Hilton

Looks like rodent damage to me

gbgastowers

928 Motorsports used to offer a block repair and Nikasil coating for about $2200. You send them the bare block with all steel removed for the process. http://www.928motorsports.com/services/uschrome.php

BC

Thanks. The only people that did wet sleeves are people that we trust (Simard/Todd) but these are one-offs, and they did their own, and it took massive amounts of time and Money. I don't know who ended up with Joe's Block that Todd made for him. Erik - do you know?

Greg - My points were walking up to the question whether you feel this is safe for the general population, how much it is, and if its good for all 8. Steel here always is spoken of as stronger, but I always hesitated because of the movement of the sleeves people mentioned. But if you trust it x8, that would be good.

GregBBRD

Whenever I undertake a new technique, I try to weigh all the options, carefully considering the pros and cons.

When I was doing boatloads of 951 emgines, I sleeved several of those emgines, using this technique. I built a couple of "test" engines to figure out the proper piston to wall clearance, in those engines, but the sleeves gave me no problems.

Using that data, this is more than a test, but certainly not a sure thing.

GregBBRD

Yes, I have been using Nikasil as a cylinder repair/alternative surface for many years.....way before 928 "Motorsports" existed.

The damage on this block made this technique not as desirable.

GregBBRD

Yes, however the use of Alusil in the GTS application leaves one with very few options other than the factory pistons, which have several "design issues".

hacker-pschorr

Sorry, I do not.

Need to ask Joe.

GregBBRD

Simply by studying the various engine blocks from the 944 and the 928 lineage, it is fairly obvious that there was considerable debate in Porsche engineering either about how much material was required to support the cast in cylinder liners in the Alusil material or at what level the water needed to be to remove heat from the cylinders. While the "early" 928 and 944 engines had very close to the same amount of material from the bottom of the water jacket to the main bearings, the 3.0 944 engines and the GTS engines are radically different....in opposite directions. The 3.0 944 engines have considerable more material between the bottom of the water jacket to the main bearings (shallower water jacket), while the GTS engines have significantly less material between the bottom of the water jacket and the main bearings (deeper water jacket.)

It's a very interesting contrast!

When the 944 GTR engines were changed to wet sleeves, Porsche was forced to abandon the Alusill material because of cracking in the main bearing area and recast the blocks in pure aluminum.

Since the 928 GTS blocks have significantly less material than all of the previous iterations of any of this lineage, I consider it to be very undesirable for wet sleeves.

mark kibort

Interesting you are seeing slipping. what torque peak are you seeing for your motor to cause slip?
I have the strengthened pressure plate on the dual disc clutch (after finding out the hard way that the stock clutch is no match for 400ftlbs of torque) . changed it at the track after a slipping qualifying and was bullet proof in the race! (Big thanks to Anderson for help on that one! .......and Greg for that design!!!)

mark kibort

these threads are always amazing...... did anyone provide a theory on how the rod nuts could have come off without mar'ring the threads at all?

mark kibort

these threads are always amazing (no pun intended)...... did anyone provide a theory on how the rod nuts could have come off without mar'ring the threads at all?

Rob Edwards

Nope.

Strosek Ultra

Rob, from what I understand you now have a repaired engine block with six factory pistons and two aftermarket pistons which are running in two CI sleeves. No doubt it should work well. Trust the rotating assembly is well balanced with all the pistons having the same weight and compression ratio. As I mentioned before there are Alusil Cylinder Sleeves Blanks made by Kolbenschmidt available over here. The Alusil blanks are very good for the making of dry cylinder sleeves for the repair of various aluminum engine blocks like the 928. In the shop I have a S4 block where all eight cylinders are Alu-sil dry-sleeved. It is probably a factory exchange engine block. Did you get two new factory GTS rods or a full set of aftermarket rods? For what are you going to use the repaired GTS-engine?
Åke

Rob Edwards

Hi Ake- Actually we're going to sleeve all 8 cylinders, run eight new aluminum pistons that match all GTS dimensions (except weight) with stock R2 rods, the repaired stock crank and cams, and Greg's latest take on breather improvements. Goal is to have a correct-looking GTS motor without the oil consumption or pretzel rods, so I can make the GTS 'whole' at some point.

Am beginning to get bad ideas about a stroker transplant into an early body where I'm unencumbered by wanting to still be able to return everything to stock. Modding a 5-speed GTS just doesn't seem like such a good idea anymore, and I need a new project.

In the meantime I spent the weekend measuring Anderson's pile of cams, so made some progress on the new Zombie motor too.

D-VO

To answer the question of how those rod nuts came off the bolts, first one, then the other. (Right, then left)