5.7 ltr engine question

[captmello]

My 5.7 motor's harmonic balancer seems to be installed incorrectly.

The timing mark does not line up with the timing adjustment guage. It's not even close.

Someone put a mark on it with a yellow paint marker to use for timing adjustment. Is this a problem? If its just a matter of removing and reinstalling correctly I may do it. I thought there would be a Key/Keyway setup on the crankshaft.

thanks.

 

[Don S]

Re: 5.7 ltr engine question

If the timing marks have moved, then the balancer needs replaced. The rubber is broken loose, and even the paint marks will keep moving.
There is only one keyway, so it's impossible to install wrong.

 

[captmello]

Re: 5.7 ltr engine question

I ran the boat all summer with that.

The motor is an 1988 aq260 with the raw water pump mounted to the harmonic balancer.

Do I need to get the balancer from Volvo of is it a standard part for the
350's of this era.

Thanks

 

[Don S]

Re: 5.7 ltr engine question

Standard Chevy part.

 

[dan t.]

Re: 5.7 ltr engine question

some chev 350 motors had the timing mark at 12:00 and some at 2:00 it sounds like you have a missmatched ballancer and t/c cover. you can buy a bolt on timing mark for the 2:00 position

 

[captmello]

Re: 5.7 ltr engine question

some chev 350 motors had the timing mark at 12:00 and some at 2:00 it sounds like you have a missmatched ballancer and t/c cover. you can buy a bolt on timing mark for the 2:00 position

Hummmm... If this is the problem, the grove in the balancer should be off by the difference of 2:00, No?

I'll have to check to see. Either way I'll need a new Harm. Balancer that fits correctly. I know the paint mark was correct from when I had the heads off last spring.

Thanks for all the great help!

 

[dan t.]

Re: 5.7 ltr engine question

for the timing mark in the 2:00 0clock position the keyway and the timing mark almost line up, for the other if the mark is at 12:00 the keyway is at 2:00

 

[ButchC]

Re: 5.7 ltr engine question

some chev 350 motors had the timing mark at 12:00 and some at 2:00 it sounds like you have a missmatched ballancer and t/c cover. you can buy a bolt on timing mark for the 2:00 position

Just found this thread. My timing mark is off by 45 degrees. Where can you get this bolt on timing mark?

Butch

 

[dan t.]

Re: 5.7 ltr engine question

try napa or lordco or any auto parts store that sells chrome accessories GM used to supply it but I dont know if they still do. good luck

 

[ButchC]

Re: 5.7 ltr engine question

Thanks Dan

 

[captmello]

Re: 5.7 ltr engine question

Hey Butch, Let me know what happens. I havent fixed mine yet as its under cover 'til spring.

Did you measure the 45 degree difference? Shouldn't it be 60 degrees? Let us know what you end up doing.

 

[ButchC]

Re: 5.7 ltr engine question

Hey Butch, Let me know what happens. I havent fixed mine yet as its under cover 'til spring.

Did you measure the 45 degree difference? Shouldn't it be 60 degrees? Let us know what you end up doing.

I used the advance on the timing light to get the scribed line on the balancer to show up on the WW marks. It read around 49. Now that I have a better idea of what it could be, I'll go out to the slip today or tomorrow and follow it as I bring the advance to zero.

The engine is running fine but I timed it 'by ear'. I am thinking of replacing the current distributor with a Mallory YLM624AV electronic distributor and would like to have a way to get it back where it is now.

Butch

 

[captmello]

Re: 5.7 ltr engine question

There must be a way to find TDC without watching the piston go up and down. I had the heads off and saw my paint mark line up. I wonder if you measure 1/6 of the way around 12 to 2, right? Make your mark and time it off that. You can't time it by ear. I can't anyway.

 

[dan t.]

Re: 5.7 ltr engine question

degree tape on the ballancer and a piston stop made from a old sparkplug with a bolt stuck thru it and welded. check out Comp Cams,site it is part of degreeing a cam. tdc #1 will put the keyway at 2:00 oclock.good luck guys

 

[captmello]

Re: 5.7 ltr engine question

dan t.

you can buy a bolt on timing mark for the 2:00 position

This still sounds like the best answer. As long as the Balancer isnt damaged like Don mentioned earlier in the thread.

old sparkplug with a bolt stuck thru it and welded.

I'll have to run that by the wife. Does this justify buying a welder?

 

[Silvertip]

Re: 5.7 ltr engine question

If the error is indeed 45 degrees, it is not a 2:00/12:00 keyway issue. That difference is 60 degrees and that also means the dampener has slipped and as Don said, it will continue to slip so there is no reason to install a bolt on tab because wherever you set it it will be wrong again down the road. Replace the balancer. It is possible though that you didn't accurately measure the 45 degrees as 15 degrees is only 2.5 clock minutes.

