180 crank

R

R&M RACING

New member
i need to get some clarity if you set up a crank at 180 degres how will the coils fire at the right time i picked up a 92 vmax 4 runs like crap looks like crap but it was cheap and i couldnt pass it up turns out crank is out of phase and im thinking while im rebuilding might as well set it up at 180 think this one is going in a light wieght frame any help would be greatly apreciated:flagge_us
 

You need a 180 firing CDI. They are quite hard to find. When 180'ed though, you definitely give new meaning to the term big twin!

-Rustman
 
If you really want to wake that thing up skip the chipped box and go with a lap-top programable digital ignition. I have both if you need one or the other
 
what's the benefit of the 180 over 90degree firing? any HP gain? I picked up a project sled 800 with the 180 degree and it's like trying to hand start a freight train! It does have 165psi compression so I'm sure that doesn't help lol
 
programable ignition?

Skinner said:
If you really want to wake that thing up skip the chipped box and go with a lap-top programable digital ignition. I have both if you need one or the other
Click to expand...

Do you sell these or just have a spare?
Thanks, Randy
 
There has always and will be debate over a 180 crank..It was first done with the 750 engines back in the day..If you spin a 90' stock 750 over 9000 rpm you will snap rods beacause of bad harmonics.So as I heard the story went was Olav Aaen,Tim Bender,Dave DeLaughter and Hauck were in a shop somewhere with Yamaha reps trying to figure out what to do..From what I was told Dave DeLaughter was the one who came up with 180' firing..Then Yamaha came out with something called a "Pony Pac" to make the engine run at 180.
Now they said no hp or touqure gain but thru my life of racing these things I always felt that my 180' firing sleds came out of the hole alot better than any 90' firing sled I've ever had..
 
i have 2 agree with u ron a 180 firing will get the hole shot all day long pyhsics will tell u that and no way aroun d that one and on the dyno i,m sure u are going 2 see more torque on 180 than u do with 90. u are fireing 2 pistons on one stroke so one needs 2 understand that one and like its said one big monster of a twin. AL
 
I have heard a lot of stories, claims and supposed truths that a 180 fired engine makes more hp than a 90 fired one but have NEVER!!!! had anyone PROVE to me this is fact or EXACTLY WHY it is fact. Most of what I hear is "it only makes sense" or "it just stands to reason" that firing two cylinders at once makes more power.

I say BULLSHIT!!

I have owned, ridden and been around race versions of both 90 and 180 sleds and I can tell you that the 180 sleds I have seen were faster than the 90 sleds but the 180 sleds ALWAYS had more mods than the 90 sleds so they SHOULD be faster. I have NEVER seen a mod per mod comparison done on identical engines (with the exception of 180 vs 90) that would prove this supposed hp gain or why it exsists (if so).

In all my years of working on mechanical things (many, many, many different things) everything my brain has delt with says it shouldn't matter. Either way you are still firing 4 cylinders for every 360* of rotation. Standard logic tells me that a 180 engine should have worse harmonics, be harder on rotating internals, be harder to pull over when starting and not sound as good as a 90. The "harder to pull over" and "not sound as good" standard logics can be easily tested. Grab thier perspective ropes and give them a yank, then listen. The only other PROVEN truth I can attest to is that anyone that owns a 180 Vmax-4 for any length of time will find the need to have a spare recoil with them.

So in short, I'm not saying "I don't believe" I'm saying "I won't believe" untill it is proven to be fact and why it is fact that 180 engines make more HP.

Lastly, unless I was racing and it was proven a 180 engine made more hp I wouldn't even think about wasting money on building one. One of the best things about a Vmax-4 is the sound. At 180 you are just another big bore twin. Common!!!

opsled

PS. This has bugged me for years and would like proof one way or the other. So as my signature says-------
 
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well opsled my friend i don,t believe any one on this posting said more hp but what we are saying is torque which are totally 2 differnt issues and i would bet u that a 180 will pull a 90 out of the hole in other words hole shot and rightfully it should. as a matter of fact i will even say that both of mine on ice 800 improver 180 against my 866 big bore 90 from a standing start the 800 pulls on it at the start then the hp difference of the 2 will be the quicker sled in the end and it should be. both have hauck howlers . the real facts are dynoed sleds. as fare as sound i don,t think ur ears can even get close enough 2 know the difference defore u blow ur ear drums out lol and i think my 180 is actually louder than the 90 .
 
GUYS, COOL DEBATE HERE ON THE 180 FIRING. GLAD I RUN A STOCK VMAX 4 lol. ACTUALLY THOUGH I DO HAVE A GREAT AMOUT OF RESPECT FOR ALL YOUR VALID POINTS HERE. NOTHING LIKE MAKEING A VMAX 4 THINK ITS A BIG TWIN. ESPECIALLY IN 500 f.t. on grass. 3:16 (yammie tony)
 
