Transmission Question

[cj222]

Hey guys!

I recently bought an old Howard 20ft GN hull as a project boat. It came with a few parts like the Casale split case v-drive, prop shaft, rudder, miscellaneous cavitation parts, a drive shaft and drive plate that I was told is for a Powerglide transmission. Any thoughts on running a PG trans? Thanks in advance!

 

[74 spectra20 v-drive]

Tons of boats have had the power glide in them and set up right they work great, we have several friends that run the PG in their Sanger Flats, I run the velvet drives just for the smaller size. When I was setting my Spectra up, I had dropped of the Velvet drive with the trans shop that rebuilds them for me, I asked him if there was an advantage going with a PG or Turbo 400, he told me he liked the velvet drives because the clutch packs are beefy as hell. if you are running a bug rumpty rump motor you may benefit from the two speed helping with manners at idle.

 

[cj222]

Tons of boats have had the power glide in them and set up right they work great, we have several friends that run the PG in their Sanger Flats, I run the velvet drives just for the smaller size. When I was setting my Spectra up, I had dropped of the Velvet drive with the trans shop that rebuilds them for me, I asked him if there was an advantage going with a PG or Turbo 400, he told me he liked the velvet drives because the clutch packs are beefy as hell. if you are running a bug rumpty rump motor you may benefit from the two speed helping with manners at idle.

Thank you for your reply and info! What trans shop do you use for these boat transmission setups?

 

[poncho]

@obnoxious001 Seems he has a lot of experience with these boats.

 

[cj222]

@obnoxious001 Seems he has a lot of experience with these boats.

Thanks bud

 

[obnoxious001]

Hey guys!

I recently bought an old Howard 20ft GN hull as a project boat. It came with a few parts like the Casale split case v-drive, prop shaft, rudder, miscellaneous cavitation parts, a drive shaft and drive plate that I was told is for a Powerglide transmission. Any thoughts on running a PG trans? Thanks in advance!

Turbo 400 is perhaps preferable for a cruiser sized boat. Some guys will lock out 1st gear and only run 2nd and 3rd, but if you are going to be doing much idling or docking, or even 5 mph zones, 1st gear is good for slower maneuvering. I currently have a blown Vector with a turbo 400, previously have owned a 20' Schiada with a turbo engine coupled to a turbo 400. Normally accelerate onto plane starting in 2nd gear and basically short shifting into 3rd depending on engine power, gear and prop.

Depending on what engine you plan to run, and how you plan to use the boat you might have a different idea of what works for you.

 

[cj222]

Turbo 400 is perhaps preferable for a cruiser sized boat. Some guys will lock out 1st gear and only run 2nd and 3rd, but if you are going to be doing much idling or docking, or even 5 mph zones, 1st gear is good for slower maneuvering. I currently have a blown Vector with a turbo 400, previously have owned a 20' Schiada with a turbo engine coupled to a turbo 400. Normally accelerate onto plane starting in 2nd gear and basically short shifting into 3rd depending on engine power, gear and prop.

Depending on what engine you plan to run, and how you plan to use the boat you might have a different idea of what works for you.

Thank you for chiming in
I have a pump gas naturally aspirated 548 with approximately 650hp that I will end up putting in this boat. I am mainly building this boat to be an average cruiser, nothing super fast. I thought about a turbo 400 setup also but being that I have the drive plate and drive line for a PG I was wondering if that would be a decent way to go. This is my first v-drive boat so I really don't what would work and what wont.

 

[sintax]

Thank you for chiming in
I have a pump gas naturally aspirated 548 with approximately 650hp that I will end up putting in this boat. I am mainly building this boat to be an average cruiser, nothing super fast. I thought about a turbo 400 setup also but being that I have the drive plate and drive line for a PG I was wondering if that would be a decent way to go. This is my first v-drive boat so I really don't what would work and what wont.

I would not be against a PG if you could build it.

I'd want to do a shorty setup, the factory units are typically super long, and I'd also want to pick my gears. Factory PG's have a ridiculously large gear spread. Skys the limit on those builds, dudes run em in funny cars

Personally, if you're talking about a situation where you're re-rigging anyway, I'd be tempted to run a velvet. They're short from the get go, can be built to handle many many hp's.

