Cylinder Head Gasket Blown Problem

[eTiKeT 0 1 Cars]

Hello, good evening, my car cylinder gasket blown this evening

xu5ja engine using 9.8:1 cr, I wanted to use xu10j2te manifold and turbo these days is 1.4 bar

Exploded 4th time around i think to use the 1.9 piston to reduce the compression ratio

 

How do you think happens? Do you have a more robust gasket or suggestions?

 

thanks

 

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Edited August 30, 2013 by eTiKeT

[DamirGTI 342]

That's head gasket damage caused by detonations .

 

What kind of ignition and fueling (fuel grade as well) system are you using on this engine ?

(suppose stock from reading some of your posts ?)

 

If it's stock dizzy ignition , and worse with std. angle curve , sorry but it just wont do on such modified engine .

So in this case , option 1 if planing to use distributor ignition system - at least get the dizzy re-curved to suit the engine modifications fit and see what happens , option 2 if you have funds to spend on making this engine really work - fit mappable ignition system only (which would be "cheaper"), or better still complete SA ECU , and get the car mapped properly .

 

9.8 static compression ratio is a bit high for turbo engine (but then not a problem if you have good engine management , which in this case you haven't .. surely you can tweak the fuel trim on stock analogue ECU easily , but stock ignition is a problem) , so i really doubt that you'll be able to run it problem free on stock ignition/fuel system .

 

 

D

[eTiKeT 0 1 Cars]

Hi Damir,

Car in the Standard Jetronic system, 250cc 4 point injection, bosch platinum iridium spark.

I used the 1.2 bar (very nice) arranged in the best way with the headset advance

yesterday I tried 1.4 bar gasket blown, my aim and OEM parts with a low cost to find the best stable value.

[DamirGTI 342]

You're really pushing it to the limit , 9.8 CR @ 1.4Bar boost with mechanical dizzy setup !

 

Have you checked the mixture on board with an aid of WB lamba sensor trough all the rev range ?

 

As for ignition , for turbocharged engine on mechanical ignition you need less total advance (it's 30deg. on stock dizzy) .. and at burst of boost and engine revs exhaust noise etc. you may not be able to hear it pinking/detonating , plus the engine management doesn't have an knock sensor to back up the timing when it senses detonations .

Get the dizzy re-curved at least , if you're down on money :

 

http://www.h-h-ignitionsolutions.co.uk/

 

It will "work" with re-curved distributor (but i somehow doubt for how long at such high CR and boost pressure) .. or consider something cheaper for ignition like "megajolt" and similar systems ...

 

Also , wiring it up on 2.0 T engine management (Bosch Motronic MP 3.2) would be certainly better than Jetronic .

 

D

Edited August 31, 2013 by DamirGTI

[eTiKeT 0 1 Cars]

damir hello again, thank you for writing, XU10 engine parts, unfortunately, hard to find around here, XU10J2TE to you is impossible to find.

I'm trying to do something with the opportunities here.

I Now existing one XU9J4 crank, I think raise volume of use 1 bar with 2mm gasket

XU5 aluminum block is actually very weak, XU10 begin using iron block, may be more resistant to very strong