Balancer Slipped on 260 Mercruiser-gctid351964

[Guest]

So last year I ran into some problems when my balancer slipped around 90* on my 260 Mercruiser. I finally figured out why my timing appeared to be way off and with the help of several folks figured out how to establish a new timing mark. My problem is, if it slipped once why is there no expectation that it won't do it again?

It seems like my timing mark would always be in question. So I am wondering if I can simply go down and buy a new balancer and bolt it on. It would seem that it would automatically be back in the right place.

I was going to do an entire rebuild but think I will put it on hold and wait a couple of years which is what I was originally planning on doing. I plan on doing transom inspection/replacement and stringers, etc.

Just wanted to get some input if it would makes sense to just replace the balancer to get that unknown out of the mix. If so, is there any difference between the marine version and the "regular" SBC version? (And yes, I know that it is important to use Marine parts in the engine compartment but it doesn't seem like a balancer will blow up! )

The good news is when I pulled the outdrive for alignment check and drain there was no water in anything! See, DIY sometimes do better than the so called marine experts!

Thanks,

Jeff

[2850Bounty]

Many of the higher end Marine Engine balancers are now marked off. I wish that they all were.

Degree decals may eventually fail as they loose their adhesive.

Rather than risk it slipping again, why not replace it with a balancer that is permanently indexed for you?





Note that these are also indexed every 90* for use in initial cam follower plunger depth setting when using the 8 stop procedure.

(handy for new engine set up)

.

[yachtman]

Yes replace it. If it moved it most likely isn't balancing your engine properly.

[706jim]

I had to replace the balancer on my 260 merc. It had done the same thing. I was able to get it off and a new one installed with about 4" of space between the balancer and the fuel tank.

[2850Bounty]

Getting one off is fairly easy!

Just make sure that you DO NOT rely on the center crankshaft bolt to draw one back onto the crankshaft! :thumb

There is a special tool for installation.

FYI: the crankshaft keyway can become a source for an oil leak. Be sure to use a sealant here.

[706jim]

2850Bounty wrote:
Getting one off is fairly easy!

Just make sure that you DO NOT rely on the center crankshaft bolt to draw one back onto the crankshaft!

There is a special tool for installation.

Too late!

Mine went on just fine using that bolt.

In any case, I can't imagine any tool that would fit into a 4" space.

[2850Bounty]

The tool will look like this, and could be shortened if need be.

[Guest]

I appreciate the responses.

So is there no key or bolt pattern that aligns it on the crank? Do you still need to go through and try to find TDC to get the alignment. Sorry but it has been years since I tore down a SBC and I don't remember having to "guess" at the TDC. I like the marine version of the balancer, thanks.

Jeff

[2850Bounty]

Jeff, I don't recall when and/or what year/model, but I seem to recall that some autos/trucks indexed #1 TDC timing mark differently.

This means that some auto/truck engine balancers were marked differently, but were crankshaft key'd the same.

For our Marine purpose, all you need to do is buy the correct balancer, seal the key way grove, and install it.

The key way will index it correctly as to align with #1 TDC marking.

(to get near absolute TDC, we use a PPS procedure)

[Guest]

2850Bounty wrote:
Many of the higher end Marine Engine balancers are now marked off. I wish that they all were.

Degree decals may eventually fail as they loose their adhesive.

Rather than risk it slipping again, why not replace it with a balancer that is permanently indexed for you?





Note that these are also indexed every 90* for use in initial cam follower plunger depth setting when using the 8 stop procedure.

(handy for new engine set up)

.

hey rick...why on earth is there an SFI sticker on that?

[2850Bounty]

courtjeste wrote:
hey rick...why on earth is there an SFI sticker on that?

Most of these balancers that are engraved indexed will be found through High Performance shops. I did a Google image search to find those pictures.

Since your eye caught that (good catch, btw), you know that it's an automotive standard for specialty performance and racing equipment.

SEMA acronym = Speed Equipment Manufacturing Association, apparently now called SFI. SFI (SEMA) approved, is a means of determining if the part passed certification to be race legal in all classes. When you get to certain speeds or ET's, the rules says that you must have SFI certified parts such as flywheels, flex plates, dampers, etc. The certification is not necessary for parts on an engine whereby the car runs slower than high 10's - 1/4 mile, under 500 HP and under 7k rpm.

.

[Guest]

2850Bounty wrote:
Most of these balancers that are engraved indexed will be found through High Performance shops. I did a Google image search to find those pictures.

Since your eye caught that (good catch, btw), you know that it's an automotive standard for specialty performance and racing equipment.

SEMA acronym = Speed Equipment Manufacturing Association, apparently now called SFI. SFI (SEMA) approved, is a means of determining if the part passed certification to be race legal in all classes. When you get to certain speeds or ET's, the rules says that you must have SFI certified parts such as flywheels, flex plates, dampers, etc. The certification is not necessary for parts on an engine whereby the car runs slower than high 10's - 1/4 mile, under 500 HP and under 7k rpm.

.

I suspected as much. I deal with SFI all the time. We make restraint straps that go around nitro harley engines to prevent blow ups from coming up through the frame, so I've got those stickers in the shop. I guess when you think of it, since balancers can come off, or apart, it makes sense that they would have a testing standard. Just didn't expect to see it.

(BTW, the 4 inch straps we assemble have to withstand a 27,000 pull test.)

thanks for the response.

toni