I could see with a big heavy boat, there might be some value in a gear change maybe, for getting out of the hole quickly maybe?

@obnoxious001 do you know anyone w/ a big hp cruiser thats done that kind of testing? a 2-3 shift vs a 3 gear launch and timed it?

 

[cj222]

I would not be against a PG if you could build it.

I'd want to do a shorty setup, the factory units are typically super long, and I'd also want to pick my gears. Factory PG's have a ridiculously large gear spread. Skys the limit on those builds, dudes run em in funny cars

Personally, if you're talking about a situation where you're re-rigging anyway, I'd be tempted to run a velvet. They're short from the get go, can be built to handle many many hp's.

I could see with a big heavy boat, there might be some value in a gear change maybe, for getting out of the hole quickly maybe?

@obnoxious001 do you know anyone w/ a big hp cruiser thats done that kind of testing? a 2-3 shift vs a 3 gear launch and timed it?

Thank you for the information only reason I'm thinking about running the PG is because I have the drive plate for it. I thought about a turbo 400 but in searching for that drive plate setup I have not found any available.

 

[sintax]

Thank you for the information only reason I'm thinking about running the PG is because I have the drive plate for it. I thought about a turbo 400 but in searching for that drive plate setup I have not found any available.

I might have a spare drive plate + spline drive for a 400 laying around. I can check the shelves this weekend


something else to keep in mind...

PG iron - about 220+ lbs
PG alum - about 150 lbs
TH400 - about 140 lbs
Velvet - about 100 lbs

 

[sintax]

re: the drive plate / spline drive

this is what i've always used, the HD plate though!

 

[cj222]

I might have a spare drive plate + spline drive for a 400 laying around. I can check the shelves this weekend


something else to keep in mind...

PG iron - about 220+ lbs
PG alum - about 150 lbs
TH400 - about 140 lbs
Velvet - about 100 lbs

If you do have them laying around and would like to sell them, I am interested in buying them off you that way I can go with the turbo 400

 

[obnoxious001]

I

@obnoxious001 do you know anyone w/ a big hp cruiser thats done that kind of testing? a 2-3 shift vs a 3 gear launch and timed it?

Depending on what you call "big hp", you could probably could time the difference with a grandfather clock. With my turbocharged Schiada, with proper shifting you could get the engine loaded up and shift and with a good skier you can pop them out of the water, it happens that fast. There are some photos floating around of good skiers in the air on the start. The difference is pretty significant.

 

[sintax]

Depending on what you call "big hp", you could probably could time the difference with a grandfather clock. With my turbocharged Schiada, with proper shifting you could get the engine loaded up and shift and with a good skier you can pop them out of the water, it happens that fast. There are some photos floating around of good skiers in the air on the start. The difference is pretty significant.

I could see that really helping overcome the turbo lag, esp with an older tech turbo setup.

Thanks for the insight!

 

[AZLineman]

I prefer a three speed over a PG. I have ran both. You can't beat the velvet drive for close quarters either if you need only one gear.

I have a polished shorty 727 3 speed built for big hp with a chev bell housing if any one wants it. I never used it and it's gonna get listed soon.

 

[sintax]

If you do have them laying around and would like to sell them, I am interested in buying them off you that way I can go with the turbo 400

I dug around a bit today and only found the the new in box set I have for a buds boat.

I might have it out in Havasu but I won’t be out there until mid April.

 

[cj222]

I dug around a bit today and only found the the new in box set I have for a buds boat.

I might have it out in Havasu but I won’t be out there until mid April.

Thank you for looking! If you happen to find it next time your in Havasu please let me know. I won't be needing it before then lol

 

[obnoxious001]

I could see that really helping overcome the turbo lag, esp with an older tech turbo setup.

Thanks for the insight!

Yep, but I am talking about all the various Gentry turbo engines that I have built and driven over the years. With the waste gates they come on strong. Got a story about a guy who was debating blown and turbo some years ago when I was assembling engines for GT Performance. We invited him down to Elsinore with a couple of the ski race boats and he was instantly sold.

