Should the entire team tag along when pitching to VCs?

We're a team of 4 (two of us are founders) and the other two are early employees.

When we go pitch VCs to try and raise a seed round, should the entire team go or just my co-founder and I?

One issue is that both of us are non-technical founders. So if a VC asks any questions regarding tech, we would need our engineers.

In general, you want to limit the number of people in meetings with VCs to an extent. If one of the employed engineers are senior level and the other is not quite as experienced, I would suggest bringing them along. Even saying that, it may be good to have the whole team since you've got just four people.

A few things to consider aside from the experience of the engineer(s).

1. Have they been in meetings with VCs before, or at least a great deal of experience in the board room?
2. Engineers do have a tendency to have somewhat off-putting personalities, where business folks are used to being much more personable.
3. Can your engineers give you and your partner an eight hour crash course in the technical aspects? It may also help to prepare an extra, technical presentation and whitepaper with the goal of alleviating as much of that pressure as possible.
4. Send whitepapers over to the VC's technical point-of-contact, if any, the afternoon or morning before your meeting; give or take depending on social context. (But not so early that they've already dissected it by the meeting, save any counter points as something you can improve for them down the line.)

Alternatively, if the VC does have a technical point of contact, invite them for a pre-meeting with just you and the engineers ahead of time. This conflicts slightly with my point #4, but does often yield good results and shows strong cooperation.

If they do not have a technical contact, consider suggesting that you contract a reputable 3rd party engineer and have both meetings with them. Specifically find one that has similar business experience under their belt. The investor(s) may wish to select their own, but suggesting it shows that you're serious about the sound technical quality of your product/service.