Super Jet Best Aftermarket Engine

[ArtMaybee]

WOW matt! thanks. It's not like I don't have 4 motors with 62T cases right now. But I've always been curious about the x cases. Remembering threads about that Keith head motor every time I look at the x cases I have laying around. Now that the issues I had going on are all sorted, I guess it's time to start building skis again

Maybe I'll try to get in touch with keith about a little work. I think I remember his prices on porting the x cases and cylinder being a tad bit on the high side though.

 

[waxhead]

Dont use the x-cases
the reed choices for them are limited at the very best
they dont flow
racers used to cut off the intake and change it to the 62t style so they could get power out of them.
The Yamaha engine went from 63 hp to 73 when they changed it to the 62t case design.
The only time you would use 61x cases is if you couldn't afford to buy decent cases

 

[whitca]

The 61x Matt is referring to is mine. I run the carbontech mono petal reeds per Art...he swears by these for the 61x case. My former roommate has the other 62t 701 Art ported that matts talking about . We've been doing a lot of comparing and they feel about the same power wise even though they're in different boats with different pumps. My 61x is in a kawi 750, using the 140m kawi pump and my buddy's 62t is in his squarenose. My boat is a little lighter so it feels a little more responsive. I'm also running bigger carbs...dual retail 44's when the 62t has Arts modded 38's. Other than that the engines are the same mod for mod....new limited b pipes, msd enhancers, Ada heads, fresh ported topends with wiseco pistons...his carbontech reeds are different for the 62t case though. I'm happy with my setup from Jetworks , it hits hard and is very smooth.

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[Big Kahuna]

Dont use the x-cases
the reed choices for them are limited at the very best
they dont flow
racers used to cut off the intake and change it to the 62t style so they could get power out of them.
The Yamaha engine went from 63 hp to 73 when they changed it to the 62t case design.
The only time you would use 61x cases is if you couldn't afford to buy decent cases

Tell Keith Head that they dont work!!!!!!

They work great for their purpose...... Smaller displacement motors that create a whole lot of bottom end. This is not a top end high RPM motor.

 

[waxhead]

Im sure you can get them to go ok but your never going to get them to go as well as a 62t set of cases with getting rid of that sharp 180 degree bend.
Every time air has to change direction more than 15 degrees it loses momentum. this is why much time is spent on 62t cases with ramps and porting to get the air to keep up its speed. The 61x has a terrible bend in it that kills momentuim and hurts air flow. I know a 62t engine also has the same bend due to the carbs being mounted higher but its not the same tight radius.

Comparing a kawi with a 701 and a 140 pump versus a square nose with a 144 mm pump is not really a valid comparison

 

[whitca]

I was stating what engines are being used with what setups that's all. I agree not an exact comparison, just putting it out there so people know what exactly we're comparing. I would think my 61x would be even better with the 144 pump.

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[Matt_E]

Comparing a kawi with a 701 and a 140 pump versus a square nose with a 144 mm pump is not really a valid comparison

Can you elaborate on this? Which pump/hull do you think is at a disadvantage in this comparison?

 

[waxhead]

Can you elaborate on this? Which pump/hull do you think is at a disadvantage in this comparison?

What ever boat that had the taper bored 38s on it

 

[Matt_E]

1. I thought you said that "comparing a kawi with a 701 and a 140 pump versus a square nose with a 144 mm pump is not really a valid comparison". Seems like you're talking pumps here. Which is it?

2. None of those two boats has taper-bored 38's on it.

 

[waxhead]

1. I thought you said that "comparing a kawi with a 701 and a 140 pump versus a square nose with a 144 mm pump is not really a valid comparison". Seems like you're talking pumps here. Which is it?

2. None of those two boats has taper-bored 38's on it.

The one with modified 38s.
Matt if you are happy with 61x cases and believe they are as good as 62t cases all power to you. Im very happy for you.

My experience with building engines based on this platform since 1994 has left me with different view

 

[Matt_E]

I don't run X-cases. I would just like to know what you meant by "Comparing a kawi with a 701 and a 140 pump versus a square nose with a 144 mm pump is not really a valid comparison".

(Because I really don't know how those two pumps stack up)

 

[waxhead]

I don't run X-cases. I would just like to know what you meant by "Comparing a kawi with a 701 and a 140 pump versus a square nose with a 144 mm pump is not really a valid comparison".

(Because I really don't know how those two pumps stack up)

Like i said Matt
you cant put two engines in different skis with different hull weights and different pumps, carbs, props and who knows what else and say one engine is better than the other or as good as another, Surely you can understand this ???

 

[Matt_E]

No one said one engine is better than the other. It was said that both boats performed Very comparably, given the obvious differences between them. The Kawi hull was quite a bit lighter, too. My point wasnt to claim that X cases are better or equal to T cases. Just that for that class of motor and their budgets, I was very pleasantly surprised how close performance was.

 

[waxhead]

I'm not sure if one is better or not Matt do you know?
What pitch prop did they have was the nozzle bored. How was the liner.
If you can not see how that two skis with such a huge difference between them can be used as a comparision between the benefit of a set of cases then clearly I have made a misjudgement in the amount of credit I gave you re your understanding

 

[MDStandUp]

Why isnt this a Pole? someone set it up.

 

[SUPERTUNE]

Why isnt this a Pole? someone set it up.

Why?
62T cases are better period.
Now it's up to the high performance engine builder to use the right combination of parts and take advantage of the 62T cases.

 

[masterblaster]

lol thats what i wanted to say....now i can alot more easy.send the 61x tops halfs to the metal scrappers and keep the bottoms for spares for your 62t if they ever wear out

 

[Matt_E]

Of course the T cases are better. But for someone on a very limited budget, X cases can be an option, no? :veryhappy:

Edit: I guess it all comes down to budget. Probably a poor choice for a performance engine that needs potential to grow.

 

[GIL]

The bottom line here is that if Jetworks is involved, it will be the best in the world, if not, well...........................

 

[PancakePete]

Will do. I would like to stay East Coast. Shipping would be no prob from my work.
How easy is the destallation/installation?

If you get ur motor and need help uninstalling and reinstalling. there are some great local nj guys that would help.