vigman
Motor head!!!!
- Joined
- Feb 13, 2001
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- 3,471
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- Valencia, CA,USA
- Corvette
- 88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Any follow up?
I'm very curious.....
Vig!
I'm very curious.....
Vig!
68Roadster
Well-known member
Vig,
It's been kind of nasty in the Big D this past week and it's kind of cold so I would imagine he hasn't had much time or good weather to work on it.
If the filter is clean an he goes back to square one on the adjustment and measures lift of each valve, this should be around 1/2 inch on each right??
The whole distributor thing still bothers me, switching around the cap and the plug wires. Thats what I would llike to personally see and verify for myself. Then start checking the valve adjustment.
Maybe we'll hear from him this week.
Cee
It's been kind of nasty in the Big D this past week and it's kind of cold so I would imagine he hasn't had much time or good weather to work on it.
If the filter is clean an he goes back to square one on the adjustment and measures lift of each valve, this should be around 1/2 inch on each right??
The whole distributor thing still bothers me, switching around the cap and the plug wires. Thats what I would llike to personally see and verify for myself. Then start checking the valve adjustment.
Maybe we'll hear from him this week.
Cee
vigman
Motor head!!!!
- Joined
- Feb 13, 2001
- Messages
- 3,471
- Location
- Valencia, CA,USA
- Corvette
- 88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Valve lift ( cam 101)
Should be a little less than 1/2 of an inch measured at the valve side of the rocker.
DEPENDING ON THE CAM!!!!!! I'm assuming stock/ hydraulic 250 ish hp, not some .600 lift monster!
The distributor would have come into play ..if it was off..not getting the lobe of the cam all the way down when the adjustment was made... (eg the cam was still on the down side of the profile but not at "0")
Cam lift 101, ( rounded numbers)
If you measure the side to side of a cam
( generic ) the dimension is 1.25 inches.
If you measure from the top of the lift point to the back side 1.50 inches
So as the lifter rises out of the block it's only moving .250 of an inch from peak to valley..
Now as you measure from the (1.5 to 1 rocker) you get a measurement of .375 of an inch... Not a lot of lift....
Note here though.. on the first side to side measurement, the profile of the cam comes into play.. that's not ALL the time the "O" point as the cam is egg shaped and might be ground silghtly off center.
The POINT here... you should see about a little more then .250 ( 1/4 inch ) of the lifter poking in & out of the cam / lifter valley and the extra lift comes from the rocker.
A test.. get a piece of cardboard.. and make a mark on a known good lobe in the up position.. then crank the engine around till the rocker/ valve is in the DOWN position.
This will be a rough template of the travel for each lobe... do this 15 more times.. and you will see the one that's ground down to a FLAT ( due to a lack of movement and I'm talking less than 1/2 of what the others do..not .0016 of an inch)....
Now the lifter COULD be bad..but at least if one the lifters doesn't move up & down the same amount as the others... and NONE of the rockers are loose.. it will let you know it's NOW time to pull the intake manifold off and do further inspection!
The other thing that comes to mind... during the distrib pull & reposition that:
a) You had oil pressure after the change was made...right?
b) Maybe the distributor was not locked down ( hold down clamp not tightened..or the fingers were not on the distrib) when you went on the test drive... and moved... changing the timing..maybe?
Vig!
Should be a little less than 1/2 of an inch measured at the valve side of the rocker.
DEPENDING ON THE CAM!!!!!! I'm assuming stock/ hydraulic 250 ish hp, not some .600 lift monster!
The distributor would have come into play ..if it was off..not getting the lobe of the cam all the way down when the adjustment was made... (eg the cam was still on the down side of the profile but not at "0")
Cam lift 101, ( rounded numbers)
If you measure the side to side of a cam
( generic ) the dimension is 1.25 inches.
If you measure from the top of the lift point to the back side 1.50 inches
So as the lifter rises out of the block it's only moving .250 of an inch from peak to valley..
Now as you measure from the (1.5 to 1 rocker) you get a measurement of .375 of an inch... Not a lot of lift....
Note here though.. on the first side to side measurement, the profile of the cam comes into play.. that's not ALL the time the "O" point as the cam is egg shaped and might be ground silghtly off center.
