Oil pan size

ericcarr

Petty Officer 1st Class
Joined
Jul 27, 2009
Messages
291
I have a quick question regarding oil pan size. I have a 1990 Siri Sundancer with the generation four, 7.4 L big block motor in it of course. I removed the oil pan to be able to change the oil pump on it before I put it back in the boat. Can somebody shed some light on what size oil pan I currently have on it and if it would hurt if I went to a lower capacity oil pan because according to the book it says it has a 7 quart oil pan. I was thinking maybe putting a five court on it instead, I was just wondering if you would hurt anything if I did that or not
 

ahicks

Captain
Joined
Sep 16, 2013
Messages
3,957
I have a quick question regarding oil pan size. I have a 1990 Siri Sundancer with the generation four, 7.4 L big block motor in it of course. I removed the oil pan to be able to change the oil pump on it before I put it back in the boat. Can somebody shed some light on what size oil pan I currently have on it and if it would hurt if I went to a lower capacity oil pan because according to the book it says it has a 7 quart oil pan. I was thinking maybe putting a five court on it instead, I was just wondering if you would hurt anything if I did that or not
I had a rather extreme big block in a v-drive "ski" boat 40 years ago. In the process of getting a durable motor I could trust, I learned that big blocks run at high rpms have a habit of pumping all of the oil from the pan because it couldn't drain back down as fast as it was being pumped out. Plenty of time spent with all of the racing tricks at the time, but after spinning the main and rod bearings 4-5 times, finally learned it took a fully baffled 17qt pan to keep this motor from destroying itself.

That experience STILL fresh in my mind, I wouldn't even consider going with a smaller capacity pan in a marine big block....
 

Grub54891

Admiral
Joined
Jun 17, 2012
Messages
6,073
It was designed the way it is because it needed it. Cutting down the capacity can starve the motor of needed lubrication. Keep the 7 quart pan please.
 

ericcarr

Petty Officer 1st Class
Joined
Jul 27, 2009
Messages
291
Thanks for the advice guys..I’ll just reuse the pan I took off of it..although it really doesn’t look like an extra capacity pan. It looks like a standard oil pan…any way to measure it to see the capacity of it?
 

matt167

Rear Admiral
Joined
Sep 27, 2012
Messages
4,150
fill it up with liquid to where a windadge tray would sit and see how many quarts that is. Thereabouts will be 'full'... If it has the dipstick tube in the pan, that is even easier.

Keep in mind that a big block engine will use about 3 quarts of the oil pan capacity while running. So if you had a 5 quart pan, it would have only 2 quarts of reserve. Many old time racers will overfill by a quart or 2 regardless
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
49,548
you should also have an aluminum finned oil pan.

I agree, leave it as is or go with a larger sump.

FYI - even todays LT trucks with just a 5.3 in them have 8 quarts of oil.
 
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