Truck motor swap...should I swap cam?

[treeeman00]

I have a 1987 2450 bayliner trophy with a OMC 305 with cracked block. I bought a used gm goodwrench 350 crate motor with 17000 miles from a 1989 K2500 that I am going to install in the boat. Boat also has a OMC cobra outdrive. Should I sawp the cam with a marine spec or use the stock cam. Motor is all stock. Should I also change the headgaskets? Can I use the truck oil pan? The 305 pan has the oil dipstick that goes into the bottom of the oil pan. The 350 oil dipstick goes thru the block and into the oil pan. I plan on swapping the 305 parts that are marine. Thanks for all the help.

 

[Scott Danforth]

Re: Truck motor swap...should I swap cam?

you need to change the head gaskets, and swap to brass core plugs. I would invest in a new marine cam, however the truck cam will be fine initially if your low on cash.

use the marine dipstick from your 305, it goes to the bottom to allow you to suck the oil out thru the dipstick for oil changes. the truck dipstick does not go to the bottom of the pan.

 

[treeeman00]

Re: Truck motor swap...should I swap cam?

I forgot to add that the boat will be run in freshwater only. Do you have the specs or a part number of a comp cams that is the cam I would need? I didnt thin it mattered if the dipstick went to the bottom or not because the tube that you stick through the dipstick tube will go into the oil pan.

 

[Scott Danforth]

Re: Truck motor swap...should I swap cam?

I would probably run the XM262H from comp cams

 

[Silly Seville]

Re: Truck motor swap...should I swap cam?

No, you don't need "marine head gaskets," they are stainless steel and very spendy. Just get Fel-Pro or Victor Reinz MLS gaskets with embossed silicon...you are in freshwater after all. If you want a mild performance cam that is boat engine safe, get this...GM#14097395. If it's good enough for Mercruiser's 350 Ram Jet and Chevy's 383 HT truck engine, it will work for you.

 

[Bondo]

Re: Truck motor swap...should I swap cam?

I have a 1987 2450 bayliner trophy with a OMC 305 with cracked block. I bought a used gm goodwrench 350 crate motor with 17000 miles from a 1989 K2500 that I am going to install in the boat. Boat also has a OMC cobra outdrive. Should I sawp the cam with a marine spec or use the stock cam. Motor is all stock. Should I also change the headgaskets? Can I use the truck oil pan? The 305 pan has the oil dipstick that goes into the bottom of the oil pan. The 350 oil dipstick goes thru the block and into the oil pan. I plan on swapping the 305 parts that are marine. Thanks for all the help.

Ayuh,.... I'd leave the cam, 'n head gaskets alone....

Make sure the core plugs are brass, swap on the oil pan so's ya can pump out the old oil, 'n drop it in...

Late model crate motors already have composite head gaskets, 'n usually have brass core plugs,...
The truck's cam is Fine,...
But, you'll need the base mounted dipstick to change the oil later on...

 

[treeeman00]

Re: Truck motor swap...should I swap cam?

Do all marine dipstick tubes run on the outside of the oil pan and mount to the outside bottom of the oil pan where the drain plug is? I just dont see how you could suck all the oil out that way. Ive been reading several different topics on truck and marine motors. I understand that mostly wahat makes marine is bolt on and that GM doesnt make a special marine block. I guess the main concern is the cam. If I leave the truck engine as is except for the core plugs and swap the starter, carb, intake, flywheel etc, am I going to get a good life out of the truck engine as I would a marine? I know it all depends on use, and maint.

 

[Scott Danforth]

Re: Truck motor swap...should I swap cam?

no, not all marine dipsticks are external. Mercruiser uses a really long dipstick in the block hole. unlike the truck dipstick that is only about 2" into the block, these are driven in about 9".

you will get the same life (based on maintenance), however the cam is what determines the power output. since your replacing the 305, the truck cam will be fine (about 260hp).

 

[treeeman00]

Re: Truck motor swap...should I swap cam?

so externally mounted dipsticks are better to suck the oil out than internally mounted dipsticks?

 

[Scott Danforth]

Re: Truck motor swap...should I swap cam?

no, marine dipsticks (whether external or internal) go to the bottom of the oil pan. truck dipsticks do not.

 

[treeeman00]

Re: Truck motor swap...should I swap cam?

so what is the reason that maring goes to the bottom and trucks do not. Forgive me for all of the questions. I am full of them! lol. All of your guys help is greatly appreciated!

 

[Bondo]

Re: Truck motor swap...should I swap cam?

so what is the reason that maring goes to the bottom and trucks do not. Forgive me for all of the questions. I am full of them! lol. All of your guys help is greatly appreciated!

Ayuh,... Because ya can't drain the oil from the base plug, so, in a boat, ya suck the old oil Out the dipstick tube...

 

[treeeman00]

Re: Truck motor swap...should I swap cam?

I didnt know that you put the hose on the dipstick tube. I always thought you shoved the hose down through the dipstick tube. Now it makes sence! lol

 

[treeeman00]

Re: Truck motor swap...should I swap cam?

I tore down the OMC 305 with the cracked block. The 305 did not have a windage tray nor a baffled oil pan. The 350 truck motor does have a windage tray. Should I be using the windage tray or no? I have read on here that marine applications use a baffled oil pan. Is this correct? Thanks.

 

[Scott Danforth]

Re: Truck motor swap...should I swap cam?

use the windage tray. my '88 350 has a windage tray.

 

[Bondo]

Re: Truck motor swap...should I swap cam?

The only other thing I feel could be possible is the trim limiter switch has went faulty. There are two from what I can see, port and starboard, located on the outdrive. Is that one assembly or two seperate?

Ayuh,.... Use the windage tray,....

I've seen both baffled, 'n not oil pans on boat motors...

I didnt know that you put the hose on the dipstick tube. I always thought you shoved the hose down through the dipstick tube. Now it makes sence! lol

Actually, it's done Both ways, dependin' on the dipstick....

The Mouller pump up, 'n walk away system, is the cats a**....

 

[Scott Danforth]

Re: Truck motor swap...should I swap cam?

actually, I really like the remote oil drain hose I just added to my motor better than trying to suck oil thru a dipstick

http://www.jmsonline.net/oil-drain-hose-kit.htm

based on measurements, I can shove the hose down the bilge plug and hang down to hit a oil pan on the ground.

 

[joewithaboat]

Re: Truck motor swap...should I swap cam?

actually, I really like the remote oil drain hose I just added to my motor better than trying to suck oil thru a dipstick

http://www.jmsonline.net/oil-drain-hose-kit.htm

based on measurements, I can shove the hose down the bilge plug and hang down to hit a oil pan on the ground.

My last rig had one of these. I like the thought of getting every last drop of the old stuff out.

 

[Scott Danforth]

Re: Truck motor swap...should I swap cam?

getting the last drop of oil out is the bonus. I just didnt like draging my oil pump into the boat since the pump discharge hose once decided to spew all over, and I can now have a bottle of liquid oil change enhancer when the oil is draining.