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1973 Rebuild


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I glass bead blasted it then went back over it with semi-gloss suspension black, Eastwood product,  then over that with a high heat clear satin Eastwood product as well.  I had bought those products for my steering rack and other bits and pieces as well. Motor mounts, oil pan and tension rods to name some off the top of my head.  Oh yeah, transmission crossmember and other suspension parts. The Diamond Clear I coated all my blasted aluminium pieces and shot the valve cover too bring the semi-gloss sheen down to a matte finish.  Turns out to be a heat resistant matte black.  Their Diamond clear doesn't yellow like other rattle cans. I bought a gravity fed cup HVLP gun from Harbor Freight for $20 or $30 bucks. Keep it really clean and it still works like new at 13 to 15 psi.  Happy, happy.  Joy, joy!

Most definitively use moisture separators, big one on my 80 gallon vertical compressor. Small one on the gun itself.

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There's a few threads on here that go into detail on reconditioning the tank.  Here's a recent one:
As long as you don't have any large holes that require welding, it's a pretty easy (though time consuming and largely unenjoyable) job.  The TLDR version is basically this: fill the tank with something like nuts to knock off any loose rust, remove remaining rust with muriatic acid, rinse thoroughly, then coat with a tank liner like Red Kote.


Okay, I'm going to revive this topic because muriatic acid is no longer available for retail purchase in New Jersey, as far as I can tell. I can't find it anywhere.

I have the Por 15 kit and plan to run through that process next weekend, but I am not certain that it will be enough and would have liked to have done the muriatic acid proves first.

I also need to wait for the red kote to come in the mail because I can't find that either.

So this leaves me with two questions:

Can anyone tell me where I can buy muriatic acid in NJ or online? I've seen it but the shipping for a gallon is $80.

Can anyone tell me an alternative to muriatic acid that is equally effective and available in my area?
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Okay, I'm going to revive this topic because muriatic acid is no longer available for retail purchase in New Jersey, as far as I can tell. I can't find it anywhere.

I have the Por 15 kit and plan to run through that process next weekend, but I am not certain that it will be enough and would have liked to have done the muriatic acid proves first.

I also need to wait for the red kote to come in the mail because I can't find that either.

So this leaves me with two questions:

Can anyone tell me where I can buy muriatic acid in NJ or online? I've seen it but the shipping for a gallon is $80.

Can anyone tell me an alternative to muriatic acid that is equally effective and available in my area?

Did NJ outlaw pools?


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I presume you already know this, but just to cover all the bases, muriatic acid is just hydrochloric acid; maybe you can find that? Otherwise, acetic acid will also dissolve rust, albeit much slower. If time isn't a factor, that'd work. Phosphoric acid won't dissolve rust, but will neutralize it. Electrolysis is another option if your inner Mr. Wizard wants to come out.

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I found something called "user friendly muriatic acid" at a Home Depot 40 minutes outside of my county. It contains hydrochloride acid, but it think it's heavily diluted compared to the normal stuff because of the claims on the label. We'll see if it does anything.

 

Edit: Got a gallon. Picked up some sodium hydroxide to neutralize it. We'll find out next week how it works.

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Engine Buildup: Rotating Assembly

   Piston and Ring Inspection and Preparation

Okay, the lower end is all together but I want to touch on a couple of things I didn't mention...

We don't want ring-bind so before doing anything I checked the ring back-clearance; You know,... the ring width subtracted from the depth of the ring groove. Also, I think it’s a good idea to make certain the right rings come in the package are the right size, so this check takes care of two things at once. The recommended “D-Wall” (radial width) dimension is in the instructions: Maximum D-Wall = Cylinder bore/22

Since the instructions indicate measurements in inches I converted the cylinder’s metric dimension first.

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So, JE recommends that maximum ring radial width of these rings should not exceed 0.1548” for an L-series engine; the recommended Minimum Back Clearance is 0.005”.  I measured the ring groove depths, made a comparison with a ring width measurement, and our rings were okay. But I still double-checked with a straight edge.

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Installing the rings straight forward using all the precautions. The oil ring expander first, followed by the lower oil ring rail, then the upper oil ring rail. The only ring I install without a tool is the oil expansion ring. Some builders spiral the oil rails down the wall of the piston into the groove but the oil rails are thin, and flimsy, and easily twisted. We don’t want deformity during heat expansion so I use the expander for the oil rails too, and place the rings as I'm showing below, so the rings don’t fall out.

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I keep my finger over the back of the ring so that if it comes off the expander, it stays in my hands.

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Oil rail expansion ring ends go under the pistion dome. These rings didn't use a locator tab on the expansion ring. 

 

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Lower and upper oil Rail locations spaced about 60°appart, opposite the expansion ring gap.

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Double check the side clearance and the piston and rod are almost ready to install.

Edited by Takhli
Formating and spelling corrections
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Engine Buildup: Rotating and Reciprocating Assembly

    Piston Installation

With the crank installed and the cylinder bores wiped clean with acetone, the block was ready for pistons and rods. 

