stunthanger.com
Engine basics => Engine set up tips => Topic started by: Terry Caron on June 27, 2015, 05:52:58 PM
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I've been breaking-in a Forster .35 for a flying buddy who wants to try OTS with a period engine.
I thought someone might be curious as to how they perform, at least on the bench.
Their preference for a wet-2 seems confirmed as on-the-edge 4-stroke is around 9000 rpm and it picks up only ~700 rpm on rotation.
I've run different fuel mixes and prop sizes with these peak results:
0/75/25
9-6 APC 12.4K
10-6 APC 11.5K
10/62/28
9-4 APC 13.6K
9-6 APC 12.7K
10-4 Zinger 11.7K
13.5/61.5/25
9-6 APC 12.8K
It seems happiest with the 9-6 on 10% @ ~10.2K, going to 11.2K on rotation, but seems quite content with no nitro.
I must say it has a distinctive 4-cycle growl, which I suspect would attract attention at a contest. :)
Terry
Added:
I have another, of unknown history, which is down only 100-200 rpm with some of the same combinations, and also does well with no nitro.
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I've been running my second Forster and it seems some Forsters will 4-2. :)
On 10/28 fuel with 10-3 1/2 TF nylon ( no worries - it's a "new" one) or 9-5 APC it's "just-breaking" 4 is at ~9.1K and turns to 10.8K on rotation.
Whether the other one will do so after complete break-in is yet to be determined.
And they have that 4-cycle growl that's like no other. ;D
Terry