How many of you set your rod bearing clearence by the slide method? Have an opinion?
I don't know what you mean by the slide method?
If by slide method you mean tapping with a hammer to check movement after removing shims---I doŚNever use plastic gauge whether new or used rods---never have trouble using this method---works for me
I use plastigage to get a ball park idea of where to start, and then remove the appropriate number of shims to give me what I want. The only thing I don't like is I can't buy shims in .001 and .002" thicknesses; I have to make them which is a pain.
Norm, yes checking the slide from movement of the rod ffom crank web to crank web by tapping it with a hammer.
Larry, the lamanated shims you can buy from Langs, synder, mac's can be pilled down to a .001 shim. These shim packs start out at a .032 thickness and can be pilled to any thickness your looking for.
I have used the slide method myself, but haven't heard it called by that name.
I like to use prussian blue to check for bearing contact, then do a little scraping on high spots, and use Plastigauge to see how much clearance it has. The slide method works and if you happen to be on the road and need a quick fix it will get you in the ballpark, but cannot tell if you have good contact all the way around. It will get tight when the high points are tight. The most exact method is to use prussian blue and Plastigauge.
We used that metohd before plastigage to fit chev. rods. In my opinion plastigage is more accurate. In tinkering tips they suggest using a strip of newspaper to check bearing clearence. I have never tried it but I may after I use plastigage. Nelson
A black magic marker will work if you don't have any prussian blue
Nelson, I used standard newspaper to set my rods, then checked with plastigage. They all measured .0015.
I use newspaper, or if I can't be bothered, just go by feel. A little resistance on the crankshaft and they're about right. Like other aspects of servicing the T, the clearance is not super critical; not too loose and not too tight. What "feels right" is learned after doing it a few times.
If you're installing conrods that have been used on another crankshaft, rather than merely taking up what's already in the car, then prussian blue and a scraper should be used to get the shape right first.
How much newspaper is used in this method?
1/2" wide strip, the width of the cap?
1" wide strip, the width of the cap?
Full length of the cap, full width?
I use magic marker to check for high spots, then check clearance with plastigage. I am fascinated by the newspaper technigue. I'm going to have to try that.
I also use a magic marker "Marks-A-Lot" brand in particular and prefer blue. When you're done coloring in the contact surfaces on the babbit, it looks like you've used prussian blue. I've tried other colors but the blue works best for me.
I still hand scrape the bearings. It takes a little time but it's very satisfying when you hit that magic moment when you give the crankshaft one turn, pull the cap and find all shiny surface with a little blue spot here or there which is of no consequence.
As for shims, I cut my own .001 and .0015 shims for fine tuning my clearances. I have hole punches for rod and main bolts and I don't try to match all the curves present on factory shims. Doesn't have to look nice, just has to work.
I've done several engines this way and they haven't had any bearing troubles.
Don't forget the Timesaver if you want to get a really good fit.
Jack Daron said: to use "one thickness".
But it seems like nobody wants to divulge the secret of what size of a piece of newspaper to use.
I tried Timesaver on a '14 block that had been rebuilt about 20-odd years ago. I knew the outfit that did the babbit work and had learned to check their fit. If you wanted a decent parade car they did okay, but if you intended to drive it a lot you had to do considerable work on the bottom end. What I learned in this case is that Timesaver won't work if the babbit is bored tapered.
The mains were so poorly done that by the time I was able to scrape the bearings down to the point where using Timesaver would work, the shims were all gone. Needless to say, I'll be pouring and boring this one all over again to make it right. The firm in question no longer does this work although they got better toward the end again. Their old babbit man died of cancer and wouldn't train anyone (job security) and this engine was basically done by someone early in their learning curve.
The last guy they had doing the work dropped dead of a heart attack 2 days before he was going to retire. By that time the firm had been purchased by a company out of Chicago that wanted to dump the antique engine rebuilding anyway so the equipment was sold off (I here the local Model A Club got a lot of it).
I started pouring my own bearings after my first experience with this firm and haven't looked back.
I use a strip about an inch wide and long enough to cover the length of the bearing but it really doesn't matter. If it locks up with the paper installed yet turns free with it removed, the clearance is correct.
Any reason you don't post your real name?
If you don't want to use newspaper, I've had good luck just using a piece of .001" shimstock. If that locks it up, you know you're right on.
Gary and Larry,
Interesting technique, but do you roll the strip all around the journal or you just use half of it- only between rod and big end, not cap ?
Thanks in advance
I lay it across the cap only and then tighten the bolts up. If it locks but is then free with the paper removed it is ok.
A receipt from Wal-Mart or Lowe's is about .0015, and there are always some of those lying around.