a new oil pump,..??

The Standard oilpump is the 1 ya need...
 
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filafella

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Re: Mercruiser or standard automotive oil pump?

Bond-o said:
Ayuh,... Are you sayin' it came Without a new oil pump,..??
Click to expand...

It was a longblock, so it didn't come with an oil pump. The Melling pumps are so cheap, so it's no big deal to replace it. I'm planning on posting a review of the US Engine longblock sometime since there's so little info on here about them. I appreciate the help! :)
 
Bondo

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Re: Mercruiser or standard automotive oil pump?

Ayuh,... I'm surprised,...
Every long block SBC I've dealt with, the oil pump was laying in the lifter valley when unwrapped...
 
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haulnazz15

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Re: Mercruiser or standard automotive oil pump?

I agree with the above. Just get a Melling oil pump, and no need for high-volume. I also think that the long-block should have come with an oil pump. However, my long-block didn't come with a oil pump drive-shaft, so I went and got a heavy-duty ARP driveshaft from the local auto racing shop. The high-volume oil pumps esecially will put a lot of torque on the stock oil pump driveshafts.
 
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dubs283

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Re: Mercruiser or standard automotive oil pump?

just make sure the pickup on the new pump you install fits properly in the oil pan
 
Bt Doctur

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Re: Mercruiser or standard automotive oil pump?

braze or tack weld it to the pump body,Hi Volume pumps only work well with 10-14 qt pans.
 
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HT32BSX115

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Re: Mercruiser or standard automotive oil pump?

That's surprising the engine didn't come with a pump.

A couple of years ago I installed a 3.0L long block from US Engines and it came with a pump. If yours didn't, you might ask them about it.

Maybe they don't supply a pump with all their engines.
 
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filafella

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Re: Mercruiser or standard automotive oil pump?

This one didn't come with the pump. I'm going to call US Engines on Monday to see if it was supposed to. Though, the price of the engine was good enough that I don't mind paying $40 for a pump from a company I trust like Melling.
 
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HT32BSX115

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Re: Mercruiser or standard automotive oil pump?

Maybe some engine builders don't supply it.

When I had my Ford Y-block rebuilt, the builder supplied the pump but did not install it.


I would put a Melling pump on it also..
 
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filafella

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Re: Mercruiser or standard automotive oil pump?

Thanks for all the input, guys. The engine definitely didn't come with a pump, just a gasket set. I can't tell if this is a mistake, or simply the way US Engines sells their 454's. I still have to return the core to them and I'll ask when I drop it off. Either way I've got the Melling pump on it now and even tack-welded the screen on (another good bit of advice!) Thanks!
 
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HT32BSX115

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Re: Mercruiser or standard automotive oil pump?

Now the next question.....


Do you have a stock 330 (crank) HP 454 and did you have them build one of the more fuel efficient engines like the following??

[FONT=Arial, Helvetica, sans-serif]454 415 h.p 1990 - 2005 uses around 25% less fuel. Replaces your factory engine[/FONT]
Click to expand...
 
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filafella

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Re: Mercruiser or standard automotive oil pump?

I bought one their "420" horsepower 454 builds. I put 420 in quotes because who knows how much it will produce and they don't offer dynos. But the price was pretty good, so if it gets me any noticeable HP improvement it will be worth it.
 
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HT32BSX115

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Re: Mercruiser or standard automotive oil pump?

filafella said:
I bought one their "420" horsepower 454 builds. I put 420 in quotes because who knows how much it will produce and they don't offer dynos. But the price was pretty good, so if it gets me any noticeable HP improvement it will be worth it.
Click to expand...

Well, 420 hp is going to be about a 25% increase in crankshaft HP if you had the standard 330hp carbureted 454.

Please post the "before & after" results!
 
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