Today was the day of judgement, the measure of my building prowness- no, not the first flight, but the weight and balance. My plane weighs 1091 lbs, weighed as it should be- no usable fuel, full oil and coolant. I for one would go with the aluminum housings if they cost me up to  $1500 more than the cast iron ones. If they saved 70 lbs total, that would be around $21 for each pound saved, to get my plane down to a more svelte 1021 lbs. I'm sure I could probably get another 15 lbs off if I did some weight reduction on my Shertz beam front mount, along with other things. I also went a bit heavy on my engine mount- 1" dia x .049 thick tubes on some of the mount. I at least have confidence that my mount should hold up. The CGs all work out OK- design range is between 68.7 -77.7 inches aft of datum. Here is how it works out:

 

 

Vans states that most RV-4s come in around 950 lbs. Gross recommended is 1500 lbs.

 

Mine:

Empty 66.2, wt.1021 lbs

with 180 lb pilot, but no fuel-68.51, just a bit out of CG by .2 inches, total wt. 1271

with 180 lb pilot and full fuel 68.8, total wt. 1465- 

with 35 lbs baggage- cg-70.38      total 1500

If I want to take a passenger with full fuel and baggage, they'd better not weigh a thing, or I'll be flying over gross recommended weight.

 

Brian Trubee