Broken Rod Opinions
Thread Starter
|
Freshman User
Joined: Aug 2005
Posts: 42
Likes: 0
Broken Rod Opinions
I sent a long winded post earlier and apologize for the overload. I have a more simple version of the question for those of you familiar with engine building.
In a freshly built motor, what could cause the rod bearing at the crank on piston #1 to badly score the bearing on the crank and then for the rod to snap by the crank?
There is no other damage or heat discoloration anywhere else in the motor and all is to spec. The oil is fine - the engine did overheat on bench testing, but mildly - again no damage elsewhere in the motor. No water/gas in the oil, etc.
I suspect an overtorqued rod connection at the crank grinding the bearing and causing heat which caused the rod to snap near the crank.
Any other opinions would be appreciated. I need to settle a dispute with the builder who claims someone shifted the timing so far it damaged the bearing.
Thanks.
In a freshly built motor, what could cause the rod bearing at the crank on piston #1 to badly score the bearing on the crank and then for the rod to snap by the crank?
There is no other damage or heat discoloration anywhere else in the motor and all is to spec. The oil is fine - the engine did overheat on bench testing, but mildly - again no damage elsewhere in the motor. No water/gas in the oil, etc.
I suspect an overtorqued rod connection at the crank grinding the bearing and causing heat which caused the rod to snap near the crank.
Any other opinions would be appreciated. I need to settle a dispute with the builder who claims someone shifted the timing so far it damaged the bearing.
Thanks.
Thread Starter
|
Freshman User
Joined: Aug 2005
Posts: 42
Likes: 0
Thanks for the quick response. I thought of the assembly procedures but all damage is limited to a single bearing on rod #1. The entire engine is perfect otherwise, top to bottom. Starvation would presumably cause damage throughout the engine, not damage isolated to a single part.
Postmaster
Joined: Apr 2002
Posts: 3,613
Likes: 6
From: Coal country
I have had the following happen to me, from lessons learned the hard way:
1. A shard of brass from a brass hammer became lodged in the assembly lube on the crank, and I didn't see it when I assemble the bearings into the rod and the cap. It chewed up the bearing and crank, and caused a knock within 50 miles.
2. Bearings placed incorrectly, with the tit in the wrong place. They spin and ruin everything. This one you won't find unless the shells are examined closely at removal - and reported upon honestly.
1. A shard of brass from a brass hammer became lodged in the assembly lube on the crank, and I didn't see it when I assemble the bearings into the rod and the cap. It chewed up the bearing and crank, and caused a knock within 50 miles.
2. Bearings placed incorrectly, with the tit in the wrong place. They spin and ruin everything. This one you won't find unless the shells are examined closely at removal - and reported upon honestly.
Logistics Pro
Joined: Jun 2003
Posts: 3,921
Likes: 272
Originally Posted by banjopicker66
I have had the following happen to me, from lessons learned the hard way:
1. A shard of brass from a brass hammer became lodged in the assembly lube on the crank, and I didn't see it when I assemble the bearings into the rod and the cap. It chewed up the bearing and crank, and caused a knock within 50 miles.
2. Bearings placed incorrectly, with the tit in the wrong place. They spin and ruin everything. This one you won't find unless the shells are examined closely at removal - and reported upon honestly.
1. A shard of brass from a brass hammer became lodged in the assembly lube on the crank, and I didn't see it when I assemble the bearings into the rod and the cap. It chewed up the bearing and crank, and caused a knock within 50 miles.
2. Bearings placed incorrectly, with the tit in the wrong place. They spin and ruin everything. This one you won't find unless the shells are examined closely at removal - and reported upon honestly.
(.010, .020)
Senior User
Joined: Feb 2004
Posts: 295
Likes: 0
From: conway arkansas
well, sounds also like it starved that journal for oil whether it had something blocking an oil passage or whatever, that is the reason if you gonna build motors for yourself or other people its extremely important to keep everything very clean and check everything twiced
Logistics Pro
Joined: Apr 2005
Posts: 4,221
Likes: 17
You're going to have problems with that builder if they're trying to tell you that timing ruined a rod bearing.
Trending Topics
Posting Guru
Joined: Jul 2003
Posts: 2,222
Likes: 1
From: East Central Florida
If your builder built the engine correctly this post would not be here. If he used palsti-guage to check fit everything B4 he socked it to torque spec. If he used both a good assembly lube & prelubed it like Wizzard said, he wouldn't owe you an engine like he does now.
1 more comment, get your Money back plus collect for the damages his incompetence has caused you. Then go to an engine builder that can get it done right. Chevy eater is Oh So right, you are going to only have problems with the builder. The guy has no Idea what he's doing. When it got hot on the initial fire up, he should have found HIS problem right then. Timing does not break one connecting rod, incompetence does.
Since he failed to dazzle you with ability & performance, he's now tryin' to baffle you with BS. . . . . don't fall for it.
And that's my $.02 on the subject.
FBp
1 more comment, get your Money back plus collect for the damages his incompetence has caused you. Then go to an engine builder that can get it done right. Chevy eater is Oh So right, you are going to only have problems with the builder. The guy has no Idea what he's doing. When it got hot on the initial fire up, he should have found HIS problem right then. Timing does not break one connecting rod, incompetence does.
Since he failed to dazzle you with ability & performance, he's now tryin' to baffle you with BS. . . . . don't fall for it.
And that's my $.02 on the subject.
FBp
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
Posting Guru
Joined: Dec 2004
Posts: 1,474
Likes: 5
From: Shasta Lake, Ca.
I rebuild marine (Boat) Engines all day long, and what you describe sounds like the bearing was contaminated with foreign matter. This can happen in the cleanest of shops. And should be covered in the builder warranty on the engine.
