Limited disassembly of a 1980 IC 196

[Mark Pietz]

Robert, we're making progress! I roughed out a mounting bracket that I will duplicate in thicker metal once I finalize its shape. I used a piece of angle iron that on the forward end, shares the upper forward motor mount bolt. I will need to weld a tab to the angle iron that will lay against and bolt to that unused fuel pump boss. Holes already tapped and ready to go. I cut out a section of the top of the angle and welded in a piece that closes the 90 degrees to 75 degrees (an acute angle). Turbo base bolts to this, and the base is level with the floor. So this bracket, that will uphold the turbo's weight, should be solid enough. Although I had done proper measurements, I inadvertently welded the "shelf" the turbo bolts to, an inch too far forward. That space is needed for the pipe to clear the back of the new vertical mounting plate. Easy to correct. At this time it looks like the turbo and exhaust pipe ell will fit as envisioned. Additional plan is to fab an additional stabilizing brace using the triangular exhaust pipe collar. Next details to finalize are to use a hole saw and cut out the dip stick boss on the oil pan, and relocate it further aft. In this hole I plan on welding in a nipple that will accept the oil return line, and it is vertically in line with the turbo's center section. Then on to crafting a pattern for a new intake elbow to cast in aluminum. But before I do much more, I'm going to clean this engine and repaint it!

Edit: updated side-shot after moving assembly aft one inch. Makes all the difference.

 

[Mark Pietz]

I've begun disassembling the engine. I was hoping for better, but it's going to be what it is. The good so far is that I can see the camshaft and the lobes look great. The lifters are also still convex, and I know they were all spinning, so I'm thinking so far that I can remove it, probably tomorrow, and set it and the lifters aside. Tomorrow the crankshaft, rods and pistons come out. If nothing is shown to be worse than what I've seen so far, fingers crossed that I can get away with grinding the journals 0.010" under. That's a win.

I've attached some pics of what I found after removing the head. Either this engine has been running real rich, or I have a lot of oil leaking by the guides? This engine has only 5K on the rebuild documented earlier, and I didn't do the head work. All the guides and most (maybe all) the valves were replaced, with new OEM springs, by the machine shop. As far as the holes go, all still have cross-hatching, and the bores have familiar fine scratches in the stroke direction (every engine I've ever had the head off of had scratches from grit or whatever along the thrust surface). Barely detectible with a fingernail, if that. The carbon deposits on the tops of the cylinders comes off with some vigorous rubbing. To me it looks more oil than rich, but I'm no expert. The tops of the pistons have a funny gold cast to them. We had set those pistons to 0.0035" recommended clearance because of adding a turbo. Maybe just lightly hone the bores? It all comes apart tomorrow for further inspection.

 

[FDChappie]

What prompted you to take the engine apart?

 

[Mark Pietz]

What prompted you to take the engine apart?

I need to run a pipe under the engine between the exhaust manifold and the turbo. The Scout II is lousy for this due to the double sump pan, and would require notching the "notch". So I pulled the pan to begin that process and saw a lot of metal in the pan. Took off a main cap and a rod cap. Bearings were already wiping, and grooving of at least one main journal. With that going on, the only thing one can do is disassemble, see what else needs to be corrected, and rebuild. I thought that rebuild would have been the last, but it was not to be. The vehicle unfortunately has had to sit outside in wet and now humid, climates (but under cover, for whatever help that provides) and that has taken its toll.

 

[FDChappie]

Sorry to hear that. Any idea what the cause of the bearing failure was?

 

[Mark Pietz]

Got the engine 98% disassembled, aside from the head. Crankshaft bearings all showing signs of wiping, mostly the load bearing halves of the rod bearings. I might be nuts but at best it looks like a polish, worst will be 0.010" under. I'm just not seeing real bad, but I'll let the pros measure and advise. As far as the camshaft goes, lobes look perfect, so that's a huge win. Since I have the engine this far apart I'll replace the cam bearings since I dinged the front one getting the camshaft out. As far as the bores go, they look good, and can see a few linear scratches along the stroke axis. Barely feel any of them with a fingernail, if that. But all the pistons have scratching/scoring (not wanting use improper terminology as scuffing is a result of overheating?) like this on the same side of the piston. This is the top (intake side). Looking like new pistons and all that are in order.

