Supercharged LD28s

[supercharged]

I run twin supercharged LD28s approx 120 hp each thru alpha 1 mercruiser stern legs on my 30 ft 5.5 ton fibreglass boat they rev out to 3800 rpm with the props set at 14 in pitch and give a top speed of 17 knots, should I adjust the pitch up to bring the revs back [propulse adjustable props] and keep the speed or would this possibly work the engines to hard spinning bigger pitch props,normal cruising speed is 12 knots at 2800rpm using about 20 litres an hour

[Fella]

Hi, I don't have an answer for your question but am looking at putting LD28's in a 8meter shark cat I have. Wondering how you supercharged the ones you have and also is your 20 ltrs an hour per engine or total fuel consumption. Thanks.

[supercharged]

My engines were supercharged when I got the boat,The guy I bought it off did the job maybe you could try him,His name is Greg Surgenor his business is Rimu Engineering in Blenheim,he has a website but you will have to google it as im not sure of the address,fuel usage at 2800rpm is about 20-25lts an hour combined giving me cruise speed of 12kts but at 3500 rpm speed is 18kts and fuel is about 20-25 lts per side so about 40lts an hour thats with the props set at 15 inch pitch,Ive tried the props at 17 in but that just cut my revs back and only gave me top speed of 13kts at 3000rpm which was all the engines could pull.hope this helps

[glenlloyd]

Any possibility of getting to see pictures of the supercharger install?

thanks

sa

[Kolatogari]

I know this is a long time dead post but, is there any change I could a pic if that supercharge setup?

[asavage]

I'm reasonably sure that when the OP says supercharger, he means turbosupercharger (ie turbo).

[Hobbit]

I believe that the original post is correct as I have just perched a 30ft boat with twin ld28 born are supercharged

[asavage]

Yup, Thanks for that picture. I'd never heard or seen a supercharged LD28 before today.

[Hobbit]

both run one supercharger needs work but it runs sounds mean bit smoky as first time thay have ben run in 2-3 years will try upload a video

[Bugly]

Hi Hobbit,

Great video. I have an LD28 and looking to either turbo or supercharge as I am after just a bit more grunt and supercharging looks like the easier route. What are those superchargers on your LD28's do you know?

Thanks in advance Bugly.