Shafts are there because piston movement is slower at the bottom than it is at the top. This causes
second order engine vibration on i4 engine configurations, shafts oppose that vibration with their own vibration. Thats why they spin at twice the speed of engine.

Shop probably needed rods and pistons for matching balance and piston weights, not to balance crankshaft.

What springs did you get? Something stronger or stock new?

 

They say they needed both pistons and rods for weightmatching, but then gave me my pistons back afterwards, but keeping the crank with conrods for balancing.. At least that's what they told me. They seem to know what they're doing, so I'm rather optimistic.

As for the springs - i can't tell you how much right now, but yes - the springs are significantly stiffer than stock. I wonder if springs alone would allow me to up the rev limiter to let's say 7.5k with stock hydraulic lifters? there are some old threads where people claimed 7200rpm to be on the safe side on fully stock 16v head. I wonder whether I can go higher or do I need to wait until i go for the solid lifters with that?

and since we got to a new page, some photos from yesterday's garage priming:

 

IIRC stock oil channels doesnt work properly in crank above 7krpm so those should be altered.

 

by altering you mean cross drill, or something more?

 

Propably yes. Don't know the details. some run 944 engines over 8krpm so they should know.
Dunno if cross drilling is just the case, or if you need to modify the crank also in some other way.
Here's one article but it only discusses wheter there's benefits to cross drill or not.
http://newhillgarage.com/2013/06/25/...tem-explained/

 

I perp drilled the 2 and 3 rod journals just for the peace of mind.

 

According to some sources the stock lifters are too soft for springs over 140 pounds seat pressure (OE springs should be 130 when new). Also have read on one older thread that the stock oil pump also reaches its limits at around 7200 rpm.

 

Oil pump wants to cavitate over 7000 rpm, but stock 16v lifters and springs are good for 7500 at least (I tested with my own engine, no valve float at 1.2 bars of boost). Scared to run it constantly that high because I see slight oil pressure fluctuation over 7000 rpm (I use 924 10bar oil pressure sender and gauge, I have 924 doh ). And that is with brand new oil pump, max oil level (using Motul 300V 20W60).

 

The ignition has a hard time keeping up at 7000 rpm's also. It gets expensive o bring these engines to 8000. I would think you would need a full blown race engine. No A/C, use under drive pulleys, dry sump oil system, stand alone engine management with coil on plugs, solid lifters with stiffer springs, lighter and stronger connecting rods, lighter and stronger Pistons,Bosch 044 fuel pump to keep up and really good oil!
Not sure cross drilling or perp drilling the crankshaft helps on these cars due to how many 90 degree turns it has to make in the crankshaft before getting out to #2 and #3 rod bearings. But it may help. I would like to know if anyone has spun the #2 rod bearing on a prep or cross drilled crank. 10 years ago when i built my engine I had the rods bearings undersized and cross drilled because I spun the #2. That was before I found an article on these crankshafts talking about its design and why it spun the #2 bearing all the time. Talked about all the 90 degree turns in the crankshaft going to the rods and centrifugal force affect on the oil.

 

Lol, ignition is the cheapest thing with standalone ECU. If you want big hp, all the mods you mentioned are obvious, even without 8000 rpm. Only extra thing really needed for higher than 7k rpm is dry sump.

 

Humboldtgrin - I expect no ignition problems whatsoever - this is a build with standalone system, 4 coils on plugs, no AC etc. As for internals - also stronger and much lighter conrods as you mentioned plus many other parts modified. Dry sump and solid lifters are a matter of next stage - in a year or so. Dry sump will come first, but nobody really knows when. I will most likely be a betatester of a dry sump system designed from scratch by a friend of mine but lately he had no spare time for that project..

 

Finally we got some paintjob.. The pictures do not give just image, but we wanted the car to be the whitest of them all. It's sprayed with pure white pigment with only minimum acrylic and resin. In sunlight it should really make other "white" cars look ivory..
A friend of mine coated the car in truly spartan conditions, so it's not perfect, but still more than enough for a trackday car. We'll be painting the rest of the panels and doors this week. Interior respray will have to wait until the car is completely ready for reassembly - I wouldn't want to drop a screwdriver on a mint floor.. Next stage will be simplifying electrical circuitry as much as possible, relocation and fabricating new brake and fuel lines..

 

Pictures wont work..

 

Strange - are those visible now?

 

Like a Toothpaste advertisement!! Whiter than White!