Hi guys, I just changed my head gasket, but forgot to mark the rotor. I think it moved. i don't want it to be on the exhaust stroke. can i tell by looking at the camshaft position if it's on exhaust or fire stroke? In theory, I think that should work if someone knows the position. If I have the rotor on 180 degrees backwards, what can happen? thanks.
Camshaft position for timing? NEWBIE
- Thread starter iteachupe
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Assume you are working with a Chilton's, Helms, Hayes or other tech manual.
Just do what the manual says - when the timing mark for TDC on the harmonic balancer or crank pulley is aligned to the pointer, and the cam pulley marks are oriented correctly per the plane of the top of the head it's at TDC on the power stroke.
At which point, simply pull the distributor cap and make sure the rotor is pointing to #1 plug wire. The #1 cylinder is the first to fire and is the cylinder at the front of the engine or closest to the cam timing pulley and belt.
Do not force the distributor in - the slot in the cam and the drive dog on the distributor are offset to prevent them from being installed wrong. #4 is closest to the distributor. Make sure the cam alignment/timing marks are oriented correctly.
Just do what the manual says - when the timing mark for TDC on the harmonic balancer or crank pulley is aligned to the pointer, and the cam pulley marks are oriented correctly per the plane of the top of the head it's at TDC on the power stroke.
At which point, simply pull the distributor cap and make sure the rotor is pointing to #1 plug wire. The #1 cylinder is the first to fire and is the cylinder at the front of the engine or closest to the cam timing pulley and belt.
Do not force the distributor in - the slot in the cam and the drive dog on the distributor are offset to prevent them from being installed wrong. #4 is closest to the distributor. Make sure the cam alignment/timing marks are oriented correctly.
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OK....So let's just say that the rotor is pointed at #4 instead of 1. Would the car not start because of that? I put it with the rotor facing 4 because that is the way that it fit in smoothly, i didn't have to force it. You said that they were offset so that I couldn't install wrong. If that is the case, then I was correct in facing the rotor to #4....however the engine doesn't start. Could you explain a bit more about the offset dog drive? I guess I'm wondering how close the spark v exhaust stroke is? Is it possible that I had the opposite of TDC, or would that mean the 1 piston would be down? It was up when I took off the head.
Thanks for your input. : )
Thanks for your input. : )
If it's pointed at #4 at TDC it will be 180 degrees out of timining with regard to the cam and 360 degrees out per the crankshaft. And, no it won't run that way.
What engine is in the car? I'm not familiar with that model. Don't know about the oil pump and dizzy being tied together.
Post some pictures please. If you don't have a book I would recommend you get one. How did you arrive at torque specifications and torque sequence for the head?
What engine is in the car? I'm not familiar with that model. Don't know about the oil pump and dizzy being tied together.
Post some pictures please. If you don't have a book I would recommend you get one. How did you arrive at torque specifications and torque sequence for the head?
The rotor "should" only go on one way but if it doesn't, then the rotor pointing at cylinder 4 to fire is correct.
When you set timing, piston 1 is at TDC on it's intake stroke, which makes it's companion piston, which is piston 4, on it's power stroke.
When you set timing, piston 1 is at TDC on it's intake stroke, which makes it's companion piston, which is piston 4, on it's power stroke.
I think on my stuff (D16A6 and now ZC) when the crank is on the TDC mark, and the cams index marks are on the top, #1 is set to the power stroke with the rotor pointing to #1 (assuming cam is set correctly).
How that relates to this older CRX I'm not yet sure.
The chart I have on Honda engines show his 1986 carburated CRX to have a D15A2 engine. I need to research that.
Looks like his setup is like my stuff with a firing order of 1, 3, 4, 2. http://www.quickhonda.net/specs.htm I beleive this to be correct?
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I have a manual. I set the bolts to 22 then 49.
I'm pretty sure it's the 1500 carbureted. EW1
Firing order is 1342
"If it's pointed at #4 at TDC it will be 180 degrees out of timiing with regard to the cam and 360 degrees out per the crankshaft."
