[C2] Timing issue with 350 engine
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 5,814
Likes: 414
From: Pittsburgh suburbs Pa.
Timing issue with 350 engine
I installed a new HEI distributor and I'm trying to set the timing which is usually an easy job . I have the engine on the compression stroke with the distributor rotor pointing directly toward the #1 tower on the cap but when I start it and turn the distributor to where it runs perfect the mark on the harmonic balancer is down below the retard section on the pointer about an inch. If I turn the distributor counterclockwise to try to line up the timing marks it bogs down the engine so does it need the distributor pulled and turned a tooth and if so what direction ? I'm thinking clockwise to advance it, Correct ?
Le Mans Master
Joined: Nov 2003
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From: Maryland
St. Jude Donor '05, '09, '15
No. Counter clockwise to advance.
The distributor shaft turns clockwise with the engine running so to advance the spark the distributor housing must be turned counterclockwise so the triggering mechanism, points or electronic module, operate sooner. Does that make sense? I have a tendency to over state things.
Tom
The distributor shaft turns clockwise with the engine running so to advance the spark the distributor housing must be turned counterclockwise so the triggering mechanism, points or electronic module, operate sooner. Does that make sense? I have a tendency to over state things.
Tom
Last edited by Sky65; Jul 12, 2022 at 09:44 AM.
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 5,814
Likes: 414
From: Pittsburgh suburbs Pa.
No. Counter clockwise to advance.
The distributor shaft turns clockwise with the engine running so to advance the spark the distributor housing must be turned counterclockwise so the triggering mechanism, points or electronic module, operate sooner. Does that make sense? I have a tendency to over state things.
Tom
The distributor shaft turns clockwise with the engine running so to advance the spark the distributor housing must be turned counterclockwise so the triggering mechanism, points or electronic module, operate sooner. Does that make sense? I have a tendency to over state things.
Tom
Pro
Joined: Oct 2013
Posts: 629
Likes: 126
From: Grapevine TX
Here's link to Lars paper on installing the distributer and setting the timing. You need to use a multimeter.
http://www.stl-vettes.com/65Vette/co...istinstall.pdf
http://www.stl-vettes.com/65Vette/co...istinstall.pdf
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 5,814
Likes: 414
From: Pittsburgh suburbs Pa.
Here's link to Lars paper on installing the distributer and setting the timing. You need to use a multimeter.
http://www.stl-vettes.com/65Vette/co...istinstall.pdf
http://www.stl-vettes.com/65Vette/co...istinstall.pdf
Team Owner
Joined: Jul 2001
Posts: 21,404
Likes: 1,011
From: Various places in Southern California.
Definitely true that turning the distributor counter-clockwise will advance the timing.
But, is that what you need? If the engine wants the spark to happen when the timing mark is, say, 10* ATDC, then moving the distributor isn't going to make the engine like timing at 10* BTDC. I'd wonder if the timing mark is correct or the balance has rotated. Was everything fine and checked out before you replaced the distributor?
But, is that what you need? If the engine wants the spark to happen when the timing mark is, say, 10* ATDC, then moving the distributor isn't going to make the engine like timing at 10* BTDC. I'd wonder if the timing mark is correct or the balance has rotated. Was everything fine and checked out before you replaced the distributor?
Safety Car
Joined: Nov 2005
Posts: 4,386
Likes: 942
From: Huntsville Alabama
I played with this on mine as well. As my new Distributor put the vacuum hitting the intake, when counter rotating it so much... so then you can move a whole tooth and start farther back basically.
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Thread Starter
Le Mans Master
Joined: May 2006
Posts: 5,814
Likes: 414
From: Pittsburgh suburbs Pa.
Definitely true that turning the distributor counter-clockwise will advance the timing.
But, is that what you need? If the engine wants the spark to happen when the timing mark is, say, 10* ATDC, then moving the distributor isn't going to make the engine like timing at 10* BTDC. I'd wonder if the timing mark is correct or the balance has rotated. Was everything fine and checked out before you replaced the distributor?
But, is that what you need? If the engine wants the spark to happen when the timing mark is, say, 10* ATDC, then moving the distributor isn't going to make the engine like timing at 10* BTDC. I'd wonder if the timing mark is correct or the balance has rotated. Was everything fine and checked out before you replaced the distributor?
