Merc 4.3 V6 / Balanced Shaft?

[300sflyer]

Could someone please tell me how to determine if a 4.3 V6 engine has a balanced shaft or not? I am converting a 1991 chevy truck engine for marine use, [1990 Merc engine with a cracked block] and want to change the head gaskets to stainless. [As well as all the other required parts including an electric fuel pump]

Felpro lists two different head/intake sets, 17211 for a balanced shaft, and 17210 for a non-balanced shaft, and I don't know which one to buy. What is the difference between these two gasket sets? As far as I can tell, both are for a 12 bolt intake and not an 8 bolt Vortec engine. To add to the confusion, I can only find one 14" flywheel to be used on all 262 V6s, including 1996 and up Vortec motors. One would think the flywheels would be different for balanced vs non-balanced shaft?

Thanks for your help!

 

[achris]

Re: Merc 4.3 V6 / Balanced Shaft?

Interesting... Merc list the head gaskets as the same. The flywheels are different and both are NLA...

 

[achris]

Re: Merc 4.3 V6 / Balanced Shaft?

Back of the engine, (if it has a flywheel, behind that) if it is balance shaft it will have 2 large plugs one above the other, above and in-line with the crankshaft, one is the cover for the last camshaft bearing, the other is the cover for the balance shaft ball bearing. Non-balance shaft engines will only have the plug for the camshaft bearing.

Easy!

Chris...........

 

[300sflyer]

Re: Merc 4.3 V6 / Balanced Shaft?

I found a flywheel listed here. It says for all marine 4.3 engines 1987 and later. Did they even make a 4.3 before 1987?


http://www.michiganmotorz.com/flywheel-1987-later-engines-diameter-p-152.html

 

[achris]

Re: Merc 4.3 V6 / Balanced Shaft?

I found a flywheel listed here. It says for all marine 4.3 engines 1987 and later. Did they even make a 4.3 before 1987?


http://www.michiganmotorz.com/flywheel-1987-later-engines-diameter-p-152.html

Merc started using the 4.3 in 1985.... it was with a 2 barrel carby and produced 185hp....
And in 83/84 they used the 229cu in, which was an uneven firing crank engine, also producing 185hp, but using a 4 barrel carby.....

Chris.........

 

[300sflyer]

Re: Merc 4.3 V6 / Balanced Shaft?

The link for the flywheel makes no mention of balanced or non-balanced shaft. It simply states it can be used on all 1987 and later 4.3s with a one piece rear main. Both of the engines I have here, [1990 Merc and 1991 Chevy truck motor] have a one piece rear main.

Now I know the 1996 and later Vortec motors have the two big plugs you speak of, and one piece rear mains. When they refer to balanced or non-balanced, are they not referring to the crankshaft?

Still confused this and about which gasket set I need.

Thanks

 

[achris]

Re: Merc 4.3 V6 / Balanced Shaft?

...Still confused about which gasket set I need.

Thanks

Did you even look at the back of your engine? Did you even read my reply to you? Why am I bothering answering if you don't read it? Shish!!! And no I will not calm down. Like a lot of people, you want me to gaze into my crystal ball and magically tell you what you have with the scant information you so grudgingly offer up..... Sorry pal. it don't work like that!!! YOU have to do some of the work too..............

 

[300sflyer]

Re: Merc 4.3 V6 / Balanced Shaft?

Did you even look at the back of your engine? Did you even read my reply to you? Why am I bothering answering if you don't read it? Shish!!! And no I will not calm down. Like a lot of people, you want me to gaze into my crystal ball and magically tell you what you have with the scant information you so grudgingly offer up..... Sorry pal. it don't work like that!!! YOU have to do some of the work too..............

So sorry to upset you, and to have wasted your time...

YES I read your reply, and YES I have seen the back of these engines many times. Neither of them have the double plugs you speak of.

Did YOU read my question about the Vortecs? Both plugs and a one piece rear main.

 

[achris]

Re: Merc 4.3 V6 / Balanced Shaft?

So sorry to upset you, and to have wasted your time...

YES I read your reply, and YES I have seen the back of these engines many times. Neither of them have the double plugs you speak of.

Did YOU read my question about the Vortecs? Both plugs and a one piece rear main.

One plug at the back = non-balance shaft engines....

You have a 1990 engine and a 1991 engine. Why are you asking about 1996 engines? Neither of your engines are vortec. Yes, Vortecs had a balance shaft and one piece main seal... If the question is about the balance shaft, no it's nothing to do with the crankshaft.... It's a balance-shaft, not a balanced shaft....

 

[Don S]

Re: Merc 4.3 V6 / Balanced Shaft?

YES I have seen the back of these engines many times. Neither of them have the double plugs you speak of.

Then you don't have a balance shaft. The 91 engines didn't have the balance shaft. You need a gasket set for the non-balance shaft engine.

If your particular engine has a one piece rear main seal, then the flywheel in the link you posted will work.

 

[300sflyer]

Re: Merc 4.3 V6 / Balanced Shaft?

I thought the "shaft" refered to the crankshaft. Now I understand... Thank you.

 

[Silvertip]

Re: Merc 4.3 V6 / Balanced Shaft?

You might also look for either a "Z" or "W" casting number on the block. "W" was a balance shaft engine and did appear in the 1991 Chev Astro AWD vans.

 

[Don S]

Re: Merc 4.3 V6 / Balanced Shaft?

Since you are looking for a head gasket set, it's really easy to tell if you have a balance shaft or not,
just look at the engine and see if it's there. The balance shaft is shown by the 3 white arrows in this picture.

 

[Fun Times]

Re: Merc 4.3 V6 / Balanced Shaft?

http://www.marinemechanic.com/merc/distributors/mercurymarine/sterndrive/gmblockcodes.PDF

 

[300sflyer]

Re: Merc 4.3 V6 / Balanced Shaft?

We took the boat out on the water for a good run this past weekend, including a few runs at WOT, and all is good. The best part, was that there was no water in the oil at the end of the day! Thanks for your help guys!