These were remanufactured 198 rods that I got from PAW some years back. They were balanced and I did install ARP bolts. Total runs on this engine were probably less than 40. They were not magnufluxed.
Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

rod bearing failure/how's the journal look ?

blow the cap on one side /rotation snap rod.

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slant six's RULE!
http://www.usajon.com

What kind of bearing clearances were you running on the rods.

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There's no such thing as too much cam....only not enough engine!

Who knows. What revs have you been turning again? Balanced rods and pistons? Rod bolt torque? I usually go a bit higher than factor spec.

Also, if you installed ARP bolts, they would have to have been resized again due to distortion. Sounds like maybe this was not done?

Lou

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Home of Slant6-powered fun machines since 1988

From the extent of the destruction I would say spun bearing. It probably smeared the oil hole shut and you never lost oil pressure until the big boom.

As Lou said, were the rods resized after you put in the rod bolts?

Building motors is a learning experience. I've been doing it almost 40 years and I'm still learning too.

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Official Cookie and Mater Tormentor.

.002
Well, I never knew that or heard anyone say that on here.
Is everyone else doing this? I guess we lucked out on Ryan's engine because they were not re-sized either.

Rods were torqued to factory specs

Rods and pistons were balanced to +- 1gram

RPM 6200

I will let you know what the crank looks like in a week or two when the engines out.

Thanks for all your opinions. I'm still learning too!

Rick

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Yes, they really need to be resized, especially as hard as the ARP bolts are to get in. It can force the big end oval.

RPM shouldn't be a factor. Mine with 198 rods has been 6700 many times.

I will be real surprised if the crank isn't burnt to hell.

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Official Cookie and Mater Tormentor.

Aw man sorry to see the engine problems Rick, that thing was running good.

Kev

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rick

how much $$$ did u have in the motor/if I remember it was quite a bit.
like $3K ?

_________________

slant six's RULE!
http://www.usajon.com

From page #38 are the details

Parts list + price

Complete 68-70 engine------------------$35 E-Bay
Reconditioned 198 rods - ---------------$90 PAW years ago
New 2.8L chevy pistons / Rings -------$35 E-Bay
Reground Cam .513/506 / 290 -------$87 Oregon Cams
Modified oil pump and hardened gear--$75 Doc
New Lifters -------------------------------$24 E-Bay
New Chromoloy Push Rods-------------$46 E-Bay
Engine Builder Valves -------------------$87 E-Bay
New Valve Springs ----------------------- $46 E-Bay
Cylinder head work -----------------------$200 Machine shop
Sonic check block ------------------------$ Free

JP Billet timing set -----------------------$79 E-Bay
Clevite Rod Bearings---------------------$19 E-Bay
Clevite Mains -----------------------------$ 38 E-Bay
Cam Bearings -----------------------------$ 22 Rock Auto
Felpro Gasket set -------------------------$54 Rock Auto
Windage Tray & Scraper -----------------$ 235 Mike Jeffrey
ARP Rod Bolts ---------------------------$ 57 E-Bay

Machine shop work -------------------- $630 Boring, decking, cooking, cam bearing, resize rods and install pistons, grind crank .030/.030

If my math is right I'm at $1860 . The only machining left is the final cut on the head which is @ $90.
So my final total on this engine should be right around $1950 which should put me solidly into the 13's


The biggest item to do another rebuild is the machine work on the block and crank. I can reuse a lot of things in a future build. I already got another piston and set of rings. Once I find a 198 rod and balance it I will have a full set for another build.

I'm not exactly sure what I will do over the winter yet. I have several options.

It would be kind of nice to cut this block in half and get a look at the cylinder walls for thickness.

Rick

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

For those who have seen this before. When a rod bearing spins, the rod loses oil, burns up the bearing, overheats the big end and then a big boom. Is this about correct. Trying to picture this in my mind.

Here is why I asked. I fished out a bearing half from the block, and while it was bent in half it does not look like the bearing material is burnt off of it. Would that lend itself more to a broken rod first, not a spun bearing?

Thanks, Rick

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

[/quote]

Well, I never knew that or heard anyone say that on here.
Is everyone else doing this? I guess we lucked out on Ryan's engine because they were not re-sized either.

[/quote]

Rick, removing and replacing rod bolts, even stock ones require you to recondition the rods, it upsets the housing bore and distorts it to the point that it more times than not makes it out of round. I have reconditioned hundreds of sets and believe me, I have searched for a shortcut when swapping bolts, even with new rods and it just isn't possible. ARP bolts also don't torque to stock specs, they have a higher torque value because they are of a much higher quality steel than the stock rod bolts. So if anything, you undertorqued them and didn't get adequate stretch on the bolts, along with out of round housing bores, this was the likely cause of the failure. Unless you checked the bearing clearances with a dial bore gage, you didn't catch that the bearing clearances were out of round and close to zero around the cap/rod parting lines.

This should be a sticky, because when using any replacement engine fasteners, it is an absolute requirement to resize or recondition the blocks(when using main studs or bolts) and rods, and even switching from head studs to bolts if torque plate honing the block when using them and to also be aware that stock specs are only for stock components.

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There's no such thing as too much cam....only not enough engine!

To All,
I am starting a new post in the racing section on ARP rod bolt installation. Please add comments there.

Rick

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

In the picture it looks like the small end of the rod is still intact. What happened to the piston and the pin?

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If you didn't drive it there, it's not a street car.

Yes small end is intact but oblonged.

Seymour, I kind of had the same thought about the wrist pin / piston?
I guess when it is all apart, I will find the piston either disintergrated or up the bore with some bent valves!

Rick

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6