Exploding mechanical headgaskets

[TedV]

On the dyno yesterday, the Victor Reinz head gasket decided to come apart.  A section under the #4 precup, from the head oil supply o ring to the head stud in the corner exited and stuck in the wiring harness.  This was at 22 psi, 3800 rpm.  The gasket did not have a spiral ring under the metal around the combustion chamber I thought TD gaskets were supposed to have.

Anyone know for sure what the strongest mechanical head gasket is? On the short list is finding a Goetze and what felpro gaskets are available Monday morning.  I'm in a hurry cause I have to leave next Friday for a big autocross in Atlanta.  Gotta love Murphy's Law, but no visible damage to head or block.

Since this car is to autocross, legaly I don't think I can use the metal HG because of the rule below so it will need to be a fiber gasket.  Unless someone has a copy of a VW service bulletin that says the metal gasket can be used on earlier motors.

"Alternate parts listed in a factory parts manual are not authorized
unless their use is specifically referenced in the factory service
manual or in a service bulletin for the specific model.
See Sections 3.8 and 8.3.1 for documentation requirements.

Alternate components which are normally expendable and
considered replacement parts (e.g., engine and wheel bearings,
seals, gaskets, filters, belts, bolts, bulbs, batteries, brake rotors,
clutch discs, pressure plates, suspension bushings, drivetrain
mounts, etc.) may be used provided they are essentially identical to
the standard parts (e.g. have the same type, size, hardness, weight,
material etc.), are used in the same location, and provide no
performance benefit.  The allowance for use of such replacements
does not include camshafts, differential covers, or ring-and-pinion
sets, nor does it authorize the use of piston rings having different
configurations (e.g. “Total Seal”) from those of the original."

[jtanguay]

sounds like its time for you to switch over to the 1.9 metal hg.  and plug the oil return hole.

[gigaz2]

he can't

as long as there isn't any VW service manual to specify that the metal HG is the correct gasket to use it would be ilegal to use it on those races.

offtopic:
racing rules suck! (and I dont have enough doe to enroll in the unlimited category on the local baja , this one counts for the world championship and all... )

[jtanguay]

woops didn't read that  :oops:

what kind of head studs are you running?

and they allow you to run 22 psi @ autocross?

if you're blowing hg from 22 psi i think somethings up... bigger exhaust to reduce back pressure maybe?

[burnt_servo]

can you o ring the head and or fire ring the block ?

[jimfoo]

He can only use stock gaskets that came on that year engine.

[TedV]

The details
About 150 to 200 miles on motor since rebuild.  I had noticed a burp of coolant from rad cap a few times, but no water in oil, or loss of pressure when testing coolant system. And coolant stayed in the proper range.  From that figured either bad cap or under boost cylinder pressure was getting to water jacket then resealing itself when boost went down.  

IP timed to .038” (.96mm) per Giles .95mm instructions.  Freshly surfaced block deck.  Piston protrusion at the high end of a 1 notch gasket, a couple more thousandths and it would take a 2 notch.  Measured by both the machine shop and myself with same resulting readings.  Gasket says Victor Reinz on it.  Brand new Topline turbo diesel head with ARP holding it down, using their moly lube.  Stock cast exhaust manifold with thermal coating, stock T3 turbo, then 3” downpipe going to 2.5” straight pipe side exhaust.  Grainger valve to control wastegate opening, gauge reads 22 lbs at full boost.  Air/water intercooler inlet pipe will be too hot to hold but outlet to motor is nice and cool to the touch.  EGT’s were about 1100 to 1200 deg F when it let go.  Boost was steady at 22, then at 3800 RPM it dropped to 20 psi, I noticed a change in tone of the motor.  Started to say “ OH SH..” right before the SPLAT of oil and coolant sprayed ALL over.  Guy running the dyno about jumped off the mustang dyno platform.  I pushed in clutch and killed motor.  Found no holes in block but found 2” section of head gasket speared into the wire harness, laughed hysterically.  Removed head and so far found no visible damage to head, block, pistons, valves, etc.  Precups were easy to remove and I am thinking of staking them in when it goes back together

About the class rules, Hardware items (nuts, bolts, etc) may be replaced with similar items of unrestricted origin.   In FSP fueling, intake, and exhaust is unrestricted but the wastegate and BOV must remain stock, but the boost can be controlled before the pressure gets to the stock wastegate and BOV, so yes boost till you blow something up.  I’m below what others say they have been able to run on the fiber head gasket.  

