solid motor mount causes damage?

[jasonp]

I have an mk2 IT racecar, 1.8l 16v. During the process of removing my gearbox I had to remove my starter and discovered the bolt hole part of the housing was broken and had been held on by the pressure of the bolt. This is where the starter attaches through the gearbox and to the motor by way of a long bolt.

I have a solid aluminum (tt) front motor mount and the Bildon racing transmission mount and an HD rear engine mount. I'm guessing all of this has contributed to vibrations and the breakage of the starter housing.

Has anyone else had this experience?

I am in my third year of racing and learning all the time. I will have to check with my engine builder to see if the 3 year old motor was balanced and blueprinted as I understand a lack of this procedure may add to the engine vibrations and associated breakage and loose bolts, etc.

Another question is, how often do us VW people rebuild our engines?

 

[Bill Miller]

I have an mk2 IT racecar, 1.8l 16v. During the process of removing my gearbox I had to remove my starter and discovered the bolt hole part of the housing was broken and had been held on by the pressure of the bolt. This is where the starter attaches through the gearbox and to the motor by way of a long bolt.

I have a solid aluminum (tt) front motor mount and the Bildon racing transmission mount and an HD rear engine mount. I'm guessing all of this has contributed to vibrations and the breakage of the starter housing.

Has anyone else had this experience?

I am in my third year of racing and learning all the time. I will have to check with my engine builder to see if the 3 year old motor was balanced and blueprinted as I understand a lack of this procedure may add to the engine vibrations and associated breakage and loose bolts, etc.

Another question is, how often do us VW people rebuild our engines?
[/b]

First off, I'm pretty sure that that solid front TT mount is not legal for IT. And, as you already know, constraining vibration in one place just chases it to another place. And while a balanced motor should produce lower vibration, not all the vibration comes from the motor. Balancing the motor is more for the longevity of the motor. As far a rebuild frequency, it really depends on how much you run the car.

 

[jasonp]

I am running in Canada under WCMA rules and they are pretty much a copy of the SCCA rules. Although they have not been updated (adding cars, etc) in a long time. The motor mount is legal in Canada.

 

[Bildon]

>> Another question is, how often do us VW people rebuild our engines?

If built properly they will (in IT configuration) last for many years. Afterall IT engines are stock engines.
Most VW's dont have the valve train problems that some cars do. However it's not a bad idea to freshen your valve seals and seats every few seasons. Rings SHOULD last years if treated properly.

Now with your mount problem. Yes a solid mount will cause problems like this. Solid mounts are really only for drag racing.
You would have been better off making them ALL solid. You let the motor rock on 2 flexible mounts and the 3rd one (front) then took out it's frustration on your gearbox case. So either make them all harder (but not solid) or make them all solid. However if you are going the solid route, I'd suggest you do a lot of vibration analysis, as you may soon find yourself vibrating the car to pieces in places you never though possible.

 

[jasonp]

Thank you for the responses gentlemen. I will remove the solid front mount in favor of a softer front mount.

Any suggestions on where to get a stiffer front mount? I have upgraded the gearbox and rear engine mounts to the ones available at Bildon. Being inexperienced at the time, I figured since the only one available at Bildon was the solid one, this must be the way to go. Should I return to the original motor mount? What are most of you using out there?

Thanks again.