Auto engine bolt patterns

[Ron Webb]

Hello

Does anyone have any experience getting the bolt pattern off the
transmission side of an auto engine?

I'm building a PSRU, and I need to make the plate that bolts to the engine.
The rest of the pattern is generic, but that is engine specific.

I have tried several ways of measuring the holes in the block, but I'm sure
I can't get accuracy better than 1/10 inch or so. Surly engineering drawings
for these patterns are available somewhere.

[Corky Scott]

On Sun, 17 Oct 2004 17:04:26 -0800, "Ron Webb"
> wrote:

>Hello
>
>Does anyone have any experience getting the bolt pattern off the
>transmission side of an auto engine?
>
>I'm building a PSRU, and I need to make the plate that bolts to the engine.
>The rest of the pattern is generic, but that is engine specific.
>
>I have tried several ways of measuring the holes in the block, but I'm sure
>I can't get accuracy better than 1/10 inch or so. Surly engineering drawings
>for these patterns are available somewhere.

Here's an idea that I've had for some time. Machine some bolts that
fit the threads of the block into points. Thread them into the block
such that the pointed end is facing out. Place an aluminum sheet (at
least 1/4 thick) over the engine and tap each bolt location with a
hammer. This center punches the bolt's location.

Take the template over to your drill press and drill out the center
punched holes. That should be very accurate.

Corky Scott

[Harry K]

"Ron Webb" > wrote in message >...
> Hello
>
> Does anyone have any experience getting the bolt pattern off the
> transmission side of an auto engine?
>
> I'm building a PSRU, and I need to make the plate that bolts to the engine.
> The rest of the pattern is generic, but that is engine specific.
>
> I have tried several ways of measuring the holes in the block, but I'm sure
> I can't get accuracy better than 1/10 inch or so. Surly engineering drawings
> for these patterns are available somewhere.

Just a thought but how about getting a new gasket that fits and using
it to transfer the holes??

Harry K

[Ron Webb]

"Corky Scott" > wrote in message
...
> On Sun, 17 Oct 2004 17:04:26 -0800, "Ron Webb"
> > wrote:
>
> >Hello
> >
> >Does anyone have any experience getting the bolt pattern off the
> >transmission side of an auto engine?
> >
> >I'm building a PSRU, and I need to make the plate that bolts to the
engine.
> >The rest of the pattern is generic, but that is engine specific.
> >
> >I have tried several ways of measuring the holes in the block, but I'm
sure
> >I can't get accuracy better than 1/10 inch or so. Surly engineering
drawings
> >for these patterns are available somewhere.
>
> Here's an idea that I've had for some time. Machine some bolts that
> fit the threads of the block into points. Thread them into the block
> such that the pointed end is facing out. Place an aluminum sheet (at
> least 1/4 thick) over the engine and tap each bolt location with a
> hammer. This center punches the bolt's location.
>
> Take the template over to your drill press and drill out the center
> punched holes. That should be very accurate.
>
> Corky Scott

Thanks guys.

Both good suggestions.

But the one dimension that must be DEAD accurate is the position of the
center of the crank relative to the dowel pins.. Neither suggestion is going
to solve this one without taking the engine apart. I am working on a new
aluminum Ford 4.6L V8 short block, so the entire lower end is already in
place.

[W P Dixon]

Just a thought,
Can you use a compass to first get the proper radius of the bolt pattern
from the centerline of the block (Yeah a pretty big compass) , then use a
smaller compass to measure centerline of bolt to bolt? If you get the radius
layout right the pattern should be perfect...or as close to it as mere
mortal man can be! hee hee

Patrick
"Ron Webb" > wrote in message
...
>
> "Corky Scott" > wrote in message
> ...
> > On Sun, 17 Oct 2004 17:04:26 -0800, "Ron Webb"
> > > wrote:
> >
> > >Hello
> > >
> > >Does anyone have any experience getting the bolt pattern off the
> > >transmission side of an auto engine?
> > >
> > >I'm building a PSRU, and I need to make the plate that bolts to the
> engine.
> > >The rest of the pattern is generic, but that is engine specific.
> > >
> > >I have tried several ways of measuring the holes in the block, but I'm
> sure
> > >I can't get accuracy better than 1/10 inch or so. Surly engineering
> drawings
> > >for these patterns are available somewhere.
> >
> > Here's an idea that I've had for some time. Machine some bolts that
> > fit the threads of the block into points. Thread them into the block
> > such that the pointed end is facing out. Place an aluminum sheet (at
> > least 1/4 thick) over the engine and tap each bolt location with a
> > hammer. This center punches the bolt's location.
> >
> > Take the template over to your drill press and drill out the center
> > punched holes. That should be very accurate.
> >
> > Corky Scott
>
> Thanks guys.
>
> Both good suggestions.
>
> But the one dimension that must be DEAD accurate is the position of the
> center of the crank relative to the dowel pins.. Neither suggestion is
going
> to solve this one without taking the engine apart. I am working on a new
> aluminum Ford 4.6L V8 short block, so the entire lower end is already in
> place.
>
>