I prefer using aluminum tube or the threaded aluminum journal protectors you can buy. I had these for the 9mm rod bolts once upon a time, but someone decided they liked them better than I did. Without them, fuel line works just as well if you inspect for rubber debris before installing the rod cap.

With the rings installed and double checked for proper clock position, I cleaned the rod end and set the bearing insert, and put the pistons into a bath of lubricant. JE’s ring installation instructions recommend Marvel Mystery Oil to lubricate the pistons during assembly and don't recommend using synthetic engine oil until after the rings are seated. Before putting the pistons in the MMO, I cleaned the oil passage in each rod with short length of stiff wire, followed by spray carb cleaner, to make certain each was clear of debris.

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Marvel Mystery Oil bath

When I installed the #1 piston and rod assembly, I found the fuel line I used to protect the crank interfered with the rod journal as the big end of the rod moved over the crank.  Not a big problem but I didn’t like the extra pounding on the piston needed to seat the assembly.  I pulled the piston out and cut a chamfer on the hose – just enough to allow the rod to move over the journal. 

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Don’t forget to lubricate the ring compressor!

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I brought the number one journal to Bottom Dead Center and Installed the piston and rod. The little change I made to the hoses let me push the pistons down the cylinder with just a little hand pressure, to seat the rod onto the crank.

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I watch for vertical scratches on the cylinder wall as I press the piston into the cylinder. If they are there I stop pushing because I know that I either broke a ring or I didn’t file a a ring gap chamfer well enough. The clock position of a scratch would tell which ring has the problem, but we had no problems with this on our build.

I check the rod end to make certain the fuel hose didn't leave debris against the journal, lay on a strip of plasti-gauge, and install the caps.

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Assembly lube is used on the bolt threads and on the machined face of the rod cap.

I use an pound/inch torque wrench and the Factory Engine Assembly Manual for the torque specs. Rod Bolt Torque can be as low as 360lb/in (30lb/ft) and high as 480lb/in (40lb/ft); I stopped at 35lb/ft then pulled the cap off for the plasti-gauge measurement.

With each plasti-gauge crush check finished I cleaned the journal and bearing and pushed the piston up a bit. This opens a small gap between the rod bearing and the journal, so when EOS is pored onto the crank the assembly lube it runs down and wets the upper rod bearing insert. This way I don’t spin the crank with a partially dry bearing. 

Untitled1.jpg 

Gap to allow EOS onto upper rod bearing insert, above.

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I moved through each cylinder with the same method until I got to number five, then had a problem...

The plasti-gauge crush for number five was a little wide but appeared to be in tolerance, according to my calipers and the scale on the plasti-gauge wrapper – too wide means not enough clearance but the crush looked okay. As I mentioned before, I work in 50lb/in increments and spin the crank one full revolution between each 50-pound torque increase. Things were good until I completed 200lb/in torque, when the crank locked up.

I pulled the rod cap off and found the edges of the bearing insert were slightly galled. The marks were very thin; only about 1/64" wide, right on the bearing's edge. I pulled the piston out and moved to number six cylinder, and – bad news! I had the same problem.

We have a polished standard crank so we knew the crank was not the problem. The bearing inserts are correctly marked “STD” so I doubted the inserts were the problem, either. The rods and inserts were cleaned before placing the inserts into the rod and cap, so I was certain it had to be that the rod reconditioning was not quite correct. I left the inserts in the rods and took these two piston/rod assemblies back to the machinist. A quick check showed that the big ends of were just barely too small in diameter. The shop made the corrections and everything was good as assembly continued.

More to follow...

Cheers.

 

 

 

 

 

 

 

Edited by Takhli
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Great work. Weird about the two rods being undersized. Let me make sure I understand what happened...
 
You checked all six with plastigage first, and all of them (including 5 and 6) appeared to measure within spec with the plastigage. But then after cleaning out the spent plastigage and lubing everything up for final assy, the crank bound up when 5 and 6 caps were tightened?
 
The implication here being that the plastigage test was unreliable for some reason or that the spec is actually a little too tight at the lower end?
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Hi, Captain.

Thanks for the question and the observation about plasti-gauge.

Yes, I did the plasti-gauge crush check on each rod and finished each cylinder completely before moving to the next. The crush test on #5 was a little wide but appeared to be within limits when compared to the scale on the plasti-gauge wrapper, so I went forward with assembly. Number six was not as tight so I completely didn't expect a problem. You understand correctly that the crank bound up as I increased torque on each cap.

Personally, I think the plasti-gauge wrapper is susceptible to shrinking and expansion with weather and temperature change. Add to that human error and tolerance stacking or decrease, and for me, plasti-gauge becomes almost the last insurance against improper clearances - the last being that you need to turn the crank as you tighten things up. As builders, we just need to make certain we're inspecting everything we can all along the way, the best we can.

Unfortunately, my bore micrometer and some of my other precision tools went missing when I was building drone engines. Since I don't build engines as much any more, I didn't replace them and use snap gauges and micrometers for dimension measurements. The big ends of these two rods were measured when our parts came back from the machinist and I thought then that they were within limits.  #5 & #6 had inadequate diameter measurements that I misread - very slight, to be sure - but that our machinist later confirmed.   

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