22-08-02, 08:25 PM
Ok well for those of u that remember before i did the ring job i was trying to figure out why i was getting white puffs out of the oil fill tube and after many hours of labor and a ring and piston job ITS BACK!!!!!!!! :evil: i am so mad it had 500 miles on the new parts and i was curious on why the turbo was keeping in the hint of yellow and with all the upgrades i had done i couldn't believe it so i tried one of Johann's tricks to see what was malfunctioning well no offense to u johann it may not be the best idea to take off the waste gate hose! :cry: i was only able to squeeze 16lbs out of her which is impressive for a stock turbo but not a stock engine even with new rings :D . When i dissasembled the engine the first time for the head gasket i put a copper one on; don't ever do that they don't seal well at all; everything looked fine and dandy no signs of odd wear or damage then i pulled the engine for what i thought were rings that needed replacing and well NO the side of the piston in the 2nd cyl and the 3rd facing the timing chain end of the engine was melted!(2nd was the worst the third was not that bad):o So yeah i am back to the same conditions as before and it is only my guess what is wrong again! so i have to pull the head to find out so yeah well i am uneasy to do it again i have almost had it with trying to up boost and no postive outcomes have come of it so well i need some encouragment as to why it keeps doing this. It is not temp as per my stock guage wherever it measures temp it read in the middle no where near the red so temp is not an issue then i scream timing and that may be it but why would it run like a beauty for so long and then say wooooww too much pressure from the turbo and no way to control it i need to melt something.??????????pls adise
A picture of the piston in the 2nd cyl can be seen in this topic: http://www.saabcentral.com/forums/viewtopic.php?t=3816
22-08-02, 09:55 PM
so say it is an injector could explain starting well every time but melted piston thoughts anyone?
23-08-02, 12:54 AM
if you are upping the boost without adding more fuel and retarding the timing more then you will burn pistons from leaning it out. i am running 25 psi boost on my 140000 mile stock never apart motor for the last 9000 miles . i have a spg9 stage 2 apc box ,30lb. ballanced injectors, rising rate pressure regulator, and a vac.can that pulls in more retard under boost and it runs GREAT . but you have to do all of it or you will have problems
23-08-02, 06:45 AM
I did suggest taking a lot of care when pulling the actuator hose and testing for boost -it's just a test to see if the turbo can actualy generate the boost - not a permenant solution :o At 16 psi you will be hitting the overboost switch and this causes massive leanout and if you keep hitting it it will damage the engine.
23-08-02, 10:45 AM
well this all sounds promising and could be it i have not played with timing it has stock vaccuum advance piece on it and the over boost fuel cutout switch how did u get around that at 25 psi i have heard of dialing it up to 18 can u do more than that thnks all for replies although if one would think about it the over boost switch should take the fuel out of the equation not lean it i don't know i am anxious to get rid of this switch it hurts more than helps i unfortunately ran it for about a 1/4 if that and were at the smae conditions as before and u people with ur stock engines i am jealous
23-08-02, 11:50 AM
ok well so we have the overboost fuel cutdown! swtich and what else is there to watch out for when incresing boost not only for me so i don't have to rebuild another saab engine but also for the rest of us anxious to get boost easily with out paying atten to precautions or well not knowing about them
From the picture it looks like the meltdown was caused by detonation. This is 'normally' caused by incorrect timing at a given rpm and/or fueling problems. Both of wich will cause high combustion temperatures.
The temperature gauge only monitors the temperature of the coolant in the engine not the the combustion temperature.
On my 8valve turbo I modified my apc solenoid and disconnected the over boost fuel cut off and had really bad pinking i.e detonation at high revs. To combat it I had to use a higher octane fuel (shell optimax in the UK) It now goes like sh*t of a shovell with no obvious side effects yet!
Hope this helps in some way.
24-08-02, 02:17 AM
well hey thnks for all the info how exactly did u cut out the over boost fuel switch did u just disconnect the wires and could u find out what the octane rating was i run 93 in it every day i fill up it has never seen lower since i have owned it so dunno i can get 100 octane racing gas at a local gas city station just price kills 3.98 a gallon thats about
52.00 dollars american that is way above my price range to fill up every week or so! well i await a better answer or well a cheaper one
Normal unleaded over hear is 97 RON octane. Shell in their wisdom don't actually have the octane rating of their Optimax fuel listed anywhere that I have found so I guess it's 98 or 99 I don't really know but it is quite expensive especially when I only average 21 miles to a gallon.
The fuel cut off is under the dash on the left hand side.
It has a vac pipe on the back, two electrical connectors on the front and a screw in the front covered with red paint.
Disconnecting and blocking the vac pipe will disable it. Another method which I use is to turn the screw in all the way clockwise.
Here we have a fine example of differences on the other sides of the Big Pond. 93 octanes in U.S. isn't the same in Europe, I'm not sure but 93U.S octanes is about 98octanes in Europe (RON) or something...but anyway, octane figures are not equivalent. :! AND THE PRICE THEN :! I DO pay ~60EUR (=$60 US) per fill up on unleaded 98(RON) here (Finland), and you Yanks get tank full racing gas for even less...Way cool... :evil:
24-08-02, 12:26 PM
thnks yeah well we have very few advantages they are a little more strict on emissions over here but prices we bargain a good deal from the kuwaities but for how long that will last who knows it was really expensive this past summer some parts got up into 2.00 a gallon for 87 and the normal price is about 1.20 so its staying reasonable for now. The fuel cutout switch i found it and dialed it up 1 1/2 turns clockwise and it didn't die when i ran it again up to the boost i figured i am looking at pretty much redoing all the pistons the compression ratings in psi which 14.5psi equals one bar (so says in the haynes repair manual)
#1 dry was 145 great,#2 dry was 120 so so,#3 well dry was 40 ouch, and #4 dry was 50 ouch again so might just drop another engine in than taking this one apart again what a pain well u live and learn thnks all for the help.