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1970 amx new timing covers |
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DHACKING
AMC Apprentice Joined: Oct/06/2014 Location: DALLAS FT WORTH Status: Offline Points: 184 |
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thanx to all for the replies.....greatly appreciated....
ESPECIALLY WANT TO THANK SC/397 FOR YOUR DETAILED TIPS....I FOUND THEM THE OTHER NIGHT ON THE WEB AND THINGS LIKE THIS ARE GOLD TO US ESPECAILLY AFTER BEING OUT OF THE HOBBY FOR 3 DECADES! |
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RAYMON H
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SC397
AMC Addicted Joined: Apr/30/2009 Location: Michigan Status: Offline Points: 5428 |
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Glad it was helpfull!
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amcenthusiast
AMC Addicted Joined: Jul/02/2012 Location: SW Atlanta GA Status: Offline Points: 1778 |
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Since all '66-'91 AMV8s use no cam thrust plate to control camshaft end play, you gotta get the cam snout assembly 'stack height' correct & use the correct grooved head cam snout bolt.
-The stock AMV8 cam bolt doubles as the 'cam button'. The grooves are there in the head of the bolt for lubrication as the 'button' butts up against the machined surface there inside the timing cover. *The stock cam bolt is actually a component of the engine's oil system, where the grooves are there to lubricate the 'button location'. IMO, the best way to measure cam bolt to timing cover clearance is to place a small lump of modeling clay on the grooved head bolt and 'dummy' the assembly together. -too much clearance and you're sure to have distributor gear problems. -too little clearance (or none at all) and the cam bolt (wrong type of bolt?) will gouge into the underside of the cover (I've seen this on junkyard engines back in the seventies where the mechanic used an ordinary hardware store type of bolt and the cam chewed a hole through the cover into the water pump cavity) Edited by amcenthusiast - Apr/25/2018 at 7:26am |
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443 XRV8 Gremlin YouTube video: https://www.youtube.com/watch?reload=9&v=2DmFOKRuzUc
XRV8 Race Parts website: http://amcramblermarlin.1colony.com/ |
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69 ambassador 390
Supporter of TheAMCForum Joined: Nov/22/2009 Location: Peoria, AZ Status: Offline Points: 3539 |
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The grooves are there to denote grade eight fastener. They are just marked that way instead of just lines to denote a special thin head fastener. The bolt DOES NOT act as a cam button and should never contact the inside of the cover. The grooves in the head of the bolt actually will destroy the cover if they make good contact with it. They act like a cutting tool. I have taken many engines apart that have had the cover almost cut all the way through by those "lubrication slots". A few have even destroyed the engine when they grab the cover and jack themselves through the water pump or push the cam out the back of the engine. You are correct in saying that you must have the correct stack height though. I often polish and thin the head of a grade 8 bolt to prevent this. The oil pump drive gears and cam lobe provide rearward thrust to hold the cam sprocket against the block. The bolt should never touch the housing unless the chain is shot or the stack height is wrong. Just saying. I do this for a living and exclusively have done AMC for the last eight years. Did three this week.
Edited by 69 ambassador 390 - Apr/25/2018 at 10:04am |
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Steve Brown
Algonac, Mi. 69 Ambassador sst 390 84 Grand Wagoneer 69 Cougar XR7 65 Fairlaine 500XL 79 F-350 Super Camper Special |
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69 ambassador 390
Supporter of TheAMCForum Joined: Nov/22/2009 Location: Peoria, AZ Status: Offline Points: 3539 |
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By the way, we have had good luck with the Omix/Ada covers but the ProForm covers are crap. The ProForms look to be a much nicer casting but the machine work was done by six year olds. Don't use the ProForm covers. Always check any cover for gear mesh pattern and backlash with lead past or blue paste. Just like any hypoid gearset. Also check pump cavity fitment and distributor to pump gear fit. Test fit gears and dizzy off engine and then on.
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Steve Brown
Algonac, Mi. 69 Ambassador sst 390 84 Grand Wagoneer 69 Cougar XR7 65 Fairlaine 500XL 79 F-350 Super Camper Special |
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Steve_P
AMC Addicted Charter Member Joined: Jun/28/2007 Status: Offline Points: 3760 |
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The screw that holds on the cam timing gear is called a place screw. The head is slotted so that it deflects and helps to lock the fastener in place. It's not for lubrication purposes and as said it acts as a cutter and saws thru the timing cover on higher mileage engines when the timing chain wears out.
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304-dude
AMC Addicted Joined: Sep/29/2008 Location: Central Illinoi Status: Offline Points: 9081 |
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My high milage (120,000 miles) engine that was rebuilt with over 95,000, still has its original timing cover. It does not show much wear at all. Since it never was high performanced I think chain stretch plays into how far the cam can walk or abruptly kick into the cover.
I also have a scrap oem timing cover of unknown history, that has pump wear (scoring) and the infamous circular gouges from cam walk. Unknown milage, but from the wear patern in the pump, i assume most of the damage is from lack of lubrication. Could be also be from running the engine hard, jeeping or strip use. |
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71 Javelin SST body
390 69 crank, 70 block & heads NASCAR SB2 rods & pistons 78 Jeep TH400 w/ 2.76 Low 50/50 Ford-AMC Suspension 79 F150 rear & 8.8 axles Ford Racing 3.25 gears & 9" /w Detroit locker |
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6PakBee
Supporter of TheAMCForum Charter Member Joined: Jul/01/2007 Location: North Dakota Status: Offline Points: 5454 |
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An absolutely correct answer. You find the same type of fastener on some flywheel/flex plate bolts for the same reason. |
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Roger Gazur
1969 'B' Scheme SC/Rambler 1970 RWB 4-spd Machine 1970 Sonic Silver auto AMX All project cars. Forum Cockroach |
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