860R in rev

[lancelarue]

Anyone running crankshop "mondos" in a rev with 860R?
Curious what you have for engine mods and what size outlet you're running in the pipes versus what altitude you're at?
Thanks, Mike

 

[revx827]

I ran mine at 600'..... Can't remember outlet size. Had to go with lower (than I had) exhaust port to get them to run good. I know BJ built a few of them. You should give him a call. He will point you in the right direction.

 

[lancelarue]

port timing

Where was your port timing at, when it didn't work with the Crankshop twins?

 

[NEWDUCK]

Ive tried running doo race twins on my 860. I tried rasing the intake ports just a hair and raised the two (boost) exhaust ports a fair amount. Ended up making the sled do all sorts of strange things. Had to drop from 470 mains to 380.. It runs but I never had time to dial it in before it caught fire.

 

[revx827]

Where was your port timing at, when it didn't work with the Crankshop twins?

It was just "peaky" with the higher port timing. Close to stock seemed to net better all around performance. I will look up what the port specs were.

 

[BIG JOHN]

Anyone running crankshop "mondos" in a rev with 860R?
Curious what you have for engine mods and what size outlet you're running in the pipes versus what altitude you're at?
Thanks, Mike

you need to verify the port timing...MY single pipe ported 860s wont work with twins...my twin pipe ported 860s work well...BJ

 

[lancelarue]

860R with twins in Rev

you need to verify the port timing...MY single pipe ported 860s wont work with twins...my twin pipe ported 860s work well...BJ

Well, been working this summer on the new dyno cell / shop. Hopefully be making some smoke in the near future. Will be interesting what the 860R wants for port timing with the "Mondos", and or what changes I'll need to do to the pipes to find the magic. Dyno is the ultimate tool !!!!!!!!!!!!!!

First setup will be: around 14.25 to 14.5 to 1 with AV gas 100 LL.
42.5mm bored carbs with rad valves matched up

 

[lancelarue]

Dyno shop

Finally going again. It's been a long haul--
Started with a 07' 800R w/ Aaen pipe(modified, same internal pipe/stinger as stock 07') and "Thing" can. Also running Rad valves. Stock 470 mains.

Did 154 hp. Fueling was about right on the computer, plugs backed it up.
I rode this a little last winter and it ran ok then too. Nice flat graph with the exhaust valves mod showing well. Tore down exhaust system tonight & installed stock pipe & can to get a base line.

Then it's 860R time!!!!!!!!!!!!!!!!!!!!!

 

[NEWDUCK]

Mind posting your porting specs with running these pipes?

 

[lancelarue]

I'll share, no problem. It will be a little while-------

 

[lancelarue]

Pipes:
Will be running Crankshops as I've said. Not familiar with these pipes, they came set up for a "donut" graphite seal. The manifolds I bought later from Crankshop, and they are for a slip fit configuration. Not knowing exact header lengths, I went ahead and made a bunch of spacers on the lathe and machined off the raised portion on the stock manifolds (for slip fit) so the manifolds are straight and I can slip on whatever spacers I want to go behind the seal. Now I can change my tuned length for the header area to whatever the motor wants on the dyno! Once I find the final "sweet spot", I'll pull the spacers off and just weld a ring for the seal to back up against.
Just keeps getting better!!!!!!!!!!!!!!!

Anybody running the Aaen single on the 860R or /?? Would like to find some lower elevation guys who've tried it.

 

[sledsrock]

Pipes:
Will be running Crankshops as I've said. Not familiar with these pipes, they came set up for a "donut" graphite seal. The manifolds I bought later from Crankshop, and they are for a slip fit configuration. Not knowing exact header lengths, I went ahead and made a bunch of spacers on the lathe and machined off the raised portion on the stock manifolds (for slip fit) so the manifolds are straight and I can slip on whatever spacers I want to go behind the seal. Now I can change my tuned length for the header area to whatever the motor wants on the dyno! Once I find the final "sweet spot", I'll pull the spacers off and just weld a ring for the seal to back up against.
Just keeps getting better!!!!!!!!!!!!!!!

Anybody running the Aaen single on the 860R or /?? Would like to find some lower elevation guys who've tried it.

Yup, but I'm at 10Kft

 

[byeatts]

Yup, but I'm at 10Kft

I believe BJ had some Dyno numbers on the Aaen pipe in Minnesota on the 07 . Cant get much lower Lol

 

[lancelarue]

Thanks for the info.
I was looking for someone that rides mountains only armpit deep sea level to 6,000'.
( Alaska is different with the low altitudes!)
Nothing against BJ, I should have been more specific!!!!!!!!!!!!!

 

[lancelarue]

Pipes

Hopefully will be making some smoke by next week. Geez, the more I look the more I find!! Turned out to be waaayyy more porting than I anticipated.
One of the goals I have on this mission is to come up a "Thing" can to run the twin Crankshops into. After I get broke in and everything dialed in with the Pipes & cans, I'll have a baseline to work off of. Collected all the parts / pieces / tubing etc to make it happen. I'm a glutton for punishment---. Want to get these twins to work up to 6,000" starting @ sea level. Running Ataac for compensating.
I didn't get carried away with the porting yet, I'm going to see how it shows first and what it wants but there's definetely room for growth. This is the first "R" motor I've done and it's been quite a study. Re-did my thinking on the exhaust valves, we'll see.
Snow is coming down lower by the week!!!! Yea baby!!!!!!!!!!!!!!!!!!

 

[lancelarue]

860R

Oh Yea, we're rolling now!
Made first smoke today / heat cycle. Geez this thing is going to be knarly!
Nothing like an 860R with 175#'s with the valves 1/2 open!!!!!!!!!!!!!!!!!!!
I started with 17.5 pilots and after it loosens up if it is still clean on the bottom & mid I'll pull it down & do some more work in the intakes

 

[lancelarue]

fueling

Well the 17.5 pilots worked for one heat cycle!!!
Would't idle down with the screws all the way out.
Talked to Larry at the Crankshop, he said to run 30 pilots. Decided to try 25's screws 1 1/2 turns out. Now it 's happy.

 

[byeatts]

Well the 17.5 pilots worked for one heat cycle!!!
Would't idle down with the screws all the way out.
Talked to Larry at the Crankshop, he said to run 30 pilots. Decided to try 25's screws 1 1/2 turns out. Now it 's happy.

Did you bore the carbs?

 

[lancelarue]

carbs

Yes, the carbs are bored. 42 or 42.5mm if I remember correctly.

 

[byeatts]

Yes, the carbs are bored. 42 or 42.5mm if I remember correctly.

Whats happening is with a 42 mm bore as you turn down the idle a gap over the top of the slide develops and allow air to slide over the top.[ slides are too short] This air over the top is Not pulling fuel and causes a lean condition. Pull carbs and put flashlight in the bore and adjust down the idle just at the point light appears, That setpoint cannot be moved any further, doing so ive dropped to 15 pilots on the 880,s mod motors.17.5 at low elevation.. As you attempt to lower the slide you are actually causing a leaner and higher idle.