Compression Test Help Please-Update Results. Opinions Needed
#31
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Ok, maybe a stupid question but stupid questions are easier to handle than stupid mistakes right? Can I undo the cam nut and turn 1-4 cam back to the middle of the rotor bolt holes?
#34
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Go to the link on this page, http://liftbars.com/ , for the manual for the cam timer to understand the method. If you let us know what state you're in someone may have the cam timer and bump stick that you can borrow.
#36
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The three small screws inserted where the rotor arm is normally secured also hold the sprocket relative to the cam. The 32VR kit has a spacer that sits between the spacer and the main locking nut and permits the cam to be rotated relative to the sprocket using the hex spacer as the prime mover when the three small screws are loose, the screws locking the cam while the main securing bolt is loose.
Rgds
Fred
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Adding the chips, x pipe and flow thru cats did make a difference.
Hopefully someone in Adelaide can lend you the cam timer to check your settings.
Regards Norm
#38
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Ok, reading the 32Vr manual I wondering whether the timing procedure assumes that both cam wheels line up on the timing marks. What if they don't, like mine?
#39
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So moved the cam back to middle on 1-4. I forgot to mark the rotors positions on the cam wheel. Can someone tell me the orientation if the engine is at 0/T. Are they both at 3.00?
Last edited by DeWolf; 04-19-2016 at 03:23 AM.
#40
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Scott,
The 32VR kit assumes that each installation is mechanically identical. As I noted earlier there has been debate about this - all I can tell you is that my cams were setup by the main agents under my direct inspection so I was confident my cam timing was spot on as per the WSM. When I acquired the 32VR kit some years later my cam timing was spot on where it was supposed to be so read into that what you will.
In your situation if you have access to the 32VR kit you can use it to try and determine just how far out you are- my assumption is that you will be off the scale on bank 1/4 and probably quite close on 5/8. Ken [Porken] did an excellent thread on the changes cam timing makes and covered a range of plus/minus 10 degrees if my memory serves me correctly backed up with dyno sessions- the effect is subtle rather than spectacular but measurable nonetheless with cam retardation giving more top end at the expense of some lower end torque. Thus if significantly retarded [as seems likely in your case on 1/4] it makes sense that compression pressure will drop noticeably at some point of retardation at cranking speed.
If the 32VR confirms you need to gain a tooth's worth of advance on 1/4 as seems likely, I see no harm in giving it a go with the 32VR kit and see how it feels. You will have to slacken off the tensioner fully, I suspect you will have to remove all the gubbins on the front of the motor to get the main cover off and then reassemble everything.
The only caveat I can offer here is whether the cam wheel can be removed without doing all this- i.e. just by releasing the belt tension and slipping the cam sprocket off. I do not know the answer to this one having never tried to do it but maybe someone else does. All I can advise is that getting the belt back on even with everything out of the way is "tightish" but- putting the belt over the 1/4 sprocket is the last step of the belt replacement procedure.
Before you do anything you can paint index marks on the belt and the sprocket to indicate either where you are at the moment or where you want to be when complete assuming the belt does not slip relative to the crank sprocket [you could index that as well]. On the other hand if you do not know the age of the timing belt [you said history was sketchy] maybe a good time to simply bite the bullet and replace the TB. A new timing belt however is not the best for cam timing as it has not had initial stretch- Ken recommends a compensation for this if using a new belt and the 32VR kit. Also the 32VR kit permits checking the timing at 45 BTDC.
Finally, just remember that the safe position for the motor when doing the TB on 32 valve motors is 45 before TDC. This is equivalent to 3 teeth on the cam sprocket before arriving at TDC. Some folks reckon it is safe enough to do the timing belt at TDC, personally I lock the motor at 45 BTDC and do not remove the crank locking tool until the belt is set once more- my personal recommendation. To do the belt you have to remove the main cover & you will need to remove the main crank bolt and thus you need the crank locking tool to achieve this.
Trust the above accurate and helpful.
Rgds
Fred
The 32VR kit assumes that each installation is mechanically identical. As I noted earlier there has been debate about this - all I can tell you is that my cams were setup by the main agents under my direct inspection so I was confident my cam timing was spot on as per the WSM. When I acquired the 32VR kit some years later my cam timing was spot on where it was supposed to be so read into that what you will.
In your situation if you have access to the 32VR kit you can use it to try and determine just how far out you are- my assumption is that you will be off the scale on bank 1/4 and probably quite close on 5/8. Ken [Porken] did an excellent thread on the changes cam timing makes and covered a range of plus/minus 10 degrees if my memory serves me correctly backed up with dyno sessions- the effect is subtle rather than spectacular but measurable nonetheless with cam retardation giving more top end at the expense of some lower end torque. Thus if significantly retarded [as seems likely in your case on 1/4] it makes sense that compression pressure will drop noticeably at some point of retardation at cranking speed.
If the 32VR confirms you need to gain a tooth's worth of advance on 1/4 as seems likely, I see no harm in giving it a go with the 32VR kit and see how it feels. You will have to slacken off the tensioner fully, I suspect you will have to remove all the gubbins on the front of the motor to get the main cover off and then reassemble everything.
The only caveat I can offer here is whether the cam wheel can be removed without doing all this- i.e. just by releasing the belt tension and slipping the cam sprocket off. I do not know the answer to this one having never tried to do it but maybe someone else does. All I can advise is that getting the belt back on even with everything out of the way is "tightish" but- putting the belt over the 1/4 sprocket is the last step of the belt replacement procedure.
Before you do anything you can paint index marks on the belt and the sprocket to indicate either where you are at the moment or where you want to be when complete assuming the belt does not slip relative to the crank sprocket [you could index that as well]. On the other hand if you do not know the age of the timing belt [you said history was sketchy] maybe a good time to simply bite the bullet and replace the TB. A new timing belt however is not the best for cam timing as it has not had initial stretch- Ken recommends a compensation for this if using a new belt and the 32VR kit. Also the 32VR kit permits checking the timing at 45 BTDC.
Finally, just remember that the safe position for the motor when doing the TB on 32 valve motors is 45 before TDC. This is equivalent to 3 teeth on the cam sprocket before arriving at TDC. Some folks reckon it is safe enough to do the timing belt at TDC, personally I lock the motor at 45 BTDC and do not remove the crank locking tool until the belt is set once more- my personal recommendation. To do the belt you have to remove the main cover & you will need to remove the main crank bolt and thus you need the crank locking tool to achieve this.
Trust the above accurate and helpful.
Rgds
Fred
#41
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Cheers Fred. Very helpful indeed. I am going to buy the 32Vr as I have two of them so it'd make sense. Just can't work out the position of the ignition rotors at the moment as in my haste I forgot to mark them!
#42
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Rgds
Fred
#44
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The 32vr has nothing to do with how the gears line up with the marks on the backing plate. You position the crank at TDC cylinder 1, make sure the belt is on the right gear tooth (1/2 tooth or less within a perfect match). Then the 32vr aligns the cams via the spider to the timing mark on the backing plate. The position of the gear can vary 1/2 tooth or less as that is determined entirely by the belt pitch and the geometry of the heads and block. Things like thicker head gaskets, shaved heads, belt stretch affect exactly how the notch on the cam gear lines up with the backing plate notch. Nothing will change that. Until you get the 32vr, you really don't know where to set the cam spider bolt holes relative to the gear.
#45
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The ignition rotor bolt holes in the spider are eccentrically located, not exactly 120 degrees apart, so the rotors will only mate in one position. They are so close to 120 degrees apart, it's hard to determine orientation visually. However, the face of the gear has indicators molded into it. The rotor tip should point between the indicators, shown below.