Weighing up crank(cases)

[CARBONX2]

To try help me decide what motor i want to get I decided to weigh up some cranks and crankcases
Cranks:
66E 26lbs
701 19.6lbs
800sxr 19.4lbs
Crancases:
66E 16.6
800sxr 10.4
No 701 crankcase on hand

I am interested to find out how much Billet cranks weigh

 

[750SX]

do a big 62t stroker!

 

[wsuwrhr]

do a big 62t stroker!

Ya ya, what he said.....

To try help me decide what motor i want to get I decided to weigh up some cranks and crankcases
Cranks:
66E 26lbs
701 19.6lbs
800sxr 19.4lbs
Crancases:
66E 16.6
800sxr 10.4
No 701 crankcase on hand

I am interested to find out how much Billet cranks weigh

Stock 701 cases 11 LBS

Stock 701 cases filled and trenched 13 lbs

Billet 10-12 MM case 17lbs
Billet 16MM 18lbs

8-10-12 Yamaha billet crank is 20Lbs

16MM billet Yamaha is 22Lbs

Billet 4MM Kawi 21lbs


I would like to add, in my opinion, more important than engine weight, is horsepower to weight ratio of each.

More important than that to freestyle, is powerplant size and compactness and placement in the boat.

Just my worthless pennies.

Brian

 

[CARBONX2]

I would like to add, in my opinion, more important than engine weight, is horsepower to weight ratio of each.

More important than that to freestyle, is powerplant size and compactness and placement in the boat.

Just my worthless pennies.

Brian

Compactness: that is strike 1 against 66E
Power/weight: 66E should be about 150hp in a drypipe freestyle setup, don't have all the weight specs but it will give you about 1.5hp/lb
If the others are tuned to the same bmep, they should be at about 1.65/lb
Exhaust outlet at flange size: Kawi gets strike 1, 66E is good, 62T can be opened up so it gets a 50/50 but still depends on cc's
Reedcages: 66E is king, the others start lacking at around 900cc

What is the smallest bore setup for the yami's?
Price on Kawi billet 4mm crank?
Price on 12 and 16mm Yami cranks(are they billet?)?
Am a bit worried about piston speed on the 16mm, what do they rev to?
Prices on cases?

Anyone got a bedplate to fit 62T into kawi hull?

 

[Crab]

Compactness: that is strike 1 against 66E
Power/weight: 66E should be about 150hp in a drypipe freestyle setup, don't have all the weight specs but it will give you about 1.5hp/lb
If the others are tuned to the same bmep, they should be at about 1.65/lb
Exhaust outlet at flange size: Kawi gets strike 1, 66E is good, 62T can be opened up so it gets a 50/50 but still depends on cc's
Reedcages: 66E is king, the others start lacking at around 900cc

What is the smallest bore setup for the yami's?
Price on Kawi billet 4mm crank?
Price on 12 and 16mm Yami cranks(are they billet?)?
Am a bit worried about piston speed on the 16mm, what do they rev to?
Prices on cases?

Anyone got a bedplate to fit 62T into kawi hull?

You mean these?

 

[wsuwrhr]

I believe we are making 160HP with a 10MM. Probably 170HP with a 12MM.

We have yet to dyno the 16MM. Estimated to be 200HP.

I opened the intake tract on the billet cases.

I believe our smallest bore is 85MM.

I have prices listed in the various threads for the cranks, I don't know off hand. I would have to look. All the Yamaha and Kawi strokers are billets.

The rods are plenty long on the 16MM crank. Side load and piston speed will be fine.

Cases are retail $2800

The steel ones may work.

I have been asked about the bedplate deal a few times.

I would have to have a hull to do it, but it could be done.

With the longer stroke of the 16MM, I don't think the engine will need to be revved as high to make the power.

Brian

Compactness: that is strike 1 against 66E
Power/weight: 66E should be about 150hp in a drypipe freestyle setup, don't have all the weight specs but it will give you about 1.5hp/lb
If the others are tuned to the same bmep, they should be at about 1.65/lb
Exhaust outlet at flange size: Kawi gets strike 1, 66E is good, 62T can be opened up so it gets a 50/50 but still depends on cc's
Reedcages: 66E is king, the others start lacking at around 900cc

What is the smallest bore setup for the yami's?
Price on Kawi billet 4mm crank?
Price on 12 and 16mm Yami cranks(are they billet?)?
Am a bit worried about piston speed on the 16mm, what do they rev to?
Prices on cases?

Anyone got a bedplate to fit 62T into kawi hull?

 

[CARBONX2]

I believe we are making 160HP with a 10MM. We have yet to dyno the 16MM.

I opened the intake tract on the billet cases.

I believe our smallest bore is 85MM.

I have prices listed in the various threads for the cranks, I don't know off hand. I would have to look. All the Yamaha and Kawi strokers are billets.

The rods are plenty long on the 16MM crank. Side load and piston speed will be fine.

Cases are retail $2800

The steel ones may work.

I have been asked about the bedplate deal a few times.

I would have to have a hull to do it, but it could be done.

With the longer stroke of the 16MM, I don't think the engine will need to be revved as high to make the power.

