This is for the person who needs to locate True # 1 TDC. 1.... Never assume that your harmonic balancer ZERO mark and your timing tab ZERO indicate true TDC. Outer rings can slip, timing tabs can become damaged, and/or, these marks may not have been accurate from Day 1. 2.....Try to NOT view this as if overly complex.... it is not. Just follow these simple steps, and you will find true # 1 cylinder TDC. 3..... finding or verifying true # 1 TDC does NOT require us to be coming up on the Compression Stroke. TDC occurs twice for every 4 engine cycles (i.e., 720 degrees of crankshaft rotation). The crankshaft, connecting rod and piston do not care what the camshaft is doing for this procedure. TDC is TDC regardless of which stroke. For distributor phasing or ignition timing, yes..... it certainly does matter. When accurately locating TRUE # 1 cylinder Top Dead Center, we use a PPS procedure.... (positive piston stop). By using the PPS procedure, we eliminate any crankshaft dwell that occurs when a piston has theoretically reached top of stroke. (there will be some crankshaft movement while the piston appears to be stationary at theoretical top of stroke) Ideally, we want to stop the piston at approximately 30 degrees before theoretical top of stroke. 30 degrees is a suggestion only. You can use 25, 28, 32 or 35 degrees, as longs as it is the same angle in either direction towards the "stop". Once the 30ish degrees has been established, the PPS tool must be locked into position. Most will offer a jam nut. First, we rotate the crankshaft until the piston is gently stopped by the PPS tool. Then we make a mark on the harmonic balancer (or on the flywheel) that aligns with a stationary pointer. Next, we then rotate the crankshaft in the opposite direction (no need to worry about camshaft drive chain/sprocket slack) until once again the piston is gently stopped by the PPS tool. Now we make another mark that aligns with a stationary pointer. This leaves us with two new marks that have aligned with the pointer while the crankshaft/piston had been stopped at approximately 30 degrees at either side of the two rotational directions. Next, we accurately and equally "split" the distance between these two new marks. At this point, we mark the "split" location. With the PPS tool now removed, we rotate the crankshaft to the location whereby the pointer now aligns with the new "split" marking. (it does not matter which direction we rotate the crankshaft) This is True # 1 TDC. This procedure is used by many profresional High Performance Engine builders.
Use a bridge and dial indicator, and you'll see that most of the time the factory marks can be off a couple degrees. Now for an oem engine this may be ok, you'd just not have optimum performance, or it could be the engine that always seems to ping during warmer weather. if you have the heads off it is a good time to use a dial indicator and verify where true tdc is.
Thank you very much. I didnt know the pressure was a sign of the compression stroke. I've been looking everywhere to tell me when is the compression and the intake strokes. THANKS VERY MUCH. I'm working on a Lexus es300 V6 with 0 previous experience.
+The Optional Kind Thank you! We love empowering our customers and showing how to perform DIY auto repairs with our high-quality auto parts. 1aau.to/m/Shop-1AAuto-c
When I assemble an engine I often times find that the harmonic balancer tdc mark isn't perfect. I usually find this using a piston stop or a dial indicator. They can be remarked for more accurate timing observation.
after i rebuilt my 53 dodge i painted the --tdc an deg marks crankcase pully ----then remove dist cap rotor will be close to 1 oclock pos. put cap backon conn timming light to # 6 wire spin eng with starter -- watch timing light --to set at 4 deg before tdc slowly rotate dist till on #4 mark stop tighten dist to eng ready to go.
once you find tdc mark with white paint and a tooth pick easy to see with timing light now you can ajdjust with eng running if you like 1----4 degs before turn dist watch timing light then lock it down.perfect
If the crankshaft and camshaft timing marks are aligned with what they should be aligned with (i.e., the other marks), that means necessarilly that it is in the TDC point?
I am currently rebuilding a cvh 1.4i engine for my '99 Ford Fiesta as a project. I'm not a qualified mechanic but I would like to think that I have some intermediate knowledge of car engines because I have had some training in Motor Mechanics as a trade course. My worry at the moment is finding TDC correctly first time when assembling the engine again. My pulley does not have any marks except for the slot that looks the same as the one in the sprocket where the woodruff key slides in. I'm just curious to know if it's possible to find TDC with only the bottom half of the engine and then later installing the cylinder head which will be timed correctly as I have sent it to the engineers. The problem with cylinder head was 2 valves bent, hydraulic lifters were gone and so was the camshaft. I plan to rebore the cylinders and fit 20thou pistons just to refresh the engine and get that little bit more performance.
I have the same problem. I was changing my intake manifold gasket on my 98 Sierra 5.7. I had put valve covers back on and manifold and when it came to putting the distributor on I had to check the tdc and I want to know how to do that without having to see the pistons someone help!
I could never figure out wat top & botom dead centre meant with piston's after looking @ a diagram i know wat is, & i think i know y a head need's to b tightened down in a particular way.
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This is for the person who needs to locate True # 1 TDC.
1.... Never assume that your harmonic balancer ZERO mark and your timing tab ZERO indicate true TDC.
Outer rings can slip, timing tabs can become damaged, and/or, these marks may not have been accurate from Day 1.
2.....Try to NOT view this as if overly complex.... it is not. Just follow these simple steps, and you will find true # 1 cylinder TDC.
3..... finding or verifying true # 1 TDC does NOT require us to be coming up on the Compression Stroke.
TDC occurs twice for every 4 engine cycles (i.e., 720 degrees of crankshaft rotation).
The crankshaft, connecting rod and piston do not care what the camshaft is doing for this procedure.
TDC is TDC regardless of which stroke.
