Merc 4.3 Info and more

[Northernbob]

New to the forum. Am not new to Mercs but its been 14 years since I sold my 206 Grew with a 5.0l Well I could not pass a decent deal on a new to me boat.
I have a 1994 Sea Ray 18ft Signature 4.3 4BBl Alpha 240hrs raw water cooling. Well I have the boat because we had an early freeze and the PO didn't winterize. He had the boat to the shop and they replaced the manifolds and the found out the block is cracked, the PO took the boat home and I purchased it as is. I have been busy reading a lot of the forum threads. I another post a member wrote that the vortec didnt appear untl 1996, is this true?? Mine has what appears to be a votec or at least the valve covers state that. If so what years of 4.3 blocks can be used for replacement. I like wrenching as a hobby, have rebuilt two Corolla engines and one Suzuki so far this year. I take it I need marine head gaskets, are the head bolts TTY?? Should I do the rings and bearings while I'm in there?
I reside in the interior of beautiful BC Canada
TIA
Bob

 

[Don S]

Re: Merc 4.3 Info and more

It's very possible the engine was replaced after 96. Do you have a Mercruiser serial number for the engine. There should be a tag just above and aft of the starter.

 

[Northernbob]

Re: Merc 4.3 Info and more

Don its dark and -15c out and the boat is well covered outside. But here is the serial number from the carb cover 0F137686 hope that helps, tomorrow I will get the one off the block and compare. AFAIK it is the original engine, but one never knows for sure.

Thanks
Bob

 

[JustJason]

Re: Merc 4.3 Info and more

found out the block is cracked

Should I do the rings and bearings while I'm in there?

Do the rings and bearings while your in where???
You need a short block at least. At most you need a complete longblock + an intake manifold.
Are you thinking of buying a junkyard block or something to that effect?

 

[Don S]

Re: Merc 4.3 Info and more

That serial number is for a 4.3LX from 94
Which valve cover do you have Left or right.

 

[Northernbob]

Re: Merc 4.3 Info and more

I would venture to say the cover on the right, they are marked vortec I remember that. Double check in the A.M.
So you dont think having the heads checked and moving all other the components to a know good STD bore block from the machine shop is a good idea???

 

[180shabah]

Re: Merc 4.3 Info and more

I am guessing, he has the cover like on the right, if they say Vortec on them.

Bob - the vortec NAME has been around since '87. However, when most people refer to vortec heads, they are talking about the '96 and later ones that incorporated the LT-1 design.
Also, welcome to iboats, and if you keep don informed, you will get squared away.

 

[Northernbob]

Re: Merc 4.3 Info and more

I am guessing, he has the cover like on the right, if they say Vortec on them.

Bob - the vortec NAME has been around since '87. However, when most people refer to vortec heads, they are talking about the '96 and later ones that incorporated the LT-1 design.
Also, welcome to iboats, and if you keep don informed, you will get squared away.

Thanks 180, starts to make sense now!!! Did not realize that tid bit!!
So it's a plain Jane 94 4.3.
Thanks for the welcome.
Bob

 

[Bondo]

Re: Merc 4.3 Info and more

So you dont think having the heads checked and moving all other the components to a know good STD bore block from the machine shop is a good idea???

Ayuh,... That's all fine,+ dandy,...
But,.. Rings + bearings are Throw-aways that are not Reused when doing it...
Use quality gaskets like Fel-pro's composite gaskets..

 

[Northernbob]

Re: Merc 4.3 Info and more

Ayuh,... That's all fine,+ dandy,...
But,.. Rings + bearings are Throw-aways that are not Reused when doing it...
Use quality gaskets like Fel-pro's composite gaskets..

Yes this is my plan, check everything while in there and replace as nescesary.
The machine shop here is very good for help and advice and has decent prices.
Will have them do what I can't. Good rings and bearing are not expensive.
I am retired so time is on my side. Cold snap here so am trying to secure a inside shop to pull the engine.
Bob

 

[180shabah]

Re: Merc 4.3 Info and more

So it's a plain Jane 94 4.3.

Is there such a thing?

