Victoria Shadow Association Members' Forum

Beverley_Dewath

Guest

Beta engine options

Hi all.  We're still (!) considering re-engining options for Victoria (V30), and the Beta 25 is currently top of the list to replace the original 2GM20.  I appreciate that some will think that 25hp is over powering, but we hope to eventually go some distance in Victoria and we'd therefore like the comfort of knowing that we have a little extra power in reserve if/when required.

I wonder if anyone who has already re-engined could perhaps offer any words of advice about a couple of things...

Firstly, I think that the Beta 25 standard sump should fit, although it is difficult to be absolutely sure with the current engine in situ.  Does any disagree?

I didn't think that we'd need custom feet, but I was a bit concerned to read in another thread that Colin Reid had found that Tui's engine bearers had a 20 degree angle.  According to the 2GM20 manual, that engine should also be installed at a maximum of a 15 degree angle, the same as the Beta, and Nanni in Colin's case.  I haven't yet checked this on Victoria, as I only re-read Colin's post this morning, but can he or anyone else confirm whether this is common to all Victoria 30s and, if so, how they have overcome the problem when re-engining?

I'm not sure of Victoria's current gearbox ratio, as I haven't checked the plate, but the V30 Technical Manual actually mentions two different 'standard' ratios - 2.6:1 and 2.2:1.  The Technodrive TMC40 gearbox, which comes as standard with the Beta 25, is offered with 1.50:1, 2:1 and 2.6:1, and we intend to opt for the latter.  Does anyone disagree?

If anyone has any other words of wisdom, they would, as ever, be very grateful received!  Thank you!

Jonathan_Hopper

Member

Registered: 2004-03-23

Posts: 161

Re: Beta engine options

Beverley -

To some extent you need to start at the prop when working out engine/gearbox upgrades.   If you have a more powerful engine, (assuming you are getting full RPM with it now), then you will either need a faster shaft speed or a larger prop to benefit from the more powerful engine.   When re-engineering the Frances there was only one option for gearbox reduction of 2:1 (2.6:1 is a slower prop speed) which gave a big increase in shaft speed (especially reverse), and the same prop could thus be used on both engines.   This is handy as the max diameter is rather restricted on the 26.   If you are similarly restrained you can up the pitch to increase top end punch, but in my view the time you want the extra power is when the boat speed is low (punching into waves), and for that you are better off with extra diameter and surface area, keeping pitch down.   

It is probably worthwhile calculating prop options based on the two gearboxes (there are free calculators on the internet, or ask Beta what they recommend), and seeing if whatever comes of this suits you.

JDH

Beverley_Dewath

Guest

Re: Beta engine options

Hi Jonathan - Thanks for your reply.

I have been using the calculator available at www.castlemarine.co.uk, but I must have input something incorrectly the first time, as I now appear to be getting different results (doh!) - I think I may have used 2.2 rather than 2.6.  I think it will need to be the 2:1 gearbox, as I don't think I can fit anything bigger than the current 14.25" prop.  The calculator suggests a 15.31" dia prop (3 blade) with 2.6:1.

Beverley_Dewath

Guest

Re: Beta engine options

Just in case anyone else is interested in this in the future, I contacted Paul at 1st Marine (his contact details are on the Beta website on their propellers page) and his recommendation in terms of efficiency would have been to go with the 2.6:1 reduction ratio with a 3BRH 16 x 10 propeller.  However, clearly I don't have space for this, and so he has therefore suggested the 2:1 reduction ratio gearbox with a 3BRH 13 X 9, which seems to be in line with other discussions here on the forum.