912 Big Bore kit ??

[WWhunter]

Has anyone heard of such a thing? I read on a different thread about someone buying a plane with a 912 in it and he stated it had a "Big Bore Kit" installed in the engine. I have never heard of this other than what I already have and that is the Extra-Performance piston upgrade. This entails installing higher compression pistons in the 80 HP 912 increasing the HP to 95 HP (supposedly).

[Esser]

There are guys running 912ULS with a turbo charger which makes 135HP. You have to machine down the piston heads to avoid predetonation and take more care to operate. There is a guy with one in a Kitfox an hour and half south of me. I have his number but I have not been able to get ahold of him

[WWhunter]

I have thought about tgoing the turbo route but not sure I want the additional headaches. I had contacted BullyHawk about their conversion but never heard back from them. I did hear through the 'grapevine' that they will no longer be available but haven't confirmed it.
I fly floats, skis, and 29" AkBushwheels so any additional help over the stock engine is a welcome addition. My engine does have the ExtraPerformance high compression pistons and I do believe it helps some but as anyone who has flown on floats knows...there is no such thing as too much power when on floats. Also, since this engine is using an unacceptible amount of oil I need to pull the cylinders off so if I can get more power out of it I am open to suggestions.

[Esser]

PM sent about the turbo

[HighWing]

I know of a large bore kit available. It comes in two versions, A large bore cylinder and piston kit with the same compression ratio of the UL and a high compression version with compression similar to the ULS. Reported HP ratings are 104 and 114 respectively. I understand price is $4500 for either.

[mr bill]

Hi Lowell:
Who is the vendor for those big bore kits? Is any machining required of the heads or crankcase? I wonder if they would affect TBO.
Thanks, Bill

[Av8r3400]

My German is a little rusty, though…. http://www.silent-hektik.com/UL_912_XL.htm

Fuel injection, too… http://www.silent-hektik.com/UL_912_1.htm

[HighWing]

Hi Lowell:
Who is the vendor for those big bore kits? Is any machining required of the heads or crankcase? I wonder if they would affect TBO.
Thanks, Bill

This is the edited version.

I just talked to Hal Stockman. He is based in Elko Nevada. His Phone number is 775-934-5714

The numbers I posted are not correct The following is what he told me over the phone.

Low Compression - $4200
High Compression - $4300

He will insert the pistons and fit the rings so it will be ready for installation for $300 and will install it at your site or his place for $500. He also has a new 1622 CC version that produces 120 HP. The conversions are on 5 airplanes at the present time. Give him a call.

[Timberwolf]

any reviews from people with the upgraded big bore kit? looks interesting...any problems with cooling?

[HighWing]

Shane,

All my info is second hand, but I have been told that the performance is very impressive, but have not heard a word about cooling and I take that as good news as one of the guys flying behind it is a very good friend and doesn't hide things. I've also known Hal for over ten years and he is a good guy. Give him a call.