• From: Greenville, TX
  • Registered: 2009-09-11
  • Posts: 169

Topic: Junkyard rods

I'm tossing around the idea of replacing a bad rod with a pull-a-part one.  Bearings are pretty cheap (~$5), so am I best off just replacing one if the crank isn't grooved, or yanking one from the junkyard which has a similar crank diameter?  Reading about the FrankenMiata made it sound fairly straightforward, but lacked details.  Is it just about as simple as crank diameter, bearing thickness, and micing the rod to make sure the tolerances are correct?  And, what about boring the rod out to accommodate a newer bearing as an easier solution?

Plain Jane '86 BMW 535i - Current
RIP People's Elbowed Protege - 2010
  • From: Toronto, Ontario
  • Registered: 2009-05-03
  • Posts: 1,114

Re: Junkyard rods

Is the bearing spun? Is the rod cracked or bent? If it's just the bearing, keep the rod and replace the inserts. If it spun because of inadequate crush, a machine shop can grind the cap mating face to restore it.......If the rod is cold-cracked, the junkyard solution may be easiest. Was the bearing installed correctly? I've seen blocked oil holes when the shells were mismatched. Don't use sealants like Loctite on the back of the shells and assemble super clean with a good assembly lube on the journals and you should be good to go. What engine? Post pics!

Jim "Endo" Anderton
30 years of racing and still not Brambilla.....
  • From: Houston - Katy
  • Registered: 2010-08-04
  • Posts: 361

Re: Junkyard rods

Agree with all that.....but maybe check your other big end bearing shells.....why did one fail....low oil pressure, dirty oil, high temperature etc......as you said, sets of bearing shells are pretty cheap.....mayeb do them all!

Is it because I is an E30 owner???
  • From: Greenville, TX
  • Registered: 2009-09-11
  • Posts: 169

Re: Junkyard rods

It's on a 2nd gen Concorde.  I'm trying to decide whether to take it on to either fix in budget, or maybe just fix for some race money.  It's a whale for a car for track duty though.  So, it might be perfect. 
Haven't torn into it, but it's said to be a rod.  They knew enough not to let it run when they heard noise.  It hasn't been re-assembled, so that part is likely not the issue.  I'll see what I can figure out.

Plain Jane '86 BMW 535i - Current
RIP People's Elbowed Protege - 2010
  • From: Corona, CA.
  • Registered: 2009-08-03
  • Posts: 359

Re: Junkyard rods

Is it the 2.7L, the 3.2L or the 3.5L engine?  If it's the 2.7L, then it is likely to have timing chain issues   and possibly other maladies.

Team Co-Craptain, Los Cerdos Voladores
Plymouth Neon
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  • wesmc
  • Paddock Rat
  • Offline
  • Registered: 2010-06-21
  • Posts: 27

Re: Junkyard rods

OlCreFoo wrote:

It's on a 2nd gen Concorde.  I'm trying to decide whether to take it on to either fix in budget, or maybe just fix for some race money.  It's a whale for a car for track duty though.  So, it might be perfect. 
Haven't torn into it, but it's said to be a rod.  They knew enough not to let it run when they heard noise.  It hasn't been re-assembled, so that part is likely not the issue.  I'll see what I can figure out.

Wouldn't the junkyard rod, assuming both cranks are still stock size, be the easiest to get in budget?  It would also be very easy as long as your considering the great points posted above.

  • From: Greenville, TX
  • Registered: 2009-09-11
  • Posts: 169

Re: Junkyard rods

It is the 2.7L engine.  And it didn't go quietly.  It didn't do away with any oil through the block, but the coolant left its normal pathways. 
I hear it's best to just ditch the 2.7 and go with the next available version, so maybe I'll start checking around.

Plain Jane '86 BMW 535i - Current
RIP People's Elbowed Protege - 2010
  • 04crx
  • Ripened Lemon
  • Offline
  • From: valpararaiso, in.
  • Registered: 2010-02-21
  • Posts: 209

Re: Junkyard rods

wont waste my time with a 2.7L just junked a really nice intrepid that had timing chain problems. wasn't worth fixing

If its not broke fix it till it is...
  • Registered: 2009-08-28
  • Posts: 606

Re: Junkyard rods

I did almost all of the engine/transmission swaps at my job (independant garage).  The 2.7 is JUNK!!  I lost count of how many of those I had to replace.  The two things I noticed  the most about them...was the fact that all of the 2.7s that I had to pull out were GRENADED.  Not just bent valves, or spun bearings, but twisted rods, pistons boring holes out the side of the block, snapped crankshafts, chunks of metal in the oil pan and in the subframe, etc, etc, etc..

The other thing I noticed about them was the number of times they would die after having a major surgery.  We did heads on numerous 2.7s that had spit off the timing chain and bent all the valves.  Typically it was only a few weeks later and they would saw themselves in half in some other fun way.  What typically happend was the coolant passages would clog with alluminim chips.  Chrysler even posted a TSB saying that cars that had cooling issues might have chips of alluminum clogging the heater core (the cure was to blow them out with compressed air...not actaully fix anything).

That being said I would be VERY leery of trying to Lemons a 2.7.  I'm a masocist ( we race a Camaro!!)  but not THAT much of a masocist!

But if you do decide to run the 2.7 Chrysler has an updated timing chain kit for the engine, its a pain in the butt to instal, but worth your while if you don't want the chain to fail and bend all the valves.

Team Sucker Punch: Winner Class B Doing Time at Joliet 2023 Autobahn ,Winner Org Choice award Were the Elite Meet to Cheat 2015
Chevy Camaro (Tiger striped #38)  (1989-2017 RIP old friend)
Chevy Corvette 1984......and still racing!
  • From: Corona, CA.
  • Registered: 2009-08-03
  • Posts: 359

Re: Junkyard rods

A 2.7L that has been abused or neglected and is badly hurt is not really worth fixing.  Your best bet is to swap in a 3.2L or 3.5L from a similar Intrepid, Concorde, LHS or 300M.  You would need the complete engine assembly with accessories, wiring and manifolds, plus the engine computer.  You MUST get a compatible engine, though, because the engine computer and cam/crank sensor signal patterns changed for the 2002 model year.  If your car is a 1998-2001, then you must use a 1998-2001 engine & computer.  If the car is a 2002-04, then your engine & computer must also be a 2002-04.

The 2.7L cars had a "lower" (higher numerical) final drive ratio than the 3.2/3.5L cars, so a 3.5L swapped car should accelerate harder than a car with a factory installed 3.5L engine.  The transmission is the same otherwise, so it will bolt up.

Team Co-Craptain, Los Cerdos Voladores
Plymouth Neon
Yeah, we're horrible...but we're LEAST Horrible
  • From: Toronto, Ontario
  • Registered: 2009-05-03
  • Posts: 1,114

Re: Junkyard rods

Intrepid R/T was a much better and faster car than people suppose....if you can find a donor...

Jim "Endo" Anderton
30 years of racing and still not Brambilla.....