loose in the lifters

The new Tardel-Bishop book recommends clamping the bolt lengthwise in a vise, and giving it a squeeze to "shorten" that necked down area of the bolt a bit. But if the end of the bolt is sticking too far down into the body, you will get the problem you have.

I think those lifters must have been made for reground cams, with smaller lobes.

I'd think it wouldn't hurt one bit to give the loose ones a super-cleaning before assembly and drop some Loctite into those threads after adjusting.
 
alchemy said:
The new Tardel-Bishop book recommends clamping the bolt lengthwise in a vise, and giving it a squeeze to "shorten" that necked down area of the bolt a bit. But if the end of the bolt is sticking too far down into the body, you will get the problem you have.

I think those lifters must have been made for reground cams, with smaller lobes.

I'd think it wouldn't hurt one bit to give the loose ones a super-cleaning before assembly and drop some Loctite into those threads after adjusting.
Click to expand...


Easy enough... Belt AND suspenders!
 
Since there are no loose ones after the squeeze I skipped the loctite. Like I mentioned before, if you were turning that 7/16" wrench down in there you would agree that at 5 ft lbs of torque, these just plain won't loosen in service. Also there was no loss of tension even when there was only a gap of 1/16" under the bolt's head. If these were not made from high quality materials I don't think they would have held up to the wrenching involved. Edit: The 7/16" bolt head had tricked me into thinking the threads were 1/4" fine, but they are bigger. Either 5/16 or 3/8"
 
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I could see no distinction between the two, other than the Drake lifters had the look of 'brand new' in a special plastic packing box and old Johnsons might be in a cardboard box and look 'old'. I could measure something because I have one old type here.
 
GB SISSON said:
Being that the closest auto parts store is an hour round trip I decided to save a couple of bucks and make a tester out of some scrap. I think this should be accurate. I even put an outboard bearing to keep things square. The lifter in the photo is one of the tight ones. Turning the bolt with a wrench instills confidence that it won't unscrew in the engine. That being said, as you can see I have the flour sack at about 6" out and that's all this lifter will stand before the sack drops. Some of the loose ones can't take any flour sack at all. Sliding the sack out to 12" imparts quite a load. Are you sure the 60 in lbs is a good number? And is my conversion correct at 5 ft lbs? Lastly, is my apparatus in order? Engineers, armchair or otherwise please chime in. I'd like to continue my work later this afternoon, after I do some chores.... Thanks, GB
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If I have no flour, can I use potatoes instead?
 
5 ft-lb = 12in x 5 lb = 60 in-lb = 12 in x 5 x 16 oz = 960 in-oz, and so on...

GB, I'd like a further explanation of your meaning about compressing the bolts in a vise. Do you mean the end of the bolt against one jaw and the head against the other jaw, or do you mean the threaded part of the bolt squeezed between the two jaws.

I think you mean the latter, since I can't see how you would compress the bolt lengthwise without damaging it. So are you then putting two flats of distorted threads on the bolt?

Always enjoy your comments.
 
J Witt.

The bolts are squashed lengthwise. It creates a pitch error between the lower and upper parts of the thread. The crush is controlled so when both the top and bottom threads are both engaged in the nut (the lifter being the nut) the desired resistance to turning is created. That's why when they are turned too far in, you lose the resistance as not enough of the lower thread is engaged.

Mart.
 
What do you think of the running surface of this lifter, which is out of my '36 LB engine. Would this be reusable without resurfacing?

These have nice tight screws, I'd guess around 5 ft-lbs.

John
 

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Mart said:
J Witt.

The bolts are squashed lengthwise. It creates a pitch error between the lower and upper parts of the thread. The crush is controlled so when both the top and bottom threads are both engaged in the nut (the lifter being the nut) the desired resistance to turning is created. That's why when they are turned too far in, you lose the resistance as not enough of the lower thread is engaged.

Mart.
Click to expand...

I took the one old lifter apart to see how the old style might differ from these new ones. The hollow body looks identical, but the necked down area in the johnson is cut deeper and closer to the bottom of the screw threads. Perhaps that is why on mine, there is no loss of tension as they near the bottom. Earlier in the thread when I said they became easier as I turned them in, I have decided that was from overuse of the threads which were marginal at the onset. All of mine were flour sack tested at 1.708, which was an average before installation and final adjustment. This left maybe 2 threads visible through the slots.
 
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