Laser 180 retrofit/swap from evolution 33cc mounting question

[Nick Stock 2]

I’m fitting a Laser 180 in place of an Evolution 33cc gas in a Hangar 9 Spitfire.

 

I presumed I’d be able to reuse the engine mount that the evo was bolted to.

 

The mount is made of aluminium and features a long slot in each beam which 4 non-metric bolts were fastened through. 

On closer inspection, I am surprised a slot system isn’t risky over the usual holes we normally drill through grp/nylon mounts where there is material front and back of the screws.

Furthermore, aligning the Laser 180 to this mount creates an overlap between the slot channel and the engine crank bolt holes.  I can only fit four M4 screws as opposed to M5s that I was aiming to use.  These will be fastened with nyloc nuts and washers.

 

Do we think this is acceptable or any risk of the engine shifting loose?

[Martin Harris - Moderator]

I do know that Neil Tidey hated the use of aluminium mounts and advised the use of plastic ones for Lasers when he was taking an active interest. Jon Harper may be able to confirm or update this. 

[Don Fry]

Can’t help thinking “what can possibly go wrong”

[Ron Gray]

Change the motor mounts to nylon ones, it’s not as if they cost a lot!

[Jon H]

The clamping force of an M4 bolt its very high so migration of the engine is unlikely. However, as Martin points out ali mounts are not recommended as they offer zero vibration damping for a single cylinder engine. If you need a mount i can provide one as we have them, or you can buy them from a model shop. Look for part no RAA1520. 

 

The holes in the crankcase are for M4 and there is no need for M5 so please do not drill them out. 

 

You are going to need one of our sleeve nuts and spinner adaptors as well. I recommend you bring the whole lot to the factory at some point as we can work out all the bits you need and get it sorted as well as taking a closer look at the fuel tank placement. 

[Chris Freeman 3]

Now this sure is customer care at its best!

[Engine Doctor]

6 hours ago, Don Fry said:

Can’t help thinking “what can possibly go wrong”

 Nothing can go wrong... go wrong.. go wrong.. go wrong.. go wrong.. go wrong..

 

Edited May 12, 2023 by Engine Doctor

[Engine Doctor]

5 hours ago, Jon - Laser Engines said:

 

The holes in the crankcase are for M4 and there is no need for M5 so please do not drill them out.

Agreed ! Why do people drill out mounting hole on engines ? I have seen countless engines ruined with drilled out mounts or even broken mounts from tiny  to big engines . Are some just too tight or lazy to buy some correct bolts to mount ? Having said that some of the dangerous bodges I've seen on cars beggars belief 

[J D 8]

             I once bought a Land Rover that pulled badly to one side. Took a while to sort until I found it had been fitted with left hand brake units on both sides! When reversing it pulled the other way and the penny dropped.