good replacement for 470?

[jeromeo25]

I am currently looking at a several old project boats, a couple of which have 470s. My research shows they can be quite problematic. Are there any other motors that would be a direct replacement or an easy swap for the 470?

 

[Eric 3.7LX Alpha 1]

Re: good replacement for 470?

No. only another 470.

 

[achris]

Re: good replacement for 470?

The '470' produced 170hp. The other in-line 4 cylinder engines are 120hp and 140hp. Swap into one of those and you will notice the power difference (and not in a good way). The engine that replaced the 470 in the Mercruiser line-up was a 2bbl carbed 4.3 litre V6, 185hp. The problem you face is that a V6 is so much wider than an in-line 4.... If you have the space in the engine box, then that is the way to go...

The advantage of the V6 is that the same drive ratio is used on both the 470 and the 185hp V6. All you need is the exhaust Y-pipe and you're ready. (oh, you'll need to glass in a couple of new engine mounts too)...

Just one thing to be careful of. The 470 era spanned two different style inner transom plates. The V6s only came out with the later style inner transom plate. So, if you buy a boat with a 470 in it, with the view to replacing it with a V6, then you need a 470 from 1983 and later. Unless you intend to replace the complete package (engine, transom plate, gimbal housing, drive)....

Chris......

 

[Live-liner]

Re: good replacement for 470?

Jeromeo25,
I don't mean to hijack this post, but I have been looking into this as well. So maybe the good people here wouldn't have to answer the same questions over and over.
No disrespect to the 470, it's given me many good hours of service, but she's getting tired.

Chris,
As you know, I have an1986 Chris Craft w/3.7 190 hp. I was looking at rebuilding existing or buying a rebuilt longblock. I have no problem continuing with a 3.7 however, the bolt on parts such as manifolds, risers, intake manifold, rochester carb, etc. are becoming hard to acquire.:grumpy:
I am thinking that the 4.3 would be a better place to put my $$. So, are you saying that as long as I can put in some motor mounts, and buy the Y-pipe, everything else (from inner transom plate to prop) would be a direct bolt on? I already have stringers on each side of motor that are 22" center to center. What other expenses would I expect to evolve?
Thanks in advance

 

[achris]

Re: good replacement for 470?

Jeromeo25,
I don't mean to hijack this post, but I have been looking into this as well. So maybe the good people here wouldn't have to answer the same questions over and over.
No disrespect to the 470, it's given me many good hours of service, but she's getting tired.

Chris,
As you know, I have an1986 Chris Craft w/3.7 190 hp. I was looking at rebuilding existing or buying a rebuilt longblock. I have no problem continuing with a 3.7 however, the bolt on parts such as manifolds, risers, intake manifold, rochester carb, etc. are becoming hard to acquire.:grumpy:
I am thinking that the 4.3 would be a better place to put my $$. So, are you saying that as long as I can put in some motor mounts, and buy the Y-pipe, everything else (from inner transom plate to prop) would be a direct bolt on? I already have stringers on each side of motor that are 22" center to center. What other expenses would I expect to evolve?
Thanks in advance

That's exactly what I'm saying. Find a Mercruiser 4.3 litre bobtail engine (balancer to coupler) and it'll drop right in there. Even the instrument harness should plug straight in.

Chris.....

 

[Live-liner]

Re: good replacement for 470?

Great, I think that would be my best bet.
As always, thanks for your knowledge!

 

[a1nowell]

Re: good replacement for 470?

Live-liner,
Before you just toss that 470, check her out. I found my 470 powered tritoon setting in a cow pasture in '08. I cleaned her up, changed the oil, plugs etc and she fired right up. I have since done the alternator conversion and some sterndrive work but as of yesterday morning after fishing, she runs like a top.

A good strong engine if maintained. Most who don't like them never owned one.

Larry

 

[achris]

Re: good replacement for 470?

...A good strong engine if maintained. Most who don't like them never owned one.

Larry

Hey Larry... (Looking hurt)... I have never owned a 470, but I also think they are a good engine. I think the minds of the designers were in the right place, just a couple of points on the execution are a little off the mark.

Basically, a strong engine, great low down torque, excellent on fuel. Power to weight ratio is fantastic. Personally, I love the idea of the engine water pump inside the housing (no belt )...

There's only a couple of issues, and they can be worked around. The biggest problem they have now is lack of parts... And their age, even the newest one is now 23 years old....

This thing of 'if maintained'... ANY engine neglected is going to have problems. The main thing with the 470 is it has its own maintenance requirements, just a little different from a GM or Ford engine.... Not more, just different...

Ok... rant over

Chris.....

 

[Live-liner]

Re: good replacement for 470?

Larry,
Thanks for your input. However, I am not just "tossing it" because its a 470. It has been in service since 1986 and has well over 1000 hours on it now. I've reached the point (if I want to continue with this boat) that I have to decide to rebuild or replace. As I said previously, the lack of parts availability is my major concern. If my Chris Craft's 470 can't have a reliable, serviceable motor, then I need either replace the motor or the boat. I'm just trying to figure out where my money should be spent. $6k to $7k thinkshould put a nice new motor in her and give me a few years of reliable service. I would need at least $20k to replace her with what I want (and have new engine problems that someone else sold me)

Chris,
Thanks as always for your input

 

[achris]

Re: good replacement for 470?

.... I'm just trying to figure out where my money should be spent. $6k to $7k thinkshould put a nice new motor in her and give me a few years of reliable service. I would need at least $20k to replace her with what I want ...

Yep, been there, done that... It's a difficult decision, that only you can make.

In 1994 I was faced with exactly the same choice. New engine in the current boat or newer boat with (hopefully) a better engine. I opted for the new engine in the old boat.... Only the BEST decision I have made in the life...

But, your boat, your situation, your decision... Good luck.

Chris......

 

[Live-liner]

Re: good replacement for 470?

So, to prove my point....
Went out fishing last night, got home about 1:30 this am. (I fish the vampire shift).
Boat was not happy idling under 1000 rpm. Lifted cover and noticed slight vapor coming out of breather hose to carb. Not steam or coolant, but light oil. I assume this can only be rings (what next?) I just replaced head gasket, riser, manifold, intake gasket, plugs, rotor, condenser, points, wires, and on and on.....
I enjoy wrenching, but not every trip. :deadhorse: