Other DASA 89mm vs. 94mm......Opinions??

[sjetrider]

IMO if your looking for longevity and are on a budget I would recomend the DASA 865 but put ALL the GOOD bolt ons on it. PFP,T/L,49mm full spec carbs. The bolt ons mean as much as the shortblock. If you do a 5mil stroker ($1100 crank) and high dollar 94mm pistons with minimal bores before resleaving and bolt crap, pipe, elecs, and carbs on it you will have the same money invested with the same power and a higher risk motor with higher rebuild costs.
If $ is no options buy all the good bolt ons and an x-scream 1200 motor, beefier crank and same piston costs. The 1200cc 66E cranks last for ever even with water injestion.

All the 89mm DASA motors with the 89mm bores are pretty proven regardless of the crank length. DASA ports them and gives them very consevative squish for longevity IMO. But, they all need the HIGH $ bolt ons to obtain maximum power. The DASA 1000 is very proven and VERY POWERFULL with the right bolt ons.
Dont forget you have to be able to put the power to water as well. The 865 works well with a 144mag, the 1000cc really likes the 148mm mags and the 1200cc you leave alot of power on the table without a 155mag

I looked at the Powerhouse Performance......Was leaning toward Dasa just because it has been around longer and is more proven. Would love to ride them both or at the very least get more feedback.
Thought about a longer stroke but $$$$ comes into play.

At 4mm I would think stock length rods would be okay for longevity and wear right? I am also trying to keep a reliable motor that I'm not tearing down all the time for top ends.

 

[sjetrider]

By the way, all these motors require 200+ compression to acheive the performance they are designed to achieve.

 

[Aircraftsalz]

I think the Dasa 4 mil is a great motor.... Cranks are cheaper than a full stroker motor... Hits a lot hard than the SS 850 ... I set mine up with TL, PFP, and loved the package... Sold it to my buddy and installed with B pipe and Stock electrics and was very happy... It lost a little top end power with the B pipe but still great hit for a surf setup....

IMO matte's right... Cant beat a 10 mil motor... We put 250-400 gallons on the cranks and everything looks new... Its all about how you take care of it.If I was building a new motor it would be a 10 mil setup

 

[Nuklear6]

There are alot of variables when it comes to this conversation/ question. Do you wanna run wot? Do you wanna run race gas? Do you wanna have to charge your battery after every ride? Do you want a stock size tank (lose ability to run power factor)?

The individual must answer those questions above before they decide what is the best choice.

Like i have told some privately and agree with power house. The +4mm strokers are great becuase they keep the rod angle conservative enough to run stock length rods with reliability. Keeping the stock length rods will give better throttle response and more bottom end. Mostly because the cylinder doesnt need to be raised up much therefore keeping crankcase volume similar to stock, which keeps crankcase pressure high. Plus the crankshafts dont cost near what a +10mm would.

I also agree with sjet that a good idea is to put all the good bolt ons coupled with a ss850 pv motor. Thats if you dont mind TL and loss of the stock size tank. The good part of this is the engine its pretty cheap to purchase and maintain. Not to mention less likely to have failure.

The x factor in all this is compression. If you dont mind running race gas you can def make a smaller engine fell like a much bigger one. That being said you will slightly reduce the the longevity of any engine when increasing from 185psi to 225+ psi.

Best to talk with who ever your thinking of having build you an engine to put together the best answer for you ....

 

[Cannibal]

Here's an honest question for you engine gurus:

So lets say I take a big pin Kawi bottom end with a (stock...obviously welded) 74mm crank and put a Kawi Dasa cylinder that (assuming it can be done) has the same port setup as a +6mm Yamaha cylinder and even has a Yamaha exhaust pattern (Dasa has done that haven't they?). With 89mm pistons, you have a 920cc engine with an inexpensive crank, and 1049cc with 95mm pistons.

So assuming all of the above, what would be the big difference here? Why would the Yamaha equivalent (+6 long rod crank [Kawi 133mm rods right?] with the same pistons) be a superior engine?

 

[623pwr]

Do you think adding additional cooling line to both cylinders would help reliability on the bigger bores? I am sure with the 89mm bore you are fine, but on the 94mm bore the sleeve size might cause an overheating issue with out additional cooling?

