Or get titanium for a hi-tech valve train....
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| Shaved deck/rocker adjustment issues. https://www.slantsix.org/forum/viewtopic.php?t=14364 |
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| Author: | sandy in BC [ Mon Sep 12, 2005 8:05 pm ] |
| Post subject: | Shaved deck/rocker adjustment issues. |
Before I fired up the new motor in the Valaint i rough set the valves. The block deck was milled 60 and the head .024 in order to get 9:1 CR. Once I got everything warmed up and made sure oil was everywhere(fenderwells , tool boxes, windows, rocker shafts) I went to reset the valves and found a couple of loose adjusing screws. Of course with .084 less "play" the adjusting screws are wound almost all the way "loose". Obviously Loctite is not a solution. Do I just bugger the threads a little? Squish the rocker arm itself? Grind the rocker to valve surface?(Do ya think its heat treated?) I dont want to shim the rocker stands....but I would. |
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| Author: | emsvitil [ Mon Sep 12, 2005 8:10 pm ] |
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It's been awhile since I've been under the valve cover, but can't you put a jam nut on them (like my toyota truck has)??????????? |
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| Author: | sandy in BC [ Mon Sep 12, 2005 8:20 pm ] |
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Well.,,,I could...and I had thought about that,,,,but Im a weight freek. I only subtract weight,,,not add. I would rather not add weight to the valve gear if possible. My thoughts had revolved around a sheet metal jam nut,,,,but I wonder how long it might work. |
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| Author: | emsvitil [ Mon Sep 12, 2005 8:26 pm ] |
| Post subject: | |
thin aluminum nut....... |
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| Author: | emsvitil [ Mon Sep 12, 2005 8:33 pm ] |
| Post subject: | |
Or get titanium for a hi-tech valve train....
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| Author: | argentina-slantsixer [ Tue Sep 13, 2005 3:52 am ] |
| Post subject: | |
if you're up to grinding and welding, I'd try first to grind some serious metal otta the rocker tips (say, at least kinda close to the amount of metal removed from your head/deck) this would involve having a fine enough stone to finish them up afterwards. If you have access to a lathe, I can send you some pix of the pushrod shortening tool I grounded for myself. piece of cake having done such work before, not too complicated for the beginner. Or you just can get an hidrolic press and carefully bent one rocker at a time (be sure you have the rockers shaft installed on the rocker or the hinge tubing would crease outta shape) I'm sure we're gonna be called some serious nasty names after all this "crazy" procedures... 
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| Author: | Dart270 [ Tue Sep 13, 2005 5:38 am ] |
| Post subject: | |
My guess is that your SBC valves, if not shortened, are about 0.1" longer than stock Slant valves. This compounds the problem. The right way to do it is shorter pushrods, which are not that expensive (Smith Bros or Mancini cut-to-fit kit for V8s). Rocker stand shims can split the stands. Adding a single nut to each rocker is insignificant, especially given the low RPM range likely (<5500). Lou |
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| Author: | sandy in BC [ Tue Sep 13, 2005 8:36 pm ] |
| Post subject: | |
I got the new motor running well today,,,set the valves 3 times by feel. My machine shop in town has ordered a set of "half nuts" for me.....they are 3/8 fine thread about half as thick as regular nuts....they will be here next week. I will use them as adjuster jam nuts. Repeated valve adjustments and test runs revealed I really only have one rocker/adjuster that would not stay set. I replaced the adjuster with one from the "slant pile"....same result. Tomorrow I will swap in another rocker. That should do till the "half nuts" get here. My GF says Im already half nuts. The new motor is really strong , specially low end...lotsa torque. It will wind freely to a much higher RPM and pulls strongly throughout. The big no no now is a midrange ping. I suspect my cylinder pressure maxes around 3000 rpm now causing part and full throttle detonation. Time to work on a new advance curve. |
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| Author: | Dart270 [ Tue Sep 13, 2005 8:43 pm ] |
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Excellent news, my friend. Timing curve is time well spent in my book. Keep us up on the fun details and test drives...  Lou |
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| Author: | Slant6Ram [ Wed Sep 14, 2005 1:52 pm ] |
| Post subject: | Great work |
Glad to hear it's working out. Hope to see it at Indy (if I can get mine running in time) Sounds like you'll have a real runner after you get the ping out of the power range. Happy curving. 
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| Author: | sandy in BC [ Wed Sep 14, 2005 5:13 pm ] |
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" When it comes to dancing shes the Queen, sounds just like a sewing machine. Peg Leg Peggy:she really knows how to Hop" While waiting for my "half nuts" (next week) I use 3/8 fine plated nuts to lock my adjusters. Turns out with the adjuster wound all the way through the nut I get prezactily 25 thou clearance. I did all the exhaust. The intakes (set at 13 thou,,,my choice) lock by themselves. The plated lock nuts have turned a cool blue colour. Start it up....purrs like a kitten. Throw the v/v cover on ,,,and off for a test drive,,,,damn! clattering valve....reset valves...purrs like pussy. Cover on....clatter! Turns out the top of the adjusters is ~just~ tapping the baffle in the valve cover.....loudly. Excuse me while I go back out to the shop and "adjust" the baffle. ,,,,and oh yeah,,,the ping is much reduced by running .025 and .015 clearances... |
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| Author: | panic [ Wed Sep 14, 2005 7:01 pm ] |
| Post subject: | |
"This compounds the problem" No, it's an error in the opposite direction. Steps to correct: Fix the geo now, which (if the valves are +.100") will require more rocker height. Don't want to use shims? You're left with 3 choices: new valves, custom rockers or bad geometry. Pushrod length change doesn't cure anything but pushrod length. Pushrods are LAST. |
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| Author: | sandy in BC [ Wed Sep 14, 2005 7:39 pm ] |
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I appreciate your concern Geoff. (I used your combustion chamber mod to allow for more flow around my Chev valves....thanks). http://victorylibrary.com/mopar/chamber-tech-c.htm I haven t changed enough things to add up to a radical geometry change. I am still within the range of the stock adjusters. The rockers are centred on the valve stems throughout the cycle. i wont need to change pushrods or shim rockers. More lift or valve length and I would be in trouble. Frankly before I would shim rockers I would mount screw in rocker studs to a "girdle" and run stamped 1.6 Chev roller rockers. An overhead oiler for the rockers would be necessary NBD. Methinks jam nuts to hold lash adjustment will suffice for now. |
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