Pinned my crankshaft

Bolt

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Coached by Greg Good:

Here is my procedure.

  • Starting with a set of gage pins from .248 to .262
  • I measure the distance from the surface of the hole in the crankshaft to the bottom of the cross hole connecting to the rod journal.
  • I mark the gage pins with two lines. First line is that depth to the hole. Second line is the .400 (length of the pin I will be inserting).
  • I use the gage pins to find the tightest sliding pin which will insert to by depth needed indicated by the second line.
  • I take that gage pin diameter and add .002 inch.
  • Next I cut the heaver gage pin to the distance of .400.
  • I chamfer the nose and scuff the sides a bit on my belt sander.
  • Next I use an electric arc pencil and dot all around the gage pin near the tail end of the pin. (This will raze the diameter by about .0015) You may think of this as knurling the gage pin.
  • Before I insert the pin I use a q-tip and brake cleaner and clean out the hole.
  • Next I put red loctite on the pin.
  • Having a mark on my punch I use a hammer and drive the pin into the hole till the oil hole to the rod journal has been cleared.
  • With the tightness of the pin, scuffing of the pin, and the loctite. These pins should never move.
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Full link of progressive pictures:
pining Viper Crankshaft

Warning: This is not for everyone to do. This is extreemy hard to do with the crank in the block. There is no room for error.

Diagram provided by Greg Good:
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Bolt

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OK. It's been 20 minutes or so since I've asked a dumb question. I'm familiar with pinning the balancer on the front, but what exactly are you showing being pinned?

I’m pinning the main Journals. The diagram shows that the main journals are cross drilled. As shown the rod journal oil path interests with the cross drilled holes. What is happening here is that as the oil travels into the main journal it veers off to the rod bearing journal. Also the oil is going out the other three holes in the main journal. Chrysler does this. Most other crank shafts just have one hole coming from the main journal to the rod journal. I am plugging the main journal just pass the intersection to the Rod journal. This will turn a Chrysler crankshaft into a Chevy crankshaft. The benefit is that the rod bearing will get higher pressure and not starve for oil at high RPMs. The stock way of the cross drilling leaks to much oil around the main and starves the rod journals from the needed oil. Hence this is why we are seeing so many rod bearing spinning. It took me a while to understand this too.

I hope this helped.

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Bolt

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I forgot to share this. Here is a picture of my Rod bearings with 32,000 miles on them. This is why I am doing the pinning. This pinning is old school stuff. I'm just doing it on a Viper.

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ViperTony

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Great info Bolt I learned something new today. Being extremely green on oil starvation...wouldn't putting in the swinging oil pan baffles also solve the oil starvation issue that leads to spun bearings? If there's no oil to feed the bearings (because it's sloshed to one side or end of the oil pan during hard acceleration/g's/banking turns) how is pinning the journals going to help get oil to the bearings that need it? Or...am I really off the topic and just confusing the issue, I do that a lot. :)
 
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Bolt

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Great info Bolt I learned something new today. Being extremely green on oil starvation...wouldn't putting in the swinging oil pan baffles also solve the oil starvation issue that leads to spun bearings? If there's no oil to feed the bearings (because it's sloshed to one side or end of the oil pan during hard acceleration/g's/banking turns) how is pinning the journals going to help get oil to the bearings that need it? Or...am I really off the topic and just confusing the issue, I do that a lot. :)

I have to leave this question to someone who is more intelligent than me on oil starvation. Myself have never seen my gage flutter during acceleration or breaking indicating oil starvation. My question is can oil starvation happen on a Viper motor? Is my car capable of oil starvation?
 

SquadX

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I've heard the swing oil pan has it's share of issues as far as providing enough to solve the problem or at least the older ones did. Dan at viper specialty has good info on this. Experts please chime in.
 
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Bolt

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bolt, hows this effect the balance now ? does it ?

I was told it does not effect the ballance since the pin is so close to the center of the crank. Plus with putting in 7 pins it would be prety hard to get them all on one side of the crank shaft.