 

[masterblaster]

some interesting things brought up here. It sounds like you are setting up a dedicated surf boat. nuklear is right,few things need to be answered. mainly can you run a smaller tank ? using a pfp would change some of your motor options. IF you ride very much like alot of surf riders,you are going through alot of fuel,None of us wana mess with going to get race fuel,hauling it to all the rides we travel too or paying more for it.
Its alot more easy and cheaper to make good power with a stock crank or cheaper 4 mil. let the bigger pistons around 980cc and good case porting make the power. this way stock elecs,bpipe and oem 46s are more than enough.this kinda setup at around 180 compression is very reliable and low maintenance. Add up the cost of tl,pfp,fs49s 225 comp and more freq crank rebuilds and top ends from high compression and what race fuel costs for the life of that motor in a surf ski and you can buy a couple spare long blocks like im describing..there is going to be a couple more setups like this on the market this season...

 

[tipafew]

Yeah, I am probably 75% surf and 25% flat water. I wouldn't mind being able to flat water flip my freak, but it's not vital. I do ride some places that make a full size tank mandatory. I also want a charging system and ideally pump gas. So yes Masterblaster.....you are pretty much correct.

I was fairly happy with my old "baby scream" motor. However, I have this little itch to be able to flat water flip. My motor threw a rod through the cases so it's time to upgrade! I have had a lot of back and knee problems so I don't ride as much or as hard as I used to so I was trying to keep the cost down in a range easier to justify.
I was originally thinking of buying something used, but the used prices are so high and you never know what you are getting so I was leaning toward starting fresh with something new.

Chad

some interesting things brought up here. It sounds like you are setting up a dedicated surf boat. nuklear is right,few things need to be answered. mainly can you run a smaller tank ? using a pfp would change some of your motor options. IF you ride very much like alot of surf riders,you are going through alot of fuel,None of us wana mess with going to get race fuel,hauling it to all the rides we travel too or paying more for it.
Its alot more easy and cheaper to make good power with a stock crank or cheaper 4 mil. let the bigger pistons around 980cc and good case porting make the power. this way stock elecs,bpipe and oem 46s are more than enough.this kinda setup at around 180 compression is very reliable and low maintenance. Add up the cost of tl,pfp,fs49s 225 comp and what race fuel costs for the season in a surf ski and you can buy a couple spare long blocks like im describing..there is going to be a couple more setups like this on the market this season...

 

[sjetrider]

Do you think adding additional cooling line to both cylinders would help reliability on the bigger bores? I am sure with the 89mm bore you are fine, but on the 94mm bore the sleeve size might cause an overheating issue with out additional cooling?

take a look at one of the Xscream boys motors built by GURU Chuckey, they look like octopusses with water / cooling lines coming off the cylinder , head and everywhere keeping the billet cool.
But too cool is an issue as well. You need a valve to turn on or off depending on water temp or you risk too cool or too hot issues.
Honestly the Dasa motors with 2 half inch lines out the head and or 4 3/8" lines seems to be adiquit for most water temps.
But 2 3/8" lines out the head and one into the cylinder between the cylinders near the exhaust manifold works well too.

 

[sjetrider]

For a 75% surf freak with charging electrics and B-Pipe i would definately not spend 1000cc 10mil crank money. But thats just me.
The 865cc Dasa would be my choice for reliable surf (pump Gas ) riding . You will struggle to flip a Freak on FW with this setup though for sure. This is what I would have if I lived close enough to surf for 75% surf rding. Freak with pump gas , ported B-pipe , full specs , but I would run T/L, screw the lock water in the box OEM electrics. With the batteries out now you can get 2 full tanks out of a low compression motor EASILY with T/L and the T/L will enhance bottom end and overcome water injestion more as well.

 

[mydixiewrecked]

Here's an honest question for you engine gurus:

So lets say I take a big pin Kawi bottom end with a (stock...obviously welded) 74mm crank and put a Kawi Dasa cylinder that (assuming it can be done) has the same port setup as a +6mm Yamaha cylinder and even has a Yamaha exhaust pattern (Dasa has done that haven't they?). With 89mm pistons, you have a 920cc engine with an inexpensive crank, and 1049cc with 95mm pistons.

So assuming all of the above, what would be the big difference here? Why would the Yamaha equivalent (+6 long rod crank [Kawi 133mm rods right?] with the same pistons) be a superior engine?

Ive always been curious about this

 

[masterblaster]

Yeah, I am probably 75% surf and 25% flat water. I wouldn't mind being able to flat water flip my freak, but it's not vital. I do ride some places that make a full size tank mandatory. I also want a charging system and ideally pump gas. So yes Masterblaster.....you are pretty much correct.

I was fairly happy with my old "baby scream" motor. However, I have this little itch to be able to flat water flip. My motor threw a rod through the cases so it's time to upgrade! I have had a lot of back and knee problems so I don't ride as much or as hard as I used to so I was trying to keep the cost down in a range easier to justify.
I was originally thinking of buying something used, but the used prices are so high and you never know what you are getting so I was leaning toward starting fresh with something new.

Chad

You will be able to flat water flip a freak with the type of motor im talking about no prob. It would be alot more easy with a pfp but still not needed,depends on your skill level. Either way,no one should choose compromising parts for a ski used 25% in flats..None of us wana run outa fuel with a smaller tank in surf rides. The dasa 850 isnt that impressive with the parts im talking about. your everyday average rider starts to be flat water flipable at the 950cc and up range with all your basic parts . I wouldnt bother with tl at 950cc and up in a surf boat. A new e box gasket and some 1211 and stock elecs and your good.....and cheap. I have a sj with tl in a dry box I made with a 800cc 6 mil. Its more necessary for the small cc motors, But if you swamp your motor in the surf..when your on the beach and have to get it going again,you have to really make sure the plug wires stay grounded well when your flipping it over or it will shock the piss out of you or ignite ANY little fuel around the carbs...and your battery is always that much closer to dead and giving up on you being a non charging system..depends how far your tow back is to the ramp if this matters or not.

 

[fatboyktm]

Ok so could you run the 94mm on a stoke stroke?

 

[Pablo]

You engine guys correct me if I'm wrong...

I always thought the ideal displacement for an internal combustion engine is for the bore and stroke to be close to equal. I understand that with the shorter stock stroke rods you get the ability to rev faster, but I thought that ability gets lessened with the greater mass of the larger pistons. I'm kind of pulling this out of my ass somewhat but I swear I remember somewhere that its ideal to have bore and stroke increase in tandem.

 

[623pwr]

I know the 94mm isn't available for sxr set up for the kawi guys. You may just want to talk to Kyle at Dasa or email him, he has been a great guy to talk to and will get back to your emails promptly. I am going to give him my business for sure.

 

[Matt_E]

You engine guys correct me if I'm wrong...

I always thought the ideal displacement for an internal combustion engine is for the bore and stroke to be close to equal. I understand that with the shorter stock stroke rods you get the ability to rev faster, but I thought that ability gets lessened with the greater mass of the larger pistons. I'm kind of pulling this out of my ass somewhat but I swear I remember somewhere that its ideal to have bore and stroke increase in tandem.

I've heard that as well, but only ever in connection with 4-stroke motors. Not sure if it would be different for 2-strokes, considering the power to weight is different.

 

[waxhead]

Any performance two stroke engine runs a square bore to stroke ratio. Its only changed in jetskis as were chasing large displacement.
A stroker jetski engine will make more power than a big bore every time as long as you are comparing them cc for cc

 

[Philip Clemmons]

Matt, I switched from a 8 mil 89 to a 10 mil 94 and it's no comparison. The 94 is much torquier and runs better everywhere. Very pleased with my choice. Best motor I've owned/ridden to date. That being said its a flatwater setup with a fair amount of compression and a PFP. Youve got my number if you wanna talk.

 

[Matt_E]

Matt, I switched from a 8 mil 89 to a 10 mil 94 and it's no comparison. The 94 is much torquier and runs better everywhere. Very pleased with my choice. Best motor I've owned/ridden to date. That being said its a flatwater setup with a fair amount of compression and a PFP. Youve got my number if you wanna talk.

I'm staying with my 10mm for a while. Switching it up to race gas and a bigger pump, though.
The videos you've put out there of your setup speak for themselves.

 

[623pwr]

It seems like the lower bore to stroke will put out more power, but it takes higher compression and total loss type set up for optimal power, which is insane. I am not factoring in the pump and prop set up. I am sure additional cooling inlets are necessary to keep things cool on the bigger bores due to sleeve size. When you have a higher bore to stroke is similar to jet maniac bb set up. It hits hard but for stock type set ups.

I read this tread by and read post #10. Here is a guy who has been there and done that. It kind of helped me understand bore to stroke a bit better, I think? I haven't owned either set ups so I am speaking way over my head here.

http://www.x-h2o.com/threads/119890...es-48-cc-what-octane-fuel&highlight=dasa+1100

In short, I am just a confused individual that thinks to much, so if I am wrong with my post please correct me.