Sanity Check: New Harmonic Balancer Installed
Thread Starter
Pro
Joined: Sep 2024
Posts: 526
Likes: 114
Sanity Check: New Harmonic Balancer Installed
When I had my heads off and I completed a cam swap, I physically verified TDC at number 1, installed the cam and the timing chain. When I put the front timing cover and balancer on, TDC was reading 8 degrees BTDC. That is correct, right? I remember reading somewhere that this is normal unless I am just crazy.
Thread Starter
Pro
Joined: Sep 2024
Posts: 526
Likes: 114
Yeah, that's why I used a brand new one. I guess the most important part is to just know that when it was installed at TDC, it came out to 8 at TDC. So when I set my dial back to 8 then the mark should read 0 with the engine running.
Drifting
Joined: Nov 2018
Posts: 1,759
Likes: 647
From: USA
Did you install a new timing chain set? If so, are you sure you used the correct keyway on the crankshaft gear. You should not be off 8° at TDC #1 if everything was installed straight up. Just for good measure compare keyway groove and timing line on both dampeners to confirm they match...they should but you never know these days! Do you have any pictures documenting the timing chain install? Dialing the timing back will work if the mark is incorrect, but will not help if the gears/chain were physically installed advanced or retarded! Good luck👍
Thread Starter
Pro
Joined: Sep 2024
Posts: 526
Likes: 114
Did you install a new timing chain set? If so, are you sure you used the correct keyway on the crankshaft gear. You should not be off 8° at TDC #1 if everything was installed straight up. Just for good measure compare keyway groove and timing line on both dampeners to confirm they match...they should but you never know these days! Do you have any pictures documenting the timing chain install? Dialing the timing back will work if the mark is incorrect, but will not help if the gears/chain were physically installed advanced or retarded! Good luck👍
Here are the specs on the timing set: Cloyes street true roller timing sets are aimed at the value-driven racer. They have precision-machined, cast iron cam sprockets and induction-hardened, billet steel crank sprockets. The crank sprockets have three keyways for timing adjustment--4 degrees retarded, 4 degrees advanced, and normal. The chains are rugged, double-row types with oversized 0.250 in. rollers that deliver long life and reliability.
Now, the thing ran fine after I installed everything (except for the rod nock I think I have and subsequently have the pan off). Like I said, I had the heads off so rather than trying to use the balancer, I just put a dial indicator on the number 1 piston and stopped rotating the engine when it hit the dwell. Then proceeded to install the cam and timing set, the cover and then the balancer.
I am going to have to look through some video footage I took to see what I did exactly.
Edit: It does look like the crank sprocket was installed SLIGHTLY to the left of the cam timing dot. Like I said, I verified that number 1 was sitting at dwell near TDC. How many degrees of dwell are there?
Last edited by marshallnoise; May 15, 2025 at 12:24 PM. Reason: notes after video review
Melting Slicks
Joined: Mar 2001
Posts: 2,150
Likes: 304
From: Timra, Sweden
I made a tool from an old sparkplug. Removed all the porclin and threded the inside of what remained of the spark plug. Then a matching screw with the tip rounded and a locking nut.
Here is someone that did the same:
https://lugnutz65chevystepside.weebl...stop-tool.html
You install the tool with the piston down.
Slowly turn the engine forward to the stop and set a mark on the harmonic balancer.
Slowly turn the engine reverse to the stop and set a new mark on the harmonic balancer.
TCD is midpoint between the marks.
You get a more exact result if you stop the piston a bit down from TCD beacuse each degree moves the piston a bit longer there.
And when the engine is at TDC, the harmonic balancer should be at the 0-degree mark.
Here is someone that did the same:
https://lugnutz65chevystepside.weebl...stop-tool.html
You install the tool with the piston down.
Slowly turn the engine forward to the stop and set a mark on the harmonic balancer.
Slowly turn the engine reverse to the stop and set a new mark on the harmonic balancer.
TCD is midpoint between the marks.
You get a more exact result if you stop the piston a bit down from TCD beacuse each degree moves the piston a bit longer there.
And when the engine is at TDC, the harmonic balancer should be at the 0-degree mark.
