HP from a crankshop triple?

[Jonnieboy]

Hello,
I got an crankshop triple 800 with rotax 670 cylinders to get out some more cc's from it, the new cylinders bored to 79 mm gives me 950cc.
Did hit it on the dyno today, best result was 184 hp @ 8950 rpm so something must be "wrong", poor effect for this kind of engine... where hoping for around 200 hp and felt kind of "sure" it would be over 190, but I was wrong.
The engine was running kind of Rich so I did go down at mainjet a bit with no winnings...
My cylinders are done some portwork with, did ask crankshop about porting also before starting with it and they told me to go for 202/132 in timings so I did. The ignition is set to 14 deg @ 8000 rpm. Im using Mikuni 44 mm carbs bored to 45.4 mm. Pipes should be set for 8800 rpm.
Any tips how to get more hp out of my little baby, it is a lovely engine for sure...

John...

 

[obr]

not sure this is what you want to hear, but I saw dynopapers on a CS 1025 triple that was making 186 hp...

 

[Jonnieboy]

LOL that cant be ture?! THen it is more ineffectiv than an old good tuned 670... Where did you saw that? I heard about som dragracing guys got out over 230 of an 1025...

 

[wheresthesnow]

I have a Crank Shop 1025, they say its 200 hp at 8800, it feels like alot less than 200. But im not any master tuner at all.

 

[Jonnieboy]

The 1025 is a reed engine, aint it?

John

 

[obr]

the 1025 is a reed engine, yes. The one i saw, was a trail motor from Crankshop. If you raceport them, I guess you can get more. But this was true hp@sea level, not any mixed-up numbers from elevation that has been' corrected' to sea level... the dyno's varied from 186 to 188... I've had one of these motors, and they run pretty good but not true 200hp good...

 

[DRD]

The 1025 is a reed engine, aint it?

John

Doo 800 bottom end with CS cylinders.
Is your motor set up for pump gas?

 

[PTE800]

Hello,
I got an crankshop triple 800 with rotax 670 cylinders to get out some more cc's from it, the new cylinders bored to 79 mm gives me 950cc.
Did hit it on the dyno today, best result was 184 hp @ 8950 rpm so something must be "wrong", poor effect for this kind of engine... where hoping for around 200 hp and felt kind of "sure" it would be over 190, but I was wrong.
The engine was running kind of Rich so I did go down at mainjet a bit with no winnings...
My cylinders are done some portwork with, did ask crankshop about porting also before starting with it and they told me to go for 202/132 in timings so I did. The ignition is set to 14 deg @ 8000 rpm. Im using Mikuni 44 mm carbs bored to 45.4 mm. Pipes should be set for 8800 rpm.
Any tips how to get more hp out of my little baby, it is a lovely engine for sure...

John...

Assuming that the pipes are what they are supposed to be I would have to say that the port timing is off some. I had similar port timing numbers on my 800 twin when I dyno'ed it and couldn't get good HP out of it either. It's alot of work to correct it but you need to be somewhere around 196/130-132 to make it better. Basically you have too much exhaust timing and that is costing you torque and hp. Of course if the porting is bad that too can be some of the problem. Hope this helps.........

 

[Jonnieboy]

My engine should probably beat an 1025... 202/132 should be kind of good I guess, 35 in blowdown, sounds okey for this kind of engine...

John

 

[gus bohne]

You are using the dual rotary valved base, What rotary valve are you using ?
what timing on the valve are you set to?

When the big bore was done, who reshaped the heads?
what is the dome to squish ratio?
what compression ratio?
waht squish clearance?
timing is way of at 14 degrees !!!
stinger size for the big bore?
Trans port roof angle ? did you at least maintain the current 4 degree's ?

Those old rotary triples made huge torque , e amil me direct at gus.bohne@comcast.net .
I'll get you straightend out..
2 hours from the cranks shop, been around those engines since the first one he welded up in 1986..

 

[skidoome]

Something's not right with that if its a rotary twin. I saw a rotary twin run at redlodge snow drags this winter and it made all the turbo's look like they were fan cooled sleds.