The POINT here... you should see about a little more then .250 ( 1/4 inch ) of the lifter poking in & out of the cam / lifter valley and the extra lift comes from the rocker.
A test.. get a piece of cardboard.. and make a mark on a known good lobe in the up position.. then crank the engine around till the rocker/ valve is in the DOWN position.
This will be a rough template of the travel for each lobe... do this 15 more times.. and you will see the one that's ground down to a FLAT ( due to a lack of movement and I'm talking less than 1/2 of what the others do..not .0016 of an inch)....
Now the lifter COULD be bad..but at least if one the lifters doesn't move up & down the same amount as the others... and NONE of the rockers are loose.. it will let you know it's NOW time to pull the intake manifold off and do further inspection!
The other thing that comes to mind... during the distrib pull & reposition that:
a) You had oil pressure after the change was made...right?
b) Maybe the distributor was not locked down ( hold down clamp not tightened..or the fingers were not on the distrib) when you went on the test drive... and moved... changing the timing..maybe?
Vig!
- Thread starter
- #44
A
andrewmckernon
Guest
Im back...
Sorry, I was out for the past five or six days in colorado skiing. Anyway...
I didn't bother to ask what the ration of the rockers was. I got them from the Landmark Auto Parts store down the street. I just asked what the stock type was and that 's what the guy gave me. Yes they are stock....
I started it up, it's still making a clicking noise. 68Roadster, if we could get together this weekend, I'm hoping the weather will be nice, maybe you can take a look at it...
-andrew
Sorry, I was out for the past five or six days in colorado skiing. Anyway...
I didn't bother to ask what the ration of the rockers was. I got them from the Landmark Auto Parts store down the street. I just asked what the stock type was and that 's what the guy gave me. Yes they are stock....
I started it up, it's still making a clicking noise. 68Roadster, if we could get together this weekend, I'm hoping the weather will be nice, maybe you can take a look at it...
-andrew
68Roadster
Well-known member
Skiing? I guess someone had to....
Sounds like a plan. Email your address and phone number and I'll give ya a buzz this weekend. Do yo have clips for the rockers??
So it does run, just clicking?? Oil pressure good??
Vig, we may be calling on you for technical assistance. Hope your support rates aren't like Microsoft's......
Sounds like a plan. Email your address and phone number and I'll give ya a buzz this weekend. Do yo have clips for the rockers??
So it does run, just clicking?? Oil pressure good??
Vig, we may be calling on you for technical assistance. Hope your support rates aren't like Microsoft's......
vigman
Motor head!!!!
- Joined
- Feb 13, 2001
- Messages
- 3,471
- Location
- Valencia, CA,USA
- Corvette
- 88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Nope... WORSE~
LOL.. No problem!
Vig!
LOL.. No problem!
Vig!
- Thread starter
- #47
A
andrewmckernon
Guest
the goods
it's running, just still clicking, and i drove it around the block for about half an hour yesterday and it wasn't responsive at all...
i dont know...
-andrew
it's running, just still clicking, and i drove it around the block for about half an hour yesterday and it wasn't responsive at all...
i dont know...
-andrew
vigman
Motor head!!!!
- Joined
- Feb 13, 2001
- Messages
- 3,471
- Location
- Valencia, CA,USA
- Corvette
- 88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Andrew
If you want to fix it... do the sequence in my post.. and you HAVE to check the LIFT before you do ANYTHING ELSE, otherwise you will be just thrashing!
Vig!
If you want to fix it... do the sequence in my post.. and you HAVE to check the LIFT before you do ANYTHING ELSE, otherwise you will be just thrashing!
Vig!
68Roadster
Well-known member
Post?? Which Post??
Vig,
So you are saying do the check of the lift with the cardboard template first. If all is good, do the static adjustment of the valves. Even if the book says adjust while running??
Let me get the other part straight...at TDC #1, adjust the 8 valves you have specified, rotate one turn on the crank and adjust the other 8....right? And this is all static...
I'm gonna try and give him a hand this weekend, weather's sucking right now but they are saying sunny and 60's.
Thanks for the help...let you know what happens, provided he wants the help.