Brian

So the 10mm is on par with 66E powerwise but is lighter I take it.
Can 66E reedcages be fitted into the billet cases?
Is the same sleeve used for 85mm up to 90mm bore?
Guessing the PFP would be pushing the revs on a 16mm, would be easy enough to build my own drypipe for it and would be a lot cheaper

 

[wsuwrhr]

So the 10mm is on par with 66E powerwise but is lighter I take it.
Can 66E reedcages be fitted into the billet cases?
Is the same sleeve used for 85mm up to 90mm bore?
Guessing the PFP would be pushing the revs on a 16mm, would be easy enough to build my own drypipe for it and would be a lot cheaper

We are using and recommending a Factory MOD pipe, instead of a more common "B" pipe for the 16MM.

With a billet case sir, I am able to fit whatever you would like to it.

The big bore sleeves are of a different design than the small bore.

Brian

 

[wsuwrhr]

Price on Kawi billet 4mm crank?
Price on 12 and 16mm Yami cranks(are they billet?)?

8-10-12MM Yamaha crank is $1450. retail

16MM $1687. retail

I believe the Kawi is the same price as the smaller stroke Yamahas, $1450 retail.

All of the stroker cranks we use are billet.

 

[CARBONX2]

I am tending towards 12mm stroker, like the piston speed and gives me option of upgrade on stroke using the same cylinder with a spacer
What are the bore options on the big-bore sleeves?
Dan put bigger reeds in the oem 66E for a reason and my calcs show they are needed
Looking at fitting efi with 50mm throttle bodies(or converted 48mm carbs), ecu can also control ignition using the msd coils, less than $1000 fitted

 

[wsuwrhr]

I am tending towards 12mm stroker, like the piston speed and gives me option of upgrade on stroke using the same cylinder with a spacer
What are the bore options on the big-bore sleeves?
Dan put bigger reeds in the oem 66E for a reason and my calcs show they are needed
Looking at fitting efi with 50mm throttle bodies(or converted 48mm carbs), ecu can also control ignition using the msd coils, less than $1000 fitted

We are currently using 89-90-91 MM pistons in the big bore motors.

I will look into 66e reeds

 

[CARBONX2]

Pretty sure i am going 89 x 80 = 995cc, with billet cases housing 66E reedcages
Can build a complete drypipe to the motor specs for $500

 

[wsuwrhr]

I corrected all the weights.

 

[wsuwrhr]

Bump for easy finding.

 

[Foximus]

damn. Why are kawi cranks so much lighter? Thinner webs? Or machined to be T-boned like the 550 cranks?

 

[wsuwrhr]

damn. Why are kawi cranks so much lighter? Thinner webs? Or machined to be T-boned like the 550 cranks?

Unless I am missing something, I think you are looking at the kawi case weight. the crank weights are nearly identical.

If you have ever seen a Kawi case, you will know why they weigh half of a Yami case and precisely why not much stroke can be added to the Kawi.

Brian

 

[Foximus]

Unless I am missing something, I think you are looking at the kawi case weight. the crank weights are nearly identical.

If you have ever seen a Kawi case, you will know why they weigh half of a Yami case and precisely why not much stroke can be added to the Kawi.

Brian

Exactly, they weight the same. But the sxr has a 6mm longer stroke. Larger diameter and longer rods. All being said it should weigh another 2 lbs over the 701 id imagine.

 

[wsuwrhr]

Exactly, they weight the same. But the sxr has a 6mm longer stroke. Larger diameter and longer rods. All being said it should weigh another 2 lbs over the 701 id imagine.

2 lbs is HUGE.

Essentially the same size bud. 6MM longer stroke is nothing to a crank diameter, you are talking a very small amount of material.

You will see that a 12MM stroker BILLET crank is only a half pound heavier than a cast Kawi crank.(a crank that is now 6 MM bigger than the Kawi and billet)

Brian

 

[Foximus]

Ah yes... I see the error in my ways. I was looking at the weight of the 8mm stroker compared to stock 701 and assumed the potential increase would be proportional. I forgot that I was looking at cast vs billet material weights.

Though I must say 3mm of iron added in diameter over the circumference of a ~100 mm crank web at ~25mm in diameter, times 4 crank webs, would actually be sizeable chunk of weight....

 

[wsuwrhr]

Yea, 2 Lbs.

Seriously you are worried about nothing.

Do you have a solid comprehension of CG, balance and HP to weight ratio?

5-10 10lbs extra in the middle center of the boat, in a lightweight hull, packing 150 MORE HP than a lighter factory setup will feel as if it isn't ins't even there.

I will have to find and weigh a stock motor setup. A fully assembled billet engine is 65 Lbs. this is everything ready to go out the door, head, domes, crank, cylinder, cases, pistons.

Brian

Ah yes... I see the error in my ways. I was looking at the weight of the 8mm stroker compared to stock 701 and assumed the potential increase would be proportional. I forgot that I was looking at cast vs billet material weights.

Though I must say 3mm of iron added in diameter over the circumference of a ~100 mm crank web at ~25mm in diameter, times 4 crank webs, would actually be sizeable chunk of weight....