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Adventures of the Jet Botë

motormonkey

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Nice, now flip the pulleys and add some 110 to your pump gas. I've seen big jumps in power with just 1 degree of timing. Are you running a boost retard ignition?
How's your plugs look with the method adder, you might be way rich at 3pounds.
 

Blackmagic94

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I’m running a Aem meth water injection system. That’s basically 120 octane fuel and cooling effect of an inter cooler over the pump gas which currently is 95 octane fuel as well. I can probably run 32 degs but I’ll do a small change to 30 first.
 

Blackmagic94

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Nice, now flip the pulleys and add some 110 to your pump gas. I've seen big jumps in power with just 1 degree of timing. Are you running a boost retard ignition?
How's your plugs look with the method adder, you might be way rich at 3pounds.

Yeah I moved the wideband today to the other header as it has 1.5” more pipe before the exit. The numbers were not right on the other header and I may need to add another 10-12” of tail pipe to help that issue.

Gonna pull a plug now
 

motormonkey

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You are pretty rich, id try and add some base timing if you have boost retard ignition and check your jetting. Definitely get your wide band going.
 

Blackmagic94

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The carbs have 10.5 power valves installed to make them work for boost.

Wideband was just swapped to the other header that has a bit more length from bung to exit and I just ordered some 15” bolt on tips to test the theory of to short of a pipe for proper signal.


No boost retard. Just using base timing plus


Timing is 11-12 base plus 18 advance so it’s actually 29-30. I was wrong of the 28.
 

Blackmagic94

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68 primary
75 secondary
10.5 power valves
6.0 psi fuel pressure

Engine runs 125 degrees coolant temp with 1-2 psi of water pressure at low rpm and about 8-10 at higher rpm and vents 15 psi excess before block
 

78Southwind

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My guess is you're running out of water with the Panther intake. Talk to Tom to see if that's what he thinks and maybe he has a fix for you. I know nothing about those Panther Conversion Kits. They sure look a lot better then the old school Panther Pump. @jetboatperformance Do they make some kind of loader for the Panther intake? If not, do you think it would help with top end speed?

ssopen_loader_shoe_plate.jpg


Brandon Intake.jpg
 
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Hallett Dave

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Just received the new jet drive from JBP today and the place diverter from Mark another member here with the shifter.


So when my mechanic gets back after the Holiday he will install it and then we will retest with the alum alum AA test impeller I was provided so we have a baseline before the 6-71 install and a mag impeller for that. View attachment 793121 View attachment 793122 View attachment 793123 View attachment 793124
First of all why the hell would you let Tom touch your pump?
Second why would you use a bronze mag impeller?
Why not a stainless inducer and a detailed stainless impeller set up?
If I were you I would seriously rethink this build.
YMMV
 

Carlson-jet

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Let him sort it out. Spending money makes the world go around.
Jetbotes are money pits like many other hobbies.
I was fortunate enough to have bought Tom Papp dinner after my Friend flew him out here to do some intake and bottom work..
One thing I learned over that weekend was horsepower was not the only solution.
 

Blackmagic94

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With a 16” extension I can grease the zerk without removal. And I am going to be running a stainless unit.
 

was thatguy

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Let him sort it out. Spending money makes the world go around.
Jetbotes are money pits like many other hobbies.
I was fortunate enough to have bought Tom Papp dinner after my Friend flew him out here to do some intake and bottom work..
One thing I learned over that weekend was horsepower was not the only solution.
Amen.

What I’ve learned is that trying to optimize 20 different things simultaneously in a jet bote is insanity.
While I always love a build thread of any kind, especially a fellow jet boter, I honestly can’t keep the data in order in this thread.

No disrespect or judgement intended at all, but reading about plugs, header lengths, Meth injection, ride plates, test impellers, timing, carb mapping, blower boost, pulley swaps, coolant pressures, all in one session is kind of headachey.
Pick one, get it right, then move to the next thing. Get it right, then move to the next thing.
One thing at a time. That’s how it gets done.
My jet boat doesn’t have 1/2 of the stuff here and it does 80+ MPH every time I drive it. On pump gas, with a $100 fuel pump...No blower, no meth, none of that.
It took a lot to figure it out. ONE THING at a time.

Oh, and I don’t lie about what it does.
Im happy to give rides!
 

