View Full Version : My 15ft Ally and 1250 SuperBP

05-17-2005, 02:41 PM
OK, New thread time.

As some of you know, I bought a 15ft Allison with a 1250 SuperBP last year.
Do to personal issues I was not able to run it last year.

So, last night, after fuel/oiling it throught the spark plug holes and through the Carbs, I fired it up. Initial inspections noted the following small issues.
big fuel leak on one of the crimped Merc fuel lines and no discharge from the water outlet. I want to correct these 2 issues before running it anymore, obviously.

1. Where do I get an impeller for a superspeedmaster? This is the first Speedmaster I have played with. Yes, I know this is not a BP gearcase, it was replaced.

2. I know I can replace the fuel lines with hose barb fittings and hose clamps, but I was kinda hoping I could duplicate what Mercury used.

3. Also, what compression readings should I be seeing once I get it warmed up? Will this thing will run on 92 and Pens synthetic @32:1.

4. For fun, How fast do you guys think it will run? 70ish?

Thanks for the help, kinda dead in here lately...everyone must be last minute thrashing to get stuff on the water.

05-17-2005, 03:47 PM
If you have a customer motor, Merc claimed these were about 140 hp. If you find the compression is higher than what Olegator suggests, you might need better than 92.

For 70-ish you need about a prop with about 13 - 14 inches of pitch. Don't lug that motor.:eek:

Steal fuel lines off of another inline 6 :rolleyes: That's what I do:D

05-17-2005, 04:28 PM
4. For fun, How fast do you guys think it will run? 70ish?

That's a good question.... you're probably about right on. Ol' gator will probably know more.


05-17-2005, 05:27 PM
Seems to me that boat should easily exceed 70. I have seen Olegator run faster than that with a stock lower unit J Production boat.

05-17-2005, 05:33 PM
I too would be curious as to what OLEGATOR says, also Raceman

a stock lower with a 28 @6200 puts you at 70ish and I am thinking the SS is
good for another 5mph

but I think there are those that post on here that should be able to tell you
exactly what it will do ;)

would love to watch you fly it !!!!!


05-17-2005, 06:13 PM
OK, New thread time.

2. I know I can replace the fuel lines with hose barb fittings and hose clamps, but I was kinda hoping I could duplicate what Mercury used.

3. Also, what compression readings should I be seeing once I get it warmed up? Will this thing will run on 92 and Pens synthetic @32:1.

4. For fun, How fast do you guys think it will run? 70ish?

Thanks for the help, kinda dead in here lately...everyone must be last minute thrashing to get stuff on the water.

I'm glad some one started something new here........

For fuel lines give Doug a call, I am sure he will make you ANYTHING you want. Check with Grubbs too.

It will run fine on 92 and Penz 100% @ 32:1

I think it should run well in to the 70's :D

05-17-2005, 07:44 PM
I think finding a blade will be your biggest challenge. I stuck a shiftable gearcase on the T2 on my 15 Ally because of lack of blade availability. Assuming it's 1:1 you're in the 30 pitch range with a 15 comparatively speaking, PLUS the little blades are hooked up so much better that they're really hard to get on top. As far as Jim (OleGator) runnin' faster with the 1500 and big gearcase, that's true, BUT........... a 1500 has more power than a 1250 Super BP. I ran a SuperSpeedmaster on my 15 Ally with a 1500XS, mostly because of handling. I don't think you'll see anything like a 5 MPH advantage over a big gearcase if it's set up right, but no question the SSM's are cool and fun to run. As of about 5 years ago I ordered some of the pre made hoses from Merc and they actually were still available. I can get the part numbers off the boxes in a day or two and you can get em checked.

05-18-2005, 07:29 AM
Thanks for the advice so far guys. I think I have about 10 blades for the SSM, 5-6 2blades and 4-5 3 blades. If that don't work I have 3 XS gearcases that are ready to run and I have a bunch of V6 props.

I am gonna track down some crimped fuel lines and an impella...When I do make it to the ramp, I will have my GPS and my digital camera.

Thanks guys,

05-18-2005, 12:27 PM
If you are going through the carbs, I would go up one jet size on the center. It may be territorial, but #3 was susceptible to go lean on today's gas.

05-18-2005, 09:47 PM
Carb to carb fuel line was part #32-31584a1. Fuel line from pump to carb was part #32-54739a1 and the line from pump to pump was # 32-52943a1. not sure if they are still good #'s or have been superceeded.

05-19-2005, 05:52 PM
Lets see some more pics of the boat!! :)

05-19-2005, 08:40 PM
Find out what your lower unit ratio is before picking a prop.

