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#1
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Timing chain
Am I nuts or is this a broken link on a chain with about a half an hour of actual run time?
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#2
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I don't think your nuts, looks broke to me. Made in China? I prefer a good quality double roller myself, but that is my opinion and others will argue.
I pulled the double roller off my 25,000 mile 400CI rebuild and the chain was a tight as the day I put it in and I did not baby the engine. Cam was the Comp XE274 with their recommended springs to give you an idea of what spring pressures I was running. Maybe higher spring pressures with a roller might be a horse of a different color. |
#3
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I think I have one but I might just order one, glad I decided to change the timing chain cover or I wouldn’t have found this!
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#4
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Just curious, what made you take the timing cover off after a half hour of run time?
__________________
My Pontiac is a '57 GMC with its original 347" Pontiac V8 and dual-range Hydra-Matic. |
#5
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I had pulled it from the chassis as it was leaking from the rear main. When I put it all back together I used a different timing cover. I’ve had it leak from between the water pump and timing cover with a pressure tester on it, first time was 15lbs of pressure over night and second time was 10 pounds in 10 minutes. So I said enough of this I’m putting the other cover back on, it never leaked. I used ultra grey both times.
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#6
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So I have another timing chain, double roller but I’m struggling to line up the keyway on the cam sprocket, I’m a hair off and it keeps pushing the key out. Can I touch the Crank a hair to get it spot on? Will that cause issues? It’s a hair off no matter how I move it.
Last edited by ITSBACK; 08-26-2020 at 09:32 PM. |
#7
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Hmmm. Don't know what a "jetway" is? You New Joyzy guys use different terms than us Connecticut guys.
Are you talking about the "keyway", that half mooned thingy and the slot in the cam snout or cam gear? You want to have the cam gear/crank gear "dot" lined up correctly. Some will simply get the No. 1 piston to TDC, the rocker arms both closed, so the cylinder would be in the firing position and then install the gears/chain with "dots" lined up. Others will be more precise and do the degree wheel install to get things aligned per the cam card specs. I am a wing-it type and get the piston to TDC, valves closed, distributor rotor pointing to No. 1 spark plug wire, and then align the "dots" as you slip on the gears & chain. If it is a hair off, yep, I would turn something, but once installed, make sure the "dots" still line up. Some can be a pain to install, but make sure the keyway is set down all the way and if it is a little cocked, it may be hard to get the gear on. Also check for any burrs. I have had that experience where I had to knock out the keyway and in doing so mushroomed and edge ever so slightly, but enough that I had to dress it up with a file. Put a little oil on the cam/crank snout which can help. It may not just "slip" on and may use a little love tap from a soft mallet or piece of wood/hammer. Just use good judgement. If it is not going on, then look for a reason. Post a photo if you can as this may help us help you. |
#8
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You need to degree it to know what's going on and adjust from there. moving the crank makes no difference. you could also buy a new chain for the linkset. the gears are so new i'm sure they arn't worn yet.
__________________
1979 Firebird Trans Am 301/4spd (Now 428) 1977 Firebird Formula 400/Auto 2007 Grand Prix GXP 5.3L |
#9
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Well first off, jetway was a typo lol. I did go back before and correct that. When originally installed I did degree the cam and also used an offset key in the cam to either retard or advance the cam, I just don’t remember. The gears are brand new with the new chain, changing it all. I’ll dry nudging it a bit, done for the night, don’t want to start throwing hammers and screwdrivers across the garage, lol. I appreciate the input and will take pics and follow up!!
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#10
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File or grind a nice lead in taper to the key groove on each gear and they will go on without driving the key out.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
#11
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^ This but don't overdo it. Sometimes it helps to have someone pinch the timing chain in from one side or the other to get it to align.
__________________
Triple Black 1971 GTO |
#12
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If the original chain/gears will slide off and on, and you have to turn something for the new chain/gears to fit... Original cam degreeing just went out the window. Doesn't count anymore.
Clay |
#13
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I was able to get it by filing a bit and getting that little pinch with the crank, then brought it back.
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#14
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What is it about those XE cams, people seem to have so much trouble around them even indirectly like this incident...
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