Hallett Dave

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With a 16” extension I can grease the zerk without removal. And I am going to be running a stainless unit.
I have bean thinking about your situation.
I'm not quite sure if the droop is the way to go.
I have a straight snoot from HTP and it works great on my Hallett Mini Cruiser.
I would get in touch with Dwayne at HTP and get his opinion.
I don't know much about the strakes nor the chines on your hull.
How heavy is the boat.

I have a Scott Foxwell naturally aspirated 10.5-1 stroked BBC making 750 HP on 91 octane in the Hallett.
The straight snoot was the ticket for me.
Give Dwayne a call and see what he has to say.
HTP straight snoot dwayne
Good luck with with your endeavor.
 

was thatguy

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I have bean thinking about your situation.
I'm not quite sure if the droop is the way to go.
I have a straight snoot from HTP and it works great on my Hallett Mini Cruiser.
I would get in touch with Dwayne at HTP and get his opinion.
I don't know much about the strakes nor the chines on your hull.
How heavy is the boat.

I have a Scott Foxwell naturally aspirated 10.5-1 stroked BBC making 750 HP on 91 octane in the Hallett.
The straight snoot was the ticket for me.
Give Dwayne a call and see what he has to say.
HTP straight snoot dwayne
Good luck with with your endeavor.
Is that a Foxwell/ Shaub combo?
 

Carlson-jet

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I have bean thinking about your situation.
I'm not quite sure if the droop is the way to go.
I have a straight snoot from HTP and it works great on my Hallett Mini Cruiser.
I would get in touch with Dwayne at HTP and get his opinion.
I don't know much about the strakes nor the chines on your hull.
How heavy is the boat.

I have a Scott Foxwell naturally aspirated 10.5-1 stroked BBC making 750 HP on 91 octane in the Hallett.
The straight snoot was the ticket for me.
Give Dwayne a call and see what he has to say.
HTP straight snoot dwayne
Good luck with with your endeavor.
Scott builds good motors. HTP does their job well.
It seems anything built East of the Mississippi is not acceptable and written off until it gets millions of hits on youtube.
I will leave this thread and wish good luck.
 

was thatguy

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Is that a Foxwell/ Shaub combo?
When my comp hyd roller lifter shit the bed I talked to Chris and Scott about it. Got morrels from them and the recommended springs and made new pushrods to wrap it all up.

No more problems. I pulled the valve covers this year just to look, first time in 8 years they’ve been off.

It’ll spin my stainless A at 5700 now with the worn out ring...lol

It’s actually a little funner to drive with it kind of “pipey”. Lol

Probably put a new ring in this winter and maybe a detailed A/B just for fun.
 

was thatguy

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Scott builds good motors. HTP does their job well.
It seems anything built East of the Mississippi is not acceptable and written off until it gets millions of hits on youtube.
I will leave this thread and wish good luck.
Ditto.
My parting advice? Drop the AA if he ever wants a shot at dialing the motor in sans dyno runs.
 

Blue

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If you are running 120 octane, black sooty plugs and getting pops I think you may have unburned fuel. Can you turn the meth injection down or jet it down? Unneeded octane isn't a good thing those black plugs are 82.67% of the problem
 

Hallett Dave

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Is that a Foxwell/ Shaub combo?
Straub cam with Morrel HYD Roller Lifters. Foxwell assembled all the good forged parts.
I had the pan off last month to replace a broken spring in the oil pump.
The bottom end from what we could see was pristine. Not bad for a 12 year old engine that still spins
a detailed Starkweather pump well over 6,000 RPM. :)
I don't know how many of you know that Scott used to do a lot of cylinder head work for Allen Johnson Racing.
He flowed my 990 rectangle port heads for my build.
There were a lot of members on Performance Boat that could not believe Scott got those boat anchors to flow that well. :cool:
I new he could.
Cheers.
 

was thatguy

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Straub cam with Morrel HYD Roller Lifters. Foxwell assembled all the good forged parts.
I had the pan off last month to replace a broken spring in the oil pump.
The bottom end from what we could see was pristine. Not bad for a 12 year old engine that still spins
a detailed Starkweather pump well over 6,000 RPM. :)
I don't know how many of you know that Scott used to do a lot of cylinder head work for Allen Johnson Racing.
He flowed my 990 rectangle port heads for my build.
There were a lot of members on Performance Boat that could not believe Scott got those boat anchors to flow that well. :cool:
I new he could.
Cheers.
Scott gave me all kinds of advice on my builds when PB was still kicking.
Even before going over with Straub.

I couldn’t justify a Straub cam at the time, still have my Comp Hyd roller, but went with the morrels, new spring set up, then new pushrods for the new lengths.
Brodix #1 heads.
 