Right now I am thinking of trying a 2 notch Goetze gasket and use a machinist rule and make sure the new cylinder head is in fact flat.

[TedV]

ment to check piston protrusion again today and compare to original readings, but power outages and helping housemate with a medical emergency with one of the Autrailian Shepherds.  

Exhaust was never anything but black so don't think too much coolant ended up in combustion chamber.  Also all 4 pistons had the same soot color.  Water in combustion chamber should show a cleaner steam cleaned piston

[RabbitJockey]

whos going to know that u have the wrong head gasket?

[Turbinepowered]

whos going to know that u have the wrong head gasket?

He is?

I like to believe folks involved in competitions have the integrity not to cheat. :roll:

[jimfoo]

Plus you can look at the protruding parts of the gasket and see it is all metal.

[TedV]

I will know, plus there is a visible difference between a fiber and metal HG.  I believe there has been some Honda found illegal because they used a stock metal gasket from another motor that fit, but increased compression over the original fiber gasket.  Increased compression is a performance advantage in a gas motor.  The metal gasket in itself is not a performance advantage since it is the same thickness as the fiber gasket, but it is more reliable even in a NA motor (once you solve the water-oil galley issue).  Is reliability a performance advantage?  I don’t want to test a protest committee on that one.  I already have enough stuff for people to complain about.  Like the Topline head, but I have my paper from VW stating the head is no longer available from VW since 1996 and VW-Bentley Manual says heads can not be milled.  Every used head I found needed to be or has already been milled.  Doesn’t that make them all illegal?  I don’t have to worry about being legal if I’m slow.  I don’t like being slow.

Yeah, rules SUCK!

I found this, but it is not from VW.  Note the "All engines built previous to the above date may be fitted with the revised gasket during service."  If it was from VW, I could use the metal gasket.


REVISED CYLINDER HEAD INSTALLATION
                                  Revised Cylinder Head Installation For
                               1993-2000 Volkswagen 1.9L Diesel Engines

The AERA Technical Committee offers the following information regarding a revised cylinder head installation procedure on 1993-2000 Volkswagen 1.9L diesel engines. Beginning in November of 1993, these engines started using a metal head gasket with a silicone coating. Using that gasket required a reduction in applied torque to the gasket. All engines built previous to the above date may be fitted with the revised gasket during service.

When making head gasket repairs with the above-mentioned gasket do not rotate the head bolts an additional 90° after the engine is hot. That final procedure is no longer required with the revised gasket.  To install the cylinder head, obtain a set of NEW head bolts and follow the procedure listed below.

Step 1. Rotate the crankshaft so all pistons are below top dead center.
Step 2. Align head over locating dowels and place head on block, remove dowels.
Step 3. Install NEW head bolts and tighten bolts by hand.
Step 4. Torque all bolts in sequence to 30 ft/lbs.
Step 5. Torque all bolts in sequence to 44 ft/lbs.
Step 6. Rotate all bolts in sequence an additional 90° turn.
Step 7. Rotate all bolts in sequence an additional 90° turn.

Note:  Leave the head gasket in its packaging until just prior to installation as scratching the gasket surface is unacceptable. Handle the gasket with extreme care as damage to the silicone coating may allow leakage.
 
                                                                                 
The AERA Technical Committee

[MJF]

Did you glue it? I had Elring gasket in my first setup, that was the cheapest hg I could find Drove it with 28psi boost and 150whp about 10kkm before head crack. But no problems with gasket. And with stock bolts.

[TedV]

I used a very small dab of hylomar close to the center of the HG to keep it in position when putting on the head. This was no where close to cylinder #4 where it came apart.  I did not put a thin coat over the entire gasket.  I've heard some say thin coat of hylomar, and heard don't do it.

so,  which one is it on a mechanical fiber head gasket???

[TedV]

measured flatness with machinist square edge and feeler gauges.  Block is perfectly flat.  Head is flat where head gasket hits it.  Only raised portion of head is between the precups and valves in the combustion chamber area, by at most .002" to .0025".  3 precups about fell out when I removed the head.  #4, where the gasket blew was the only one really stuck in the head.

Seached for peening precups while eating dinner, will give that a try with a nice rounded drift punch.  Have my junk heads to practice on.

Only head gaskets in town were Victor Reinz at my local VW shop.  noticed the 2 notch gasket has thicker metal, wel duh, it is a thicker gasket.  Hope second time is charm :lol:

back to the garage....