930 rebuild in progress.......I need your help and opinions on the mess inside

[adomakin]

ill be running a J+S safeguard on my street engine. it seems like a no brainer to me, even for a street car. i wont be boosting much past 1 bar, if at all, but if it saves my engine then its worth its weight in gold (literally!)

[cnavarro]

J&S recommends that their unit is threaded into the case in a central location. On the four cylinder applications I've just tapped a hole in the bell housing, since that doesn't involve having to have the case apart for something that protrudes into the case near internals. They also were originally introduced especially for aircooled engines, even with all the "noise", so there's no problem there- some people believe you can't run a knock sensor on an aircooled engine! They just haven't seen any late model 911s and the factory knock sensor bridges. :-)

[WERK I]

Originally posted by cnavarro
They also were originally introduced especially for aircooled engines, even with all the "noise", so there's no problem there- some people believe you can't run a knock sensor on an aircooled engine! They just haven't seen any late model 911s and the factory knock sensor bridges. :-)

Aren't most aircraft engines equipped with knock sensors? Is their cost prohibitive?

[cnavarro]

That's a good question. I didn't think they did. I know nothing in the experimentals I have dealt with do.

[Steve@Rennsport]

Dave:

Aircraft engines generally use two magneto's so they are self-contained redundant ignitions that will run the engine without any electrical system.

No knock sensors on any Lycoming or Continental 4 or 6 cylinder that I've ever seen or flown behind,...

These all use twin-plugs with each magneto firing one plug in each cylinder.

[WERK I]

Steve and Charles, thanks.

[Craig 930 RS]

Initial verdict (not mine, local shop(s)) on some of the parts - P&Cs:

The short skirt pistons are known to slap and scrape a bit - just as the ones in this 930 did. We could almost call this 'normal' - for a short skirt.

Long skirt Mahles are going in.

[JeremyD]

You still looking for an andial fuel enrichment? saw this on PCA site and thought of your woes - no affiliation just trying to help a brother out...

Link to Fuel Enrichment

Brand new Andial Fuel Enrichment Kit. Never removed from packaging. I am keeping my car stock. $450 (25% off wholesale). I have other 930 performance parts for sale.

Type of Seller: Private Seller
Company:
Name: Ronald Howard
Street Address:
City: Naples
State/Province: FL
Zip/Postal Code: 34105-4526
Country: United States

[Craig 930 RS]

No, I've solidly learned that the system isn't a good idea - but I do thank you for the help!

[Craig 930 RS]

Moving on to the build process!

-------------------------------------------------------

Ni resist rgrooves have been cut:


Crank actually looks pretty good - will only need a polishing, even after the spun bearing. One scratch, but the bearing shell covers it and is not a *raised* gouge:

[frencjas]

Craig,

I saw your car at the shop... MAJOR bummer! Hopefully you'll be back in action soon!

Jason

[patkeefe]

Craig:
Did you do an oil analysis on the drained oil? I would guess from the pictures that you were running excessively rich at some point in the RPM range, but were too lean at the points of obvious detonation. The bearings look like a case of fuel diluted lubricant, as do the distinct band of scored areas of the cylinder walls. I can only guess that you couldn't hear the detonation at the track because of road noise and the helmet. The signs of detonation are not as obvious or severe in the chamber pictures. Please keep in mind that I am by no means any sort of expert in this matter (I likely couldn't carry the bags of most of the posters here), but have seen many of the forced induction VW derivative air cooleds in this exact same condition. This may be more of a pre-ignition condition than true detonation. I also wonder of the effects on timing with the higher overlp 964 cam you have.

The knock sensor is a great idea, which I will try to put on my little SC turbo project. Good luck with the rebuild.
Pat

[Craig 930 RS]

What the he** caused this?




#6 cam lobe was apparently very worn (it was ent off for repair, did not see it), and BOTH #6 rockers look like crap - 3 distinct flat spots on each one.

WHY?

[CBRacerX]

Oil sprayer bar failure.

[john walker's workshop]

better pull the spray bars out and clean them real well. amazing that the crank journal survived the spun rod bearing. i've never seen one live. the journals can look ok, but a mic says different.

[frencjas]

Hmmm, the plot thickens...

Say hi to my S4 next time you're at R.E. visiting your car. I think yours is the only one there in the shop longer than mine (if it's still there)

[Craig 930 RS]

I wonder if the #6 rod material made its way to the spray bar - possible?

[WERK I]

If you had any coking in the oil, it is possible that can clog the spray bar.

[Wayne 962]

Sorry guys, but I'm thinking that a large contributor to this failure was a distinct lack of oil pressure. I would check the case oil pistons and their respective bores to make sure they are working properly. You just don't see this type of damage with oil running around in there, even if the engine gets hot.

-Wayne

[CBRacerX]

Great point Wayne, I was thinking this was localized damage to a single cam lobe (wait, isn't that what this is?). OK, I stand by my clogged spray bar theory