989cc at adaracing.com

njfl

X-H2
I was wondering when they would start advertising this. I learned about it a month ago when I was inquiring about bigger sleeves for my current billet ADA cylinder.

This one that they are advertising will be able to take up to a 91mm (Seadoo 951) piston and 8mm stroke. It will be a builder's kit like the ones they offered last summer. It will have a girdled head, but only because they are not using bolts in the center. Brooks sent me some pics of the head last week and said that it is OK to share.
 

Attachments

  • adabillethdtop.jpg
    adabillethdtop.jpg
    22.2 KB · Views: 85

njfl

X-H2
Mile9c1 said:
Yeah, I just figured it'll be a 91mm bore.

It'll be interesting... did he say what kind of hp it'll make?

No, but you could do a linear extrapolation from some known smaller motors to get a theoretical number (you're an engineer, right Mike:)), but then again, as we've often discussed, there may be some transfer port issues that make it a nonlinear curve.

I do know that he designed it with input from quite a few builders of the sport, so it wasn't just a modification of the old billet one (which was designed for racing and top-end rather than freestyle).

I'd like to do one of these, but I'd like to be the second or third build-up and let someone else be the guinea pig.
 

njfl

X-H2
MADMAT said:
Damn! Is this gonna be a complete shortblock ready to go?
No, just a cylinder/sleeves and head/girdle, but I think the price is going to be pretty attractive, although they didn't finalize on that yet.
 

njfl

X-H2
djkorn1 said:
Will this head, cyllinder and piston kit bolt up to a stock 701?
Yes, it will "bolt" up, but I recall hearing that the port positions require a minimum crank of +5mm with the sleeves set up for up to 91mm. Because of this, the OD of the sleeves would likely be at least 93mm which is way bigger than can fit into stock 62T cases.

You'll need to have the cases clearanced for the stroker crank, bored for the bigger sleeves, and epoxied to support the now-thinner walls.

I'm sure Paul is aware of this cylinder and I hope he will build one. Can't wait to hear about it.
 

SkiDaddy

Just Havin' Fun!
Location
Orange City, FL
The 951 is a PV cylinder, runs low compression & timing (it's in a couch) and is tuned more for mid & top end. I'd think Paul can easily make 130 w/out PVs on pump gas....:Banane01:
 

Mile9c1

X-H2O.com
Location
Grand Rapids, MI
I don't know all the 951 engine specs, but you can't run as much timing advance or compression on a big bore. Say on a 701 the safe limit is a 2 degree advance and 185psi... that wouldn't be safe on a 91mm bore.
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
Correct. On bigger bores, the allowable compression for a set octane levels goes down.
 
Y

yamaslut

Guest
I bet my motor makes around 130hp... I'm only assuming, but Christ a stock gp 800 motor makes 120hp and I have almost the size displacement w/ higher comp., porting, and all the extras... even the same size carbs...

Am I way off here??
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
The GP800 is a bit different from what you have, Nick. It's got the extra transfer ports that a Lamey cylinder boasts, in stock form. That is a big deal as far as power is concerned.
I believe the quality of porting may be a bit better than the 701/760, as well.
And keep in mind, it's making that 120HP with a stock exhaust system - a huge restriction.
Only Paul can answer the HP question - there are many factors involved: carbs, intake, ignition, pipe, etc...
However, I would guess that you are under 130HP.
Remember, there's not only HP - torque plays a big part as well.
 
Y

yamaslut

Guest
Matt_E said:
The GP800 is a bit different from what you have, Nick. It's got the extra transfer ports that a Lamey cylinder boasts, in stock form. That is a big deal as far as power is concerned.
I believe the quality of porting may be a bit better than the 701/760, as well.
And keep in mind, it's making that 120HP with a stock exhaust system - a huge restriction.
Only Paul can answer the HP question - there are many factors involved: carbs, intake, ignition, pipe, etc...
However, I would guess that you are under 130HP.
Remember, there's not only HP - torque plays a big part as well.

yeah... thanks
I wonder what my motor puts out???? Not that it maters really, just would be cool to know
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
Call the man...I'm sure he'd be able to at least give you a rough estimate.
Don't get too hung up on numbers, though - the important thing is that it rips like nothing you've ridden before and is reliable, right?
 
Top Bottom