| Installing push rods and rockers [message #228747] |
Thu, 07 November 2013 08:28  |
budworks521
Messages: 137
Registered: October 2013
Location: Grand Rapids MI 1974 Pain...
Karma: 4
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Senior Member |
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Hello again, I have my heads on and now attempting to install push rods and rockers. Spoke to Paul Bartz and Dick Paterson about the sequence and have a few more questions. When you start at TDC on intake stroke #1 should it be at 0 degrees or 8 degrees and is the cam lobe always down to it's lowest point on intake stroke or both intake and exhaust stroke. I know I need to start at TDC intake stroke. Then turn 1/4 turn and go to #8 and follow firing order with install. Also, does the pulley system/cam turn clockwise or counter when under the coach. If the rotor turns counter I am guessing the cam does do. I have the manual but it doesn't give me enough info. My so-called mechanic helping me is a no show of late and might try this on my own. I know to be careful with the rod install and go back and forth on the tightening of the bolts to get right tension on the rods. If anybody feels like calling me for some insight I would appreciate it. I can supply number.
1974 Painted Desert
455 upper half rebuild
constant project inexperienced mechanic
Grand Rapids Mi
Always trying to learn
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| Re: Installing push rods and rockers [message #228768 is a reply to message #228747] |
Thu, 07 November 2013 10:12  |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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| budworks521 wrote on Thu, 07 November 2013 09:28 |
Hello again, I have my heads on and now attempting to install push rods and rockers. Spoke to Paul Bartz and Dick Paterson about the sequence and have a few more questions. When you start at TDC on intake stroke #1 should it be at 0 degrees or 8 degrees and is the cam lobe always down to it's lowest point on intake stroke or both intake and exhaust stroke. I know I need to start at TDC intake stroke. Then turn 1/4 turn and go to #8 and follow firing order with install. Also, does the pulley system/cam turn clockwise or counter when under the coach. If the rotor turns counter I am guessing the cam does do. I have the manual but it doesn't give me enough info. My so-called mechanic helping me is a no show of late and might try this on my own. I know to be careful with the rod install and go back and forth on the tightening of the bolts to get right tension on the rods. If anybody feels like calling me for some insight I would appreciate it. I can supply number.
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Bud,
I wish you were a little closer, but GR is kind out of striking range for a day's job.
In an Olds engine, the cam is chain driven, so it has to turn the same way as the crankshaft. The crankshaft turns clockwise as viewed from the front.
It is the cheap engines that GM built that have the distributor going the wrong way.
Still confused?
Get you body to where you can see the timing saw...
The marks are degrees of ADVANCE, so, the mark on the damper should be turning toward the 12 end of the scale.
If you take the cap off the distributor and point it at number one and then take masking tape and mark around it 1-8-4-3-6-5-7-2 counter clockwise, now you have a pointer to which is at TDC.
Do you have the intake in? If you don't, you can watch the cam followers (lifters) move.
Whenever I work on the valve gear of any engine, I write the firing order and the reciprocal on a card that I put in front of me. So for an Olds it would look like:
1 8 4 3 6 5 7 2
6 5 7 2 1 8 4 3
When the lower line is in cross-over (the exhaust is closing and the intake opening), it is safe to mess with the valves of the one above. This may seem somewhat complex, but it really isn't and it is completely safe as long as you get the firing order correct. AND, It works on EVERY engine that has intake and exhaust valves. I developed this because when you work in a supplier's or a contract lab where you can be running anything at all, often data is unclear or only available in some other language that the tech's don't understand (sometimes it seemed English was not one of those).
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Installing push rods and rockers [message #228859 is a reply to message #228747] |
Fri, 08 November 2013 05:50 |
budworks521
Messages: 137
Registered: October 2013
Location: Grand Rapids MI 1974 Pain...
Karma: 4
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Senior Member |
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The intake is out and the cam lobes are visible. Right now I have number 1 at TDC and the lifters are down. Not completely sure but it looks like both are down the same. Maybe the exhaust is a bit higher?? Anyway, I was under the impression that both rods on one piston can go in at the same time. As long as the cam lobe is down I should be fine correct? I never have done this before and my mechanic is not much help right now. Thanks for the suggestions.
1974 Painted Desert
455 upper half rebuild
constant project inexperienced mechanic
Grand Rapids Mi
Always trying to learn
[Updated on: Fri, 08 November 2013 05:51] Report message to a moderator |
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| Re: Installing push rods and rockers [message #228874 is a reply to message #228859] |
Fri, 08 November 2013 08:24 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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| budworks521 wrote on Fri, 08 November 2013 06:50 |
The intake is out and the cam lobes are visible. Right now I have number 1 at TDC and the lifters are down. Not completely sure but it looks like both are down the same. Maybe the exhaust is a bit higher?? Anyway, I was under the impression that both rods on one piston can go in at the same time. As long as the cam lobe is down I should be fine correct? I never have done this before and my mechanic is not much help right now. Thanks for the suggestions.
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Bud,
On an OE cam with OE followers, the followers and pushrod tops should be at the same elevation. And yes, the pair for any cylinder should be able to be installed at the same time and set to, or checked for lash.
Actually, you can load all the followers and pushrods at the same time, but if this engine has had significant work, you will have to bar the crank to all eight TDC positions to check that the valve train lash is within the range that the lash adjuster (lifter) can accommodate.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Installing push rods and rockers [message #228885 is a reply to message #228859] |
Fri, 08 November 2013 08:57 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Senior Member |
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| budworks521 wrote on Fri, 08 November 2013 04:50 |
The intake is out and the cam lobes are visible. Right now I have number 1 at TDC and the lifters are down. Not completely sure but it looks like both are down the same. Maybe the exhaust is a bit higher?? Anyway, I was under the impression that both rods on one piston can go in at the same time. As long as the cam lobe is down I should be fine correct? I never have done this before and my mechanic is not much help right now. Thanks for the suggestions.
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If the lifters are down, then the valves are closed which would indicate TDC for # 1 (top of compression cycle.)
Bob de Kruyff
78 Eleganza
Chandler, AZ
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