Question: I have already purchased a .40 to .52 size engine. How do I know if my engine will fit properly between the engine mounts that are installed in many VMAR ARF's?
Answer: Most popular .40 to .52 size two stroke engine cases will fit between the engine mounts that are pre-installed in many VMAR ARF's. Most popular two stroke engines of this size have similar case dimensions. For example the VMAX, Thunder Tiger and OS .40-.52 size engines are very similar in size. The OS 40LA and 46LA have non-standard (too narrow) cases and pose difficult installation problems. We do not recommend the use of these engines unless you are able to modify either the engine mount T-beam spacing by removing and reinstalling the engine mounts OR can build and install a shim set (2 shims) to narrow the gap between the pre-installed engine T-Beams OR can cut a 1/8-3/32" plywood mounting plate and install it on top of the T-beams after cutting a horseshoe U-shaped recess for the engine case.
Supplementary Information: Although case sizes vary somewhat we have ensured that most popular engines fit. To get an idea of a typical case size that does fit, consult the VMAX .46 - .52 Engine Operations Manual at ... http://142.179.114.175/novo/default.asp?SID=&Lang=1&id=4002&Lang=1&SID= See the dimensional diagram on Page 7 and note carefully the sizes denoted D, A and G. Metric dimensions in mm can be converted into imperial inches by dividing by 25.4
Some engines may be a tight fit when trying to install them. In this situation we recommend removing the steel clamp plates from the factory installed engine T-beam engine mount and using self tapping sheet metal screws or bolts, nuts and washers when trying to install a tight fitting engine. If the engine case is too wide to fit between the factory installed engine mount T-beams after the metal clamps plates have been removed from the engine mounts carefully determine how much additional clearance you required. If you need only 1-2 mm more of total clearance to accomodate your engine, you may wish to grind or file away up to 1mm of material from the inside faces of each engine mount T-beam. If more than 1-2 mm of total clearance is needed to install your engine, you will need to consider a different engine or repositioning the factory provided engine mount T-beams or replacing the factory installed engine mount with a third party engine mount having enough clearance to accomodate your particular engine.
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