Twister1 question for Willabee and anyone else who wants to chime in

[Raceman]

'Bout 25 years ago or more I bought a Switzer Shooting Star with a Twister on it from a guy in Idaho. I also got from him what he referred to as a Twister1 upgrade kit which was basically a complete powerhead in the box that was disassembled. It was very complete with exhaust log and plates, pistons, reeds, all small parts, etc, and even had the blue Twister1 stickers in the box. Odd thing was, it had a T2 crank in the box with the ridges on the 3 main bearing journals where the reed blocks would normally go. Nobody's ever been able to say if this was to give the guy a way to change the firing order in a T1 after doing some machine work either to the crank or to the reed blocks to accommodate the ridges. This was a pleasure boat with complete interior, and the guy wasn't a racer, so seems doubtful he was well enough connected to get prototype stuff. Opinions????

[Dave S]

The exhuast pulses on the T1 and T2 were diff... putting a T2 crank would not help in any way. You say ridges? Do you mean the blocks that holds the bearing s in place? Did ya ever wish I coulda kept that one????

[Raceman]

The exhuast pulses on the T1 and T2 were diff... putting a T2 crank would not help in any way. You say ridges? Do you mean the blocks that holds the bearing s in place? Did ya ever wish I coulda kept that one????

By ridges I mean the raised up ridge on the main bearing journal of the T2 crank that centers the bearings. Obviously these would interfere with the reed blocks used on the standard inline crank. This kit contains a different exhaust log, which I haven't paid much attention to, but it's possible that it's different internally from the regular Twister and Twister 1????? I would have built this powerhead long before now but prefer to put an NOS crank and NOS rods in it and so far have never run across them except for 3 rods on e bay several years ago for $125 each. There's a guy who keeps cranks on E bay, listed as NOS, but they're always used.

[Dave S]

If the exhaust log is diff than it will work. I like the newer style rods that have just bolts... I think they are better as having no stress points like the old ones with nuts and bolts ....and notches that make stress points

[Tom Smyth]

By ridges I mean the raised up ridge on the main bearing journal of the T2 crank that centers the bearings. Obviously these would interfere with the reed blocks used on the standard inline crank. This kit contains a different exhaust log, which I haven't paid much attention to, but it's possible that it's different internally from the regular Twister and Twister 1????? I would have built this powerhead long before now but prefer to put an NOS crank and NOS rods in it and so far have never run across them except for 3 rods on e bay several years ago for $125 each. There's a guy who keeps cranks on E bay, listed as NOS, but they're always used.

so what kind of NOS crank and rods are you looking for ?

[Tom Smyth]

I have a friend just north of me and he has shown me three different log designs that has has in his shop. Not sure why the differences but they were known to have overheating issues and the last log design he showed to me was the best to minimize this.

[Raceman]

so what kind of NOS crank and rods are you looking for ?

Twister1 to build this powerhead. I assume they're the same as 1500. As a side note, the first Twister I ever bought was from Noah Legear and it was in a box where a rod had gone through the side of the block and got the front half too. The rods that were in that engine were ground smooth on the sides of the I beam. I've never known if that was factory in a Twister or somebody's idea of blueprintin'.

[Raceman]

I have a friend just north of me and he has shown me three different log designs that has has in his shop. Not sure why the differences but they were known to have overheating issues and the last log design he showed to me was the best to minimize this.

I've got at least 3 different style logs also, but haven't looked to see if they're different internally. The first one that I'm aware of had the water discharge at the top with a large moulded hose behind it coming to the bottom of the bottom cowl. I've also got 2 different style bottom discharges with one having a very large 90 degree brass elbow, probably at least 1" inside diameter and the other having a much smaller one that's more like a conventional 90 degree brass fitting. To the best of my knowledge this is the second design, original to the Twister (red) but not early enough to have the top discharge.

[FMP]

The 6 divided into a pair of triples and the the pairing within those triples are dependent on the firing order of the two cranks, T1 andT2 .

[Tom Smyth]

The 6 divided into a pair of triples and the the pairing within those triples are dependent on the firing order of the two cranks, T1 andT2 .

T1 NEVER ran a three into one exhaust. Firing order not right for that to work. Only the T2 and T2x did..

[FMP]

Ex chest T1 pic please. No chance they had six into one chest, 60° pin spacing between pairs would be the result and way too early pairing arrival except if very low duration ex porting and/or super high rpm.

