Janina993

Hi, I'm rebuilding my engine at moment and I'd like to chare my modifications with you. I would like to have tips and comments from you what I need take into condiseration?

I'm rebuilding engine for street use and occasionally track use. So this will NOT be a race engine. I'm looking to find 550hp and 700Nm from the bullet proof engine. Any additional hp is bonus.

Here is list from parts:
-Mahle 3,6 piston & cylinder set. Weight reduce -6g/cylinder
-Arrow precision connecting rods. weight reduce -76g/cylinder
-Crank, pulley, LWF, pressure plate, conrods and pistons counter weighted
-Head gasket "L" type flame ring
-Head porting with K-line valve guides and new design valve seats
-3.8 n/a RS camshafts for hydraulic lifters. STZ 1,55mm
-New rocker arms and shafts with hydraulic lifters
-Stronger valve springs with titan retainers. Weight reduce -12g/cylinder
-ARP head stud kit
-K24RS special turbo made by RS-tuning
-Turbo oil backflow kit
-Sport catalysators by Cargraphic
-sport mufflers by Cargraphic
-LWF and sasch motorsport clutch kit. Weight reduce -7kg
-5bar fuel regulator
-Bosch fuel pump. Over 200l/h 5bar back pressure
-New distibutor cap, rotor and wire set
-GT2 EVO oil cooler
-ECU reprogramming by wizard from Finland

Two question at start. I will use single plug ignition---what spark plug you suggest for me?

What you think about aquamist (water injection)? If I choose to install it, what could be the best place for injector? There is good place right after IC but there is also temperature sensor and it can give wrong result if it gets wet.

Acropora

Stronger valve springs would prevent a rebuild if you accidently over-rev on a downshift.

Jean

Good build. I would go with OEM pistons instead of JE and your stock fuel pump should be fine. wait for the gurus to chime in though.
Cheers

Kevin

Don't waste your money on the JE's.. Also, the Total Seal rings system will tear up the Nikasil lined cylinder.

Cargraphic cat is smaller than your stock cat. It might be 100 cells, but who cares if it has the diameter of a straw..

Water injection and Nikasil liners don't mix.. You have a high chance of water sitting in the flat cylinders=rust.. You'd have better results taking the aquamist and cooling your IC.

dbf73

I assume you meant do NOT waste money on the JE's. Also, don't the water injection systems only operate under boost? It seems like the water would be long gone by the time you shut down. Or is there a problem with these systems leaking/weeping water when the engine is not running?

Janina993

Nice to have board like this and active users. 10 points!
I forget from my list, I have stronger valve springs by eibach and titan retainers.
My ecu tuner have noticed the stock pump output capacity doesn't enough when fuel back pressure is raised to 5bar + boost 1,3bar = 6,3bar. (72,5psi + 18,9psi = 91,4psi)
To be honest I'm litle disappointed to JE pistons. (I have them in my garace already) They supposed to be lighter then stock but they are not! But I believe they are very strong. Piston top design looks much better in Mahle for one plug ignition. Really don't know what to do with piston issue...

This is new infromation from Cargraphic cat's Have you measured?

Do you have personal experiences from total-seal gapless rings in Porsche?

Aquamist goes on only after preset boost point and it is reading fuel injection pulse and mixing correct batch of water which isn't much. Water pressure is 8bar and injected thru high speed valve (250hz). Injected water is very thin fog. In most cases injection is switched on after 0,7bar (10,2psi). There is no change of rust. It will keep your engine clean.

Kevin

Why raise the fuel pressure when you can install larger injectors that will flow more at 3.8bar and not tax your fuel pump?

Yes, I have personal experience with the Total Seal rings with the Chrome liners.. Call Total Seal, they will not recommend it either..

Again, do you research and measure your stock cat vs Cargraphics then compare it to a 130mm cartridge.

Personally I think that you are stepping backwards when running the JE vs the Forged Mahle..

Janina993

There is no specific reason. At least after break-in cycle is complete, it's easyer to change regulator then injectors. good pretence
Definitely will call. If it's so, I will call to someone else too...
Parts should arrive soon. I will inform.

Janina993

I'm glad Kevin you open conversation about Total-Seal rings!!

I did call them and we recheck part numbers. The rings which came with pistons was wrong! 2nd ring wasn't suitable with Nikasil.
They send me new one which is suitable with Nikasil.
Gapless ring is good for Nikasil but it need to be specific material.

Quite a big mistake from piston supplier!

Kevin

2nd conversation to open..

Don't install the JE's in your turbo engine..

Janina993

Can you specify features between Mahle and JE?

chris walrod

Kevind, Due to high silicone content in the alloy and the extra -cold- clearances needed for JE's, is this the reason you recommend against such a piston?

Kevin

I have seen alot of failure with the crown seperating from the wrist pin boss on 5 engines 3 (local) within the last 2 years. All 100mm castings. For the air-cooled turbo I think that Mahle has nailed the piston to liner clearances. I also view the Mahle's to have a better casting, generally lighter and less bulky.

Steve Weiner-Rennsport Systems

I'll chime in here and agree with Kevin on using Mahle over JE's in an engine where longevity is important,... I won't use JE's where one expects the motor to last well over 50K. Some of JE's designs have not been real reliable.

JE's are fine for race engines where custom CR's, long rods, and other custom configurations are required.

Also, for the record, I've been using (the correct) Total Seal rings (2nd groove only) in different size Nikasil cylinders since 1978 with no problems. One enjoys remarkably low leakdowns through the life of these assemblies but they do take longer to seat than Goetze rings and patience is required.

Janina993

Like I said before I wasn't pleased when I saw JE's quality. And heavy structure and wrong 2nd ring...
Now you have bring me even more aspects to delete JE pistons.

Only reason why I try hang on to JE's skirt is the costs.

"bulletproof" is the name of this engine modification and I will spend some more $$$$'s and go for Mahle.

Even though now I have correct Total-seal for Nikasil bore. Have you Steve use gapless 2nd ring in Mahle?