[sleepy6]

In article >,
says...
>
>
>"Corky Scott" > wrote in message
...
>> On Sun, 17 Oct 2004 17:04:26 -0800, "Ron Webb"
>> > wrote:
>>
>> >Hello
>> >
>> >Does anyone have any experience getting the bolt pattern off the
>> >transmission side of an auto engine?
>> >
>> >I'm building a PSRU, and I need to make the plate that bolts to the
>engine.
>> >The rest of the pattern is generic, but that is engine specific.
>> >
>> >I have tried several ways of measuring the holes in the block, but
>I'm
>sure
>> >I can't get accuracy better than 1/10 inch or so. Surly engineering
>drawings
>> >for these patterns are available somewhere.
>>
>> Here's an idea that I've had for some time. Machine some bolts that
>> fit the threads of the block into points. Thread them into the bloc
>k
>> such that the pointed end is facing out. Place an aluminum sheet (a
>t
>> least 1/4 thick) over the engine and tap each bolt location with a
>> hammer. This center punches the bolt's location.
>>
>> Take the template over to your drill press and drill out the center
>> punched holes. That should be very accurate.
>>
>> Corky Scott
>
>Thanks guys.
>
>Both good suggestions.
>
>But the one dimension that must be DEAD accurate is the position of th
>e
>center of the crank relative to the dowel pins.. Neither suggestion is
> going
>to solve this one without taking the engine apart. I am working on a n
>ew
>aluminum Ford 4.6L V8 short block, so the entire lower end is already
>in
>place.

How about working from the transmission/bellhouseing assembly instead?
Put transfer punches in the holes as suggested. Machine a short
extension for the transmission shaft to transfer its location to your
pattern.

[Rich S.]

"Ron Webb" > wrote in message
...

> But the one dimension that must be DEAD accurate is the position of the
> center of the crank relative to the dowel pins.. Neither suggestion is
> going
> to solve this one without taking the engine apart. I am working on a new
> aluminum Ford 4.6L V8 short block, so the entire lower end is already in
> place.

I'm thinking of a jig for this. Insert something in the back of the crank
which will extend the centerline of the shaft past the plane of the dowel
pins. Something like the alignment spuds used to center a clutch plate.

Make a block with a hole in it to slip over the crank extension. This block
should have adjustable arms on it (equal to the number of dowels in the bell
housing. Those arms could be slotted like the arms on an engine stand.
Assemble the whole mess so that the ends of the arms are located on the
dowels and tighten it down. Slip it back off the crank extension and you
have a pattern. For one-time use, you could just weld it together from
scrap.

Wish I could draw it with a pencil.

Rich S.

[Matt Whiting]

Ron Webb wrote:

> "Corky Scott" > wrote in message
> ...
>
>>On Sun, 17 Oct 2004 17:04:26 -0800, "Ron Webb"
> wrote:
>>
>>
>>>Hello
>>>
>>>Does anyone have any experience getting the bolt pattern off the
>>>transmission side of an auto engine?
>>>
>>>I'm building a PSRU, and I need to make the plate that bolts to the
>
> engine.
>
>>>The rest of the pattern is generic, but that is engine specific.
>>>
>>>I have tried several ways of measuring the holes in the block, but I'm
>
> sure
>
>>>I can't get accuracy better than 1/10 inch or so. Surly engineering
>
> drawings
>
>>>for these patterns are available somewhere.
>>
>>Here's an idea that I've had for some time. Machine some bolts that
>>fit the threads of the block into points. Thread them into the block
>>such that the pointed end is facing out. Place an aluminum sheet (at
>>least 1/4 thick) over the engine and tap each bolt location with a
>>hammer. This center punches the bolt's location.
>>
>>Take the template over to your drill press and drill out the center
>>punched holes. That should be very accurate.
>>
>>Corky Scott
>
>
> Thanks guys.
>
> Both good suggestions.
>
> But the one dimension that must be DEAD accurate is the position of the
> center of the crank relative to the dowel pins.. Neither suggestion is going
> to solve this one without taking the engine apart. I am working on a new
> aluminum Ford 4.6L V8 short block, so the entire lower end is already in
> place.

Take the block to a machine shop with a CMM and they'll have your
dimensions in no time.


