Installing Cloyes 9 keyway timing gear question?
April 12th, 2015, 05:12 AM
#1
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Installing Cloyes 9 keyway timing gear question?
Hello everyone.
Actually my engine builder installed this and I want to verify the timing.
He has it installed 2 degrees retarded which is 1 degree retarded at cam.
As far as the instructions from Cloyes, retarded will give top end power, advanced low end torque.
It's a 69 400 G block, with C heads.
Any input on this?
Actually my engine builder installed this and I want to verify the timing.
He has it installed 2 degrees retarded which is 1 degree retarded at cam.
As far as the instructions from Cloyes, retarded will give top end power, advanced low end torque.
It's a 69 400 G block, with C heads.
Any input on this?
April 13th, 2015, 06:49 AM
#3
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As with many things in life, you may not be able to have the best of both worlds (top end/bottom end), as indicated in the Cloyes instructions. Back in the 1970s some manufacturers did a slight retard on the timing gear for emission purposes without changing the cam grind. This is a good question for those familiar with the cam's characteristics. I don't know enough to advise accurately. A while back I installed a Cloyes on a 460 Ford engine from 1976 and ended up putting it "straight up" on the recommendations of the Ford "experts" which seems to have worked well. You really need to hear from someone on the forum who is familiar with your cam. 
April 13th, 2015, 07:17 AM
#4
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It is impossible to see any of the markings on those gears.
The Cloyes setup will allow you 0°, 1°, 2°, 3°, or 4° of either advance or retard (as measured at the cam).
I am not sure why your builder would have set your cam retarded for your engine and car - I would have been inclined to set it to Zero or slightly advanced, as you are probably going to be running between 1,000 and 2,500 RPM most of the time, and not at 4,000 RPM very much.
Before messing with it, I would check the actual timing with a dial indicator (if you don't have one, you should),and then work from there. It's simple enough to change the advance while the timing cover is off.
- Eric
ps: when I installed mine, I set it up at Zero, and it measured out to about 1° advanced, so I left it there. You just reminded me that I may just want to go in this spring and put it in the slot that will advance it another 2°, just to see what happens.
The Cloyes setup will allow you 0°, 1°, 2°, 3°, or 4° of either advance or retard (as measured at the cam).
I am not sure why your builder would have set your cam retarded for your engine and car - I would have been inclined to set it to Zero or slightly advanced, as you are probably going to be running between 1,000 and 2,500 RPM most of the time, and not at 4,000 RPM very much.
Before messing with it, I would check the actual timing with a dial indicator (if you don't have one, you should),and then work from there. It's simple enough to change the advance while the timing cover is off.
- Eric
ps: when I installed mine, I set it up at Zero, and it measured out to about 1° advanced, so I left it there. You just reminded me that I may just want to go in this spring and put it in the slot that will advance it another 2°, just to see what happens.
April 13th, 2015, 09:57 AM
#5
With your engine builder being a professional, I'm sure he dialed the cam in.
Being machined parts the plus or minus either way may have lead him to set the chain up in that manner. Of which may have brought the cam in at zero or maybe even one advance. I've seen the same brand of timing sets produce different number on the same cam.
Before you change anything, talk to your builder and see what he has to say about why he set it up that way.
Gene
Being machined parts the plus or minus either way may have lead him to set the chain up in that manner. Of which may have brought the cam in at zero or maybe even one advance. I've seen the same brand of timing sets produce different number on the same cam.
Before you change anything, talk to your builder and see what he has to say about why he set it up that way.
Gene
April 13th, 2015, 06:20 PM
#6
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His builder needs to be able to tell him at what intake centerline the cam is installed at. 110 would be straight up, 108 is advanced 2*.
Which keyway he uses is irrelevant, the resulting icl is the important part.
Which keyway he uses is irrelevant, the resulting icl is the important part.
April 13th, 2015, 08:27 PM
#7
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According to him, the builder installed it at 111°.
If he degrees it himself, he will know for sure, and he won't have to rely on his builder, who may or may not be as skilled as he hopes.
I always advocate for a person to check everything that he possibly can for himself, rather than letting the guy who may -- or may not -- have screwed it up check his own work.
Too many cooks spoil the broth, but an extra set of eyes is always helpful.
- Eric
If he degrees it himself, he will know for sure, and he won't have to rely on his builder, who may or may not be as skilled as he hopes.
I always advocate for a person to check everything that he possibly can for himself, rather than letting the guy who may -- or may not -- have screwed it up check his own work.
Too many cooks spoil the broth, but an extra set of eyes is always helpful.
- Eric
April 14th, 2015, 08:28 AM
#8
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Sadly my engine builder isn´t available at the moment. BUT.
Am I correct that the cam sprocket only has one possible position on the cam shaft? That it only installs in one position.
And degree changes are made at the crank sprocket?
If this is correct it is setup at 112 (111 at cam)
Am I correct that the cam sprocket only has one possible position on the cam shaft? That it only installs in one position.
And degree changes are made at the crank sprocket?
If this is correct it is setup at 112 (111 at cam)
April 14th, 2015, 09:23 AM
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No it's not Eric, sorry. I think there is a misunderstanding here about how this all works together. Let me explain.
The keyways on the crank gear represent a change of that many degrees in CAM timing. If you're looking for an icl of 106*, then that means the VALVE is at midway lift when the PISTON is 106* past tdc. If its set at 111, then the valve is at mid lift when the piston is 111* after tdc.
And don't assume a 4* change on the gear will make a 4* change in cam timing. Although that Cloyes set is normally very good, it's always best to check it anyway.
I'd shoot for a 108 icl with that cam fwiw.
The keyways on the crank gear represent a change of that many degrees in CAM timing. If you're looking for an icl of 106*, then that means the VALVE is at midway lift when the PISTON is 106* past tdc. If its set at 111, then the valve is at mid lift when the piston is 111* after tdc.
And don't assume a 4* change on the gear will make a 4* change in cam timing. Although that Cloyes set is normally very good, it's always best to check it anyway.
I'd shoot for a 108 icl with that cam fwiw.
April 14th, 2015, 09:41 AM
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April 15th, 2015, 02:49 PM
#15
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That's why it's important to measure the actual valve events with respect to actual piston position. Take all the middlemen out of the picture.
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