best way to pull my 350

[Static01]

I just picked up a 1980 mark twain bow rider 19' and the guy kinda screwed me and told me that the electronics were just messed up cause I couldnt get power to anything while looking at it before I bought it. I got it home last night and today I got the electronics fixed and the motor is locked up and the block is cracked. I only paid $300 for it and its really not in horrible shape at all so I am not to concerned about it, but I am going to have to put a new motor in it. I found a 350 long block at a junk yard and I heard it run and checked it out and its all good to go. I will be installing all my marine equipment on it as well as marine gaskets and bronze freeze plugs. So here are my questions. Ive read about something with the flywheels not being the same and it causes problems could this be solved by swapping the flywheels with what I have now or is there a certain year chevy block I should be looking for? Also what is the best way to get the motor out. I have an A-Frame hoist but should I pull the outdrive off as well? Thanks for all the help. This is my first boat and I am really excited to hit the water with it.

 

[45Auto]

Re: best way to pull my 350

First thing you need to do is go to the Adult Only sticky at the top of this forum and get Merc Factory Manual #3, 1974-1984 Engines. Get familiar with the manual. It will tell you how to remove it. Yes, you do need to pull the outdrive, takes 5 minutes.

 

[TilliamWe]

Re: best way to pull my 350

Static, starting in 1986 (or is it 87?) GM switched to a one piece rear main seal, requiring a different flywheel, starter, and a different outdrive coupler. If you bought a 350 from before that year, you can transfer everything to it. If you bought a one piece rear main seal motor, you are gonna need to replace some parts.
Pulling the outdrive should be the easiest part of your whole project.

 

[Static01]

Re: best way to pull my 350

Static, starting in 1986 (or is it 87?) GM switched to a one piece rear main seal, requiring a different flywheel, starter, and a different outdrive coupler. If you bought a 350 from before that year, you can transfer everything to it. If you bought a one piece rear main seal motor, you are gonna need to replace some parts.
Pulling the outdrive should be the easiest part of your whole project.

Wow I didnt think I would get such a good answer. Usually people beat around the bush but you told me what I needed to know. Thank you. Is there anything I should be cautious of while doing the swap? Finding a GM 350 with a two piece rear main seal might get difficult so would you happen you know where I can get the parts I need? I am new to all this so I until it comes out I dont know what I am going to need till I can see it in my hands lol. any tips on how to pull the motor?

 

[danond]

Re: best way to pull my 350

Static - you really need to get and read the service manual for your drive. Check the "ADULTS ONLY" section of the forum for more information. It tells you step by step how to pull the engine.

The primary thing you need to do is remove the outdrive. It has a driveshaft that goes into the back of the engine, into the coupler, which is bolted to the flywheel. You can't pull the engine without removing the outdrive. Luckily it's very easy to remove the drive, and you should do it anyway to inspect the u-joints, bellows, gimbal bearing and sealing surfaces.

Aside from that, make sure you label everything with masking tape, and take pictures with a digital camera before you pull it.

 

[Static01]

Re: best way to pull my 350

yeah I keep trying to get to that page like the instructions say and it just sits there and loads. been loading for over two hours now.

 

[TilliamWe]

Re: best way to pull my 350

Yeah, a one piece rear main seal engine is a lot easier to find.

iboats should have the starter you would need. They might also sell the coupler needed. If you didn't get a flywheel (and I mean a flywheel from a manual transmission equipped car/truck, not a flexplate from an auto transmission) with your replacement engine, go back to the salvage yard and get one.

Also, your intake manifold will not fit on the heads from the post 1987 motor. The center two intake manifold bolts are at an odd 72 degree angle. You'll need an intake manifold too. They are available aftermarket, from like Summit, or maybe even here on iboats.

What engine are you getting exactly? Cause in 1996/1997 GM changed again to "Vortec Heads" which require a different intake manifold, again. But the flywheels stuff is the same, at least.

 

[Static01]

Re: best way to pull my 350

ideally I would just like to find a direct replacement long block. The intake manifold isnt a big deal because the salvage yard I am getting what ever motor I can find that checks out is going to have the intake manifold as well as the flywheel. I am not sure what coupler I need or where I would find it though. Like I said I am new to this whole thing. I have been working on cars and motorcycles for a while now but this stuff is completely different. If the coupler is cheap enough then I will just go with a motor with a one piece rear main seal and call it a day. I was also wondering about the drain ports below the cylinders on the block, would those need to be drilled on a motor from a truck or are they just plugs that I pop out and install the drain ports in? I know this is a lot of questions but I just want to make sure I am not going to have any issues with pulling a motor out of a car and using it in my boat. I know I have to pull the heads to put the cam in so I am going to use marine head gaskets at that time and I will pull the plugs and use marine plugs. Let me know if I am forgetting anything. I am going to go check out my options tomorrow and I will post up what I find and see where it goes from there.

 

[45Auto]

Re: best way to pull my 350

The manual is a huge file, 1.5 GB. Could take a while depending on the speed of your internet. Start downloading it before you go to bed and just let it run all night.

 

[wca_tim]

Re: best way to pull my 350

you have to pull the heads to put the cam in?

The scrap yard will have a car intake, you'll probably want a marine version or basic aftermarket.

Drain plugs should be there.

Flywheel you need is from a manual transmission car/truck

new coupler is ca. 200 I think of the top (I priced the other day), or can probalby find a used one if you get the right flywheel, etc...

By the time you finish monkeying around with mixing and matching parts to get a used one piece rear main seal engine to work, you might be cheaper off to buy a reman sjortblock or longblock with a two piece seal. I like the one piece seals, but if you're trying to do it on the cheap...

Note that you will very likely need new exhaust manifolds and risers (ca. 600???) or run the chance of trashing the "new" engine right after you get it going.

Have you drained the fluid in the drive to see what kind of shape it's in? and once you pull the drive by removing the 6 nuts facing aft and puling it out, let us know what things look like in there. If the bellows has been leaking you're in for significant additional expense before you're ready to be on the water.

Not trying to be negative, just a lot to go wrong when someone lets one go...

For the things you need used parts for, ebay can be a very good place to get things if you're careful. I've bought a lot of used boat parts, props, etc... there and find that the vast majority of people I've dealt with have been straight up.

unless you enjoy tinkering, it may be that a free boat costs more than buying one that's in good shape and ready to go... especially if you assign any dollar figure to the investment of your time.