Matt

[Andy Asberry]

On Sun, 17 Oct 2004 17:04:26 -0800, "Ron Webb"
> wrote:

>Hello
>
>Does anyone have any experience getting the bolt pattern off the
>transmission side of an auto engine?
>
>I'm building a PSRU, and I need to make the plate that bolts to the engine.
>The rest of the pattern is generic, but that is engine specific.
>
>I have tried several ways of measuring the holes in the block, but I'm sure
>I can't get accuracy better than 1/10 inch or so. Surly engineering drawings
>for these patterns are available somewhere.
>

It is called Technology Transfer or Tek-Connect or some such depending
on manufacturer. If you or someone you know belongs to the Specialty
Equipment Market Association www.sema.org , the manufacturing specs
are available. That is how you are able to pick up a brake rotor at
your local auto parts and it will fit.

[Ron Webb]

Thanks Andy.

That's the information I was looking for.

Course, not being a member kinda puts a damper on things. Membership looks
to cost about $350/yr, so I guess I'll just measure things as best I can.

I knew the info was out there - I suppose I shoulda guessed it wasn't free!
;^}


"Andy Asberry" > wrote in message
...
> It is called Technology Transfer or Tek-Connect or some such depending
> on manufacturer. If you or someone you know belongs to the Specialty
> Equipment Market Association www.sema.org , the manufacturing specs
> are available. That is how you are able to pick up a brake rotor at
> your local auto parts and it will fit.

[Keith Olivier]

Seriously, this is least painfull and most reliable approach.

You not only need to do the right thing, but also document what you did for
the future...

Keith
"Matt Whiting" > schrieb im Newsbeitrag
...
> Ron Webb wrote:
>
>
> Take the block to a machine shop with a CMM and they'll have your
> dimensions in no time.
>
>
> Matt
>

[Ben Haas]

"Ron Webb" > wrote in message >...
> Hello
>
> Does anyone have any experience getting the bolt pattern off the
> transmission side of an auto engine?
>
> I'm building a PSRU, and I need to make the plate that bolts to the engine.
> The rest of the pattern is generic, but that is engine specific.
>
> I have tried several ways of measuring the holes in the block, but I'm sure
> I can't get accuracy better than 1/10 inch or so. Surly engineering drawings
> for these patterns are available somewhere.

Contact me off list and I will help ya. It is a pretty easy procedure.
Look at the pics of my set up and see if yours will be about the same.

http://www.zenithair.com/stolch801/builder-pics/bh2.jpg
http://www.zenithair.com/stolch801/builder-pics/bh1.jpg

Ben Haas N801BH

[Ben Haas]

"Ron Webb" > wrote in message >...
> Hello
>
> Does anyone have any experience getting the bolt pattern off the
> transmission side of an auto engine?
>
> I'm building a PSRU, and I need to make the plate that bolts to the engine.
> The rest of the pattern is generic, but that is engine specific.
>
> I have tried several ways of measuring the holes in the block, but I'm sure
> I can't get accuracy better than 1/10 inch or so. Surly engineering drawings
> for these patterns are available somewhere.



In my case I built my own motor since I used to build NASCAR motors in
a previous life. What I did was to fabricate a aluminum shaft that was
the same OD of the crank housing bore in the block, laid it in the
block and lightly tightened the main caps.On the end of this shaft I
machined a smaller size stub that fit my outboard bearing perfectly.
Thats how I got my PSRU centered. Since your motor is all built you
can get your PSRU aligned the same way I double checked mine. Get a
block plate that is used on automatic tranmissins that fits your
motor. This is the thin metal plate that sandwiches between the block
and the bell housing. You can borrow on from a friend, trans shop or
even get one from a Ford dealer, transfer the holes and return it for
credit.The pattern on this plate is pretty close to what you want. The
real critical dimension is the dowel holes and that will be done at
the end of the process. Transfer the holes onto your PSRU block plate,
the one thats getting mounted to the rear of the block. This plate
sould be .375" minimum. You will have to machine a large round circle
in this plate since the flywheel needs a place to reside in. When you
machine this be careful to make it as round as you can since this will
be your indexing surface. Now with this plate built bolt it on the
rear of your motor and lightly tighten the bolts, take a dial
indicator and fasten it to the crank rear flange. Position the
indicator so that it measures the round hole where the flywheel rides
in. Turn the crank andlightly tap the plate around till it reads .001"
or so runout. Tighten the bolts up .Now the trick that makes this
process work perfectly is to got get a bottoming reamer. My block had
..500 dowel holes in and I assume yours does too. I ordered a .562
reamer from MSC tool supply. You can find one at any large tool
supplier. They cost 12 -15 bucks. Ream the existing dowel holes to the
..562 and make two new oversize dowels. Now every time you remove and
re install the PRSU it will mount on perfectly. This sounds like a lot
of work but it is really pretty simple to do. The PSRU does need to be
mounted on the motor as precisly as possible so take your time.

Good Luck.

Ben Haas N801BH