 

[Robert Kenney]

Sorry to see the damage!

In general on the pistons, if you ran out of clearance from whatever, you would have the scuffing on both sides 180* from each other. More on the thrust face but still on both sides.

From what I am seeing, the scuffing, rod bearing damage and boosted induction, you're lean and had some detonation.

I don't remember if you were pulling timing out while under boost. If not you need to pull out 1-1 1/2 degrees per pound of boost without a knock sensor.

Run 11.5-12.5 AFR's while under boost.

I would run the pistons again. Level out the scuffing and leave a sanded finish on those areas. Double check the clearance.

Look at boost referencing the power valve. It is possible that you were under boost while the carburetor was still in cruise mode.

 

[Mark Pietz]

Sorry to see the damage!

In general on the pistons, if you ran out of clearance from whatever, you would have the scuffing on both sides 180* from each other. More on the thrust face but still on both sides.

From what I am seeing, the scuffing, rod bearing damage and boosted induction, you're lean and had some detonation.

I don't remember if you were pulling timing out while under boost. If not you need to pull out 1-1 1/2 degrees per pound of boost without a knock sensor.

Run 11.5-12.5 AFR's while under boost.

I would run the pistons again. Level out the scuffing and leave a sanded finish on those areas. Double check the clearance.

Look at boost referencing the power valve. It is possible that you were under boost while the carburetor was still in cruise mode.

Towards sorting this out...

I had a programmable crank fire system, and emulated a stock 196 n/a curve. IIRC, I had a max of 32 degrees advance @ 4K, n/a. Boost was retarded 2 degrees per pound, so at 8 lbs., the highest I had opportunity to see, I was at 16 degrees BTDC. In between is simple interpolation. Maybe that was enough, maybe not. Something to play with when I get this going again, but I think I will pull out a few more degrees. I know that after doing some data logging, I thinned out the end of the carb needle and ended up at 11.4:1, which was right. What it was doing under other conditions is now the unknown, but I still have some old data to go back after I added the UEGO, to look at. Be nice to know when that occurred, if possible.

The path forward, then. Getting the crank repaired w/new bearings is the easy part. The pistons - what, 280 grit sandpaper lightly perpendicular to the stroke, smooth it out. Check.

Lightly ball-hone the bores or just leave them be?

Reuse the rings?

Since I have a valve spring compressor, I'm going to pull out a few valves just to look at them and see if they noticeably wobble, and go from there.

Time to also have a discussion about "carburetion", or EFI. I don't need another learning experience after I reassemble this engine.

 

[Robert Kenney]

Towards sorting this out...

I had a programmable crank fire system, and emulated a stock 196 n/a curve. IIRC, I had a max of 32 degrees advance @ 4K, n/a. Boost was retarded 2 degrees per pound, so at 8 lbs., the highest I had opportunity to see, I was at 16 degrees BTDC. In between is simple interpolation. Maybe that was enough, maybe not. Something to play with when I get this going again, but I think I will pull out a few more degrees. I know that after doing some data logging, I thinned out the end of the carb needle and ended up at 11.4:1, which was right. What it was doing under other conditions is now the unknown, but I still have some old data to go back after I added the UEGO, to look at. Be nice to know when that occurred, if possible.

The path forward, then. Getting the crank repaired w/new bearings is the easy part. The pistons - what, 280 grit sandpaper lightly perpendicular to the stroke, smooth it out. Check.

Level the high spots on the skirts with a flat stone or shoe shine with wet/dry 320-400. Finish similar to SL factory perpendicular roughness

Lightly ball-hone the bores or just leave them be?
I would glaze break them.

Reuse the rings?
Not unless they are unavailable. Did you but a v8 set? Oil in the combustion chamber is not good

Since I have a valve spring compressor, I'm going to pull out a few valves just to look at them and see if they noticeably wobble, and go from there.