05-20-2005, 05:41 AM
That's good advice since the exhaust snout is cut pretty short and the SSM might be a lot newer than the rest of the rig. One tooth off isn't going to be much different from 1:1 .... reduction gears from a 700x would be sweet and a lot less likely to bog the motor with the most common props.

05-20-2005, 08:27 PM
.... reduction gears from a 700x would be sweet and a lot less likely to bog the motor with the most common props.

Reduction gears....tell us about this. Thanks.... :eek:

05-20-2005, 10:01 PM
What Sam is referring to is the 13:16 gear ratio available on the 650X and 700X 3 cyl Mod 50 engines ONLY. All of the other SSM's of that style were either 14:15 or 1:1. As Sam already pointed out, that housing appears to be the latest style and they were almost always 14:15, although I do have a 1:1 in the late housing also. Decent blades of less pitch than 15" are VERY hard to find.

05-22-2005, 09:46 PM
He's not kidding. Those props are tough to find these days. Here is a photo of a 17 pitch Merc Racing prop that I have. I use an identical 15 on my Ally/Twister 1:1.

05-26-2005, 10:43 AM
I have a NOS set of 13-16 gears which I think are for this lower unit that I probably don't need. I might be interested in trading for something I could use like 75H parts (yea,right) or D quicksilver gears/parts. E-mail for pictures and your fascinating trade possibilities. alanaker@comcast.net
Identification of these gears: Here are a few clues which may help since there are no part #'s on them. The pinion gear seems to have a similiar size driveshaft spline as a Mark 58 fishing motor. The propshaft gear seems to be 3/16" diameter too big to fit into a 75H housing, and has the speedmaster type internal propshaft spline in it.

05-26-2005, 12:31 PM
Alan, could you mic the OD of the prop shaft gear ?? .... it sounds big for a SSM, too. The spec I just looked at shows a SSM as only 3/32 fatter than a 75H. (Could be a bad spec from Merc .... wouldn't be the first time.

If it is a 13:16 set for a SSM, I might be able to find a set of D Quickie gears to trade ;)

05-26-2005, 04:33 PM
I gave the incorrect diameter info. Actual, fresh measurements are below. I remembered this quite wrong, so the good #'s are:

pinion gear diameter = 1.728"
Prop gear diameter = 1.806"
75H prop gear housing bore diameter = 1.951"

So the 16T prop gear does indeed fit in the 75H housing but is the wrong ratio. (I must have been remembering something else.) The 13T pinion gear spline wouldn't fit a 75H either, as Sam knows.

I'm thinking this is a set of 13/16 650xs/700xs NOS gears. They feel too good meshing together to be mis-matched. Anyone have a set of Bass 1 tooth over gears, 75H stuff, or NOS D gears? Don't offer me your mothers' cat, etc...$$ is not as desireable either.


05-26-2005, 06:31 PM
Jason, tell us how it runs, tap tap tap...... :eek:

09-13-2005, 03:54 PM
OK...well I finally made it to the ramp. taking advice from you guys here I picked the smallest SSM blade I have, which happens to be the 15 that came on it.
The 15 was a little tough to get up on top, but once up i spun it up to 6k fairly easy. I was running around with it up on the pad, but unable to fly it cause my trim wasn't working. It kinda felt like it wanted to walk a bit up on the little pad.
I found both the fittings on the bottom up the pump crossthreaded in the pump housing...Duh..Wasn't me.
I swapped trim pumps out and need to retest it to see if I can drive it better.

So..I am curious, if a 15 blade is similar to a 30p on a big case, what is a 19p...I guess that must have been for the 1750XS. Do you guys think a 2 blade would be worth a try? I think I have 5-6 of them.

Also, the prop shaft appears to be about 2-3in below the pad with the clamp bracket on top the standard transom. I know Bridges has his motor higher off the transom and I think our mids might be similar if not the same. Where do you want to run a ssm on an Ally like this.

Also 2, is the standard pad width enough to lift this little boat? If I remember correctly, it is like 5in wide.

Here are some pics...sorry no action shots, I was alone.

09-13-2005, 03:55 PM
Mo pics...

09-13-2005, 03:56 PM

09-13-2005, 04:11 PM
LOOKS GOOD! Is it noisy? :eek:

09-13-2005, 04:28 PM
What? j/k...Na my 2.5 is louder.

09-13-2005, 05:08 PM
The pad width is fine on those boats.

I never figured out what the larger pitch blades were good for. Most of the guys with the 1750XS's ran 15's or 16's (occasionally 17's) with the 14/15 gearcases when they were runnin' in circles. I bought several 17's and 18's back then that the racers had and didn't like. They were good for kilos and not much else. Maybe they used the 19's for the same reasons (kilos) or on multi engined boats since they didn't turn the inline stuff as hard as the V6's.

