Engine Case Alignment Question
 

How is the engine case (3.0L in this instance) supposed to maintain proper alignment at the pulley/#8 bearing end? Reason I ask is because i'm going thru my case bores with my bore gauge and from #4 up to #8, the case parting line at the bores is not lining up well.

Case is bare & very clean with through-bolts and perimeter bolts all torqued to spec. Checked it with all bores clear and also with only #8 bearing installed, no difference in case alignment. After handling the case regularly for a while now, it strikes me as odd that there is no means of alignment at the pulley end, similar to how the flywheel end is sleeved. I don't think my instance is unique, as all engine cases have the ability for this misalignment?

Thanks,
Kevin

#8 is all that is used for alignment. I assume 8 was tight?

Your saying the case is shifted side to side?

As stated, #8 is aligned by the bearing and #1 is aligned by dowel pins which hopefully your case still has. I was told by a professional builder that the ends should be torqued first for this reason.

Yep the case is shifted side-to-side w/out #8 installed, which would make sense. I suspect to check #8 bore, or when being machined, you have to play with that end of the case a little bit while torquing down that end?

I'll open it up again and install #8 again, remeasure again. At least my gut feeling was right the first time- had #8 installed. However the problem is that my bore gauge is not long enough to reach #5, #6, #7 when the #8 is installed....... :confused: Might have to install the gauge inside the case and then bolt the case together! :D

Hey Kevin, just wondering how you got this done?

Kevin: You have to install the #8 bearing and use a extra long dial bore gauge to measure the #7,6and 5 main bearing bores. . The case aligns on the #8 bearing , unlike the rear main end which aligns on the dowels.
aws

AWS, how long does the bore gage need to be? I've been looking at some B&S intermiks and stuff on e-bay. Is there a brand/model you recommend?

I purchased mine from Goodson Tools....part number MCB20.... 20" extended reach dial bore gauge. aws

I use the Eastwood cylinder bore gauge for both cylinder bores and case bores. It is long enough to reach all the case bores.

Dial Type Cylinder Bore Gauge Kit 2-6in Range

Thanks guys, very good information.

Yep I just installed the #8 bearing to recheck and the bores were better aligned.

The standard size gauge like Tom linked is good for the first four mains, starting from the flywheel end. After that you can't reach the next three because #8 bearing is in place, if you were to measure from that side. That's what prompted me to ask the question. The 20 in. gauge like aws mentioned is the hot ticket. Or else buy a small head dial indicator to go on the standard gauge body.

That Eastwood dial bore gauge looks a lot like the Fowler brand gauge I have. Decent quality for the occasional use like us DIY guys. Plus the price that Eastwood has is VERY good.

I highly recommend anyone building an engine to get a bore gauge and some decent micrometers. They don't cost a ton of money and they let you pre-check and post-check your parts before and after machining. If you're willing to spend some good money on some of the Porsche specialty tools (cam holder, engine stand adapter, etc.) then don't skimp out and avoid buying (or borrowing) some more tools that REALLY help you with your engine build. My bore gauge is fantastic for measuring the cylinders, case mains & spigots, and conrod big ends.

OK, thanks for the advise. On the Goodson tool website they also have 90 deg bore mic's, but it don't think I could get to all the bearing saddles with that one either. I will probably go with the one AWS and you are recommending, unless I can find an equivalent Brown & Sharpe or Sunnen on e-bay for close to the same money.

I have been buying some B&S indicators and Etalon mics off ebay. Once i get everything I think I need, I will send off for calibration. So far this seems to be a cheaper solution than buying new. We'll see.

If you're interested in metrology or just instrument repairs/ calibration, I found this website very informative....027 : Long Island Indicator Service : Sales, Repairs and Spare Parts

http://forums.pelicanparts.com/uploa...1334790369.jpg

Shuffle pinning like the 934/935s works for a bullet proof case. Go ahead and get a line bore if you go this way. I used Ollie's BTW, nice work.

I think two saddle pins at the #8 bearing bore would be sufficient for a mild race engine? I just think they'd be a good thing to have for making bore alignment more consistent.

How does a machine shop align the case when the #8 is removed for boring the mains? Or do they leave #8 in place and begin boring from the flywheel end? What happens when #8 bore needs work and you can't have the bearing in there to establish alignment? A couple of pins in the case at that end would answer the questions!

Mike, very nice work on your case. Is Olies just a machine shop or do they provide other services?

Kevin, I found this vid on YouTube. It looks like they have a jig. They probably indicate off both the bores as well as the transmission mating flange. Looks like the case has through bolts and perimeter bolts installed, although no way to tell if it has or hasn't already been shuffle pinned. Boring starts at the 35 second mark.

Porsche 911 Machine Work & Racing - YouTube

I have a decent idea about how they would go about doing the boring job, but I have a harder time figuring out a good way to do the shuffle pin machining. I mean you've got to be dead on, you're working with two separate pieces, and trying to get them to match perfectly. If I have this done to my case, I would definitely be taking video or at least pictures.

Ollie's provides many machine services! They are one of the best, IMHO.

(928)855-6101 7:00am to 3:30PM (PST)
website>>>http://www.olliesmachine.com/

Click on price list (in red)

SmileWavy

Costa Mesa is well renowned. I recall Henry Schmidt mentioning that shop when discussing the "honing" of nikasil cylinders and testing the surface roughness. Check out some of his other videos. Does some good stuff.

Now THAT bore gauge John is using in the video has to be one spendy tool!

"How does a machine shop align the case when the #8 is removed for boring the mains?" Not sure how a machine shop does it or if a 3.0 is much different than my 3.6, but. While the case is on the bench and torqued just enough so I can still adjust each half, I measure on the diagonal across the parting line, adjusting the case halves until each of the #1 & 8 bores are equal or at least within a 1/2 thou. I then put it in the stand, torque to spec, then remove it from the stand to have unemcumbered access from both ends and I'm able to reach each saddle with a standard length guage.

Hope this helps

Thanks for the Olies link, I'm smitten!!

That's what I was thinking- manual alignment. Thanks for confirming my thoughts.