Time to also have a discussion about "carburetion", or EFI. I don't need another learning experience after I reassemble this engine.


No intercooler or oil cooler can make a significant difference on piston temperatures. Might run a thinner oil unless you were already at XX- w30 or-w40.

Paste from Silvo-Lite oem piston to cylinder clearance
P# P-Dia P-C-C
7080D 4.1250 0.0030 I like .005 for your application.
7082D 3.8750 0.0030
7084D 4.1250 0.0020
7096D 4.0000 0.0050

 

[Mark Pietz]

Good thing I'm retired. Moving to a new place and locating an engine machine shop you can trust can generate some anxiety. Local, very active Scout club member recommended a shop that has just done his engine. Unfortunately I am rural, on the other side of Houston. Drove almost 90 miles to deliver the block, head, crank, flywheel, and have a show-and-tell with the rod/piston assemblies. Four or five hours out of my day on the freeway in Houston traffic. Owner looked at the scoring on one of those pistons, ran a finger across it, and made a comment to the effect, "not a big deal at all". Of course he'll tank the block, assess the bores (in one is an odd slight discoloration and spot the size of a fingerprint that feels different), check the crank, disassemble the head and clean and assess and look at the piston pins, but this is more for peace of mind as I have this thing completely torn down and at this point in my life I don't ever wish to see the inside of this.engine.ever.again. Might be getting off with just bearings, a polish or grind, and honing. In any case it will all be tidy and clean. Updates as they come!

 

[Mark Pietz]

A call today from the machine shop. Good news and bad news. Good news is that the crankshaft will polish out, so that's standard bearings. Bad news is that the pistons have collapsed. Guess that's the favor detonation does for you. Bores are good; he said that they were within the 0.0035" done at the rebuild. Honing will clean that up. He said to get the same 0.020" pistons. He recommended a speed shop that can cut the tops of the pistons to increase the size of the heel, as I need to increase the reliefs on the top of the pistons by 4 cc, the get the c.r. down to 8:1. This time I won't have to resort to the caveman method I did before.

Excuse the crude combustion chamber "rubbing" I did yesterday to characterize the IC196/392 quench space overhang, which are actually two crescents roughly opposing each other. For future reference, a band 0.400" wide around the piston's circumference will easily shade these crescents and preserve the quench effect, here being a tic over 0.040" piston-to-head clearance. By my calculations a circular recess 3.345" in diameter (leaves that 0.400" wide band around the outside) and 0.030" deep will increase the negative space by about 4 cc since roughly half of that machining will be over the existing heel. This will put me at 7.95 - 8.0:1.

Looks like it's time to put together an order for parts and give Jeff a call.

 

[Robert Kenney]

Do your rods have oil jet holes pointing at the cam. Usually on the top side of the big end. The 152's did and only the 4 cyl bearings had the hole in the bearing shells.

 

[Robert Kenney]

See if you can still get the same pistons. I thought United/ Silvolite stopped making them.
Second where did they collapse and how much.

 

[Mark Pietz]

See if you can still get the same pistons. I thought United/ Silvolite stopped making them.
Second where did they collapse and how much.

I'm going to try to retrieve the pistons just because. He said that dimensionally they were all over the place. I noticed the piston tops were turned a gold-ish tone, thought maybe that was oil or varnish or maybe fuel, but when I dropped them off, I looked at the underside of the pistons and saw this odd gold discoloration there. Can the aluminum discolor from overheating? It didn't look right to me.
Yes, oil spit holes, and the rod bearings have a hole to feed them. Can the rods be installed backwards??? The pistons have an arrow indicating top, and the heel is down.

Investigating further. I have a pic of my piston/rod assemblies, maybe I can glean an answer to the spit hole question.

 

[FDChappie]

I put the Silvolite .020 over in my 345 during the rebuild. That was a few years ago now (6).

 

[Robert Kenney]

While I can't see the underside discoloration, that is not totally unusual due to oil will coke under high temps. While that does indicate some heat, it does not dictate overheat to the point that the casting has annealed. Typically 350-400*F is needed to take the hardness out of aluminum castings.

