360 Timing Mystery

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SLC Duster Dude

SLC Duster Dude

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A while back I had a question on here about my timing marks being off and because I couldn't see them very well because my power steering pump was in the wrong position (the original builder used BB brackets and it was high rather than low). I'm tearing everything down now to put on some Eddie heads and cam and the deeper I get the more mystery I find. Keep in mind I haven't been this deep into an engine in 40 years and that was a Ford so try to be tolerant of these questions.

When I started the tear down I stopped the crank at TDC. I know it is TDC because the rotor is pointing to the #1 cycl and the valves are both closed. The first pic is the balancer/dampener and you can see it's about 36* before TDC. Weird, but I know they slip sometimes and I figured the mystery would be solved when I took off the timing cover and found the timing marks all in order. But they aren't. In the second pic you can see they aren't lined up at all. So, I guess when I install the cam and dist. I make everything line up as it should, but can anyone explain how this engine was running...and running good? Started easily, good at higher RPM's and no popping or dieseling.

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First - Just because the rotor is pointing towards the #1 tower does not mean that the piston is actually at TDC. The crank could very well rotate another 36 deg. before reaching TDC.

Second - when the marks on the timing gears line up is not usually TDC on the #1 cylinder. I believe they line up on the #6 cylinder at TDC.
 
Interesting. But when I install the cam with all the marks lined up shouldn't I drop the dist. in to line up the #1 plug?
 
SLC Duster Dude said:
Interesting. But when I install the cam with all the marks lined up shouldn't I drop the dist. in to line up the #1 plug?
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Nope. Remember, the timing gear marks don't line up when the #1 cylinder is at TDC. They line up when the #6 cylinder is TDC. You could actually line up the gear marks and move the dizzy to line up with the #6 tower.
 
OK, this is making more sense. In the direction from Edelbrock, which I just glanced over and now I'm re-reading, talked about lining up the marks but now I see where they say to turn it until the intake valve closes and then go 5* BTDC and then drop in the dist. to #1 position.
 
1st thing I see is your timing tape is on backwards, if the crank rotates clockwise then your 36* mark is after TDC not before.
2nd is line up the dots (straight up) not the key on the crank
 
brian6pac said:
1st thing I see is your timing tape is on backwards, if the crank rotates clockwise then your 36* mark is after TDC not before.
2nd is line up the dots (straight up) not the key on the crank
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He placed the tape (it's not stuck) backwards as one way to see how many degrees he was off. I understand what he did.
 
^^And to add a side note to the info above, when you DO "redo" all this be careful if you use a 3 or multi key lower sprocket for cam degree changes. The timing marks on those sprockets (they are not gears LOL) have thrown a few people off!!
 
man, I don't know where to start. I never caught what year SB you're dealing with. I believe there are two different timing covers with different timing mark loc'ns. There are also some aftermarket distributors with indexing different from oem distributors. There is also the oil pump drive indexing to check. Plus, it appears you have a multiple keyway crank sprocket. If you want to be 100% positive of the cam timing, I'd be inclined to dial the cam in, but I don't know if you have the cam specs or even know the manufacturer. Can the PO help with any details?
 
The older timing cover has the marks on the otherside
 
rustycowll69 said:
man, I don't know where to start. I never caught what year SB you're dealing with. I believe there are two different timing covers with different timing mark loc'ns. There are also some aftermarket distributors with indexing different from oem distributors. There is also the oil pump drive indexing to check. Plus, it appears you have a multiple keyway crank sprocket. If you want to be 100% positive of the cam timing, I'd be inclined to dial the cam in, but I don't know if you have the cam specs or even know the manufacturer. Can the PO help with any details?
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The engine is a 74-79 LA according to the castings so the timing cover is correct. It has a Davis distributor and the cam along with chain and sprockets are being replaced so I do know the specs. My main question about why the marks aren't lined up has been answered. Thanks.
 
SLC Duster Dude said:
The engine is a 74-79 LA according to the castings so the timing cover is correct. It has a Davis distributor and the cam along with chain and sprockets are being replaced so I do know the specs. My main question about why the marks aren't lined up has been answered. Thanks.
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You cannot degree a balancer by simply going by where the rotor is pointing. You have to remember initial timing is rarely set at TDC and the rotor phasing in the distributor could easily be off 10 degrees or more. Rotate the engine till the marks on the timing set line up at 12 O'clock on the sprockets and I bet you'll find the balancer is lined up at TDC. BTW: the only proper way to check a balancer's accurateness (is that a word?) is with a TDC indicator screwed into the #1 spark plug hole or with the head off to measure the piston height
 
That balancer doesn't look original. I think it's aftermarket and who's to say it's ment for this engine.

Pull the nr1 sparkplug and stick a blunt screwdriver or something in it to feel if the piston is indeed near TDC.
Turn the crank left&right to see if the screwdriver comes up more or not.
This is a crude way of locating/eyeballing the whereabouts of TDC.
The proper way would be to make/install a piston stop, rotate the engine both ways until the stop blocks the piston, and mark the balancer exactly halfway in the unswept area for TDC.
 
That looks like a precision balancer, for a 360 it should have a weight bolted on the back
 
teringer said:
the crank timing key should be at 2 o'clock when at true tdc.
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Yes, this is the first thing I see... the engine/crank is not at TDC for #1. Key shold be around 1:30.... The crank sprocket's timing dot position relative to the sprocket key looks correct. (I have not dragged one out to be sure it is exactly on.)

BTW that chain looks to have a bit of slack in it....
 
SLC Duster Dude said:
A while back I had a question on here about my timing marks being off and because I couldn't see them very well because my power steering pump was in the wrong position (the original builder used BB brackets and it was high rather than low). I'm tearing everything down now to put on some Eddie heads and cam and the deeper I get the more mystery I find. Keep in mind I haven't been this deep into an engine in 40 years and that was a Ford so try to be tolerant of these questions.

When I started the tear down I stopped the crank at TDC. I know it is TDC because the rotor is pointing to the #1 cycl and the valves are both closed. The first pic is the balancer/dampener and you can see it's about 36* before TDC. Weird, but I know they slip sometimes and I figured the mystery would be solved when I took off the timing cover and found the timing marks all in order. But they aren't. In the second pic you can see they aren't lined up at all. So, I guess when I install the cam and dist. I make everything line up as it should, but can anyone explain how this engine was running...and running good? Started easily, good at higher RPM's and no popping or dieseling.

View attachment 1715118034

View attachment 1715118035
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