For distributor phasing or ignition timing, yes..... it certainly does matter.
When accurately locating TRUE # 1 cylinder Top Dead Center, we use a PPS procedure.... (positive piston stop).
By using the PPS procedure, we eliminate any crankshaft dwell that occurs when a piston has theoretically reached top of stroke. (there will be some crankshaft movement while the piston appears to be stationary at theoretical top of stroke)
Ideally, we want to stop the piston at approximately 30 degrees before theoretical top of stroke.
30 degrees is a suggestion only. You can use 25, 28, 32 or 35 degrees, as longs as it is the same angle in either direction towards the "stop".
Once the 30ish degrees has been established, the PPS tool must be locked into position. Most will offer a jam nut.
First, we rotate the crankshaft until the piston is gently stopped by the PPS tool.
Then we make a mark on the harmonic balancer (or on the flywheel) that aligns with a stationary pointer.
Next, we then rotate the crankshaft in the opposite direction (no need to worry about camshaft drive chain/sprocket slack) until once again the piston is gently stopped by the PPS tool.
Now we make another mark that aligns with a stationary pointer.
This leaves us with two new marks that have aligned with the pointer while the crankshaft/piston had been stopped at approximately 30 degrees at either side of the two rotational directions.
Next, we accurately and equally "split" the distance between these two new marks.
At this point, we mark the "split" location.
With the PPS tool now removed, we rotate the crankshaft to the location whereby the pointer now aligns with the new "split" marking. (it does not matter which direction we rotate the crankshaft)
This is True # 1 TDC.
This procedure is used by many profresional High Performance Engine builders.
Fast and to the point but a word of advise. Dont claim to be the best. Claim to get it done and professionally
Use a bridge and dial indicator, and you'll see that most of the time the factory marks can be off a couple degrees. Now for an oem engine this may be ok, you'd just not have optimum performance, or it could be the engine that always seems to ping during warmer weather. if you have the heads off it is a good time to use a dial indicator and verify where true tdc is.
Thank you very much. I didnt know the pressure was a sign of the compression stroke. I've been looking everywhere to tell me when is the compression and the intake strokes. THANKS VERY MUCH. I'm working on a Lexus es300 V6 with 0 previous experience.
+The Optional Kind Thank you! We love empowering our customers and showing how to perform DIY auto repairs with our high-quality auto parts. 1aau.to/m/Shop-1AAuto-c
Me: receiving an engine block and cylinder head dismantled and I have to assemble it and they ain't any marks.
Me: oh I'm f*ck@d
Is it true that when you take out the plugs it helps release the compression to turn the crank on the engine??
When I assemble an engine I often times find that the harmonic balancer tdc mark isn't perfect. I usually find this using a piston stop or a dial indicator. They can be remarked for more accurate timing observation.
+Oldsmob455 Thank you for the tip! We appreciate the feedback for assisting other viewers! 1aauto.com
1A Auto: Repair Tips & Secrets Only Mechanics Know Can you correct or set the timing on a 2001 Ford Mustang 4.6L like this
after i rebuilt my 53 dodge i painted the --tdc an deg marks crankcase pully ----then remove dist cap rotor will be close to 1 oclock pos. put cap backon conn timming light to # 6 wire spin eng with starter -- watch timing light --to set at 4 deg before tdc slowly rotate dist till on #4 mark stop tighten dist to eng ready to go.
I heard I gotta do this to change the valve seals and lifters, retainters, & keepers
once you find tdc mark with white paint and a tooth pick easy to see with timing light now you can ajdjust with eng running if you like 1----4 degs before turn dist watch timing light then lock it down.perfect
Why on some engines you can turn clockwise and others counter clockwise to get tdc.. watching a lot of videos im curious. Thanks
If it didn't get tight, wouldn't it be in it's exhaust stroke rather than intake stroke?
read my comment about tdc
Good work done well
If the crankshaft and camshaft timing marks are aligned with what they should be aligned with (i.e., the other marks), that means necessarilly that it is in the TDC point?
Super awesome video!
Thanks for checking us out. 1aauto.com +Patriot / Kenneth Burlingham Burlingham
I am currently rebuilding a cvh 1.4i engine for my '99 Ford Fiesta as a project. I'm not a qualified mechanic but I would like to think that I have some intermediate knowledge of car engines because I have had some training in Motor Mechanics as a trade course. My worry at the moment is finding TDC correctly first time when assembling the engine again. My pulley does not have any marks except for the slot that looks the same as the one in the sprocket where the woodruff key slides in.
I'm just curious to know if it's possible to find TDC with only the bottom half of the engine and then later installing the cylinder head which will be timed correctly as I have sent it to the engineers.
The problem with cylinder head was 2 valves bent, hydraulic lifters were gone and so was the camshaft.
I plan to rebore the cylinders and fit 20thou pistons just to refresh the engine and get that little bit more performance.
I have the same problem. I was changing my intake manifold gasket on my 98 Sierra 5.7. I had put valve covers back on and manifold and when it came to putting the distributor on I had to check the tdc and I want to know how to do that without having to see the pistons someone help!
How would you be able to tell when you top dead Center on the Exhaust stroke
Excelent video very simple instruccons
+Jorge Ponce Thanks for checking us out! 1AAuto.com
How long is the intermediate exhaust 98 dodge ram 1500 5.2 l
Thanks sir
Ideal TDC?
So Louis C.K. works as a mechanic now, huh.
Hey...accurate.
I could never figure out wat top & botom dead centre meant with piston's after looking @ a diagram i know wat is, & i think i know y a head need's to b tightened down in a particular way.
Crap
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