Saving a 906

[Mighty2.0]

Beautiful engine. Couple questions:
1. What oil pump did you use, and is it modified or different from a street pump?

2. Do you actually measure the Play-Doh after it squished, or just see if there's enough clearance?
I've been reading about the solder method, which holds up enough to measure.

Thanks for the pics, looks great.

[Henry Schmidt]

Originally Posted by Mighty2.0

Beautiful engine. Couple questions:
1. What oil pump did you use, and is it modified or different from a street pump?

The oil pump is a flow modified 3.0 911SC pump.

2. Do you actually measure the Play-Doh after it squished, or just see if there's enough clearance?
I've been reading about the solder method, which holds up enough to measure.

Thanks for the pics, looks great.

The substance is actually modeling clay. It is rigid enough to measure.
You turn the engine over, squish the clay and simply push the depth gauge through the clay to measure the thickness.
I've been doing it this way for 30 years. I have never seen a better way to check multiple clearance dimensions.

[Joeaksa]

Very nice build. Brings back old memories...

[blue72s]

Great engine. Henry, years ago you posted a thread about your own 81mm 906 cylinders with later sealing surface (link 81mm 906 cylinders). Why was it not chosen for this engine?

[Henry Schmidt]

Originally Posted by blue72s

Great engine. Henry, years ago you posted a thread about your own 81mm 906 cylinders with later sealing surface (link 81mm 906 cylinders). Why was it not chosen for this engine?

The 906 cylinders are already aluminum and dual/full finned so we took the original 906 cylinders and had the Chromal stripped off. Then we had Millennium replace the Chromal with Nikasil. This made the old cylinders better than new.
We chose not to run my cylinders because the 906 heads have too much value and modifying then seems somewhat sacrilegious.
We actually welded a set of 906 heads recently to bring them back to original.

[motogman]

Awesome. More please... I need another fix!

[panama911]

Hi Henry,

May I ask what is the black coating used on these fasteners - and why?
Looks very good to me, something distinct from the yellow zinc plating we're used to see here!

Originally Posted by Henry Schmidt

[mreid]

That does it. If I need a rebuild, Henry gets it. Fantastic stuff here!

[IXjamesXI]

I am curious about the fasteners also! Could they be black oxide? But if I had to guess I would say they are zinc plated with an olive drab chromate. Could it be so? If so, that would be too cool for school.. I was thinking of doing that on my motor instead of yellow zinc. Better corrosion resistance, and looks bad ass.. but I am worried it might be too thick for the fasteners to thread correctly. This is based on zero experience on my part.

[911 tweaks]

his prices are very reasonable for what you receive back...= a very well built engine w/ long life ahead of it...

[Henry Schmidt]

Originally Posted by panama911

Hi Henry,

May I ask what is the black coating used on these fasteners - and why?
Looks very good to me, something distinct from the yellow zinc plating we're used to see here!

In a resent thread, I was accused of "archaic methodology" so in this case that claim fits (at least on the outside).
The hardware is black oxide because in 1964 most of the 906 hardware was either black or clear cad.
With some of these projects, appearance counts almost as much as performance.
Strangely enough, this engine had a premature failure do to what appears to be a lack of proper hardness on the lash caps we purchased from Porsche Motorsport.
Sometimes even sourcing parts from the "best" supplier can throw you for a loop.

[IXjamesXI]

Guess I should have stuck with my first hunch based on period correctness... Maybe zinc with black chromate would give one both proper appearance and up to date performance, but maybe the thickness issue I was worried about becomes a problem then. Thank you for sharing this engine with us!

[panama911]

Originally Posted by Henry Schmidt

In a resent thread, I was accused of "archaic methodology" so in this case that claim fits (at least on the outside).
The hardware is black oxide because in 1964 most of the 906 hardware was either black or clear cad.

Thanx for the info, Henry - while black oxide then probably wouldn't be the best idea for ordinary cars driven in ordinary corrosive environments... I can totally understand that yellow zinc plating wouldn't be authentic for this very special application

[Lapkritis]

Originally Posted by Henry Schmidt

In a resent thread, I was accused of "archaic methodology" so in this case that claim fits (at least on the outside).

I believe the term was "antiquated" but that is another discussion/topic.

Shame to see the engine failure.

Working with aged/used parts often means you're either lucky or dead even when greatest lengths are taken to inspect, refurbish and source suitable replacements. Comes with the territory. Hopefully the owner understands this is an inherent risk of mechanized toys.

[lindy 911]

Andrew, you never cease to amaze me with your absolute grip on the obvious; thank you for that.

[Henry Schmidt]

Just to be clear for those who seek accuracy, the failure was simply excess valve clearance.
Valve noise caused by lash cap failures. After the replacement of lash caps, the engine runs perfectly.

[Lapkritis]

Originally Posted by lindy 911

Andrew, you never cease to amaze me with your absolute grip on the obvious; thank you for that.

Would you have preferred me to use more color and less tact similar to that which those afford me?

Originally Posted by Henry Schmidt

Sometimes if you try to make candy out of shyt, you end up with shyt candy.

[TimT]

Strangely enough, this engine had a premature failure do to what appears to be a lack of proper hardness on the lash caps we purchased from Porsche Motorsport.

Unfortunately not everything from Porsche Motorsports... is what it seems.. We sourced some Pankl ti rods for a cup engine a few years ago from them.... They were delivered in a large padded envelope 6 Ti rods, just tossed in a padded envelope... not a thing to prevent contact between the rods....

We thought for about a second that we might try to use the rods... until we took a close look... and saw the nicks and blemished that were present from the way the rods were shipped....

Returned to PMNA

[Henry Schmidt]

Originally Posted by TimT

Unfortunately not everything from Porsche Motorsports... is what it seems.. We sourced some Pankl ti rods for a cup engine a few years ago from them.... They were delivered in a large padded envelope 6 Ti rods, just tossed in a padded envelope... not a thing to prevent contact between the rods....

We thought for about a second that we might try to use the rods... until we took a close look... and saw the nicks and blemished that were present from the way the rods were shipped....

Returned to PMNA

Hi Tim
Thanks for the input.
Your issue sounds more like competence in the shipping department as opposed to quality control.
We have rarely seen an issue with quality from PMNA but with the advent of sourcing small quantity items for vintage race cars (old street cars as well) from previously untested or new management suppliers, we really have to be on our toes. I feel certain that this lash cap issue will be address but after 30+ years I'm constantly surprised at where the next challenge will come from.

[Henry Schmidt]