After looking at you SN, you have a Gen II 4.3LX.
LX = 4bbl, in this case you have a Weber carb (easy and cheap to service)
GEN II = balance shaft and electric fuel pump and composite vortec valve covers, but still the old style heads under them.

FWIW - if you are repowering, now is the perfect time to think about a vortec ugrade. good for about a 35hp improvement at the prop.

 

[mkast]

Re: Merc 4.3 Info and more

I am retired so time is on my side.

You might try the local technical college. Night class, rebuilding engines.
$100 to attend the class. Depending on the equipment the shop has, you can do around $1500 worth of machine work to an engine.
After the class is over, you WILL know that engine.

 

[Northernbob]

Re: Merc 4.3 Info and more

Is there such a thing?

After looking at you SN, you have a Gen II 4.3LX.
LX = 4bbl, in this case you have a Weber carb (easy and cheap to service)
GEN II = balance shaft and electric fuel pump and composite vortec valve covers, but still the old style heads under them.

FWIW - if you are repowering, now is the perfect time to think about a vortec ugrade. good for about a 35hp improvement at the prop.

I will check with my shop see what he has. Going there today with a page of questions.

 

[Northernbob]

Re: Merc 4.3 Info and more

Update.
Found a 1994 GMC Jimmy 4x4 auto 4.3 engine 60,000 miles.
Still has cross hatch!! No bore job.
So bought it and took it to the engine shop.
Got it back, as a long-block, ready for
me to add the rest of the parts and do the install.
Total was $2300 taxes in, about $700 (and $80taxes) less than a crate engine. Things in Canuck land are not cheap!!!
There is a lot to those 4.3 as far as keeping them balanced.
So we used all the old engine internals, ground the crank 10 thou, and a reground marine cam, the old both had watermarks.
New valve guides and seals,and lifters.
I made a oil primer from the old jimmy dizzy
Now if you guys could just push spring ahead!!!!
I have been browsing thru the 1500+ threads, sure are a lot with no
ending, but sure a lot of very good info.
Will post as things progress.

 

[tractoman]

Re: Merc 4.3 Info and more

At what serial number did the heads change? I have a 1995 4.3lx and the boat was made in late '95. Could I have the newer heads?

 

[Northernbob]

Re: Merc 4.3 Info and more

At what serial number did the heads change? I have a 1995 4.3lx and the boat was made in late '95. Could I have the newer heads?

I am not sure, my old and the new had the same casting numbers, one of the old was cracked.
I believe the vortecs came in 96.
Count the intake bolts 12 is old style 8 is vortec, the vortec bolts go straight down and the old ones go at a angle.

 

[180shabah]

Re: Merc 4.3 Info and more

At what serial number did the heads change? I have a 1995 4.3lx and the boat was made in late '95. Could I have the newer heads?

Don't have the SN's handy, but I seriously doubt you have vortec heads. Merc denoted them initialy as Gen+ from '96-'98 as they worked trhough thier stock of the "older" design. Both were available for those years. A quick visual will answer the question for sure. Look at the intake manifold bolts. Six on each side running into the head at an angle = old style. Four bolts on each side running straight up and down = vortec.

Your valve covers probably have vortec "stamped" into them, but that doesn't mean anything at all. Just some GM marketing crap.

 

[180shabah]

Re: Merc 4.3 Info and more

I guess bob types faster...

 

[tractoman]

Re: Merc 4.3 Info and more

Good info, and if I go out in the cold and remove the cover I'll have a look. I'm thinking old style. So the 4.3lx 4bbl is 205hp or thereabouts. I know it's a balanced shaft. Do these have roller lifters or just the newer ones?

 

[180shabah]

Re: Merc 4.3 Info and more

Good info, and if I go out in the cold and remove the cover I'll have a look. I'm thinking old style. So the 4.3lx 4bbl is 205hp or thereabouts. I know it's a balanced shaft. Do these have roller lifters or just the newer ones?

Roller cam goes all the way back to '87.
'93-'95 4.3LX's are 175hp at the prop. older 4.3's were rated at 205hp, but that was a crankshaft measurement and equals 175 measured at the propshaft.