Question 4.3l cracked block?

[steves937]

Hello,
After finding rot under my Thompson Carrela's deck, I bought my dream boat a aluminum Starcraft Chieftain, It has a new deck, and interior, sound hull and cracked exhaust manifolds. So I am removing the engine to go through it. Heads will be at the machine shop tomorrow, and the bock will follow.
I read in a different post that if the block might be cracked, someone said it would be hard to find and you should just get a different one instead chancing it.
I would like to Know why it would be hard to find (cracked block)?
I want a it right, want to know what i have, and not have to deal with it later after a disapointed fishing trip.

my hull is a 1988, the 4.3l is the thunder ignition and i see it has the roller tappets i believe this is the vortec.
What year auto blocks would work with my intake and heads?

No i did even look for water in the oil before removing the heads, im sure there is water now.

Thanks, Steve

 

[actionljackson]

Re: Question 4.3l cracked block?

Steve it is not always hard to find the crack you just read a thread where someone had a hard time finding the crack.You don't say what year motor you have? If it is a 1988 I don't believe it's gonna have the Vortec heads as they did not come out until 1989 or 1990.Others will correct me if I'm wrong.I had a cracked 4.3 block and the crack was very visible.It's just as easy to start with a fresh block as to weld your old one.Some say they have had theirs welded and have had no problems.Others will say get a new block as you never know when that weld is gonna fail.I replaced my block with a new machined one delivered for under 280.00. I purchased the boat in this condition with the hope it was only a blown head gasket and worst case a cracked block. Hope what ever you do works out well for you.Just wanted to let you know a fresh block need not be expensive and well worth the peace of mind....Action

 

[ScottRogers]

Re: Question 4.3l cracked block?

Want piece of mind? Go for a reman. or new crate motor. You can get them complete, carb to oil pan, ignition, the whole 9 yards.

 

[180shabah]

Re: Question 4.3l cracked block?

The vortec name was introduced in 1987 and there were GM heads that were associated with this new name. They had a small "ramp" forced extra swirl as the intake charge entered the cylinder. These heads were used by GM on all of thier TBI engines, and commonly referred to as "TBI heads". I am pretty sure, but not positive, Mercruiser never used these heads on anything, and used the traditional heads until the "real" vortecs were introduced in 1996. The 96+ vortec heads basically LT1 heads for GM's traditional small blocks. When people talk about vortec heads, these are the heads that they are talking about. They can be identified by the simple fact that they only have 8 mounting bolts(running verticaly) instead of 12 used on earlier heads. They also require vortec specific intake manifolds.

 

[steves937]

Re: Question 4.3l cracked block?

Thank you for the replys, My heads have more than 8 bolts so it is not a vortec. Did they always use cam roller tappets?
I plan on having the block cleaned and inspected at this point and will start checking prices for remain, but i believe it will be around a thousand less to find a good used block, if heads, crank and intake check out.
Where is the best prices for mercrusier parts, gaskets sets, hoses etc?
I,m in Ohio
Thank you