How 'bout shootin' some pics of the starboard side of the engine with the cowl off and postin' em. There was some discussion about makin' a Super BP block from a 1350 block with a 1250 front half, and some thought it would be cosmetically different. I've been meaning to go shoot some pics of mine to post, but keep forgetting it.

Super neat combination you've got there.

09-14-2005, 08:58 PM
I wanna see a couple of pictures of that bad little girl on the pad and making a pass for the camera! That is so sweet I could cry..... My God that is nice. Old school forever!!


05-24-2006, 04:20 PM
I thought I'd revive this old thread. You have a sweet outfit there, Jason and that Super BP is really pretty. Have you run it since?

I agree that the little 9x15 prop makes it tough to get on plane, but once it's up (if it's trimmed right) your ally will run well over 70 with the SS lower unit.

I've run mine alone three times this past week and haven't pushed it hard, easily making the low 70's with the T-1. I'm running Quicksilver Premium Plus 25:1, which was the original recommendation for the T-1. It smokes a lot, but I'm not sure of a comparable synthetic I could use. Maybe Amsoil?

I have a little movie that I made with my camera yesterday but I don't know how to get it where it can be viewed here. I'm hoping to get some new running photos soon; and maybe some video and sound to demonstrate the one-of-a kind T-1 sound.

When is the Carrollton, KY meet this year?

05-31-2006, 08:17 AM
Tap Tap Tap................more Please..........and A Quick Question Concerning Pad Width, And Set Back. On My Invader I Set The Engine Back About 4 Inches, I Also Raised The Motor Even With The Pad, Runs Hard But Doesn't Seem To Fly The Bow As Well, Is This A Problem?? Mt Pad Is Also Only About 5" Wide, If I Widen The Pad Wouln't That Help Get The Boat Up More? I Love These Older Rigs Please Keep This Going, Great Thread. Thank You.


05-31-2006, 10:58 AM
Chris, in the 70's I bought a 15 Ally with a short 1500 on it. The 15 has the smaller pad and the 16 has the wider one. On the 15 I ran multiple engines, starting with the '73 model short 1500, then going to a 1500XS powerhead on it, then a Super Speedmaster on the 1500, a T2 powerhead on the 1500 mid (total abortion that wouldn't run), a complete T2, the first 20" V6 in the world that had the mid shortened to 15", a T3/1750XS, and finally the last engine with a mod 2.4 powerhead with nitros. The little 15 ran in the range of 104 to 106 at the Kilos in Knoxville the year I took it with the 2.4 powerhead in the T3. Later I stuck this whole setup on a 16 Ally that was decked over and it was about 10MPH faster, but there were other changes as well.

I do think the wider pad on the 16 made it faster. I've also heard that Paul Allison (Darris' father and the original Allison designer) didn't ever like the 16 Ally because of the extra lift in the front of the boat because of the way the deck flared. Paul looked at my boat extensively at Knoxville, but his comments/observations were concerning my pad rather than the boat as a whole.

If I was playing with a 15 Ally now as a lake toy, I would NOT go to the trouble to widen the pad to the configuration of the 16. I don't think the difference is significant enough to go to the trouble, and the 15' boat is an excellent performer/handler in it's stock configuration.

One thing about running Super Speedmasters on em is that they won't run as high and tote the nose as well as a big gearcase on the same boat with the same power. The boats respond well to the high rake cleavers and if you could find one in 15" pitch that'd be my choice. It seemed like the little round ears worked extremely well on the V bottoms too, although they don't have the rake OR the diameter of the cleavers. I had a smaller pitch one on the 1500, seems like maybe a 13 or 14, but can't remember for sure now.

Somebody asked about running a 2 blade. It's a miserable choice by comparison, and even more so on a V bottom. The vibrate and tear up parts and have poor bow lift by comparison to the 3 blades.

05-31-2006, 01:21 PM
Great Info Norris, On Your Allison (15 Ft ) Did You Add Any Set Back To It Or Clamp Right To The Transom? When I'm Out Of The Boat Watching It Go By It Seems To Have A Level Ride Attitude With
A Slight Lift In The Bow Area, Not Much Though, And It Is Running A Xs Gear Case. Someone Along The Line Sent Me A Picture With Art Kennedy Running A 15 Ft Invader Like Mine, Except His Was Aired Out Nicely Where Mine Seems To Be Stuck To The Water, I'm Still Able To Spin 6200+ Running A Dah 26 Round Ear With The Fish Line Cutters Cut Off. Or Do I Have The Prop Worked And Add Bow Lift To It? Or Add An Extention To Mt Steering And Move My Seat Back A Little?
All Opinions Are Appreciated As I Have Hit A Wall And Know There's More There.thank You!


