1969 Allison 15 / Merc Twister

[bridges]

Many of you have seen my boat on the S&F boards. for those who haven't, I hope you enjoy these photos.

[Mark75H]

Beautiful!

If you can make a copy of your video, I'll try to digitize and post your sound clip.

[bridges]

Beautiful!

If you can make a copy of your video, I'll try to digitize and post your sound clip.

Thanks Sam. I took the movie on a digital camera, so I may be able to do it easily. I'll try to get it on here today or tomorrow. It's a little sketchy since I was alone and sitting on the dash trying to throttle up on plane, so I really need to get a better one....but let's see what I can do with it. ~Scott

[DonChichoJr.]

........wonderful Boat !!!!!!!!!!!!
How Fast Is It ????

Don

[John (Taylor) Gabrowski]

I had a Merc Twister and it had the real big, long nose coned Speedmaster MC-1 gearcase. The engine had single barrel carbs and a almost chromate green painted flywheel. I noticed your Twister has a way smaller Speedmaster gearcase, so it begs the questions; Is yours a 2 barrel X 3 carb later model?? and if you know, what other differences other than the gearcases were there between yours and the I guess, older Twister I had? Seems that information on these older Merc racing 6s is pretty hard to come by.

[Mark75H]

The MC-1 or regular right hand SSM were options on both the Twister and Twister-1. Powerheads were the same except for some exhaust tuning: same carbs.

If you do a search on screamandfly.com we have them all pretty worked out

[John (Taylor) Gabrowski]

In these parts a couple of Merc Twisters were sold to non-racing private hands. I found the first one and now it lives. The second one has now been located albiet its not all in one piece but it is all there none the less. Won't know the vintage until next week, so stay tuned.

[Dago Fast]

In these parts a couple of Merc Twisters were sold to non-racing private hands. I found the first one and now it lives. The second one has now been located albiet its not all in one piece but it is all there none the less. Won't know the vintage until next week, so stay tuned.

Found this one today. Frozen. Looks like it was stored on dirt of maybe
it was submerged at some point. Exterior is in good shape, no corrosion.
Any one have any advice as to how I can disassemble this one to check
it out.
Thanks, Dagofast

[Mark75H]

That is a "BP", the Frankenstien of Merc racing lower units. I would not advise taking it apart unless you are already pretty much a Speedmaster expert. Instead of 2 driveshafts, this unit has 3. The fat section under the exhaust outlet is a full gearshift transmission. From the driveshaft to the propshaft there are 15 gear surfaces.

I can't tell for 100% certain, but it looks like the 1968 version. The 1969-70 version had exposed mounting nuts in scalloped side notches on the sides of the mid; the 1968 mid was smooth sided.

[bridges]

Dago,

I'd be interested in that BP prop if you want to sell it...looks like a RH?

Scott