 

[Don S]

Re: 5.7 ltr engine question

If the balancer is slipping, the engine will still run ok. The mark doesn't affect the timing unless you turn the distributor to TRY and get the timing to where the slipping mark is at that point.
The piston stop is about 8 bucks and adjustable.
http://store.summitracing.com/partd...=SUM-900189&N=700+4294855958+115&autoview=sku

With it, you can find TDC EXAXTLY. Put a mark on the dampner where #1 TDC is and start the engine and see if the mark is anywhere close to your timing tab that is welded on the TC cover. If it's missing, then by all means get a bolt on. But you will still need to find TDC so you can set the pointer.
This is done on outboards all the time with piston stops.

Volvo didn't use any 12 o'clock timing marks on any of the 80's 5.7's that I am aware of.

And, as I said way back in the beginning, if the timing mark keeps moving around you need a new balancer. The yellow mark you have is NOT a factory, so unless you know what it indicates, it's usless. It could be 0?, 8?, 6?, 10? who knows.

 

[Howard Sterndrive]

Re: 5.7 ltr engine question

There must be a way to find TDC without watching the piston go up and down.

you can make a TDC tool. (I made mine out of an old spark plug - drilled the porcelain out and slid an old pushrod through) I wasn't too cheap for the 8 bux, just don't live handy to any place that sells them. You install the tool in the spark plug hole and very carefully roll the piston up towards TDC until it hits the tool, - mark the damper to the cover, then remove the tool and roll the engine over TDC and reinstall the tool.
Roll the engine back until the piston touches the tool. Mark the damper to cover again.
Now, split the difference between the 2 marks (I wrapped a plastic ruler over the dampener to measure accurately) and that's TDC.

I did that on my Mercruiser V6 when the cam cover rotted out and I bought a chrome one.

 

[ButchC]

Re: 5.7 ltr engine question

Silvertip
"If the error is indeed 45 degrees, it is not a 2:00/12:00 keyway issue. That difference is 60 degrees and that also means the dampener has slipped and as Don said, it will continue to slip so there is no reason to install a bolt on tab because wherever you set it it will be wrong again down the road. Replace the balancer. It is possible though that you didn't accurately measure the 45 degrees as 15 degrees is only 2.5 clock minutes."

I have not been able to track down the two different types of balancers. If the difference is 12 vs. 2 then 60 degrees is correct. However, if the position is really 1:30 then it would be 45 degrees. Do you have a reference for the two possible markings?

I went to the boat yesterday and set the adv. on the light to 45. The timing mark showed up on the WW indicator. I then rolled the advance back to zero and the timing mark proceeded to a vertical position. As well as I could see as that position is hard to see. If I move the timing light pickup from plug 1 to plug 6 (180 deg on distributor, 360 degrees on balancer) I see the timing mark at 45 adv on the light. There is no telling what balancer a previous owner may have put on this engine. But since I see the timing mark go to vertical as I bring the adv to zero I am guessing that this is the problem. I don't think the balancer is slipping. A mark I put on the balancer in March is at the same position and the engine has about 50 hours on it since then. I have no experience as to how quickly these may slip but I would have expected some movement over the summer season and I saw none. I placed the mark so that I could check advance at higher rpm. Since I had no real TDC mark I tuned it by ear. I retarded the spark until the engine started to stumble and noted the timing light position. I then advanced the distributor until it stumbled again and noted the timing light reading. I then split the difference with a slight bias to the retarded side since the engine runs against a constant load and I did not want any damage. This is what I did with engines as a kid with no money. This procedure always worked reasonably well. The engine ran great all summer and I wanted to put off the real solution to this fall. Our lake (Hartwell in GA/SC) dropped quickly in August as the drought worsened and is now down 22 feet and it is a little risky to run at speed with tree tops starting to pop up here and there!

With these observations I am beginning to suspect an incorrect balancer rather than a slipping one. I priced a Volvo OEM balancer and they want over $200. Pretty pricey for what should be $70 part.

I am going to purchase the Summit part (thanks Don) and get a real TDC and set up my (2 or 1:30) to work. I really should just buy the $200 part but I am going to use what I've got unless you guys convince me that this would be dangerous. What started all this was the behavior of my old distributor (seemed sloppy) and after 25 years I thought I would upgrade to an YLM624AV electronic unit. These are pricey and buying both the balancer and distributor would get nasty stares from the wife ;>)

Thanks for all the input and any recommendations would be welcome.

Butch

 

[captmello]

Re: 5.7 ltr engine question

I priced a Volvo OEM balancer and they want over $200. Pretty pricey for what should be $70 part.

I asked Don about this earlier in the thread, He said standard Chevy part.

I'm going to pick up the new balancer when I drag the boat out in the spring. Be done with it.

What do you mean about the sloppy Distributor? If boats been running good, why not buy points, condensor, cap, rotor and if you don't have one, a dwell meter and get that motor dialed in right!! I did this last summer and motor went from running good to Purring like a kitten.

Let us know what you decide to do.