Cee
Vig,
So you are saying do the check of the lift with the cardboard template first. If all is good, do the static adjustment of the valves. Even if the book says adjust while running??
Let me get the other part straight...at TDC #1, adjust the 8 valves you have specified, rotate one turn on the crank and adjust the other 8....right? And this is all static...
I'm gonna try and give him a hand this weekend, weather's sucking right now but they are saying sunny and 60's.
Thanks for the help...let you know what happens, provided he wants the help.
Cee
vigman
Motor head!!!!
- Joined
- Feb 13, 2001
- Messages
- 3,471
- Location
- Valencia, CA,USA
- Corvette
- 88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
"So you are saying do the check of the lift with the cardboard template first"
YES!... If you suspect any of the lobes.. get to the bottom of the cam... find the "0"lash point and retighten 3/4 turn.. and re check.. if it's the same.. you found your suspect.
"if all is good, do the static adjustment of the valves. Even if the book says adjust while running??"
YES!.. the GM shop manual states static is the prefered way to do it.. and I like it for less mess!
"at TDC #1, adjust the 8 valves you have specified, rotate one turn on the crank and adjust the other 8....right? And this is all static..."
YES... but the trick is finding ACTUAL TDC first..
Remember 1 rotation of the crank is 1/4 of the cam... both valves HAVE to be closed during the #1 piston move UP.. if a valve is moving CLOSED while your coming UP to tdc
Your on the WRONG part of the cam. The trick here is that ALL the spec'd valves will be closed at this point.. so if 1 or 2 are in the WRONG position ( like partially open ) crank around again.
THEN you can do the running adjustment if you feel better about it!
Vig~
YES!... If you suspect any of the lobes.. get to the bottom of the cam... find the "0"lash point and retighten 3/4 turn.. and re check.. if it's the same.. you found your suspect.
"if all is good, do the static adjustment of the valves. Even if the book says adjust while running??"
YES!.. the GM shop manual states static is the prefered way to do it.. and I like it for less mess!
"at TDC #1, adjust the 8 valves you have specified, rotate one turn on the crank and adjust the other 8....right? And this is all static..."
YES... but the trick is finding ACTUAL TDC first..
Remember 1 rotation of the crank is 1/4 of the cam... both valves HAVE to be closed during the #1 piston move UP.. if a valve is moving CLOSED while your coming UP to tdc
Your on the WRONG part of the cam. The trick here is that ALL the spec'd valves will be closed at this point.. so if 1 or 2 are in the WRONG position ( like partially open ) crank around again.
THEN you can do the running adjustment if you feel better about it!
Vig~
- Thread starter
- #51
A
andrewmckernon
Guest
Cee, For help...
Um... i'd really appreciate the help. I think sunday would be the best day for me, and probably weather wise also. Tell me what you think...
-andrew
Um... i'd really appreciate the help. I think sunday would be the best day for me, and probably weather wise also. Tell me what you think...
-andrew
A while back I bought a new set of comp cams roller rockers for my '85 vette and used the supplied locking nuts. I had similar problems wherre the rockers kepted coming loose. I finally put the stock nuts back on and all my problems went away. I say change the nuts.
- Thread starter
- #53
A
andrewmckernon
Guest
Cee...
Hey cee. so what ya think.... what's this about a cardboard template...?
What do you think we should do now....?
-andrew
Hey cee. so what ya think.... what's this about a cardboard template...?
What do you think we should do now....?
-andrew
68Roadster
Well-known member
Andrew,
Vig asked if you pumped up the lifters before you installed them??
Also, did you use cam lube when you put them in??
May still want to pull the oil filter and see if it's clean....
The cardboard thing was to see if all the valves moved up and down the same height. This was to ascertain if a cam lobe was gone. They looked OK to me when we ran it thru.
Let us know about the lifters......
Cee
Vig asked if you pumped up the lifters before you installed them??
Also, did you use cam lube when you put them in??
May still want to pull the oil filter and see if it's clean....
The cardboard thing was to see if all the valves moved up and down the same height. This was to ascertain if a cam lobe was gone. They looked OK to me when we ran it thru.
Let us know about the lifters......
Cee
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