Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - bergy

Pages: [1] 2 3 ... 11
1
Restoration / Re: Reproduction 69 Endura bumpers available?
« on: July 30, 2017, 05:24:17 PM »
I thought that we were talking about the new one?

2
Restoration / Re: Reproduction 69 Endura bumpers available?
« on: July 30, 2017, 10:56:11 AM »
have any pics of the initial fit without any modifications to the bumper?

3
Restoration / Re: Reproduction 69 Endura bumpers available?
« on: July 29, 2017, 08:50:59 AM »
You made it fit way better than the originals IMO.  Looks like the ends of he bumper didn't stick outboard from the "pocket" in the fender like the old re-pops did. 

4
Restoration / Re: What is this firewall penetration for?
« on: July 21, 2017, 06:26:12 PM »
Back up plug in place

5
Restoration / Re: Reproduction 69 Endura bumpers available?
« on: July 20, 2017, 10:29:29 AM »
any more feedback on the "new" endure bumper fit?

6
Originality / Re: 67 BB frame mounts - question
« on: May 26, 2017, 03:36:33 PM »
there were 2 different bolts in securing my frame mounts

7
Restoration / Re: Reproduction 2 piece rotor review
« on: May 25, 2017, 02:11:37 PM »
we had the unmachined hubs traveling down a belt conveyor at the foundry.  Hitting a ductile hub versus a cast iron hub yields a dramatic difference in "ring".  We always cast a gray cast iron "test" hub & painted it fluorescent orange so that it wouldn't get mixed up with the ductile hubs.  The test hub had to fail both the ring test and the ultrasonic test.  it's the wheel hub that you should be ringing, nut the rotor itself. 

8
Originality / Re: 67 BB frame mounts - question
« on: May 25, 2017, 09:41:00 AM »
yes - gas clip on the rear bolt - you can see it in the first picture that I posted above.

9
Restoration / Re: Reproduction 2 piece rotor review
« on: May 25, 2017, 09:38:10 AM »
If one is made out of cast and the other is ductile, those hubs shouldn't sound the same on the "ring" test Mike.  Did the ring like a bell, or just have a dull thud?

10
Originality / Re: 67 BB frame mounts - question
« on: May 24, 2017, 07:39:42 PM »
no stamped numbers that I can see

11
Originality / Re: 67 BB frame mounts - question
« on: May 23, 2017, 07:41:09 PM »
Those are the same mounts that were in my car.  I removed & cleaned them today.  The car has been in this configuration since at least the late 70s.

12
Originality / 67 BB frame mounts - question
« on: May 23, 2017, 12:38:25 PM »
I'm disassembling my 67 BB Camaro & noticed that the motor frame mounts are different heights - which they should be.  The problem is that the passenger side mount is higher than the driver's side mount.  My understanding is that the driver's side mount should be higher on first gens.  The distance from the cross member to the bottom of the bolt hole is 1.75" on the driver's side and 2.00" on the passenger side.  The mounts can't be reversed due to the small flange on the trailing edge.  Has anyone run into this before - or is it just time to replace the motor mounts?

13
Restoration / Re: Reproduction 2 piece rotor review
« on: May 18, 2017, 01:07:27 AM »
It's hard to tell the difference visually unless you know what to look for at the parting lines and in the size of the "in gates".  Ductile iron requires larger feed gates and also needs larger risers to adequately supply iron to the solidifying casting.  To tell if a casting is gray or ductile.... remember that those same flakes in cast iron that stop cracks from propagating also interfere with sound waves traveling through the matrix.  So, if you tap a nodular casting with a hammer - it tends to ring like a bell.  Gray iron just yields a dull thud.  Sounds like a crude test, but we used the same principal to ultrasonic test 100% of the ductile hubs that we produced to make sure that they had acceptable nodular microstructure. 

14
Restoration / Re: Reproduction 2 piece rotor review
« on: May 17, 2017, 11:44:25 PM »
OK - but the answer gets kinda far into the weeds!  The foundry that I owned made 100% of the Motor Wheel hubs that they supplied to Ford & Chrysler passenger cars in the 80s.  Also, I'm a metallurgical engineer - so here goes.

Ductile iron should be made from its own base iron.  High production gray iron base has too many tramp elements in it which can hurt the elongation of as cast ductile iron.  Also, gray iron melters often use scrap iron for melt stock that has too many tramp elements in it.  Melt stock that contains thing like old bathtubs and steam radiators contains relatively high amounts of phosphorous.  If used for ductile iron, phosphorus in the metal raises the brittle transition temperature too much.  In which case - ductile iron becomes strain rate sensitive and can experience brittle failure at room temperature.  Even at lower phosphorus levels - traumatic brittle impact can occur in severe cold weather environments.

The excellent elongation of ductile iron (versus gray cast iron) is achieved by adding magnesium as an alloy to the liquid iron post melt.  The magnesium causes the graphite that precipitates out of the liquid iron as it goes through the solidification process to have a spheroidal morphology (round "nodular" graphite in the ferritic matrix).  These spheroids of graphite don't interrupt the metal matrix of the iron as much as the "flake" graphite that is seen in gray iron.  As a result - ductile iron can stretch before fracture a lot more than gray iron.

Gray typically has more pearlite stabilizers in the chemistry.  So in addition to the graphite "flakes" interfering with its ability to "stretch", it also has a matrix that is just not conducive to ductility to begin with.

We didn't cast cranks, but to my knowledge - GM crankshafts from the late 60s were either cast or forged.  Actually, one of the advantages of cast iron is that it has great anti vibration qualities.  Also, after a million cycles (doesn't take long for a reciprocating part) it generally has an infinite fatigue life.  Steel, on the other hand, will continue to propagate fatigue cracks to eventual failure even after a million cycles.  I'm sure that many of you have noted these fatigue cracks when crack detecting old forged cranks.  So, don't use forged cranks with significant cracks thinking that they aren't too bad.  Steel fatigue cracks will continue to propagate to eventual failure.  Cracks in cast cranks generally stop propagating when they hit the flake graphite structure (kinda like drilling a hole at the end of a crack to stop it from propagating).

15
Restoration / Re: Reproduction 2 piece rotor review
« on: May 17, 2017, 08:21:19 PM »
Oh my Jimmy - that ductile iron explanation/comment is incorrect on so many levels!

Pages: [1] 2 3 ... 11