The TVR-400L & LV-N motors ... go boom.

[LordFerret]

I've found that using the TVR-400L Stack Quad-Adapter with LV-N Atomic Rocket Motors tends to cause one (1) of the rocket motors to explode at 100% throttle ... an overheating issue ... and backing the throttle down a notch alleviates it.

Anyone else run into this?... or is this old news?

[mckamx]

Depending on what they are attached to, the LV-N motors can overheat. It depends on how fast the motor heat is transferred out of the attachment point, which depends on the number of objects the heat can be transferred to.

[Renegrade]

Anyone else run into this?... or is this old news?

Not that issue specifically, but heat transfer is kinda borked in KSP. Can't say I'm surprised.

The one engine that explodes is probably receiving slightly more heat (or is the first to receive each successive wave of heat updates) because it's the first or last one placed or somesuch...and the others won't be able to reach overheat levels once it's gone.

Note by changing what the adapter is attached to, you might be able to increase the cooling rate enough for the engines to not critically overheat.

[LordFerret]

The TVR-400L adapter (with its LV-N motors) attach to a Rockomax Jumbo-64 Fuel Tank. There is nothing else attached to the adapter to dissipate heat. I prefer the LV-N's over the LV-909's, which, when used in the same configuration, do not explode... at least not yet, and I've had some long burns with them.

[quasarrgames]

Doesn't happen for me. Happens within seconds for rocket-mode RAPIERS though.

[Laie]

Anyone else run into this?... or is this old news?

A quadcoupler full of nukes works fine for me. Aerospikes however...

And yes: if things overheat, slip in some small part. A small tank, a battery, a cubic strut... anything really.

[Renegrade]

The TVR-400L adapter (with its LV-N motors) attach to a Rockomax Jumbo-64 Fuel Tank. There is nothing else attached to the adapter to dissipate heat. I prefer the LV-N's over the LV-909's, which, when used in the same configuration, do not explode... at least not yet, and I've had some long burns with them.

Try slipping the little 4-ton 2.5m tank in there (uhh.. X200-8?) between the Jumbo64 and the adapter.. the longer the tank, the poorer the heatsink effect for .. whatever bizarre reason.

(real life thermal transfer depends on thermal conductivity, cross section of the material and temperature gradient... not quite the same in KSP)

[problemecium]

What I do (because the joint strength on the quad adapter is pathetic) is use Radial Attachment Points on 4x (or some other number) symmetry to make engine clusters. They're much stronger and apparently dissipate heat better.

[merendel]

They're much stronger and apparently dissipate heat better.

Thats cause your haveing 4 engiens dumping their heat into 4 different parts instead of all 4 into a single part. between the tank and the 4 attachment points they dissipate heat faster.

Asuming the OP is set on the quad coupler he can also try just sticking one of the T100 fuel tanks between the coupler and the LV-n's. Shouldnt overheat for the same reason as the 4x attachment points.

[LordFerret]

Thanks for the ideas. I'll experiment with all of them.

[Archgeek]

Yup, just to pour salt on a dead horse, I had this exact same issue trying to use quad aerospikes in my Eve return lifter. 'Wound up with skippers and too little TWR because the spikes run hot to start with (as do LV-Ns), and they'll treat the part immediately above them as their one and only heat sink. 4 spikes sharing a quadcoupler as a heatsink -- immediate overheat bar, can barely run 'em at 60%. 4 spikes stuck on FL-very-small tanks on a quadcoupler, no problem. Bar shows up, but cooling's logarithmic so nothing explodes even at full power all the way, since each spike has its own personal heat sink. I should really redesign that lifter, thinking about it...I was quite fond of the transfer stage.

[PB666]

Two examples

1. Big Orange, Quadadapter 2880 fuel and 4 engines. Over heat

2. MK3 to 2.5 Fuled adapter, Kerbodyne S3-3600 - 2745 fuel - Radial Attachement Point spread wide as possible. I I attached 6

BTW don't attach strut connectors to your engines.

Another possibility, use girder piece I-650 and attach 4 of these to the big orange tank and then 4 engines, I got eight engines on S3-3600 with nominal overheating.

My opinion, best solution is to separate the engines.

[Guest]

This is like the old Mainsail issue where, for best results, Mainsails were attached to the smallest 2.5m tank and then to the orange tank, as opposed to putting the Mainsail directly under the orange tank (with the old part joints and "rubber dong" rockets, you'd also have to stitch strut all that together, massively increasing part count). Heat transfer/modelling in KSP isn't really that good.

[Sidereus]

Haven't had this problem. I came close once when under 4x physics warp, but usually they go up to about 80% overheat and stop. I put RCS thrusters pretty close to the attachment point for the quad adapter, so maybe that helps