Rods installed on crank....check!

[efhughes3]

I know it ain't much, but it is THE start of my build. I got the rods on today using a stretch gauge on my new ARP rod bolts. I'm going to wipe the case halves again tomorrow, and place the bearings in as well as the crank, layshaft and oilpump in preparation for the case assembly next weekend. Thanks to all who stopped by today, I appreciate the help and support!!

PS- i also made up some supports out of auminum sheet to support the rods and the timing chain on the left hand side of the case when I mate the two halves. You can see them in the last picture.

[304065]

Looks clean Ed!

So I have the same setup, ARP rod bolts, Summit Stretch gage (decimal inch, not metric, but the spec from ARP is in decimal inch so it doesn't bother me). I see also an allen wrench, used to tighten up the stretch gage on the bolt, and a 13mm, used on the bolt heads.

So how did you do it? Snug the nuts up, apply the stretch gage so it hung down from the bolt, zero the gage then used the box end of the 13 to apply torque until the correct stretch was achieved on that bolt, then go on to the other side?

I see you have your P221 and P222 ready for the next step and the requisite post-procedure cold one handy!

[efhughes3]

John: Actually, I thought the stretch gauge would be a slam dunk. But, it turns out, the spring tension on the gauge itself isn't strong enough to support the weight of the "frame". So, it took a little playing to get a feel for it.

So, here is how I did it:

1. I put the cap and rod on the journal, and then put the nuts on. I snugged them up to pull the cap and rod together, then backed the nut off enough to where there was no load on the bolt.

2. I then put the gauge on the bolt, with the "C" portion of the frame over the rod. I had the crank as you see it mounted to the flyheel with a couple of bolts. You need to do one side of the rod with the gauge oriented so that it is in mid-air past the rod end, if you understand me. (I can take pics tomorrow to show what I mean, if not). When you do the other rod bolt, you need to rotate the gauge 180 degrees so that it again is in mid-air past the rod end. The gauge won't sit parallel to the rod itself, as it wont clear the rod. When you try it, you'll see what I mean, but again I can take some more pics.

3. Using all THREE of your hands, or with a helper, push the two tits of the gauge into the rod bolt dimples. It takes a bit of jiggling around to get the minimum measurement (I think ARP could dimple the bolts a bit more), and then zero the gauge. You'll need to have some pre-load on the gauge assembly, so don't stress on the gap between the tits on the gauge.

4. I then took the gauge away, and used my open end (with a pipe cheater bar) to tighten. I checked several times until I got a stretch of .012" (the spec on my motor). I used an 11mm box end wrench which fit on the 12 pt. nuts.

5. Go to the next bolt and repeat.

6. Repeat on the other rods.

It took a couple of rods to get the feel of this. I had help (another set of hands) for the first one, but the others I could do by myself. It does help to have someone hold the top of the crank, as you put a bit of pressure on the wrench while tightening, which wants to tip the crank.

I hope this helps!

[Jeff Alton]

Looking good Ed!!! Keep it up! Noticed you always have a beer in your pics, I think I have a similar pic or two.... (thought you were a wine drinker )



Can't seem to find my "crank and rods with a beer" pic.....

Cheers

[efhughes3]

Beer, wine, rum, it works for me!

[304065]

Ed, wow, that is very helpful.

I am seriously thinking about returning the Summit gage and getting an ARP like Jeff's. As you have probably seen here on the forum I have a little collection of metrology equipment like dial indicators, and have a good sense of who makes the good ones, e.g. Mitutoyo, Mahr, Compac, Kaefer, etc. Anyway it was hard for me to bring myself to pay $62.00 for a steel rod, two clamps, a metric allen screw with the end turned to a point and an el cheapo, made-in China, decimal-inch dial indicator. But the reason I sprung for it (pun intended) was because I believed the gaging force, or the strength of the spring in the indicator, was sufficiently high to allow the gage to hang on the rod by itself, so I could use a wrench with one hand and hold the crank with the other.

Now hearing that it's a three-handed operation makes me want to rethink that particular gage, or roll my own (as has been discussed here) using an indicator with high gaging force, or even install a spring to hold it. Of course, there's a certain amount of backlash between the rack and pinion in any dial indicator, and all indicators have a little spring to take up the backlash and make the indicator as accurate as possible. Higher than normal force puts wear on the rack and might be responsible for "hysteresis" i.e. the gage doesn't quite respond the same way it does with the teeny weeny internal spring.

Ravings of a madman? Perhaps. Anyway, thanks for that oustanding contribution to the forum. Are you going to measure the rod side clearance? Would be interested to see what you come up with there.

[Jeff Alton]

The ARP one is single person job, it will stay on the rod bolt on its own.

Cheers

[efhughes3]

Originally Posted by john_cramer

Ed, wow, that is very helpful.

I am seriously thinking about returning the Summit gage and getting an ARP like Jeff's.

Now hearing that it's a three-handed operation makes me want to rethink that particular gage, or roll my own (as has been discussed here) using an indicator with high gaging force, or even install a spring to hold it. Of course, there's a certain amount of backlash between the rack and pinion in any dial indicator, and all indicators have a little spring to take up the backlash and make the indicator as accurate as possible. Higher than normal force puts wear on the rack and might be responsible for "hysteresis" i.e. the gage doesn't quite respond the same way it does with the teeny weeny internal spring.

Ravings of a madman? Perhaps. Anyway, thanks for that oustanding contribution to the forum. Are you going to measure the rod side clearance? Would be interested to see what you come up with there.

John: That is probably not a bad idea. Hearing that Jeff's is truly one-handed, I'd go that route were I to do it again. The cheapo Summit unit is made by ARP, I believe, but who knows where the gauge comes from?

My side clearances were just a hair over .254mm, my next feeler was .305mm, but it wouldn't clear. From what I see, .200-.350mm is the tolerance for my 3.2L

[Harpo]

Will the ARP bolt stretch gauge do all Porsche con rods (2.0 -3.6)?

Thanks

David

[Jeff Alton]

Yes