Chrysler Conqueror SIII with Chrysler Jet

[blazeracer]

This is a very unique project. I hope to see it on the water this summer. I've seen pics of the Chrysler pump, but have never seen one in action. You're doing great work on it. Keep it up!! Summer is on the way.

Where are you going to boat at?

 

[jdeaton]

Being a budget builder myself, I have a suggestion that may apply.  When you look for a cam for the Mopar, consider an RV grind.  They are readily available, considerability less expensive than a custom Marine grind, and for a Chevy it's the first step to make a truck motor work in a Boat.  Just my .02

 

[ChryslerJet]

Being a budget builder myself, I have a suggestion that may apply.  When you look for a cam for the Mopar, consider an RV grind.  They are readily available, considerability less expensive than a custom Marine grind, and for a Chevy it's the first step to make a truck motor work in a Boat.  Just my .02

Jim  I was under an understanding that the Truck grind and an RV grind were very similar and that the Truck Grind may work just as well.  From what I understand is that you want max low end torque.  Of course I am still learning and I know I dont know anything I just read a lot.

 

[ChryslerJet]

Where are you going to boat at?

I have only boated in Lake Dunlop here in New Braunfels its a damned lake basically a wide and deeper section of the Guadalupe River that's been damned to form a pseudo lake.

I haven't ever been to Canyon Lake to be on the water and been told the ramps there are horrid at least the public ones my neighbor uses.  I did take my last boat to Lake Limestone up north of Bryan two summers ago that's when the motor died on me before we got to do anything.  I spent the whole time trying to rig something up for a water pump so we could use it and finally gave up.  I kinda swore off outboards from that point.  I am a hot rod guy so I know my way around an engine just never liked 2 strokes much.  Sold that boat and motor to get this one. 
I did buy another junked boat with a good merc 115 in the meantime to try to transplant the motor to that boat but since I found this one I ended up parting out that boat, motor and trailer.  I paid $50 for it sold the motor for $300, trailer for $150, gave away the boat but got paid $50 for delivering it.  I kept a piece of 3/8" aluminum that was on the transom hold the motor since there was no wood in the boat that I figure was worth $50.  All in all a good deal.  By the way the last boat part of the reason I bought it was because it had a Chrysler Outboard.  Yeah I am a big Mopar guy.  I used to have a 68 Barracuda and a 71 Roadrunner regret selling both of these.  This boats not going anywhere aint never gonna sell her.  If I have to its getting buried with me.  Am I mad? maybe?

 

[ChryslerJet]

Okay so there was one section of the boat and pics that I hadn't posted here yet but they were on Photobucket and that's of the crazing and stress cracks.  So here are those.
This one is on the transom it appears to be a typical stress crack from hitting something


These are on the front cap and could possibly be from heat or people walking on it.  There isn't much in the way of support there.




These are on the back deck which was designed to be walked on as well but since the support frames were not attached when I got it who knows when they happened.  By the way one really cool thing about this boat it has hood pins for the motor cover like a hot rod.

 

[blazeracer]

From what I understand is that you want max low end torque.  Of course I am still learning and I know I dont know anything I just read a lot.

On a jet boat you don't need any torque under 4,000 rpm. When you nail the throttle the tach will snap at least to 5k, and that's for us with slow boats. Some of these guys on here have big blocks that scream 6,500 to 7,000 with blowers, bottles and turbos!

You said you're running a 360, right? I'd look for a nice Mopar cam that already exists and calls for headers with a 3,500 or more stall converter. Couple that with a double pumper that can flow a good 750 CFM or so sitting on top of a single plane intake and let that small block rev.

I'm partial to the VooDoo's myself.

http://www.summitracing.com/parts/LUN-60404LK/
http://www.summitracing.com/parts/DCC-4529408/
http://www.summitracing.com/parts/HLY-0-80537/

 

[jdeaton]

Not sure I agree with James disregarding the need for low end torque on a jet boat, after all you are pumping water as soon as the motor starts to turn.  Gues I need to read more.

 

[blazeracer]

Not sure I agree with James disregarding the need for low end torque on a jet boat, after all you are pumping water as soon as the motor starts to turn.  Gues I need to read more.

Pumping yes, pressurizing no. You gotta get the impeller spinning fast to pressurize the water enough to give you leverage inside the bowl. At 3,000 rpm mine won't squirt enough to get my boat up on plane. If it's already up on plane it will barely stay up if at all at that impeller speed. When I threw a rod at Somerville, shaking and rattling on 7 cylinders the motor could still turn the imp 2,500 easily and the boat barely moved. You need the big torque once you pressurize the bowl and create the leverage. IMO, that doesn't happen till a good 4,000 on your average pump. Lower on a prepped pump.

