Vintage Mustang Forums banner

1 - 3 of 3 Posts

·
Registered
Joined
·
4,926 Posts
Discussion Starter #1
For the past 2 weeks I've been trying to adjust the valves on cylinders 4-6 on my I6. The problem is the gap between the valve stem and rocker roller tip is so large that adjusting the adjustment screw to take out the slack sets the screw so deep into the rocker there are no threads for the lock nut to grab.

I thought I had gunked up the lifters with assembly lube from the ends of the push rods, thus keeping the lifters from pumping up. Over the weekend I pulled the head, pulled all 12 lifters and took them apart, cleaned them, re-oiled, reassembled and then reinstalled the lifters. I dropped the head back on, re-installed the roller rockers (mounted on 6 shafts, 2 rockers to a shaft. Again, cylinders 4-6 would not adjust.

ok, I pulled the rockers from 4-6 and also 3. I measured the shaft diameter, the rocker thickness, the length of the adjuster screw, the length of the push rods, and everything was the same between #3 and ##4-6. Huh? At this point I am thinking the custom ground cam was a little too custom ground, particularly the lobes for 4-6. I take off the rockers again and using a depth gauge measure each of the 12 push rods at its lowest point as I rotate the crankshaft twice. All 12 pushrods have the same measurement. Well, that eliminates the cam as being the problem, unless the last 6 lobes were ground out of phase with the cam timing.

I re-read the instructions for installing the roller rockers and see a sentence: Note, spacers may need to be ground. ok, I figure I need to grind 1/8th off the spacers which shim up the rockers from their mounting plates. I started to grind one down, but without a jig and using freehand, the face was irrigular angles and I knew that would not work. I stopped at that point. Finally, I remember that I had rotated the rockers on three shafts 180 degrees. hmmm, I wonder if that is the problem. 45 seconds later my problem went away.

After spending 20 hours on this over the past 2 weeks, it turns out to be a 45 second solution. I could have done that last weekeend and saved 3.5 days of work. I feel sooooo dumbbbbb! BTW, it is not easy to drop an I6 head onto an engine by yourself. I used dowel rods in two of the bolt holes in the block to hold the head gasket in position, then dropped the head over the dowel rods. Now that was a PIA, even standing inside the engine compartment on the frame rails, the angle does not allow you to see the rear part of the head to line up with the dowel. The third time I put a piece of 2x4 on edge on the block and rested the head on that, rather than smashing my fingers. Was interesting to figure out how to use two hands to lift up the head and then push out the 2x4. Times like that I wish I had a wife or child around to lend a hand.

Well, now I have to replace the spacer I took a grinding wheel to. The machine shop tells me it is hardened steel, metric, and to fabricate a duplicate using a drill bit collar as hardened steel stock will cost me $60 or 70 a pair. And, the collars have to be ordered out of Los Angeles. The manufacturer of the roller rockers is in Australia, so the best recourse seems to be the custom fabrication here in town. :wall:
 

·
Registered
Joined
·
6,163 Posts
And you almost made it to the end of the year too, I hate when you get this close to the end of the year before being a doofus. :wall:
 
1 - 3 of 3 Posts
Top