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#1
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how does a camshaft get stuck
tried to pull out cam and it came out about 4-5 inches and thats it.
Didtributor is out Lifters are out Any suggestions Am I forgetting something Thanks Greg |
#2
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They're sort of snug anyway, but it's probably just tight in the bearings.
Make sure you still have the timing gear on the front so you have some leverage.
You're most likely at the point where each cam bearing journal is starting into the next bearing and they're not quite lined up straight. The timing gear gives you some leverage on the cam. You can also use a coat hanger to support the back end of the camshaft and it might come out easier. You hardly ever have this problem is the engine is sitting on its' backside and you are lifting the cam straight up and out. Good luck! |
#3
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As joe mentioned put the cam gear on to assist in pulling the cam. The gear on also allows you to twist the cam to help keep it moving.
__________________
1967 GTO, 432 (428+.030), 4-bolt mains, factory Nodular crank, scat rods, icon dished pistons, Lunati HR 243/251@.050, .618/.622 lift, Edelbrock 72cc round port heads, 10.5:1, offy 2-4 intake, Edelbrock 650cfm carbs, Super T10 trans (2.64 first), BOP 10 bolt w/ Eaton posi and 3.36 gears |
#4
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#5
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I have always removed the factory style camshafts using a coat hanger to support the rear of the camshaft so that the camshaft goes easily thru the #4 camshaft bearing (which also happens to be about 6 inches from the end of the camshaft. Then do the same routine on the other camshaft bearing locations.
You can see the camshaft, just slip the hanger curve past the lifter bores and locate it as far to the rear as you can on the cam. Then gently pull on the timing gear while finding the center of the next camshaft bearing. Patience and it comes out pretty easily. Tom V.
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
#6
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Be careful Greg getting the cam out.
Once you pull it out of the rear saddle it will want to drop so as Tom said use some support or you will gouge the cam bearings Jeff
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Carburetor building & modification services Servicing the Pontiac community over 20 years |
#7
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Lifter or two in the blind around the middle valley.Or just hung up on a wiped out cam bearing.
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#8
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upload tezt
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#9
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I used a hanger and got it out but there was cam bearing on it.
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#10
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Better check that cam bore closely. Having a press fit cam bearing come out with the cam ISN'T "normal".
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“It takes considerable knowledge just to realize the extent of your own ignorance.” Dr. Thomas Sowell |
#11
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Quote:
Probably not good either way |
#12
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Are going to install a new cam or completely rebuild the engine? IF you are doing a complete rebuild it would be and excellent time to check the cam bore alignment.
__________________
“It takes considerable knowledge just to realize the extent of your own ignorance.” Dr. Thomas Sowell |
#13
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Quote:
But after seeing cam bearing shavings I am concerned |
#14
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You need to be...
__________________
“It takes considerable knowledge just to realize the extent of your own ignorance.” Dr. Thomas Sowell |
#15
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You probably just scraped the edge of a bearing as you pulled the camshaft forward and it dropped. If you were yanking on it and letting it rattle around unsupported, you probably scraped the edge of one or more bearings. If you can run your finger around the edge of each bearing, feel for any rough edges and also for deep scratches on the actual bearing surfaces.
Lightly scotchbrite the edges of any deep scrapes on the bearing surfaces … do not try to polish them out completely. You just want to dress down the high spots of any displaced bearing material to prevent a "tight bearing". If you mangled the edge of a bearing, you can lightly chamfer the edge of the bearing material but there is no thrust surface, the cam just rides inside the bearing. Short of pulling the engine and having new bearings installed, there isn't much you can do. A light burnish with a scotchbrite pad will smooth that out. If you can't Just clean the bearings well and oil them before you reinstall. If a deep scrape runs continuously front to back on a bearing or across an oil hole from the edge, a loss of oil pressure can occur depending on how badly scored the bearing is. That said, there is a lot of bearing surface relative to the load and there are a lot of cam swaps that run for tens of thousands of miles with a scrape or two on the cam bearings.
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Triple Black 1971 GTO |
#16
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I don't know why but I'm hearing a lot more cam bearing issues?We had a issue with one of my engines and have seen a few more blocks that have line bore problems.Tom
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#17
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And expounding on that, if the engine required a line bore when rebuilt it wasn't because Pontiac got the mains out of line, it's because the block twisted and curved slightly over the years from the heat cycles. This curvature is throughout the entire block including the cam tunnel. If the cam bearings weren't clearance when the new cam was installed and went in tight, it is going to make room for itself. Unlike removing a thousandths or so of material with a knife or homemade cam cutting tool, the cam will generate heat on the Babbitt until the material gets hot enough to move around out of the way. Enough binding and the Babbitt smears over and covers the oil hole. Then the Babbitt gets hot enough to drip out of the shell. If a lip is created then it is difficult to remove the cam without knocking the bearing loose. Even a little generated heat can be enough to delaminate a layer of Babbitt and there will be flaky holes visible.
Anyway, a good look at the bearings will tell you whether you were just a little out of line pulling the cam or if you have problems that need to be addressed before putting in the new cam. The new cam needs to turn with minimal resistance or it will have problems later on.
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Mick Batson 1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 2+2 survivor AC auto -- 1965 Catalina Safari Wagon in progress. |
#18
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sounds like the builder didnt put breakin lube on the rear cam bearing and lobe. i would replace the cam bearings(all). this will require you to pull the motor or trans to change the rear one. make sure the oiling holes are alingned with the galley holes too.
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1970 firebird, 468, e heads, |
#19
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Quote:
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“It takes considerable knowledge just to realize the extent of your own ignorance.” Dr. Thomas Sowell |
#20
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I'd suggest taking this to someone who knows that they are doing!
__________________
************************************* 1968 Lemans. 37,000 original miles. GTO clone. 462ci/KRE 290 heads. UltraDyne 280/288 Solid/850 Qjet by Cliff/Performer RPM/TSP 9.5" in TH400/8.5" 3.42 gears/3950# Race weight/12.58@106 at Bandimere speedway high altitude |
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