broken mounting

[se7enmad]

Hi !

 

this follows a previous posting of mine on chit chat.

 

In short - I broke a mount yesterday. To be exact one of the bolts on the right side engine mount (Vx 1600), shore off, whilst the other broke, leaving mount intact and shorn bolt stuck in block.

 

Question, why does the mounting only use two mounting points; as far as I can see there is a third point (above) which is unused and could be used by a mounting. Is there any ready made mount available that uses all three points. I would have to forget the shorn bolt one but still work on two bolts. That would save a new mount being manufactured.

I was mentioned triumph mounts? Any ideas people?

 

Thanks beforehand for your replies.

 

Antonella

1998 Caterham Classic

(Malta)

 

my site here

[Lee]

I had the same thing happen a couple of years back on my Vx1600 (after a racing incident though). Managed to drill out the bolt with an industrial strength drill (although it blew up towards the end), and a friend retapped the thread so we could reuse the mounting.

 

Lee

[se7enmad]

Hi Lee!

 

Thanks for the reply - in order to gain access to the bolt however, you do need to get the engine out. Can't afford to do that as first hillclimb this year is in ten days time.

 

Mount now ok as it has been reconstructed to use the third bolt I mentioned earlier.

 

We have thought much about the possible cause and the only factor that seems to have caused the shorn bolt may be the frequent resting of the sump on the steep ramp that I had in my previous garage. The sump is undamaged, apart from a few marks, but the force that was exerted sump up may have been enough to snap the bolt after a few good runs up the local raceway. I think this shearing has been coming a long time. In fact it is more than a year since the garage was replaced with another.

 

That mount seems to be the stronger one, it must have been some sort of unilateral force that has made the bolt give.

 

 

 

Antonella

1998 Caterham Classic

(Malta)

 

my site here

[Ben_S]

I've broken two of these bolts now. First time the car went back to Caterham and they claimed I'd fitted the wrong bolt (possible), but its happened again since (another 12k miles or so).

 

I managed to get the stud remaining in the block out, without taking the engine out, taking the steering column out gives enough access to tap the stud round on the threads and eventually out.

 

I think the aluminium spacers between the engine mount and the block put a torque on the bolt that they're not strong enough to cope with. I think if the engine mount fitted flush with the engine (with no need for the spacer), you wouldn't get the problem.

 

 

[se7enmad]

>I think the aluminium spacers between the engine mount and the block put a torque on the bolt that they're not strong enough to cope with. I think if the engine mount fitted flush with the engine (with no need for the spacer), you wouldn't get the problem.

 

 

100 per cent with you on this. I was thinking why would anyone would want to stick a spacer which would arguably increase the shear forces on the retaining bolts. I wonder why mountings are not constructed differently to make them as strong as possible. Said spacer also diminishes the distance from the mount to the steering column, even though this seems to be a comfortable clearance. However, I still am missing the logic of such mounts.

 

 

Antonella

1998 Caterham Classic

(Malta)

 

my site here

[AndreK]

If you wish, have alook in the technical archive around May-June 2001 under engine mount bolt. You will see that I suffered the same issue on the right hand (o/s) engine mount with this car. It appeared that mine was partly caused by the cap head high strength bolts being fitted without lock washers by the original owner, therefore came loose and sheared. You are right though in that the aluminium spacer creates a 'moment' on the bolt as it is not screwed fully home.

 

I suggest drilling the #bolt out carefully with a centre-drill (see the above archive, a fellow member helped me very much with this, sending me the centre drills required). If you are careful, then you will not need to helicoil the thread.

 

Good luck, you will need to lift the engine and gearbox up with a crane, so far then put a substantial support underneath, in order to drill. It's all rather frustrating but you will be OK

[Chelspeed]

The spacers are there for a reason. The 16V engine uses the same layout and came either wet or dry sump. The dry sump pump mounted between the engine and the mount. The alloy spacers are used when you don't use this dry sump pump. It means Caterham only had to make one engine mount for both applications. I said it was a reason, not a good reason...

 

Incidentally the mounting holes on the block were never intended by Vx to support the whole block, they're power steering pump mounts, the engine mounts are the 3 bolts in a triangle in the middle of the block. I'm surprised the block doesn't fall apart, but it doesn't so don't worry about it.

 

I've run the 16V engine for 8 years or so (was going to write 5 years then did a count and it's actually 8....) and have the same mount and the same alloy spacers as my dry sump pump is front cover mounted. I've had the same cap head bolts in there for 8 years without any problem. They're fitted with spring washers and are drilled for lock wire. I did the latter as they're hidden by the steering column in use and the first year one was loose and I didn't know. Ever since I tighten them up pretty tight and the lock wire them together.

 

Not had any problem since. Suggest you replace bolts with 12.9 cap heads (most cap heads will be 12.9 by definition), fit spring washers and then either 242 loc-tite, locking wire, or regular checks through the season. So long as they're tight I don't think they'll break again.

[EFA]

I agree with Graham....replace bolts with 12.9 cap heads.

 

Fat Arn

Visit the K2 RUM website

See the Lotus Seven Club 4 Counties Area Website here