Ya never know after I get this thing all back together I may be posing up. " I blew my motor" :)


I'll try anything once. It's only a car.
 

kennyhemi

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I have to leave this question to someone who is more intelligent than me on oil starvation. Myself have never seen my gage flutter during acceleration or breaking indicating oil starvation. My question is can oil starvation happen on a Viper motor? Is my car capable of oil starvation?

Bolt, The oiling system design of a 426 Hemi is by far the most superior (wet sump) ever made! Think of top fuel and what it can handle! And yes the new nitro systems are by far better than the original but it's still the same concept. I believe pinning the crank the way your doing it is the least intrusive and less expenseive way, But the best way to avoid oil starvation in a wet sump application is a swivel pickup and high volume oil pump. Then dowel pin the rods! This way if you happen to lose a little oil pressure in a turn or a drag race ie.. when oil moves around in the pan (swivel should have you covered on this senario) But it still happens! your rod bearings will not spin no matter what unless you lose total oil pressure, By then you have bigger problems than just rod bearings. Enough with worst case senario! Anyway dowel pin rods/bearings will last longer and are safer than none ones. If you like to see a "pinned" rod I might be able to snap a pic and show you guys. One more thing! For ultimate protection think drysump and not to mention freed up HP!$$$$$:D
 

Frankster

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Glad I discovered this thread. Been thinking of how to address the problem of the spinning bearing on the third rod. Just happened to me last month.

I notice in the pics to be what look like normal rods. Are these the stock rods?

They're different than what's in my engine. Mine have bolts that screw into the rods. Makes me think maybe I already got Carillos. I'm not too sure because I haven't looked close enough at the beams to know.

One thing for sure is a regular 12 point don't fit on my rod bolts. Not sure what does fit.......but that was a question I was going to ask the board.

Why not groove the bearings and then drill a small hole in the rod caps. Use an oil squirter pointed at the rod cap. Do you think it will get enough oil to the bearing? Or would it weaken the rod too much?

Trivia: When does the rod experience the most stress? During the power stroke or during downhill engine braking? (normal engine)

Just for you guys that don't know me, I'm the techie type. I love technical details like this. Glad I discovered what you guys are doing here. LOOKS GOOD!
 
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Great info Bolt I learned something new today. Being extremely green on oil starvation...wouldn't putting in the swinging oil pan baffles also solve the oil starvation issue that leads to spun bearings? If there's no oil to feed the bearings (because it's sloshed to one side or end of the oil pan during hard acceleration/g's/banking turns) how is pinning the journals going to help get oil to the bearings that need it? Or...am I really off the topic and just confusing the issue, I do that a lot. :)


That make shift drawing are of main journals 2 and 5. They are cross drilled twice, making them what we refer to as X drilled. When the oil passage that feeds the rod journal lines up with the passage in the block the oil going into the crank is fed to 4 passages, not one (the rod) as it should. You can have great oil pressure on the gauge, but not enough oil volume to pressurize the passage to the rods bearings, leading to oil starvation. *If* you could pace an oil pressure gauge in the passages feeding the rod bearings, you would see low pressure. This mod directs all of the oil entering the crank to the rod bearings, which is what we refer to as Chevy oiling. If you buy a $4500 Moldex crank, it will have Chevy oiling, no cross drilling.

I see posts where people mistakenly believe the Viper crankshaft is not cross drilled and needs to have it done in order to improve the oiling to the rod bearings. In fact the opposite is true, they ARE cross drilled from the factory, and need to be altered in order to improve oil volume to the rod bearings.

The weight of the slug is small and it is very close to the centerline of the crank, so not much effect on balance.

I am proud of Bolt for doing this. He performed this in the car without removing the crank. He had to gage each passage and choose the right size pin gauge for it. He only had one shot to get it right on each passage. :2tu:

I've done them with the pics as Bolt used, but if the crank is out of the car you can also tap the passage with a 5/16"-18 tap and use allen head set screws with Loctite.
 
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plumcrazy

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I see posts where people mistakenly believe the Viper crankshaft is not cross drilled and needs to have it done in order to improve the oiling to the rod bearings. In fact the opposite is true, they ARE cross drilled from the factory, and need to be altered in order to improve oil volume to the rod bearings.

thats what i was told back when my engine was being built.

great info greg !!
 

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