Pro
Joined: Oct 2013
Posts: 629
Likes: 126
From: Grapevine TX
bj1k, this might sound stupid and please don't be offended. Are you sure the harmonic damper has not slipped and the tab is correct. And are you sure you are reading on the number one plug wire. Tim
1967 Pedal Car Champion
Joined: Mar 2020
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From: US-PNW
A photo of the front of the balancer may reveal deteriorated rubber. You can also mechanically check by bringing your #1 to top dead center using a piston stop and checking the balancer mark to the tab.
Pro
Joined: Oct 2013
Posts: 629
Likes: 126
From: Grapevine TX
That's a good double-check suggestion. #1 is the forward most on the driver's side.
A photo of the front of the balancer may reveal deteriorated rubber. You can also mechanically check by bringing your #1 to top dead center using a piston stop and checking the balancer mark to the tab.
A photo of the front of the balancer may reveal deteriorated rubber. You can also mechanically check by bringing your #1 to top dead center using a piston stop and checking the balancer mark to the tab.
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 5,814
Likes: 414
From: Pittsburgh suburbs Pa.
Pro
Joined: Oct 2013
Posts: 629
Likes: 126
From: Grapevine TX
I agree, it doesn't make sense. That's why I ask such a basic question. Clearly you have worked on more engines than I have and thanks for nor being offended.
Did you try using a multimeter as in step 7 of lars paper?
http://www.stl-vettes.com/65Vette/co...istinstall.pdf
Did you try using a multimeter as in step 7 of lars paper?
http://www.stl-vettes.com/65Vette/co...istinstall.pdf
Instructor
Joined: Jun 2021
Posts: 197
Likes: 52
From: Oregon
That's a good double-check suggestion. #1 is the forward most on the driver's side.
A photo of the front of the balancer may reveal deteriorated rubber. You can also mechanically check by bringing your #1 to top dead center using a piston stop and checking the balancer mark to the tab.
A photo of the front of the balancer may reveal deteriorated rubber. You can also mechanically check by bringing your #1 to top dead center using a piston stop and checking the balancer mark to the tab.
Team Owner
Joined: Jul 2001
Posts: 21,404
Likes: 1,011
From: Various places in Southern California.
This is a good used engine with only 48k. miles that I just bought without a distributor . I bought a new HEI small cap distributor . It started immediately and runs perfect but only if I set the timing mark on the balance below the retard scale on the pointer about an inch , so I'm wondering if it is still one tooth off and needs to have the distributor shaft itself turned clockwise one tooth to bring the timing marks together at 8-12 degrees before top dead center. Right now if I turn the distributor housing counterclockwise to bring the marks together it runs rough and stalls.
Here's how I'm thinking about this:
--The timing light flashes when the spark happens (unless you're using a dial-back light)
--The flash illuminates the balancer at that point, which allows you to see when the spark occurs relative to when the #1 piston is at TDC (assuming the timing light is on the #1 wire), by looking at the balancer index mark relative to the index tab affixed to the timing cover.
--How the distributor is oriented changes when the spark happens, which you see by the change in viewed position of the timing mark relative to the index tab
--Your engine doesn't want to run when the spark occurs before #1 piston is at TDC, but appears to like to run with the spark happening well after #1 piston is past TDC.
--It's unlikely the engine really prefers a spark well after #1 passes TDC
--While moving or resetting the distributor will change when the spark happens, it won't make the car suddenly like a spark before TDC when it didn't like it before.
--So, I conclude that there is something likely wrong with the balancer (or possibly cam phasing, but that's much less likely, in my view)
I think you should definitely get #1 to TDC and see where the timing mark lines up. That should be a pretty easy test.
Pro
Joined: Oct 2013
Posts: 629
Likes: 126
From: Grapevine TX
One more thing, what timing chain cover is installed? A 350ci and not a 327ci? As you know the tabs are different. In the tittle of your thread you show 350. do you mean HP or CI?
I know, another dumb question. LOL
I know, another dumb question. LOL
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 5,814
Likes: 414
From: Pittsburgh suburbs Pa.