05-31-2006, 04:07 PM
I am running a little 9.25 x 15 cupped round ear three blade with a Super Speedmaster on the Twister-1. I have no setback or trim on a fixed set up bracket and the nosecone is even with the back of the pad, putting about 1/2 of the prop in the water on plane. It's a bit of a job to get on plane, but once there, it has tremendous acceleration. I've had it to near 80 (according to the speedo) with little throttle to spare. Of course I need a GPS to get an accurate speed.

I agree with Raceman regarding the big gearcases lifting the nose higher. My dad ran this boat with a 1350 and a club foot lower unit in 1980 and as you can see in these pics, the nose is way on up there:

06-01-2006, 12:31 PM
Hey guys...thanks for the compliments.

My Ally is in my storage still this year, I have a jetski and a lummie boat I have been working on right now.

Here is the shot you asked for a year ago Raceman...

Dave S
06-01-2006, 07:53 PM
And you can see the port covers are the stock type, just has the small pumps from the early motors. By stock I mean not the 2tx with the 3rd port in the middel.

06-01-2006, 08:02 PM
And the starter mounts like a 125 & earlier, full ring boss at the top, bolt on bracket at the bottom, not the split cradle type starter mount found on later Direct Charge 6's

06-03-2006, 07:42 AM
Hey guys...thanks for the compliments.

I have a jetski and a lummie boat I have been working on right now.

A what?

06-05-2006, 11:41 AM
A what?

yeah, i know...lake lice. I couldn't pass it up though. a Nice 97 Tigershark with a blown motor almost free.
And I also have a 50's 14ft Mirro Craft complete with steering controls and a 10hp Johnson to play with.

06-05-2006, 09:09 PM
LR99, a friend had a T2 on a 19 Allison in the late 70's, inspired by Gator's cowling black/blue boat we saw at the OPC nats in 75 or 75. It was fun to drive with the SSM but I found if the nose got too light it was HARD to get it back down with the small unit. I was damn near on the deck once before it settled. Boat ran around 90. We didn't spend a lot of time with it, went back to JP with a 1500E. Sure would like to se some running pictures.

06-06-2006, 11:46 AM
Rm, the 16 has a totally different pad than the 15. It also has a slight V to the pad. I believe the 15 was faster in acceleration, top end and handling. But the 16 was a Cadillac ride and handled rough water much better. Not faster just ran smoother. That's not to say the 16 was far behind.
The last few 15's made Darris added the little wedge to the trailing end of the pad. It ran very good with it. I had to rebuild the bottom in my boat and the wedge gat screwed up. Even with a template f it I could never get it the same so I changed the bottom a slight bit and went with a flat pad in the trailing end and the boat came back alive.
I run a cleaver and have found it the best for racing. The round ears and choppers worked better on the 16 than the 15 but again the cleaver was the better choice here too. We are talking about a boat used strickly for racing.
With the boat an open boat I ran a half hub on the prop, a hub takes away bow lift. With a full capsule I removed the hub and the boat ran much better.
I also found the normal mid 80's type gearcase much faster and better handling than any XS gearcase with better water pressure.

06-06-2006, 12:01 PM
Rm, the 16 has a totally different pad than the 15. It also has a slight V to the pad. I believe the 15 was faster in acceleration, top end and handling.

I'm very familiar with the pads, having both a 15 and a 16 at the same time. I still have both, but the 15 is in poor shape from years of shoddy storage and the 16 is totalled, although it's in Fla. supposedly being patched back together after all these years. My experience was that the 16 was a faster boat when power was added. I never ran my 16 with inlines, but did run the same T3 on the 15, then the 16 several days apart.

Interestingly my 15 had a wedge on the back of the transom when I bought it. By wedge on the transom, I mean the back of the boat, NOT the bottom, and it extended the running surface about an inch, maybe a little more. It was glassed on with wood and went all the way across the back of the boat and was tapered down to nothing at the top and the width at the bottom. My boat originally ran out of Bateman Marine in Martinez (Augusta) and I was told by the previous owner that they did it to make it handle a little better in rough water. None of the boats then ran setback, and that was about the same as negative setback in a manner of speaking. Of course back then the tunnels were experimenting with all kinds of measurements of the relationship between the rear of the sponsons and transom, with earlier ones being straight all the way across the back, and some others having the motor back a foot or so.