The most direct comparison I have was my own boat with the same 505 cubic inch engine, first with a super charger and no transmission, and later I rebuilt the boat, still with the same 505 cubic inches, but with Gentry turbo kit and turbo 400 trans. A lot of guys were asking me how it compared, but I always explained the difference in horsepower did not allow an apples to apples comparison. Rough numbers the blown engine may have been 800 horsepower, and the turbo probably over 1000 horsepower, with a different level of boost and thus more expensive fuel requirement. 110 octane Union 76 racing gas was $3.75 per gallon back then.

 

[obnoxious001]

If you do have them laying around and would like to sell them, I am interested in buying them off you that way I can go with the turbo 400

I believe I have a used drive plate here, but no spline drive that I can think of.

 

[BamBam]

I believe you can build the PG with the same ratios that would be 2nd and 3rd in the TH400. Does it matter? Guess it depends on driver (and budget) preference. I have a TH400 and it still has 1st gear. As stated earlier it is nice to have 1st gear in 5mph zones and around docks. There is no way you would ever try to start off (hole shot) with 1st gear as it would be on the rev limiter before you could shift. There are two reasons that you might still consider the PG. First is the size. The PG is shorter and lighter than the 400. Second is parasitic loss. I believe the 400 takes more power to run it, meaning you will put more power to the prop through the PG than you will with the 400. Strength of the PG is not an issue with the right builder and the right parts. The overdrive ratio you run in your v-drive will also dictate the need for a 2 or 3 speed transmission at all. On big HP motors they are running 43%, 48%, 50% and sometimes more overdrive. That necessitates having a lower gear to initiate the hole shot and have a much lower 1st gear for docking etc. Just 1 guys opinion.

 

[cj222]

I believe I have a used drive plate here, but no spline drive that I can think of.

Thank you I am undecided on which way to go. The boat came with a 2 blade prop. I believe it is a 11-1/2 x 15 , hard to read the numbers stamped in it.

 

[obnoxious001]

Thank you I am undecided on which way to go. The boat came with a 2 blade prop. I believe it is a 11-1/2 x 15 , hard to read the numbers stamped in it.

That would be about the correct size for speed, if that's your intention. A 3 blade will be smoother out of the hole, but probably sacrifice a bit on top end speed. If you intend to go fast, a well matched prop makes a huge difference in the way the boat handles.

 

[Eliminator21vdrive]

I have one of these for a 400 new that I do not need.

 

[cj222]

When using a spline drive and drive plate for a turbo 400, do you use a flexplate or a flywheel?

 

[AZLineman]

Direct drive hub/pump drive. Couple places have them including Teague and Connolly. I think it's a TCI part number 162000

 

[cj222]

Direct drive hub/pump drive. Couple places have them including Teague and Connolly. I think it's a TCI part number 162000

Thanks bud. My transmission I bought came with the spline drive and new drive plate. Was hoping to use it lol

 

[BamBam]

When using a spline drive and drive plate for a turbo 400, do you use a flexplate or a flywheel?

The drive plate bolts to the flywheel using the holes that the pressure plate would normally use to bolt up. Check your clearance when mating the transmission to the motor when using a motor plate. You need a little play for crank thrust but you will likely need to build a spacer to go over the spline drive that is the same width as your motor plate. If there is too much play (like not using the correct spacer) the spline drive will walk out of the pump drive on the trans. I believe you will also need a pilot bushing in the crank for the spline drive to center itself. Hope the make sense.

 

[cj222]

The drive plate bolts to the flywheel using the holes that the pressure plate would normally use to bolt up. Check your clearance when mating the transmission to the motor when using a motor plate. You need a little play for crank thrust but you will likely need to build a spacer to go over the spline drive that is the same width as your motor plate. If there is too much play (like not using the correct spacer) the spline drive will walk out of the pump drive on the trans. I believe you will also need a pilot bushing in the crank for the spline drive to center itself. Hope the make sense.

Copy that! Makes total sense, thank you! Are you guys using and aluminum flywheel or a heavy steel flywheel.

 

[Eliminator21vdrive]

When using a spline drive and drive plate for a turbo 400, do you use a flex plate or a flywheel?

I have had both flywheel and flex plate with the Hughs style.


