Help me find how much oil my new gm350 needs

[sarantis]

The block you see in the pictures is suposed to be brand new.I say suposed because here in Greece some wierd things hapen.I've heard that even the official representative of Mercruiser sold a rebuilt motor for brand new possibly without Knowing what was inside the box.As about the company that i bougth the block ,the man disappeared (i've heard that he has been sow because he sold bad motrs) and i can't comunicate with anyone of them.Anyway,I 've to fill it with oil to see if it' s running well.The dipstick tube was absent and i made one similar to my friend's engine that has THUNDERBOLT IV and it looks the same apart from the fact that below the intake manifold it has a big plate holding the lifters down(probably it has the roller system,i don't know). Some things more about this block:1)it's one piece rear seal 2)it has a 12 bolts intake manifolds and the the bolts above the exhaust crossover are at a bigger angle than those at the water passages 3) it works with mechanical gas pump.4)At the back of the engine and above the flywheel there is the number 10243880 and above the water circulator pump the number 1M920 and 2G37.
Please help me it's the last thing to complete the swap 305 to 350.

 

[Bondo]

Re: Help me find how much oil my new gm350 needs

Ayuh,...

You Should be able to use the Dipstick from your 305,+ this motor Should also hold the Same amount of Oil...

 

[Fishermark]

Re: Help me find how much oil my new gm350 needs

The dipstick tube was absent and i made one similar to my friend's engine

How did you make one? There could be differences in pan capacities, etc, but if the tube sticks into the block, and you have the correct dipstick for the block and tube... then it should read correctly. PROBABLY around five quarts - but the most important thing is to get a matched tube and dipstick.

 

[sarantis]

Re: Help me find how much oil my new gm350 needs

Bond-o and Fishermark
The dipstick tube and dipstick from the 305 (1979 year) don't fit.The 305 has the dipstick tubes' base at the port side head since the 350 has it at the starbord side a litle above the oil pan's top.How i made it? I tried my friend's tube (which is a long tube,it's end reaches the water circulator's area) and it fited fine.So i baught a tube a litle bigger diameter and with the bench grinder i shaped a similar one but much shorter and without curves.(It ends below the exhaust manifold).Counting the distance from the thunderbolt's tube end to its dipstick's end i modified my 305's dipstick .

 

[Bondo]

Re: Help me find how much oil my new gm350 needs

Ayuh,...

So you're trying to find Where to mark the oil level on your dipstick,..??

Dump in 5qts,... Start the motor, run it to fill the filter, etc...
Shut it down for a minute, pull the dipstick,+ Mark it at that level...
That Should be a reasonable point,+ not be too high...
I'd try to run the motor at or slightly below that mark...

 

[Don S]

Re: Help me find how much oil my new gm350 needs

Close to what bondo says, but just put in 4 quarts. Run the engine for a minute, shut it off let it drain and recheck. Then put a mark on the dipstick, this would be the minimum line. Then add quart #5, re run, let it set and check it. That should be the maximum line.

 

[sarantis]

Re: Help me find how much oil my new gm350 needs

Thank you very much!

 

[Rat Capri]

Re: Help me find how much oil my new gm350 needs

5 1/2 quarts if you have a single short filter

 

[KJSmitty]

Re: Help me find how much oil my new gm350 needs

I would wager given the year of that 5.7 that it's between 5 and 6 qts. Will you be running a remote oil filter setup ?

It looks like the same vintage as my 5.7 and mine takes 6 qts with the large external filter. I say large ext filter yet it's the same size as you could place on the engine/block as well.

Main thing is: 5 qts will either be perfect or at the min line (no 5.7 ever took less than 5 that I am aware of).. I definitely wouldn't run with any less.

However, someone should be able to take those block casting numbers and tell you exactly.

Hope it runs well for you!!

Cheers

 

[Don S]

Re: Help me find how much oil my new gm350 needs

However, someone should be able to take those block casting numbers and tell you exactly.

The block has nothing to do with quantity of oil. It's the size of the oil pan that says how much oil it will take.
Since no one here knows how much that particular pan holds, then I guess we're all just giving a bunch of WAG's .............. Right?

For Sarantis, best to contact the mfg/builder of your new engine and find out the capacity for that pan.