That depends on if ur using a 2nd pair of gunners for HH/AA.
If you dont have that 2nd pair of gunners, either 7 engineers with 3 reps, or 8 engineers with 2 reps.

If you do have that 2nd pair of gunners, you can best use 5 engineers with 3 reps, or 6 engineers with 2 reps.

 

and your engies should already be lvl 100 or better above 103

It depends on how much money you have for this game, meaning how many experts you are willing to burn for your sailors.

If your budget is couple of hundreds of dollars, then you can use the crew setup in the way that is on my L2:

2 Main Gunners (Late-classed, seed sailor = Elite Repair)
Stats: ACC=1275, RLD=1974, REP=1946, VET=290, Total Rep TA=6M

2 AA Gunners (On-time classed Huge Reload Gunners) or 2 HH Gunners

8 Late-classed Engineers
Stats: REP=1900, ENG=3300, VET=340, Total Rep TA=30M, Total OH Time = 8 Minutes

1 Scout

Advantage: Most crew are late-classed, meaning the total crew weight is less than that of on-time-classed (which means you can put on more deck/bulge); Using late-classed, Elite Repair to be the main gunners combined with 8 late-classed Engineers, gives you Repair TA cap (which is 35M) and also a total OH time of 8 minutes (which means you can keep accelerating in GB from beginning to end pretty much). This is one of the most powerful setups.

Disadvantage: It's not easy to reach VET cap for each sailor. It takes money and luck.



If you have not that money to spend in this game, which means you want to keep the vets on your sailors low (around 109 to 150), then I recommend you:

2 Main Gunners (On-time classed Huge Reload Gunners; remove rookies to keep your sailor light)

7-8 On-time classed Engineers

2-3 On-time classed Repairers

1 Scout 

This setup will only give you a total OH time of 5-6 minutes, and you won't have HH/AA ability. It's still a great setup for regular GB but you won't be able to put on as much armor as the setup above, and in many cases, you will find your OH time not long enough to chase your enemies.

If you want to keep HH/AA ability while maintaining the Repair TA cap, then you have to sacrifice at least 2-3 Engineers, which means your total OH time will be reduced to 3-4 minutes or so. It's still not bad; but you'll become other BB/CV's food once your OH time is over.

To sum up, the 1st setup is the most versatile compared to other setups but it requires money and luck. So it all comes down to how much budget you have for this game and what abilities you want to keep on your L2 (HH/AA, Repair cap, OH time, etc).  Everything is a tradeoff, friend...

I got my L2 a few weaks ago, i use 6 Engineers (2 EBVE - 4 base 11/12 Repair/Engine BVE) 4 repairers and 1 scout. With lvl 100 guns my L2 runs at 40 knots, 39 if i add 0.2 belt, 3 bulk head and about 100 bulge. No HH/AA. 

Agreed with lordfailz. 

If you have patient though, and a very tight budget, you can just keep grinding. I speed capped with 6 engies I am not gonna say their base they're embarrassing, around level 115 with no vets and the experts gain from battle. Meaning I didn't spend a dime on those sailors.