It makes total sense because bone stock at 330hp my original 30+ year old 460 could turn the imp at 4,600. To get another 500 rpms out the impeller with no pump efficiency mods took a wicked cammed and aluminum headed motor that made almost 200 more horsepower and probable just as much more torque. Even the slowest jets out there (Cliff, LOL) can easily turn the pump with an A at 4,000. Beyond that, you need to be making some big numbers. It's probably more like 4,500. I think most of the boats that have stock mills can still turn 4,500.

If you needed low end torque you would see a lot more boats with dual plane intakes and a lot less with tunnel rams. My personal opinion is that you don't need to worry about torque at all on a jet. Take care of the high end horsepower and the torque will take care of itself.

On the drag strip, torque gets you a good 60ft time, but horsepower get you a bigger trap speed. Jet boats live their entire life on the big end. Let the discussion begin!! LOL

 

[blazeracer]

Here's a good thread on it torque vs. horsepower..

http://speedtalk.com/forum/viewtopic.php?t=5934

I like the bucket analogy, it's spot on.

"I have a bucket that hold 5 gallons (representing torque) and I can carry 4 buckets (representing RPM) and my brother also has 5 gallon buckets (same torque) but only carries 3 of them in the same amount of time, (lower RPM) then I have done 33% more work, or have accelerated more mass in the same time ( or same mass in less time - lower e.t.)."

I'll be proving this point when my high RPM 325 inch small block spanks some big blocks this summer.. LOLOL

 

[jdeaton]

Good article, If I were building a car.  Also your example of the effectiveness of your pump at 3000 RPM, although reasonable, is not taking into account the boat at an idle, is still pumping water, "rule of hydraulics" and the pump does not have the benefit of any ram input from forward movement, the pump must pull the water and push it. A feat not easily accomplished without ample low end torque.

The intake, dual plane vs single plane statement you made is true to form.  Dual plane is a low RPM torque builder, but as you stated, we need (want) more RPM because we need (want) more speed.  3500 max RPM just wont cut it for us, that's why the need for single plane or tunnel ram intakes.  The single plane intake will still make good low end torque with the right cam and starts to shine when the need to deliver high RPM Horsepower.

As far as your 325 cubic inch engine smoking us old school "no excuse for cubic inch" dinosaurs we will continue to pour fuel down our 500 cubic inch motors and let the "side by side tuning runs" tell the story. 

 

 

[Last Mohecian]

LOL.  Everyone is feisty today.  James & Jim on the engine builds.  Kona & I on the fiberglass.  :smile28:

 

[KONA77]

LOL.  Everyone is feisty today.  James & Jim on the engine builds.  Kona & I on the fiberglass.  :smile28:

LOL,    :laugh: :laugh:

 

[spd500]

Sometimes a good debate is great for sharing both sides of a topic.  I learn alot from these type of discussions.

 

[ChryslerJet]

Seems as though I have awoken a beast or two.  Since I am new I bring with me all my years of building motors.  I think the most logical scenario is to build a motor with a very wide torque band say from 1500 to 6500 then and as such it would be very useful.  Now the question is what is the torque I need to use this pump and push this boat fully loaded to a decent speed for tubing, skiing and wakeboarding at our little lake.  My guess is I need a hellava holeshot quick start up on plane cause our little lake has quite a few blind bends that come up quickly at even 30 mph.  A nice well matched dual plane can handle that torque curve for my smallblock.  If I go to the 4" stroker making it a 408 might have to change that out.

Regarding this discussion I am even more confused.  I guess I won't know until I put a motor in the boat and try it out then I will have a baseline as to where to go from there.

Thanks for all the entertainment and discussion.

 

[Last Mohecian]

Seems as though I have awoken a beast or two.  Since I am new I bring with me all my years of building motors.  I think the most logical scenario is to build a motor with a very wide torque band say from 1500 to 6500 then and as such it would be very useful.  Now the question is what is the torque I need to use this pump and push this boat fully loaded to a decent speed for tubing, skiing and wakeboarding at our little lake.  My guess is I need a hellava holeshot quick start up on plane cause our little lake has quite a few blind bends that come up quickly at even 30 mph.  A nice well matched dual plane can handle that torque curve for my smallblock.  If I go to the 4" stroker making it a 408 might have to change that out.

Regarding this discussion I am even more confused.  I guess I won't know until I put a motor in the boat and try it out then I will have a baseline as to where to go from there.

Thanks for all the entertainment and discussion.

These beasts are awakened quite frequently around here and not just by the newbies.  Be aware that many an automotive engine builder has been humbled very quickly when it comes to putting a boat motor together.  There is no shortage of stories from people putting their well built, very reliable, high dollar, high HP motor from their car into a boat just to hear it go boom in 15 minutes or less.  Get used to seeing these 3 debates frequently.  New school VS old school power,  Epoxy VS polyester resin and Zinc in motor oil.