Two separate chests of three through one tuner , later two?

Either way when the fire order changes as does the pairing.

[FMP]

Some pics
https://www.screamandfly.com/showthr...ial-lookup-T2&
Someone put up some more pics of both

http://www.drolsum.net/mercury/inline6/index_5.html

Some good pics here

[willabee]

'Bout 25 years ago or more I bought a Switzer Shooting Star with a Twister on it from a guy in Idaho. I also got from him what he referred to as a Twister1 upgrade kit which was basically a complete powerhead in the box that was disassembled. It was very complete with exhaust log and plates, pistons, reeds, all small parts, etc, and even had the blue Twister1 stickers in the box. Odd thing was, it had a T2 crank in the box with the ridges on the 3 main bearing journals where the reed blocks would normally go. Nobody's ever been able to say if this was to give the guy a way to change the firing order in a T1 after doing some machine work either to the crank or to the reed blocks to accommodate the ridges. This was a pleasure boat with complete interior, and the guy wasn't a racer, so seems doubtful he was well enough connected to get prototype stuff. Opinions????

My opinion is that you should call that guy in Idaho and ask if he is still looking for that TII crank that he knows is in his shop somewhere! Tell him to quit looking, you have found it! .....

You guys have touched on a number of things, here's what I remember (or think I remember).....

The practice of using connecting rods with polished I-beams began with the 1350 stacker. There was a bit of a rod breaking problem that carried over from the 1250. Engineering determined the problem was a small percentage of defective forgings. From then on, all of the rods used at Racing were sent to the engineering prop shop where they were ground and polished. Racing bought a zyglo machine and all the polished rods were examined for cracks before they could be used in assembly. The Twister sold to the racing public was assembled at the Fond du lac boathouse, not at Racing in Oshkosh. I think the use of polished rods was continued for the build of 100 Twisters.

I don't remember the sequence of events that affected the location of the water discharge on the exhaust log. Seems like we tested the Cowbell before the Twister, late summer of 1970 I'd guess. The Cowbell, being a shorter log, probably had the discharge on the top. When we started testing the Twister, I think it was determined that letting the water exit early was causing a hot spot in the middle of the block, so we switched to a discharge at the bottom of the log. The specs for the Twister build may have already been established with a top discharge by then and the change to the bottom may have just fallen through the cracks. I know that when we ran the Twister in Paris that year, it had a bottom discharge. I also think the Offshore group at Lake X used a different configuration, making three different looks?

So in 1971, the racing public is buying the Twister and the Racing Team is using changes from engineering at Plt #6 to make the Twister stronger. When finished, these changes will be incorporated into the Twister I. I think the TI build called for 50 complete motors and 50 rebuild kits. The reason for the kits was to allow those racers that had the ability to rebuild a powerhead an opportunity to get updated for far less than the cost of a complete new motor. The kit required a new block because of the milled intake 'fingerport', new 'scalloped' reed blocks, bigger carb jets and all the other items you would want to use when rebuilding your powerhead (bearings, rings, etc.).

However, I don't remember the kit including a crankshaft. The Twister and TI used the same crank, why increase the kit cost by including a new one? Especially one the buyer can't even use without some very expensive machining if he can even find someone that can do the work? Sounds like a mistake to me.

One additional little tidbit ..... When the company decided that it was going to offer the Twister I and the rebuild kits, our racing group was the only one building that version. As a result, we were the most familiar with it and I was told to put a list together of what would be included with the kits. I did that and someone then turned it into the official bill of material for the people in Fondy that would be putting the kits together. You would think that I could remember whether or not a crankshaft was on the list ....

Your Switzer and Twister I believe .....

[Mark75H]

Actually all these motors have 3 into 1 exhaust, just differently achieved. The T2 motors are stacked as 3 over 3, the other motors are alternating even/odd three into one. Length determines the time one pulse hits an adjacently timed cylinder's exhaust. The fishing motors and Twisters have cylinder spacing that limits peak rpm below 7,000; the T2 & X have the grouped cylinders closer together, but so close that an extension housing and passage were needed to work in the 7,000 - 8,000 rpm range.

I have and have possessed a bunch of Twister and apparent T-1 silos. The water outlets vary quite a bit as does the internal water flow in the silo, but the tuning appears to be the same in all.

[Mark75H]

If there were a significant tuning difference between the Twister and T-1, it would be apparent in the side to side width of the silo.