What do you mean 360 out per the crankshaft? I think i get what your saying. The cam goes around 2x for every 1x that the crankshaft goes around? That would mean that the mark on the cam pulley is only correct 1/2 the time because it's either for 1 or 4? That's what I was wondering, how do I know it's TDC for 1 and not 4? All I know is 1 was at the top when I took the head out, and so was the last one, farthest away from the timing belt.
stupid question, but i can't find how to attach pics. I see the insert image link, but that needs a url. I have the pics on the cpu.....
thanks again,
I'm pretty sure it's the 1500 carbureted. EW1
Firing order is 1342
"If it's pointed at #4 at TDC it will be 180 degrees out of timiing with regard to the cam and 360 degrees out per the crankshaft."
What do you mean 360 out per the crankshaft? I think i get what your saying. The cam goes around 2x for every 1x that the crankshaft goes around? That would mean that the mark on the cam pulley is only correct 1/2 the time because it's either for 1 or 4? That's what I was wondering, how do I know it's TDC for 1 and not 4? All I know is 1 was at the top when I took the head out, and so was the last one, farthest away from the timing belt.
stupid question, but i can't find how to attach pics. I see the insert image link, but that needs a url. I have the pics on the cpu.....
thanks again,
Crank turns 2 to 1 against the cam. So, the crank hits TDC twice per camshaft index mark (actually it hits TDC 4 times per revolution). Each time the cam hits it's index marks which on my stuff indicates #1 is at TDC on the power stroke. Yours should be the same.
That's why I keep referencing the cam index marks. The rotor should be pointing at #1 on distributor cap when the cam index or timing marks are set to "Top" when you align referencing the crankshaft via the #1 TDC index mark on the harmonic balancer, to set cam timing.
That should all be in the book. But, may be scattered all over the place, hence the questions.
Everything in these older engines is referenced from #1 @ TDC on the power stroke. All the injector timing and ignition timing is referenced #1 @ TDC on the power stroke.
That's why I keep referencing the cam index marks. The rotor should be pointing at #1 on distributor cap when the cam index or timing marks are set to "Top" when you align referencing the crankshaft via the #1 TDC index mark on the harmonic balancer, to set cam timing.
That should all be in the book. But, may be scattered all over the place, hence the questions.
Everything in these older engines is referenced from #1 @ TDC on the power stroke. All the injector timing and ignition timing is referenced #1 @ TDC on the power stroke.
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Just started reading this thread.
Reads like the head was removed and the rotor on the dizzy moved (accidentally) before it was re-installed
I have read of guys being able to connect the dizzy 180 degrees out
But I have tried it with B-series motors and it would not go in (at least with minimal force)
If the bottom end and top end were on #4 when you took the head off.....and the dizzy goes in better that way....seems to be right.
I always do #1 @ TDC for a variety of mechanical changes (cams, timing belt, etc)
And take note of the rotor position (and markings) when I remove it b/c things happen and it may accidentally move.
Reads like the head was removed and the rotor on the dizzy moved (accidentally) before it was re-installed
I have read of guys being able to connect the dizzy 180 degrees out
But I have tried it with B-series motors and it would not go in (at least with minimal force)
If the bottom end and top end were on #4 when you took the head off.....and the dizzy goes in better that way....seems to be right.
I always do #1 @ TDC for a variety of mechanical changes (cams, timing belt, etc)
And take note of the rotor position (and markings) when I remove it b/c things happen and it may accidentally move.
Hey guys. Took me a while to get back to work. Put the distributor on the only way it would go in without me forcing it. Car would not start. Ended up looking at fuel because I was getting spark. Possibly the fuel pump needed to be primed, so I took an air hose and put it into the gas tank, which forced gas into the pump. She eventually started! A lot of burn off, but that's to be expected right? Now onto the next problem...the temp gauge doesn't work anymore. May have blown when the car was over heated. Thanks for all your help regarding the dizzy and the timing!
Hornet racer
New Member
To be sure that you have the engine in time take off the timming cover and make sure you have the engine tdc then look at your timming marks on the pulleys to be sure that you have them lined up properly E blocks typically have a small upsidown triangle behind the timming belt at the hermonic balancer the key way will line up with that then the camshaft pully will have a notch on one of the teeth that should be pointing up also there should be marks on the camshaft to line it up with the top of the head