He even let them have two -three lenth head start in a 600 foot race and beat them.
I would say that one had an honest 200 horse
hope you figure it out
jon

 

[Woody1050]

Hello,
I got an crankshop triple 800 with rotax 670 cylinders to get out some more cc's from it, the new cylinders bored to 79 mm gives me 950cc.
Did hit it on the dyno today, best result was 184 hp @ 8950 rpm so something must be "wrong", poor effect for this kind of engine... where hoping for around 200 hp and felt kind of "sure" it would be over 190, but I was wrong.
The engine was running kind of Rich so I did go down at mainjet a bit with no winnings...
My cylinders are done some portwork with, did ask crankshop about porting also before starting with it and they told me to go for 202/132 in timings so I did. The ignition is set to 14 deg @ 8000 rpm. Im using Mikuni 44 mm carbs bored to 45.4 mm. Pipes should be set for 8800 rpm.
Any tips how to get more hp out of my little baby, it is a lovely engine for sure...


Hey, i had two of these 950cc in my dyno this winter and they did 185hp 9000-9400rpm, 48mm rundslide and pumpgas heads.
Be sure you dont have to hard/long exvalve spring, that was a problem with one of these two, when the right spring moved in it was ok.
This engines is verry nice in the dyno, easy to handle.

 

[Jonnieboy]

You are using the dual rotary valved base, What rotary valve are you using ?
what timing on the valve are you set to?

When the big bore was done, who reshaped the heads?
what is the dome to squish ratio?
what compression ratio?
waht squish clearance?
timing is way of at 14 degrees !!!
stinger size for the big bore?
Trans port roof angle ? did you at least maintain the current 4 degree's ?

Those old rotary triples made huge torque , e amil me direct at gus.bohne@comcast.net .
I'll get you straightend out..
2 hours from the cranks shop, been around those engines since the first one he welded up in 1986..

1.Crankshop did the heads.
3. 12.3 Kg
4. 1.2mm
5. what should I set the timing to?
6. Not sure about that one, how fat should I have?
7. About 10 degree's.

 

[gus bohne]

16-17 degrees at 8600

what rotary disc is in it ?

what needle jets

needles


and mains?

28mm stinger diameter for drags and 4000+feet ele..safe ===== 27mm is better for higher octane fuels.
this should get you going much better

 

[Jonnieboy]

16-17 degrees at 8600

what rotary disc is in it ?

what needle jets

needles


and mains?

28mm stinger diameter for drags and 4000+feet ele..safe ===== 27mm is better for higher octane fuels.
this should get you going much better

dosnt remeber that, but can look up that to until later... Mainjets is 480, 500... Did measure up stingers, they are 29mm. Not sure about rotary valve.. Asked crankshop about ignitino also, they told me to go with 12-12 degres at 8800 rpm...

 

[BIG JOHN]

johnnyboy...get gusbohnes phone number and call him..everyone else on here wont know that engine like him...BJ

 

[bigbird]

dosnt remeber that, but can look up that to until later... Mainjets is 480, 500... Did measure up stingers, they are 29mm. Not sure about rotary valve.. Asked crankshop about ignitino also, they told me to go with 12-12 degres at 8800 rpm...

I have an 889 built off of a 809 bottom. with jaws high elevation pipes it made 195 and 197 on 2 very stingy dynos here in Edmonton. so i would think yours is off a bit. pump gas setup with stock carbs.

 

[Jonnieboy]

16-17 degrees at 8600

what rotary disc is in it ?

what needle jets

needles


and mains?

28mm stinger diameter for drags and 4000+feet ele..safe ===== 27mm is better for higher octane fuels.
this should get you going much better

Did found out the ignition got to 9 degree´s in any what so set it to 15 @ 8800 rpm, to scared to go higher.. It is same modell as they uses in 670 i guess, looks like it. Did found out the one disc where set from crankshop to 110 and the to others to 145, so I did take care of that to, hopefully im on the dyno soon again.


John...

 

[Jonnieboy]

Oh lol,
that cant be easy to understand, so I write it again and does it right this time... The disc closest to the clutch controlls 2 cylinders, and the timings on this one where 145/80. At the one most to the right the timings was; 113/117, so hopefully I found some power there
Anyone knows what porttimings to go for if im going to build a real lakeracer?

John...

 

[Givemeaboost]

Something's not right with that if its a rotary twin. I saw a rotary twin run at redlodge snow drags this winter and it made all the turbo's look like they were fan cooled sleds.

He even let them have two -three lenth head start in a 600 foot race and beat them.
I would say that one had an honest 200 horse
hope you figure it out
jon

That Skidoo that you speak of was a 1170 tripple with 270 hp and it did not make mine look like a fan cooled sled. I lost to him on a holeshot by one length and I set the fastest time of the meet on Sat. I got put in the left lane every race which was consistantly .5 seconds slower than the right lane on Sun. If I hadn't have redlighted agaist Schmause I woud have been in the finals against him so I wouldn't say it made ALL THE TURBOS look like fan cooled sleds. Ken.