replace 4.3 in kind or upgrade to vortec with ramifications/problems?

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matt167

matt167

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Re: replace 4.3 in kind or upgrade to vortec with ramifications/problems?

I would find a V belt pulley that works with the '11 balancer. The '92 engine may run a different balance.. You might be able to have a machinist make it fit.

Oil pan should work if you can get it to fit where you need to. Not sure on any part numbers for the serpentine system, but see if your front accessory brackets will fit onto the new motor. If they do, just take care of the crank pulley and run them
 
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theboatfloats!

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Re: replace 4.3 in kind or upgrade to vortec with ramifications/problems?

Brackets fit. 92 water pump does not . My 2011 looks like 1996 and newer 4.3 from pics from engineguy.com. So I need pump part #s/mercruiser serial #s for 96 and newer for finding circulating water pump, starter, and thermostat housing. I buy new parts on ebay and amazon with namebrand but cheaper than Merc dealer. I don't understand tech reasons why 92 harmonic balancer would not work on 2011 : majority of new and reman engine dealers do not sell engines with harmonic balancer, I'm curious about tech reasoning behind this.
Thank you.
 
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matt167

matt167

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Re: replace 4.3 in kind or upgrade to vortec with ramifications/problems?

I wrote it right in there. The '92 engine may run a different balance weight or be different in another way.. Chevy changed 4.3's 4- 5 times thru it's time in production ( 1985- current ). Most of those changes were for the balance system, so the balancer is something I would keep togther. It does not effect how the engine bolts up, you should just keep that stuff with the engine.. The marine long block is listed as 2007-2011, so it's pretty safe to say that most are not going to try to put a 1992 balancer on a late '00's motor because that's not what they are replacing. Your situation is a bit different so my recomendation is to make the 2011 balancer work

If the water pump does not fit, you may need to convert to serpentine, because that would mean that one critical part that GM changed with the timing cover. Iboats does list this pump as 2007 to current Circulating Pump 18-3506 - Sierra - iboats
Reason for this is, serpentine pumps spin backwards as they run on the back side of the belt. They are not reverse cooled, but the impellers are reversed to work that way, so you can not spin them standard rotation and have it work, unless you had someone trustworthy rebuild pump and the swap the impellers with one for std rotation.

I think this is what your looking for with the serpentine brackets OEM Parts Finder Deep Creek Marina McHenry, MD (301) 387-6977
 
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theboatfloats!

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Re: replace 4.3 in kind or upgrade to vortec with ramifications/problems?

I sent e-mails with pixs and spoke to March Pulleys today. They're working on it. I looked up some car parts site and found that there are harmonic balancers out there for this 2011 engine with a "flat" face like the 1992 that the old 1992 double V belts crank pulley will fit to, as the current 2011 harmonic balancer has a 1/2" ring that protrudes out. This would allow me to reuse my 1992 brackets which fit perfectly, perhaps with some shimming if needed, along with 1992 alternator and 1992 power steering pump.
From browsing through various posts, I saw that Bondo and others have said that upgrading to serpentine belts can be quite expensive. I saw that Volphin upgraded his to a 4.3 Vortec with V belts. Somebody out there has done what I am trying to accomplish. Any suggestions is greatly appreciated.
Thank you.
 
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theboatfloats!

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Re: replace 4.3 in kind or upgrade to vortec with ramifications/problems?

2014-03-16 17.14.29.jpg2014-03-16 17.13.38.jpg2014-03-16 17.12.38.jpg2014-03-16 17.11.27.jpg


Update on converting a 2011 Silverado 4.3 truck engine with 234 casting for marine use. Job is complete and engine is running well:

1. Could not find a Mercruiser timing cover that fitted, as the hole pattern were not the same. So I took my aluminum one that came with the truck engine to a machinist, who for $60, welded the bottom sensor hole shut, welded the sensor hole under the water pump shut, and grinded that same sensor hole flush with the cover, as it conflicted with the water pump. But due to dumb engineering of the oil pan gasket, you have to remove and reinstall the oil pan with a new gasket after reinstalling the timing cover: you can't reinstall the timing cover otherwise.

2. Water pump from 93 did not fit, as one of the leg had 4 holes, but new 234 engine casting has 3 holes per pump leg. I confirmed with Sierra that their water pumps are bi-directionals. So I installed a Sierra #18-3506 water pump.

3. Harmonic balancer. That is a misnomer, as it is actually an Harmonic Dampener. I could have used the one from the 93 and it would have worked according to several Harmonic Dampener experts (sellers and harmonic rebuilders) that I spoke to and Hot Rod articles. But I took the one that came from the 2011 Silverado with 234 casting and had the protruding lip grinded off by a machinist for $40. Then I installed my 93 v-belt pulley on top of it and bingo all v-belts lined up perfectly with new water pump, '93 alternator, and '93 power steering pump.

4. All accessories from the 1993 fit perfectly in front of the 2011 engine,as the bolt patterns were the same.

5. Brand new exhaust manifold that I bought for 93 fit perfectly.

6. I had to buy a new 8 bolt manifold as the '93 12-bolt manifold did not fit.

7. the 4 barrel Weber carb from 93 fit perfectly on new manifold. Changing to carb from truck fuel injection worked.

8. I reused the 2011 aluminum oil pan that came with the truck, same clearance under the pan as the 93

9. The 93 distributor fit perfectly on the 2011

10. The 93 starter fit perfectly on the 2011

11. Truck engine already came with brass plugs.

12. I removed the truck head gaskets, which were metallic just like the '93 Mercruiser and look EXACTLY the same. Put in new Fel-Pro Marine head gaskets. Wondered if the truck metallic gaskets were worth replacing.

13. Truck dip stick tube interfered with marine exhaust manifold. Transfered the '93 dipstick tube to the 2011.

Anything can be done if you put your mind to it. Do your research and verify.

And thank you to all for all your help and input! There is great help here!

Video of 2011 with casting 234 running engine:

<span style="font-size: 7.5pt; line-height: 115%; font-family: Verdana, sans-serif;">[video]https://www.dropbox.com/sc/r30vhmz8yzthxma/YE7jxkH_d-[/video]

 
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