180 verses 90

I have been searching for a cdi system which fires at 90 for almost a year for my twin cylinder flat track bikes.
There are some guys in Australia doing some wild stuff to the banshee engines, and you can see the mechanical information, and other technical information regarding the difference between the two degrees, and how the 180 is harder on the engine components, due to the bang effect of both rods hiiting top and bottom at the same time.
Searching TSS500, will bring you there, then you can search around and do some reading.
The reason I have entered the vmax region is to obtain info from you guys on the vmax 750 and 800 cdi boxes.
Both of my engines came stock with 180 cranks and these motors break the rear tire loose so quick, it's hard to keep them on a blue groove oval flat track.
We run about 85 -95 on a 1/2 mile straight away, then back them into the corner and roll the throttle back on from about 50-55, until almost the whole way through and then peg it.
The harley davidson engines which are built at 90 degree, are hard to beat and pretty much dominate, because the engine rolls on a lot smoother.
I have purchased two complete vmax4 units from a salvage yard and they should be here in a few days.
I will reverse the flywheel and mount the stator and pickups to the engine case outside the crank seal, and run two single coils.
I haven't been able to find any dyno information so far, that would start at a lower rpm range than what I have seen on this site at 8,500.
If anyone has any info they can share, I would sure be greatfull.
 
dt38k said:
I have been searching for a cdi system which fires at 90 for almost a year for my twin cylinder flat track bikes.
There are some guys in Australia doing some wild stuff to the banshee engines, and you can see the mechanical information, and other technical information regarding the difference between the two degrees, and how the 180 is harder on the engine components, due to the bang effect of both rods hiiting top and bottom at the same time.
Searching TSS500, will bring you there, then you can search around and do some reading.
The reason I have entered the vmax region is to obtain info from you guys on the vmax 750 and 800 cdi boxes.
Both of my engines came stock with 180 cranks and these motors break the rear tire loose so quick, it's hard to keep them on a blue groove oval flat track.
We run about 85 -95 on a 1/2 mile straight away, then back them into the corner and roll the throttle back on from about 50-55, until almost the whole way through and then peg it.
The harley davidson engines which are built at 90 degree, are hard to beat and pretty much dominate, because the engine rolls on a lot smoother.
I have purchased two complete vmax4 units from a salvage yard and they should be here in a few days.
I will reverse the flywheel and mount the stator and pickups to the engine case outside the crank seal, and run two single coils.
I haven't been able to find any dyno information so far, that would start at a lower rpm range than what I have seen on this site at 8,500.
If anyone has any info they can share, I would sure be greatfull.
Click to expand...


Checked it out and that is some cool stuff being done with those twins. Don't think I could be of help on your questions but even though the stock Vmax-4 ignition fires at 90* it does so like a pair of 180* twins would if married at the crank 90* from each other. The rod pins on each Vmax-4 crank half are set at 180*. The halfs are coupled together at 90* so as one of the 4 pistons is reaching TDC every 90* of rotation. As I understand the stock ignition has one pickup and coil for each crank half. If I'm right in order for this system to fire a 90* twin you would need to use half of what it produces from both sides to make it work.

Good Luck, opsled

PS, Allarson, you proved my point.

PSS, Tony, I see ya been gettin some BS over your use of caps on other forums. I say keep it up and next time you get shit over it just blame it on the fact that you were born with three balls and it is your only outlet for aggression short of beating the snot out of the "grammar nazis".
 
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Just stumbled on this thread even though its been here for about 2-weeks now, LOL! I can't coment on a 90 degree vs. 180 degree in a naturally aspirated world, but in the turbo world the 90 degree makes more horsepower/ torque than a 180 version...it has been done. Jim at Dynotech Research has info on this comparison. The 180 version lacked significant horsepower, but they really couldn't come up with a real reason. Personally, I have always felt the 90 degree firing order creates a consistant flow effect on the exhaust which creates better consistant heat and pressures in the exhaust housing while spinning the hotside turbine wheel. I feel the 180 created stronger exhaust pulses with small pauses creating a disruption allowing differences in the exhaust housing. Again, this is in the Vmax-4 Turbo world. I don't anticipate building a N/A Vmax-4 anytime soon, but I think I'd stick with a 90 degree firing order turning 12,000 rpms, the bottom-end when properly built and modified is not an issue on this sled as we've proven with 332.0 ft lbs of torque.

I'm with Opsled on this one...I'm not buying it! It was a good fix to an old problem that stuck around with the introduction of the 800. I'd rather work with the initial timing curve to compensate. Just my .02 as well....good thread!
 
quadzillaracer said:
Just stumbled on this thread even though its been here for about 2-weeks now, LOL! I can't coment on a 90 degree vs. 180 degree in a naturally aspirated world, but in the turbo world the 90 degree makes more horsepower/ torque than a 180 version...it has been done. Jim at Dynotech Research has info on this comparison. The 180 version lacked significant horsepower, but they really couldn't come up with a real reason. Personally, I have always felt the 90 degree firing order creates a consistant flow effect on the exhaust which creates better consistant heat and pressures in the exhaust housing while spinning the hotside turbine wheel. I feel the 180 created stronger exhaust pulses with small pauses creating a disruption allowing differences in the exhaust housing. Again, this is in the Vmax-4 Turbo world. I don't anticipate building a N/A Vmax-4 anytime soon, but I think I'd stick with a 90 degree firing order turning 12,000 rpms, the bottom-end when properly built and modified is not an issue on this sled as we've proven with 332.0 ft lbs of torque.

I'm with Opsled on this one...I'm not buying it! It was a good fix to an old problem that stuck around with the introduction of the 800. I'd rather work with the initial timing curve to compensate. Just my .02 as well....good thread!
Click to expand...

....yeah!!!!
 
I have 3 inch paddles and 162 inch track and what I find is bottom end is lesser than a twin but top end beets all twins so in climbs it just dose verry good just cant keep front down
 
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