 

[blazeracer]

These discussions are awesome. I just think your average weekend cruiser jet boat will be much happier with a single plane intake and a carb that flows about 100 more CFM than you would put on a car accompanied with a healthy flat tappet hydraulic cam. That will get that peak torque up around 4,000 or so. That is if your not sporting an EFI roller motor.. LOL

Dual planes belong on the tow rigs.

With the scale of this project, your major restoration on the hull is the bigger issue right now. Just get it running and on the water with what you got and you'll be fine, then upgrade later.

 

[blazeracer]

These beasts are awakened quite frequently around here and not just by the newbies.  Be aware that many an automotive engine builder has been humbled very quickly when it comes to putting a boat motor together.  There is no shortage of stories from people putting their well built, very reliable, high dollar, high HP motor from their car into a boat just to hear it go boom in 15 minutes or less.  Get used to seeing these 3 debates frequently.  New school VS old school power,  Epoxy VS polyester resin and Zinc in motor oil.

Drag motors run wide open for 15 seconds at a time. Then when they drop it in a boat and cross the lake with the hammer down for 4 minutes, boom they go! LOL

Don't forget the two never ending debates on here, Ford vs. Chevy and jet drive vs. v-drive. We'll be nice to the Mopar guy, for now....

 

[ChryslerJet]

With the scale of this project, your major restoration on the hull is the bigger issue right now. Just get it running and on the water with what you got and you'll be fine, then upgrade later.

That's exactly what I am thinking partly because I am in uncharted water here since there is not much known about these Jets and I am running Mopar and seems like so far no one else here is unless there is someone I need to wake up from their hibernation.

I agree on the drag motors wont live in a boat environment that building for a constant 4k rpm versus raps up at 6k rpm are totally different.  For a boat you really need a bullet proof motor one that if designed for drag would spin 8-10k and survive so that it could spin 4k-5k all day long and have no issues.  Also that although torque really is still a deciding factor most guys build for max HP in a drag motor.  I have always been more inclined to differ on that in that a motor should always be designed max torque and long flat torque curve that way it pulls all the way through the curve.  That's how I built the 383 in my 68 Cuda to run 1.65 60' times with 3.23 gears with dry bearings in the rear (oops).  I had thought about using that motor in the boat but that's a lot of weight and major expense to get all the change over parts.  All that being said building a boat motor really is no different you just have to build for the application and design for the purpose and buy the parts that fit that.

I will be using a 93 and up Magnum 360 Truck motor for now it has the newer better flowing Magnum heads, Roller valvetrain setup for less friction in the motor and more power going to the output, I plan on using a dual plane that is designed to work with a torque curve from 1500-6500 and the Carter AFB carb I have on the RH 360 I have now.  I am also planning on lightning the flywheel as much as I can because I truly believe that less rotational weight is better and the stock one for the boat is way too heavy.  It's heavier than a 60's car flywheel with a clutch.  Less rotational speed means faster spin up so I will be able to get to the 4k faster and with more power and less fuel.  Where the heavier flywheel though does have an advantage is once its in motion it keeps wanting to spin (kinetic energy) so it takes less to keep it spinning and will want to help the motor keep spinning.  I wonder if that was the reason they did it.  And yes I am some what of a nerd as I learn a lot, read a lot, and pickup a lot of knowledge along the way with my trial and errors. I have been working on cars and other vehicles for over 30 years and have picked up a lot of mistakes.  I will learn a lot more with the boats as I go along.  With this boat I am sure there will be a lot of trial and error in trying to get the most speed out of it safely.  Now if I could only figure out how to safely put a turbine in a boat hooked up to the jet.
:smile17:

 

[blazeracer]

My Glastron had an AFB carb on it when I got it. I can't tell you how many times I got holeshotted waiting for that damn weighted secondary valve to open. Matt has a video of it somewhere. I picked up a ton of off the line grunt and 5mph on the top end switching from the Carter 750 to a Marine Demon 850 with no other changes.

Keep in mind also that if you have an engine cover you should really have a marine carb. The bowl vents have J hooks that dump into the venturi and all the shafts are o-ringed so they can't leak. Plus if the lake police ever looked, which they never do, you can get ticketed for for that. The alternator, starter and dizzy should also be marine pieces under a cover. If you have an open engine compartment it's no biggie. Just something to keep in mind.

 

[Patchman]

Also keep in mind marine motors run very cool! Need to be a little looser than their street loving counterparts. Sounds like your combo is spot on! Plus the big factor here is how that pump works. With none of us having experience with that pump, it's hard to say what he needs to do! think.gif