Converting a non-marine 305 and is it worth it

[Krause87]

Hey guys I'm for sure going to start my Audeen build end of December beginning of January. I have been doing alot of research and have come to the engine possibilities part. I have a non-marine vortec 305 GM motor just sitting in my garage waiting on a project. My question is, is it worth converting the engine I have or should I, when the time comes just purchase the Marine 4.3ltr v6 I have been eyeing? Thanks in advance

[Soloboat]

The differences between a marine engine and an automotive engine as we know it are the ancillary components. the starter and alternator are such that they inhibit wayward sparks and carbureted engines have a flame arrestor instead of an air cleaner exhaust is usually water cooled and some other mics stuff, so if you have an engine for which parts are readily available then proceed you will be ok

[kens]

does the 305 long block need overhaul, or, is it ready to go as is?
a long block is about all you will have from the auto engine, everything that bolts on will be a marine item.
even on the long block, you replace the freeze out plugs to marine, and install a marine cam.

is that the vortec with roller lifters too??

[Krause87]

The motor really only has about 30 minutes on it. It is a 1996-1997 vortec 305 with the roller cam. I would also need to replace the head gaskets correct?

[Milhouse]

Have you already figured out the transmission? My velvet drive required a funky oil pan cause it was mounted backwards.

My ski boat has a 1962 327 and I have spent $$$ on marine accessories (Water pump, Distributor, carb, alternator, fuel pump, starter (yet to buy it), etc.)

[Milhouse]

I would also need to replace the head gaskets correct?

Not sure how being on a boat would require different head gaskets?

[Krause87]

From some of the research I have done, the Marine headgaskets use stainless reinforcement to combat salt water applications. I have not looked into a transmission yet I was actually going to see if I could get some advice on that as well. From what I understand there are quite a few to choose from.

[Krause87]

Also I failed to mention that my uncle has an old Carver cuddy cabin with a mercruiser 350 in it. The boat is beyond repair and the engine suffered some internal damage but I was hoping that maybe the engine's Marine components would work on my 305. Also the boat has alot of salvageable teak on it that I think would fit in well on my future Audeen deck.

[riplash]

The motor really only has about 30 minutes on it. It is a 1996-1997 vortec 305 with the roller cam. I would also need to replace the head gaskets correct?

The head gasket replacement depends on if you use raw water cooling which is sea water, or if you use fresh water cooling (which is sometimes called closed cooling- it is antifreeze. And rather than cooling the antifreeze with an air cooled radiator, typically you cool the antifreeze with a heat exchanger.

If you use raw water cooling you should definitely plan on changing the head gasket. If you use closed cooling you probably do not need to change the head gasket.

[kens]

if you talking about marinizing a auto engine, the transmission is the least of your worries.
if you get to that point, all you need is the Borg/Warner bellhousing and proper flywheel drive plate.
All the various transmissions bolt up to that Borg/Warner bolt pattern

[Krause87]

Well looks like I'll be saving some money going with the engine I already have. Thank fellas!

[ian bell]

Hi Krause , I had a 350 chev vortec that I marinised , with marine gaskets.Alloy exhaust ,marine carby and starter motor and alt which I already had .put in a cam for a marine engine ,can't remember the grind for that.Launched the boat last year ,runs like a dream.
Ian

[Krause87]

Sounds about like what I plan on doing! We will see, thanks for sharing!

[watkibe]

Read the Glen-L book "Installing Inboard Engines". It goes into detail on the marine conversion process. Glen-L also sells some of the needed and hard to find parts.
Personally, after reading it, I decided to go with an outboard setup...

[Krause87]

Thanks watkibe! I actually purchased the inboard engine installation book and It should be in this evening. I looked at some outboard models but for what I am wanting as far as look, purpose and of coarse safety. I feel the inboard setup would be better. Besides, I grew up around hot rods and am/was a GM mechanic so what better way to build a boat that fits me than stick a hot rodded car engine in it!