Porsche 911 rods direction

[proporsche]

I am doing another 911 engine 1970 911 S...

Since ever i put the rods to each side so the numbers are facing up 3left +3right...That is what i was taught back in the days.
What do you do, which direction are you putting the rods numbers.Is it really that wrong to have them rods facing to one direction with numbers ?
Again i was told they should be either facing down with numbers 3+3 to each side never facing all if the rods are facing all ,let's say left....

Ivan
How has the factory done that?

[Flat6pac]

Having taken apart many factory assembled motors I face the crank with #8 to my left and the rods pointing towards me and I record the rod numbers, which are all facing up,
That’s the way I reassemble the crank.
Bruce

[proporsche]

Hi Bruce..so you do all the rods facing one way with numbers up,correct?
Thanx BTW
So if i have it one facing away and the next to me, is not right(numbers up)....you are saying..i do not mind to change the technique;-)

Ivan

[Walt Fricke]

Sounds like having the numbers all facing up makes it easier to record things as you use the stretch gauge.

But as long as the cap and rod both have the numbers on the same side, it can't matter in a running engine how you do things. Bruce assembles a lot of engines, and routine keeps errors from happening. Me, I'd not undo a rod just because I had the whole rod facing differently than the rest. There is no up or down when you balance rods, is there?

[proporsche]

Thanx Walt..very good point too..;-) i did today weight them and all are amazingly 691g precisely;-)
So i just will keep doing the way i did for past 38 years...
i was just wondering and again thank you both for the input...
Ivan

[dannobee]

I think we all get into "our" routine when we build engines. Those of us fortunate enough to tear apart virgin engines are probably more anal about putting stuff back together. And those of us who worked at dealerships were really anal about minutiae like correct hardware and harness routing. Especially when we could look at umpteen brand new cars on the lot for reference.

[boyt911sc]

Originally Posted by Flat6pac

Having taken apart many factory assembled motors I face the crank with #8 to my left and the rods pointing towards me and I record the rod numbers, which are all facing up,
That’s the way I reassemble the crank.
Bruce

While I have done only a tiny fraction of Bruce total engine tear down, I have also found out that the numbers were facing you while the connecting rods were hanging on the crankshaft and #8 bearing to your left. And I bring this up in my classes as a guide.

Tony

[faapgar]

I always put the rods back in the same direction as they were spinning for many years.But I agree with Bruce & Tony about their orientation as the original motors followed that format.Ciao Fred

[proporsche]

good words boys;-))

[Walt Fricke]

Tony - You have the crank horizontal in a fixture/vice when installing the rods? Perhaps that lends itself to a certain orientation?

I have the crank standing up bolted to a junk flywheel clamped to the bench, so gravity doesn't come into play, which may be why I've never paid any attention to this.

[Neil Harvey]

In my small pee brain, the tang side of the shell should always be in the direction of rotation. This was always based on shells with the tangs broached into the shell.

Most modern shells now have the tangs machined only on the backside, no broaching so the reason is probably mute.

[boyt911sc]

Originally Posted by Walt Fricke

Tony - You have the crank horizontal in a fixture/vice when installing the rods? Perhaps that lends itself to a certain orientation?

I have the crank standing up bolted to a junk flywheel clamped to the bench, so gravity doesn't come into play, which may be why I've never paid any attention to this.

Walt,

If you use P 209 A, either installed on a vice or engine stand like I do, the crankshaft is at a horizontal orientation. And the connecting rods are hanging down. If you approach the crankshaft assembly with the #8 bearing on your left and #1 at your right, you will find that all the markings for the connecting rods are facing you.

There is a good picture in the SC Bentley Manual on page 130-13. Plus I find this set up very helpful in comparing one connecting rod to another for their tightness after setting the correct torque spec. Set them upright and watch them rotate downward. Not scientific but I find it useful.

Tony

[boyt911sc]

Originally Posted by Neil Harvey

In my small pee brain, the tang side of the shell should always be in the direction of rotation. This was always based on shells with the tangs broached into the shell.

Most modern shells now have the tangs machined only on the backside, no broaching so the reason is probably mute.

Neil,

English is my second language and struggling to understand the “tang side of the shell” terminology in your above post. A picture would be great or some description that we could understand and visualize. Thanks.

Tony

[Mark Henry]

They're not directional rods so it doesn't really matter. I was taught tangs down.
I was building a 996 engine with Carrillo rods so I emailed Carrillo with this question and the reply was it didn't matter.

Directional rods like VW type1 it does matter because they have an offset (big end) to center the rod in the bore. If in doubt place a straight edge on the rod to look for an offset. The offset on the VW T1 rod is easy to see, don't remember the spec but it's something like .080".

If you built an engine and didn't check you have nothing to worry about.

[Walt Fricke]

My wife's introduction to Parade level concours judging involved following the 356 team around at Milwaukee. She noted that a car got points off because a nut and bolt holding something in the trunk had the nut/bolt combination the wrong way. Either orientation just as functional, of course. But not the way it came from the factory.