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Re: Re[T3]forging ahead with short block

On 6 Mar 2002, at 17:08, Type 3 Junkie wrote:  

> Yes the Rear engine hanger will need to be cut, but the machine shop that you
> have been working with can do this for 15 bucks or so. Take them the full
> -flow kit [if you get it]and the oiul pump and the hanger and the back of
> your fan shroud, show them all the parts and will have no problem making it
> all work. 

I sell a drawing that shows exactly what you need to do to your rear mount 
crossbar to machine it to clear the full flow oil pump cover. The price is $1, 
including postage in the US.  

> HEY Jim- not to question you , or step on toes here , but your saying that
> RIMCO is the only machine shop you would ever deal with ? 

It's a fair question, and no offense taken. Forgive me if I answer at length.  

You're right, there are certainly other shops that will do it right, but they are 
outnumbered by those who will do it poorly. Yes, I know that RIMCO will do 
it right, so why should I experiment with unknown shops.  

The problem here is that this is work that most shops see very little of. They 
may not have done another one in the past year. Is their tooling in top 
shape? Are they likely to invest $200 to fix up an old tool if they suspect 
they'll never see another VW case? Have they ever heard of doing a cleanup 
thrust cut and machining an undersized bearing to fit?  

Frankly, I worry about RIMCO. When I first started dealing with them, air 
cooled was all they did. Now they do lots of water cooled VW stuff. How long 
will they be able to keep up the level of workmanship? There was a time that 
they probably did 20 cases a day. Today they probably do 10 a week.  

> Are you saying other shops cant do the job or dont have the ability? Isnt
> that a bit harsh, no? 

In the US alone, there are probably thousands of shops who can do this. 
Among those there are likely several dozen who will do it consistently right. 
RIMCO is the only one I happen to know of who will take off .004" from the 
thrust surface and custom cut a #1 main bearing to fit. This means that my 
#1 main bearing web is still that much stronger AND that this case still has 
significant life left in it, since they can cut the thrust like this several times.  

They also have the .010, .020, .030, .040, .060, & .080" cutters. Most places 
have .020 and maybe .040." RIMCO carries ALL the bearing sizes, too.  

Next, they are experienced, inexpensive, and fast, and they can do all the 
other case work at the same time (8 &10mm case savers, deep sink case 
savers, drill & tap for full flow....) Even with shipping from Wisconsin it is 
cheaper AND quicker for me to ship a case to them via UPS. I think their 
turnaround time is about 1 day; for me, that means a 2 week wait, which is 
insignificant, at least to me.  

> I think if you have a local machine shop with good background  and you can
> speak with them directly and direct them in what you want done, you are far
> better off than shipping your stuff to a shop far away , that if you have
> questions or problems with it you would have to pay freight to ship or long
> distance phone calls when you could just go to local guy and speak with him.
> We have a great machine shop in town that i use over and over with no
> problems. 

Your shop may well be great. Take a look at their align bore machine. If it is 
one of the cheap ones that is driven by a hand drill, I'd go elsewhere. If they 
have one of the big case machining centers, then they may be one of the 
exceptional shops and you should tell everyone in your part of the country.  

Bob Hoover tells me that even the hand drill boring bars will do a good job 
when they are new, but that they seldom get oiled as they should, and the 
bearings get loose so that they slowly bore oversize. These tools are ALL old 
now, so I wouldn't trust them.  

That said, I have a good machine shop here that I use for some things, 
especially valve jobs. He's a good, friendly machinist and he cares about his  
work. I feel lucky to have found him. I hope your experience is as good as 
mine has been.  

> As far as the larger oil pump using hp for nothing, i not to sure about that,
> once you add the full-flow kit and the extra sump you are moving quite a bit
> more oil, and since i like to drive hard, for me i would rather make sure i
> am getting the oil pressure in need. 

Don't confuse the pressure that you see in the oil galleys with the pressure 
that exists in the bearing. The latter pressure is actually generated exactly 
where you need it and is MUCH greater than the pressure we see on our 
gauges. This hydrodynamically generated pressure goes up with RPM, so it 
is at a minimum at idle. Fortunately, that's when the need is also minimal. 
We're talking here about that much misunderstood marvel of the mechanical 
age: the journal bearing.  

The oil pressure we see at the gauge is only what is necessary to deliver the 
oil to the bearings. Oiling problems don't occur because our pumps don't 
deliver enough oil, they occur because there is a problem somewhere so that 
all the oil leaks out somewhere and never gets to some other critical part. 
You CAN compensate for this somewhat with a bigger pump, but this is 
hard, and it is MUCH simpler to just make sure that you have covered all the 
bases correctly beforehand, especially if you are in the process of building 
an engine.  

Let me give an example: I once had an engine that a friend had bought from 
a junkyard in the hopes that it would replace a worn out engine in his type 3. 
The junkyard engine had almost no oil pressure and it was clear that it was 
in truly desperate shape. We "quickly" just put in a bigger pump to see if this 
would help, but it changed almost nothing.  

Eventually I got to tear this engine down and I found that the nuts had fallen 
off the two # 2 main bearing studs, leaving the #2 main bearing web in the 
case unsupported. This allowed that web to warp outward, leaving about a 
1mm gap between the case halves here. This meant that almost all the oil 
simply spilled out of the oil passages there, rather than being pumped into 
the bearing.  

No amount of pumped oil would have helped this engine. The only fix was to 
attack the problem, not the symptom. I actually managed to save this case, 
with RIMCO's help, but that's another story.  

Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA

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