I wonder if you had very high oil temperatures. How long did you run it continuously on boost? An oil cooler might be good.

The rod is not symmetrical because they were a a v8 made to run against another rod. See my photo of a 152 rod (similar to 196) marked for install orientation. The 4 cylinder crank has a small and large fillet on each rod journal to suite the V8 rod.

 

[Mark Pietz]

While I can't see the underside discoloration, that is not totally unusual due to oil will coke under high temps. While that does indicate some heat, it does not dictate overheat to the point that the casting has annealed. Typically 350-400*F is needed to take the hardness out of aluminum castings.

I wonder if you had very high oil temperatures. How long did you run it continuously on boost? An oil cooler might be good.

The rod is not symmetrical because they were a a v8 made to run against another rod. See my photo of a 152 rod (similar to 196) marked for install orientation. The 4 cylinder crank has a small and large fillet on each rod journal to suite the V8 rod.

View attachment 37430

I never really ran it very long under boost. I think the longest time was on a particular grade that was one mile in length, but the boost built slowly during that interval and it for less than one minute. Never ran it more than 8 lbs., once, just to see, and there was more to have but I didn't want to find out under those conditions. Usually around 5 lbs and for short bursts. I have that oil cooler/heat exchanger and I never ran the oil over 220 at the worst. Regarding the spit hole, I can call the machinist tomorrow and ask him where the boot heel is with respect to the spit hole. Boot heel is on the low (exhaust) side. Spit hole should be on the other side (intake)? I know I paid attention to this detail at the time but now don't recall anything about it. I thought it was all sorted out and done right; perhaps it wasn't. Hope to know more tomorrow.

On a separate note. Replacement pistons are now problematic. Spoke with IHPA this afternoon and we're working on solution. I can report that I have a handle on some NOS 0.020" over pistons but moly rings are another challenge. Should know more tomorrow. Question about the NOS pistons. I'm hoping or assuming that they will be dimensionally interchangeable with the Silvo-lites and have identical height from the piston pin, and if IH left the boot heel at 10 cc or if they increased it. I'll need to account for that in any case before getting the pistons cut. Also thinking the NOS is a better quality piston?

This will have to be the last time I go into this engine. Period. Time for a margarita.

 

[Robert Kenney]

Just know that your zero decking to the SL pistons means the NOS (IH?) could be slightly different. Hope shorter not taller.

 

[Mark Pietz]

At this point the IH NOS pistons are the only ones on the horizon. And I'll likely have to buy them first before I can check them to find out. Devil's advocate. If taller, then what? Seppuku?

And if that isn't enough for a case of heartburn, I pulled a pic from page 6. I had posted a picture of the hung pistons (tonight is absolutely without humor) and it appears that the spit holes were mounted on the boot heel side. In other words, pointing and spraying away from the cam. So no extra oil was getting to the top side of the bore, where the scoring was. I have a very sick feeling right about now. The machine shop mounted them backwards and I didn't know enough to catch it.

In the pic, the heels are down. You can make out the presence or absence of the hump on the rod where the little spit hole is. Tell me I'm wrong.

Margaritas.will.not.help.

 

[Mark Pietz]

For what it is worth at this moment. I remembered that I had kept a couple of the worn out OEM pistons that this engine was born with. Wrist pin bore measures 1.060", book says 1.063" minimum, so that's close enough. Adding half that to 1.388" from the top of pin bore to top of piston and we have a nominal 1.919" piston height. I am assuming the OEM IH pistons I have a handle on would match this. I just now saw in the SL catalogue that their comp height is 1.907". IIRC, my pistons sit about 0.004 - 0.006" in the hole. Let's call it 0.005". So it is conceivable that the an OEM IH piston is maybe 0.007" proud of the deck (SL 1.907 + 0.005 = 1.912" and flush; IH @ 1.919 - 1.912 = 0.007"). If so, then the question is can I trim 0.007" off the top and leave that 0.400" band around the circumference, and relieve another 0.040" deep and 3.145" in diameter. That should get me to the 8:1 c.r.