Part # for 3/8 plate. You have to call and order not listed on website

 

[lenmann]

I have had both flywheel and flex plate with the Hughs style.


Part # for 3/8 plate. You have to call and order not listed on website

View attachment 1360262 View attachment 1360264

Which set up to you prefer and why?

I have only run the spline spring drive plate type.

 

[BamBam]

Copy that! Makes total sense, thank you! Are you guys using and aluminum flywheel or a heavy steel flywheel.

I currently run a heavy steel flywheel but there is no reason you couldn't run aluminum

@lenmann I prefer the spline drive. First because it's what I have and have used on lots of boats. Second because once the set-up is done the trans r&r is much easier. If you run the hughs style you need to get under the trans (in the bilge) to bolt and un-bolt the drive from the flex plate. If you run the spline drive you just unbolt the bell housing and slide it back. I'm sure everyone has an opinion as to why the one the run is best, so take this as my opinion.

 

[cj222]

This is what I have. I'll need to buy an internal balanced flywheel for it and I'll need to machine a spacer for the thickness of my motor plate.

 

[Eliminator21vdrive]

Which set up to you prefer and why?

I have only run the spline spring drive plate type.

Personally I ran the aluminum flywheel with the direct drive (no damper springs ) for 27 years with 600ish hp so did it cause any problems IDN. The difference between a flywheel and a flex plate is just that. As the transmission pump makes pressure you can get thrust from that forward. so if the flex plate flexes then it is not pushing as hard on the thrust surface of the crank. IDN.
I have dealt with motor homes with the thrust knocked out due to converter / trans thrust so bad that the counter weight hit the block.
So do you need damping in the hub? My personal experience with a V drive is no.
If you are running an out drive I think it may be useful as they are not nearly as strong.

 

[RaceTec]

This is what I have. I'll need to buy an internal balanced flywheel for it and I'll need to machine a spacer for the thickness of my motor plate.

Way back in the day when I worked at Art Carr, this is the combo we would sell most frequently. There is also a damper plate that uses an elastomeric material instead of springs. You may want to mock up everything before you make the spacers, the spline drive should have been made to make up for your engine plate... When we made them we always asked if there was a mid-plate and the thickness to make sure that there was the proper engagement and no thrust.

 

[cj222]

Way back in the day when I worked at Art Carr, this is the combo we would sell most frequently. There is also a damper plate that uses an elastomeric material instead of springs. You may want to mock up everything before you make the spacers, the spline drive should have been made to make up for your engine plate... When we made them we always asked if there was a mid-plate and the thickness to make sure that there was the proper engagement and no thrust.

OK, thank you! When I do my mock up, how much play should there be for the spline shaft?

 

[RaceTec]

OK, thank you! When I do my mock up, how much play should there be for the spline shaft?

.100" to .150" clearance typically... It should slide easily, make sure it doesn't bind in the pilot bushing...

 

[cj222]

.100" to .150" clearance typically... It should slide easily, make sure it doesn't bind in the pilot bushing...

Copy that! Thank you

 

[obnoxious001]

Thanks bud. My transmission I bought came with the spline drive and new drive plate. Was hoping to use it lol

I would use those, that's what I ran in my turbo charged ski race boat, no issues. Like Jeremy says, .100" end play is good. Make sure it's not too tight, you will take out the rear main bearing in the engine.

I would use the heavy flywheel in most applications. For ski racing it made a smoother speed transition for the skier.

 

[cj222]

I would use those, that's what I ran in my turbo charged ski race boat, no issues. Like Jeremy says, .100" end play is good. Make sure it's not too tight, you will take out the rear main bearing in the engine.

I would use the heavy flywheel in most applications. For ski racing it made a smoother speed transition for the skier.

Right on! Thank you

 

[Mark Caton]

Hello Barry: Who's the trans guy in Big River that I think you use for your 400s. Thank you Mark

 

[obnoxious001]

Hello Barry: Who's the trans guy in Big River that I think you use for your 400s. Thank you Mark

Just saw this, sent him a text to find out what his status is, and if he is able to help you out.

 

[Mark Caton]

Thank you, Sir! Appreciated.