Change oil in a mercruiser 470

[Dustin1984]

So I received a 1980 Edson Crusader with a Mercruiser 470 in trade for a car I had. I received no maintenance guides or anything of the sort, so how do I change oil in this thing?

 

[Bt Doctur]

In most cases you pump it out from the dipstick tube using a pump that threads onto the fitting
NEVER EVER let the temp go above 175, NEVER

 

[Dustin1984]

hmm... not liking that idea. But I guess I have to do what I have to do

 

[Bt Doctur]

Why not, that what the fitting on the tube is for . In most boats you cant even get to the pan plug

 

[Bt Doctur]

 

[Dustin1984]

I see no fitting on the tube, just a friction fit dipstick like an automotive dipstick tube... never mind, I just looked again and saw it. Guess I need to pick up one of those oil pumps

 

[Scott Danforth]

Before even running the motor:

• Change the raw water pump (not just the impeller)
• Change the lower unit oil
• Pull the drive and inspect the u-joints and bellows and gimble bearing and bellows and alignment - most likely is you will be replacing some of those components

Read up on the 470 and its issues.

And never, ever ever let the temp move a tick over 170....ever or the motor will spit the head gasket

 

[Dustin1984]

Scott, aside from the head gasket issue, the main thing I've been seeing is the electrical charging issue... and this has an alternator installed on it already.
Down the road I'm probably going to pull this engine and build the 350 block I have and drop it in... even though I truly hate Chevy anything...

 

[Scott Danforth]

here are the fundamental design issues on the 4.3:

• soft cam snout, leading to leaking seals at the water pump - fix is speedy sleeves or having the cam removed, welded up, and re-ground. this is the number two problem with the 470. every one will suffer this problem
• stator in harmonic damper for charging, however external voltage regulator cost more than the engine - solution - external alternator conversion. In theory a great design, in practice, however the $500 regulator is a serious achilles heel. this is the number three problem. not every one of them will suffer this problem.
• alloy block with floating bores and steel Ford FE head - requires a heat exchanger. first few years had smaller HX, however if a fish swam by the boat, the motor would over-heat and spit the head gasket. solution - 4" HX. This is the number one problem - every one needs the upgraded HX
• alloy block with floating bores and steel head - coeficient of thermal expansion different enough, head gasket will continue to be a problem. - only OEM Mercruiser head gaskets actually seem to live. This is the number one problem. Every 470 will have its head gasket replaced.....often.
• floating bores. did I mention the floating bores....... this is the number one problem.

anything more than a 10 degree rise in the coolant temperature - the head gasket will spit. this could be from sucking up a bit of silt from the water, a leaf blocking the water pickup, running in aerated water, or a larger fish swimming by

as for the corrective action on the block/head, etc. an edelbrock head for the 460 can be adapted by drilling a large hole for the 90 degree fitting. this takes care of the differences in the thermal expansion. a bore girdle can be added, however requires a laser cut plate and some machining prior to welding in the girdle.

if you plan on a small block, remember, you will be unbolting everything and replacing everything as the gear ratios for V8's are different and the input shaft of the drives are different between in-line motors and V-motors.

Did I mention the floating bores?

 

[Dustin1984]

I'll run it 'til it dies if the power is satisfactory, otherwise I'll get some parts and build this v8... any way I go about it it's all gonna cost me money! anyhow, this has gotten a little off-topic, But thanks for the oil change advice!

 

[Scott Danforth]

boating costs money......no mater what....it is an expensive hobby.

 

[therealjoeblow]

hmm... not liking that idea. But I guess I have to do what I have to do

From page 24 of the owner's manual for the 470, section titled "Draining Engine Oil and Replacing Oil Filter":

"NOTE: If drain plug is not accessible because of lack of clearance between oil pan and boat, pump oil out of oil pan via the dipstick tube with a suction pump. An Oil Drain Pump is available for use on you engine. Contact your authorized MerCruiser dealer should you desire to purchase this pump."

Cheers
TRJB