 

[Robert Kenney]

Lets look at your rod chamfer in relation to the oil hole.
The 4 cylinder is the rear most bank of cylinders on a V8, that means you are only utilizing the rear portion of the V8 rod journal narrowed to one rod width . If you put the large chamfer to the rear that means you were correct in how you assembled your engine.

If I am visualizing this right, it means the design sprays up from the outside, by timing of the oil hole in the crank, it is on the case wall side almost all the way out. The oil will be aimed at the piston for the most part.

 

[Mark Pietz]

Lets look at your rod chamfer in relation to the oil hole.
The 4 cylinder is the rear most bank of cylinders on a V8, that means you are only utilizing the rear portion of the V8 rod journal narrowed to one rod width . If you put the large chamfer to the rear that means you were correct in how you assembled your engine.

If I am visualizing this right, it means the design sprays up from the outside, by timing of the oil hole in the crank, it is on the case wall side almost all the way out. The oil will be aimed at the piston for the most part.

I'm having difficulty visualizing this, and am not familiar with some of the terms. So please bear with me. If I consider a V as two banks, the top of a piston marked "up", "up" would be the bore surfaces inside the V, towards the intake ports. Down or bottom of same piston would be on the out sides of the V. So for a 196 four, piston "up" side is towards intake (cam and tappet area), bottom towards exhaust, outside of block. Which is case wall side? Phrased another way, is the spit hole supposed to be leading the rod in the direction of rotation and spraying the cam side first, or trailing?

Here is a pic of one of the pistons. The scoring is on the up side (intake). If you look at the rod big end, that little hump might be the spit hole boss. If so, hole was pointing down. I don't know if this helps at all, but in the pic I took to document orientation of rod cap witness numbering, the numbers for all rods faced outwards. Can't see detail in the blue circle, which might hide the boss. I looked at your rod cap pic. I remember that on mine, the tabs to prevent shell rotation on the shell halves, butted against each other, that is, were on the same side of cap. Maybe that's another clue to the chamfering. I don't have the parts in front of me so this will have to be sorted later.

Back to the pistons. Spoke with Mike D. at IHPA. They may have a handle on some Sealed Power 0.020" pistons. I'm also still waiting for a call back from another vendor they steered me to that might be able to put together four IH NOS pistons. So we'll have to wait to see who salutes first. My preference should be NOS, I think, if I can't get the SLs. Thoughts on the Sealed Power pistons? I thought those were destroked, so how would those play out if they became the only option? Mike said the SLs were good in that they had a steel insert for the upper ring; SPs do not.

 

[Robert Kenney]

Yes spit hole opposite side as cam. My faulty memory. Other manufacturers spit towards the cam side. I got mixed up.
Oils when crank gallery lines up with spit hole. By looking at a crank that I have here and the direction of rotation, in my mind it oils on the up stroke.

Took liberties with you posted photo and marked it up for clarity of my ramblings. Imagine the 152 rod photo I posted in place of your circled rod. Look at the chamfer with dictates the rod and journal orientation.

 

[Mark Pietz]

So it's looking like the pistons were put on correctly, rod chamfers were facing the correct way, and spit hole facing down is correct. That's good to know. And your thought about spitting oil out on the up stroke. I think this picture indicates that that is so. Too bad the flow from this teeny hole cannot be effective as an oil jet to cool the underside of the piston.

Thank you.

 

[Robert Kenney]

One common alteration to the oil hole trailing edge exit on the journal is a teardrop shape. That among other benefits increases the effective pulse length and allows a feathering in of oil to the bearings hydrodynamic layer. I added a link to a good write up on the subject

chamfering oil feed holes in cranks

READ THESE LINKS in a properly set up block a pressurized oil film supports the cam and main bearings, pressurized oil flows from the oil passages in the block to the main bearings where its routed through feed channels to rod bearings, the rotating crank helps to feed cooling oil to the...

garage.grumpysperformance.com

Just as effective could be more oil directed at the piston is lowering the oil temperature.