Split the case.... now what?

tadel001 · 09-12-2009, 06:33 AM

I split the case. I wanted to get some thoughts on the condition. Please see the pictures. My thought is to not disassemble the crank. This 76 911s 2.7L engine had 77K miles and was not raced.

4sd911 · 09-12-2009, 07:28 AM

When you say "disassemble the crank" do you mean leave the rods on? At the minimum you'll need to throughly clean the case. Magnesium corrodes look for flaking inside the case, see if the oil pump turns freely. Show some pictures of the main bearings. What was the purpose of opening the case?

tadel001 · 09-12-2009, 07:53 AM

I split the case because during the disassembling process, some debri got into the crank gears. The engine was not turning smoothly. The main bearing look good. there are no scratches, gouges, etc. I was thinking of not removing the rods. Is there a compelling reason to remove them?

al lkosmal · 09-12-2009, 08:10 AM

Hard to tell from the photos, but it appears to be in nice shape. This is something that you will decide for yourself, but if I was in that far, I'd take it all the way down and inspect , measure ,clean...replace, as required. I'd definitely replace the bearings (main and rod), etc. (77K miles is not much...but...you are already in there.

PS:now that you've cracked the case open, the case may require line boring.......it's a 2.7 feature. In for a dime..in for a dollar.

regards,

Al

4sd911 · 09-12-2009, 08:41 AM

Also the head studs need to be time certed and at lest the lower studs need to be replaced with factory 993 dilivar studs. The studs threads will be weak and will likely pull if not addressed.

JFairman · 09-12-2009, 09:36 AM

You've gone this far...

Look for uneven wear patterns on the main bearings still in the other case half. It can give a visual clue on the condition of the case as far as ever being overheated, and possibly needing a line bore now.

Eagledriver · 09-14-2009, 01:48 PM

I rebuilt my 2.7 about 5 years ago and I'll give you my advice. I can understand wanting to save the money on rod bolts and bearings, but if you can afford it I'd replace them. The case needs to be checked by a good shop for alignment of the bearing saddles. There are studs that need to be timecerted including the one that is at the intermediate shaft bearing. You won't believe how easy it is to pull the case studs out when you put the engine back together. For some reason the threads pull much easier than aluminum threads. A good shop will know which ones to timecert. Be careful when you tighten the dome nuts on the rear studs that go around the number 1 main bearing. They will also pull. I tried using the larger o-ring on the number 8 bearing to get a better seal and the caused problems. The seal pinched in between the case halves and I pulled the studs around it trying to get the case seam to close. (so I recommend using the correct o-ring).

-Andy

tadel001 · 09-15-2009, 02:58 AM

Are time serts something easy that I can do? It looks like it is just using a tap, right?

Steve@Rennsport · 09-15-2009, 07:52 AM

A few thoughts,

1) One cannot see the rod bearings without disassembly and those are stressed parts.

2) The main bearing saddles do not remain in alignment after the case is split on magnesium-cased engines,..especially the '76-'77 cars due to excess heat. I would have the case align-honed to see if that will clean it up.

3) I would not use Time-serts,..Case Savers are a much better repair for reinforcing the threads on these mag cases. This is done in a milling machine and cannot be accurately done by hand.

stownsen914 · 09-15-2009, 08:56 AM

Once you have the engine this far apart, I'd definitely do the rod bearings. They tend to go before the main bearings in any case. Cheap insurance, really.

Scott