Harmonic Balancer Wobble ?
Thread Starter
Pro
Joined: Oct 2012
Posts: 613
Likes: 3
I highly recommend a race type balancer i had to replace my timing cover twice. 
both times the harmonic balancer outer ring had moved from the hub, they always move toward the timing cover when you hear a scraping noise it is already too late.
The race type will not explode or allow the outer ring to move backwards
(man was a lot cheaper when i got mine).
My race balancer has nice timing marks all around it very clear to see when adjusting timing, i know it is over kill for a TPI but worth it in the long run as it will outlast many std harmonic balancers.
Needless to say i have not had a problem since, I will never go back to a standard balancer again. It is a real pain to have to replace the timing cover (unless you want to upgrade to a double row timing chain at the time)
http://www.ebay.com./itm/Pro-Race-St...item4abd89d8db
both times the harmonic balancer outer ring had moved from the hub, they always move toward the timing cover when you hear a scraping noise it is already too late.The race type will not explode or allow the outer ring to move backwards
(man was a lot cheaper when i got mine).My race balancer has nice timing marks all around it very clear to see when adjusting timing, i know it is over kill for a TPI but worth it in the long run as it will outlast many std harmonic balancers.
Needless to say i have not had a problem since, I will never go back to a standard balancer again. It is a real pain to have to replace the timing cover (unless you want to upgrade to a double row timing chain at the time)
http://www.ebay.com./itm/Pro-Race-St...item4abd89d8db
Thread Starter
Pro
Joined: Oct 2012
Posts: 613
Likes: 3
Just did it last winter on my 84. The power steering bottle leaked and ruined the rubber in the dampener. it was separated and chirping. the seal in the timing cover was shot also. this happened on my 87 iroc with the 5.7 tpi engine too.You can get a SFI certified dampener for under 100 dollars. its not going to see 8 or 9 thousand rpm, so i decided not to get the rattler or any high dollar one, just one that was sealed. Be prepared to unbolt and remove all the accessories in front of the engine and drop the oil pan too. An interesting thing discovered was the use of a nylon single roller timing gear, which had about 2 inches of play at 78 thousand miles. So i went with a comp double roller. And to complete the project I replaced the water pump just because I don't want to go that deep again if the original one starts leaking. You guys earlier were talking about the ep241 upgrade, did that also. that was the best performance thing I have done and cheap too. No more hesitation, accelerates faster, and starts better. you are only going from 15 to 30 psi fuel pressure, I think the reg can handle that.
I've heard updating to the 85 fuel pump is best, BUT it must be regulated down to 15 or 14 then the stock regulators can bring it down to 13 or 13.5 as needed,
While others suggest that the stock replacement pump is just fine.
Once i work out all the bugs i'll start testing fuel pressure and see what works before i spend more on fuel system upgrades beyond stock.
I did install a new knock sensor recently and new ESC module, however the original wire to it was not connected.
I soldered on a new wire to the blue module wire and it ran ok, BUT when started cold bluish smoke blew out the exhaust, then it felt like it wasn't running on all cylinders weird miss, then finally it would not start.
Disconnected the knock sensor, checked base timing with est wire disconnected, reset the ecm by disconnecting the battery now starts and runs as good as before.
So further testing is needed but until then knock sensor is not hooked up.
Race Director
Joined: Jan 2005
Posts: 10,641
Likes: 13
From: Slidell Louisiana
The harmonic balancers of old did not have a bolt to hold them in place. Strictly a press fit. I think the bolts were added around 1980 (just a guess -- my '78 Corvette did not have a bolt, my '86 does).
The outer ring on both the '78 and the '86 came loose from the hub. I found the problem on the '78 when I tried to set the timing and the engine wouldn't even run when I lined up the mark. The '86 balancer ring moved inward until it hit the timing chain cover and ground a hole in it. I found that when oil started pouring out. I filled the hole with J.B. Weld about 10 years ago because I didn't want to go through the hassle of replacing the timing chain cover. Still holding so far...
The outer ring on both the '78 and the '86 came loose from the hub. I found the problem on the '78 when I tried to set the timing and the engine wouldn't even run when I lined up the mark. The '86 balancer ring moved inward until it hit the timing chain cover and ground a hole in it. I found that when oil started pouring out. I filled the hole with J.B. Weld about 10 years ago because I didn't want to go through the hassle of replacing the timing chain cover. Still holding so far...
Although you are correct sometime in the early life of the SBC the damper was not retained by a bolt.
Mike
Race Director
Joined: Jan 2005
Posts: 10,641
Likes: 13
From: Slidell Louisiana
Thanks for the tip, planning on installing an ATI one, very pricey but worth it for the peace of mind ! still working out some basic maintenence bugs such as coolant temp sensor and all other sensors, it's been running good and have been enjoying some before i start digging into more time comsuming stuff.
MIke
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
If you use the stop and rotate the eng one turn clockwise til it hits then mark it. Go 1 turn the opposite til it stops then mark it again. The difference should be TDC if I typed this out right.
Eroded plugs can cause rough running do those first. If it still pops under WOT Id be looking at your valvetrain (cam lobes)
Eroded plugs can cause rough running do those first. If it still pops under WOT Id be looking at your valvetrain (cam lobes)
