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3300 Exhaust and Intake Screw Torque

PostPosted: Wed Oct 27, 2021 7:21 pm
by nippaero
I've been looking around for the torque for the cap screws that hold the intake manifold and exhaust to the cylinder heads. Also, should there be some anti sieze or other lube on the threads?

Re: 3300 Exhaust and Intake Screw Torque

PostPosted: Wed Oct 27, 2021 8:03 pm
by peter anson
Can't find any torque specified in either the maintenance manual or the overhaul manual but most other 1/4" UNC cap screws on the engine are specified as 8 ft pounds so that should be a good guess. I would definitely put anti-sieze on at least the exhaust bolts.

Peter

Re: 3300 Exhaust and Intake Screw Torque

PostPosted: Thu Oct 28, 2021 2:11 am
by Kai
Well,

Yes, antiseize is a must, but take care not to use copper paste. You could perhaps find either nickel paste or some metal free stuff.

Thx

Re: 3300 Exhaust and Intake Screw Torque

PostPosted: Thu Oct 28, 2021 10:12 am
by builderflyer
Not to be different but at one time the previous owner of Jabiru USA recommended that the header screws be torqued to 125 in-lbs and use blue loctite (still have his email). We had more of a problem at the time with the screws coming loose, not seizing. You may want to check with the current owners of Jabiru USA to see what they have to say regarding the most current recommendation.

Art,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,Jabiru 3300 #261

Re: 3300 Exhaust and Intake Screw Torque

PostPosted: Fri Oct 29, 2021 12:52 am
by peter anson
Nothing on the Henkel website about the temperature limits of blue Loctite but I did see a service guide that said the service temperature upper limit was 300°F or 149°C which I think would often be exceeded around the exhaust port. My engine came with star washers on the bolts and that is what I fitted when I refitted the exhaust and inlet pipes. Haven't had any problems with them coming loose.

Peter