building: Fitting gearbox first?

[squirejo]

Hello team,

I took delivery of a 360R kit a few weeks ago that I am building with my 13yr old son. He's in charge of the IG account @caterhamdiaries if you want to follow our progress.

The caterham guy who delivered the kit was very helpful, staying around an hour and showing us a variety of things to do, hints and tweaks to aid the build.

One he suggested was to install the gearbox before the engine. I haven't seen that done. It seems a good idea: much less mass to swing around from the engine hoist and easier to install in the small tolerances down there. Thoughts? Can the bolts be accessed to attach the engine to the bell housing doing it this way?

Thank you!

Edited by squirejo on Tuesday 11th January 11:50

[BertBert]

People generally are mixed on this. My preference is to fit the engine to the box outside the car. Experience shows that there is a lot of lining up and jiggling to do to get the two together which I prefer to do outside the car. But that's the only way I have done it!

[DCL]

I think generally engine and gearbox go in OK together, but there are some variations don't - Sadev' with the Duratec can be very tight on S3 chassis with the fixed gearbox mount. I think provided you pre fit them together out side the car (to check the clutch alignment) it is easier to do them separately as there's less to watch and angles are more sensible. Support is needed for the gearbox of course (I use a strap and length of wood across the top chassis rails). Access for the bolts is fine but using a torque wrench may need the car jacked up quite high. Best tip I got was to leave all the engine mounts loose (where they bolt into the engine) so that's there's plenty of play to align the rubber mounts.

[squirejo]

thank you so far. Either way sounds a wiggle / tolerance nightmare but i feel like wiggling 2 smaller lighter bits may be easier than the whole in the hole from whats been said so far.

[BertBert]

One thing I have found to be extremely helpful is the engine load leveller. Means you can easily change the angle of dangle. So steep to start with and then flatten out as the tail goes in (as it were).

[stunt.monkey]

I put the gearbox on the engine first. Dropping both in the car together was just a little fiddly but not too tricky with a load leveller and two people.

Mine was a Sigma in an SV chassis so a bit more room to play with though.

[Rockets7]

Did a few swaps on my 7. Always put the box in first, a leveller is essential but I managed alone so it’s not too bad in a 7 just cover the frame rails before you do it.

[Paynewright]

I’ve removed / installed several types of engines (kseries, BDR, xflow & vauxhall 16v) and mostly done engine & box together. A load leveller is essential for this - ensure you put the crank handle in open space if using a floor mounted crane. It can clash with the lifting boom (ask me how I know!).

I have done the VX engine on its own and apart from supporting the gearbox it was easy with a moveable crane. If you have a fixed lifting point eg an RSJ and have to move the car as the engine goes in I think its better eng/box together (unless you can support the box on the chassis rather than a jack)

I use pipe lagging to protect the chassis or old MTB inner tube wrapped around like handle bar tape - whichever is handy.

Its better done with two of you - one on the crane / load leveller and one watching / guiding as its lowered.

[Boggo]

I've had my engine in and out a fair few times - and I've gone both routes.

Personally I prefer to remove the engine separately from the box.

Both ways are entirely acceptable - but I can do the separate method on my own - connected is a two man job

[squirejo]

Thanks to you all. As the mixed replies show- both work! I do feel that for a first time, separating them means smaller units, let potential for damage and more manageable weights etc. so I reckon we will try that!

[squirejo]

It’s in….so we can start to build up the rear. Whether we can get the engine in will have to wait for now…

[BertBert]

Good work!

Is that heat insulation in the tunnel sides? Is that standard now?

[Boggo]

BertBert said:

Good work!

Is that heat insulation in the tunnel sides? Is that standard now?

yup

[squirejo]

Boggo said:

yup

indeed it extends from the rear of the engine bay to the rear of the gearbox - ie lining the "cockpit" both sides. And its a little vulnerable to damage as the gearbox goes in - another reason I decided to do that and engine in halves. I am going to supplement on the inside of the driver and passenger pods with Dynamat

[BertBert]

It makes me wonder whether it's a corrosion trap. If it gets damp between the insulation and the Ali it will corrode. In restoring my older caterham, the boot floor had been sealed to the inside of the skin with that alloy tape leaving a horrible corroded mess!

[agatebox]

“ I am going to supplement on the inside of the driver and passenger pods with Dynamat”

My 2 cents worth …. I’m not sure what you mean by the inside? If you mean next to and under the seats I would strongly advise not to do it unless you never intend to go out in wet or get caught in a shower. Both the Caterhams I’ve owned let water into the cockpit area from various places underneath the car, nothing to do with what type of hood is on at the time, on numerous occasions with water ending up under the seats etc. As mentioned above adding any material around that will create an unwanted moisture trap. Even if you could seal the underneath, water will still find its way in from above, therefore you need to give it the best chance to evaporate and not be trapped.

[K800 RUM]

The Duratec engine seems to transfer a lot more heat than the Sigma engine in my car.

re the comment above, wash the car and you will find the footwells have water in them. Leave with just rubber mats then easy to mop out.

Edited by K800 RUM on Sunday 30th January 10:52

[lowndes]

A couple of thoughts based on the 420R I installed in an S3 a couple of weeks ago. In my case the engine and gearbox were already mated at the install but during that initial mating it was necessary to slightly twist the gearbox to get the splines to engage with the engine. It is also worth noting the bell housing guide studs are a quasi interference fit and need some horizontal forces to overcome.

The Duratec engine lifting points mean the engine will have a twist when hanging normally on the hoist. I partially compensated for this by a ratchet strap on the LH mount. Nevertheless, I guess you will have to take out the twist completely to mate to the gearbox.

Throughout the install the engine crane was stationary and all longitudinal movement was done by the chassis on its wheeled axle stands. If you leave the axle stand under the gearbox as per the photo all longitudinal movement will have to be done by the engine crane and there will be a lot of inertia to counteract to prevent the lump impacting the chassis.

Those would be the issues I would want to at least have an initial plan for.

Good luck

[squirejo]

In summary: very easy to fit the engine in this way with the gearbox already installed; we replaced the axle stand under the bell housing with a jack to allow some up.down movement. Once we’d practised with the engine hoist away from the car we made a start. We replaced some of the foam pipe lagging in chassis rails with duct tape to give greater clearance and the engine just dropped straight in. We were able to pull it the inch or so towards the bell housing by hand (nearly used some small clamps but didn’t need to and could get 3 or 4 bolts engaged before slowly getting the rest in place.

Then we added the engine mounts with every bolt loose. Bell housing/ engine was then tightened in a star format then torqued up before doing the same on the engine mounts.

We’d recommend this method to others, especially bearing in mind we were one adult and one 13yr old and coped absolutely fine.

[squirejo]

Regarding dynamat: it’s a bitumen type layer with an adhesive backing and foil outer and is applied firmlynusing a roller. It won’t hold water. So it’s in along both sides of the transmission tunnel floors and the rear bulkhead panel behind the seats which will then be covered in a nylon carpet material.