Timesaver

[Jack Innes]

Has anyone first hand experience with Timesaver Lapping Compound for fitting babbitt bearings? It has been around since 1919 & some of the antique engine fellows say it works well. There is a lot of information at http://www.newmantools.ca/lapping/time.htm but they do not say what size to use for a desired clearance. I need to create .0015 clearance on a 1.60" diameter shaft.

 

[gz]

Yes, I have had really good luck with it. I believe there is a course and fine grade. I typically start with the course and finish with the fine.

 

[yachtsmanbill]

Jack... whats the line bearing (babbit) size versus the 1.600" shaft size (kind of a weird size. 1.625= 1-5/8" If its any more than .001-.002" Id get an adjustable reamer and get it down to within reason before using the timesaver. YMMV ws

 

[Jack Innes]

Bill, Here is what I am dealing with. It is a 5 main bearing engine with heavy babbitt lined bronze inserts. It has been line bored & the clearance is set at .0015. It takes a 2 ft. bar to start turning it. I think there is enough misallignment in the bearings to cause this.

Hopefully the Timesaver will take over where my scraping leaves off.

I cannot turn the crank to check it properly so a trip to the junk yard yielded a gear reducer from a conveyor - output 21 rpm, the pto shaft of a wrecked tow truck winch plus a few pipe pieces. The result, after some modification, works well. I will use it to run in the assembled engine as well. The rods holding the engine down are threaded into the steel work bench.

If this all works out I have 2 T engines that will get the same treatment.

 

[yachtsmanbill]

I can see that you are already well in to it, but I hafta ask a few questions... Are you sure its a clearance problem? Is the shaft straight? Was it ground, and if so, were the throws radiussed properly to clear the bearing edge?
Now I have to overstep my bounds... Did this situation occur on the bench or was it bolted down already stretching the block. Was the line bore done with the head(s) or torque plate bolted down to the deck? Is there any thrust clearance yet?
I am gonna add two comments; take them with a grain of salt, but, I see the tube-o-blue sitting there. Do you have any spray blue? Id do all the points of contact and then roll it. A shiny spot may indicate a fatal rub. Make sure the inserts are CLEAN and DRY before rolling them into the recievers. A stoopid hair under a shell can tighten the stuff up in a hurry. I hate to se you wear in a crank thats irreplaceable with timesaver or, as I use, CLOVER brand lapping compound.
In a galaxy long, long ago, I built a roller LT1 SBC. The mains got snugged up to about 50 lbs and it was stuck tight. The line boring job was spot on, and the shop said to pull them down to 100 and it spun with a flick of the wrist. .. just saying. BTW, nice pics! ws

 

[yachtsmanbill]

Ive gotta ad a few more ideas. Is the block clamped down to a substantial table, I mean like a milling machine table? You need something that will traverse against a dial indicator. If the table wont stroke far enough, can you use a straight edge against all the recievers and at least check with a feeler gage?
You may need to line bore the inserts after they are installed and torqued down as well. I hope I am not overthinking this, but like I said, once material has been removed, its hard to put it back on... ws

http://www.enginebuildermag.com/Article/1227/line_boring_equipment_a_boring_subject.aspx