Blackmagic94

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I have bean thinking about your situation.
I'm not quite sure if the droop is the way to go.
I have a straight snoot from HTP and it works great on my Hallett Mini Cruiser.
I would get in touch with Dwayne at HTP and get his opinion.
I don't know much about the strakes nor the chines on your hull.
How heavy is the boat.

I have a Scott Foxwell naturally aspirated 10.5-1 stroked BBC making 750 HP on 91 octane in the Hallett.
The straight snoot was the ticket for me.
Give Dwayne a call and see what he has to say.
HTP straight snoot dwayne
Good luck with with your endeavor.

Not sure if this is even considered a droop

4CE545CD-5EA3-4208-B469-787E83B0A06C.jpeg
0BDCD94A-27C3-4061-A985-3304260D6814.jpeg
 

motormonkey

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You need to boost reference your carbs, the 10.5 power valves are not helping either. Your over fueling.
Get a boost timing setup or a msd grid ignition.
Your initial timing is way to low.
 

jetboatperformance

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To start they (the carbs) need to actually be boost referenced , re loading one of the things we discovered early on was that the OE Panther axial flow intake actually charged too much for the Axial flow impeller and thus the mixed flow conversion actually "liked" it , cavitation issues would typically manifest as climbing RPMs vs speed, The AA was a base point in this jet as a starting point ...
 

Blackmagic94

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10.5 power valves are the same as a boost reference per Bob Teague and Larry Peto
 

Blackmagic94

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You need to boost reference your carbs, the 10.5 power valves are not helping either. Your over fueling.
Get a boost timing setup or a msd grid ignition.
Your initial timing is way to low.

I was told that they aren’t reliable and also are not marine grade. I run a billet distributor with a msd digital marine 6M-3L ignition box. Pulling timing out isn’t really an issue when you have methanol water injection
 

Blackmagic94

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With the low boost pulley.


Engine vacuum at the carbs above the blower is

17.5 at idle and 20 at 1200-1500 rpm

At the intake below the blower it is

12-13 psi at idle


So looks like I can actually step down to a 8.5-9.0 power valve and keep the 10.5 for the big boost pulley and probably why the big boost pulley revs cleans
 

motormonkey

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Is it hard to start with timing now in the water? If not try the black bushing in dist, if yes try the blue bushing. Run light springs, if surges put one heavy on with one light one.
Id flip the pulleys and I can't stress enough the boost reference of the carbs, it will respond much cleaner. I think people use the 10.5 non reference as a blanket tune. Your plugs say nope. If you keep running the way you are your going to need a rebuild soon.
 

was thatguy

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Is it hard to start with timing now in the water? If not try the black bushing in dist, if yes try the blue bushing. Run light springs, if surges put one heavy on with one light one.
Id flip the pulleys and I can't stress enough the boost reference of the carbs, it will respond much cleaner. I think people use the 10.5 non reference as a blanket tune. Your plugs say nope. If you keep running the way you are your going to need a rebuild soon.
I run the black bushing in my R2R with a light silver and a light blue.

Completely different set up than his engine but what it does is start perfect and idle at 900 RPM at 16* lead.
At 2000 RPM +- everything is in at 34* total.
I spent a LONG time trying all the combos!

I prefer this as opposed to many jet boaters who lock it out.
Never had a starter or flex plate issue in 14 years.
Hell, I’ve never even changed it and it was used when I bolted it on all those years ago.
 

Blackmagic94

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It starts very easy


black bushing in the distributor

the msd can pull 10 or 20 deg out for start up as well
 

Blackmagic94

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Attached these 15” long exhaust tips to give a cleaner signal to the wideband since it was short length from the bung to tail pipe. Not sure how I feel about the looks but it made the gauge read better so proof of life on that


Bumped the base timing to 14 deg from 11 so now a total of 32. Seems to rev better as well
6240EA77-EA21-4BBA-9E00-2D0909A85046.jpeg
4403E749-2E34-4689-8766-102DA8261F8E.jpeg
 

Blackmagic94

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Now boost reference your carbs.

Absolutely not. They are via the 10.5 power valves which does the same thing and I even had a second conversation with Larry Peto and flat said they never run that style anymore and only run high number power valves on the dyno.


Worse case he said change to a 8.5 but that’s it. And Larry is of Larry’s engine and marine. Who was a long time friend and builder of the predator boat that Vern owns now.
 
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