Twin Nitro Engines....

[julianconde]

I think you should use the 91rs from cmb, 0.017" head clearance and 25% nitro. Easy to dial in and will run every time, even if you drive very slow.

In my hydro, the vac vas good, but the rs was so much stronger and faster, no doubt.

Really ? This is surprising , what type of hull is it ?

It is an sgx, single, but is it so big difference from twin?

To litle clearance burns plugs and makes an unstable motor, leans out when you give full throttle and gets to ritch when you give less throttle, in my experience.

Pistion and combustion chamber look like brand new when you run with right headclearance.

Simen thats kind of interesteing i run 101RS on my Twin and i have never burned a plug or leaned out and my head clearance is no where near 17i also use Zoom Carbs on my Twin..

the changes going from a single to a Twin are huge. everything has to be the same needles,fuel filters, fuel lines,Pipes, headers,tanks,head clearance,props, struts, shafts, my advice if you are going to do a 101rs twin let Steve Wood here on IW do your mototrs he does some of the most outstanding work,great person to talk to and do business with.. Like that you wont have any issues with your 101RS..

you run 25 % nitro and we run 60-65% theres a difference..

 

[BigChuck]

Guys, on 25% with a STOCK head buttons the motor will live at .017. I have lived on .021-.024 on 60% with the stock heads for years. This was on 90/1.0 an Rs91. The 101,s are a whole different stadium.............

 

[julianconde]

Guys, on 25% with a STOCK head buttons the motor will live at .017. I have lived on .021-.024 on 60% with the stock heads for years. This was on 90/1.0 an Rs91. The 101,s are a whole different stadium.............

agreed

 

[Andy Brown]

25% nitro runs better with .017" than it would with .012 or .014". I know Simen has a large amount of expericence with the RS 90's. He will do well with his known set up in a twin and will run faster on that 25% than many would think.

 

[Tom Foley]

25% nitro runs better with .017" than it would with .012 or .014". I know Simen has a large amount of expericence with the RS 90's. He will do well with his known set up in a twin and will run faster on that 25% than many would think.

Save big money on fuel as well as weight in the hull! Nitro is heavy !

 

[Joe Warren]

Well depending on the Engine you SELECT and the adjusted head volume.VAC91 head volume is correct and added clearance only makes one lean the needle more....... to clean the engine out on the pipe..... ( this is cause we still tune by ear) Also the VAC 91 in Cool Water & Cool Air can easily be overcooled with the current head cooling.... High Head Clearence and over cooling = a high flow number on the needle...... and a cooked engine. The best volume I have found for a RS91 button is the Stock RS101 head button cut down for the 91 bore size. Good Luck in whatever you choose...... Nothing like the CACKLING OF A BIG BORE TWIN ........

 

[dwilfong]

I saw a littel of the outer side of the spectrum this weekend at the race.

High compression ,clearance as tight as can go and not hit the head with a cooling cap separate from the button and clamp used to hold the button in place. the cooling cap looked like a can on top covering every thing including the plug.

The revs where over the top. with lots of nitro to boot.

The sound out of this eng was like a top fuel dragster.

Every thing I have bin doing in the opposite direction.

Was a very impressive display of burning nitro.

I can say this is not for the first timers or the faint of heart.

Way to go Stan the eng man.

David

 

[Andy Brown]

I saw a littel of the outer side of the spectrum this weekend at the race.

High compression ,clearance as tight as can go and not hit the head with a cooling cap separate from the button and clamp used to hold the button in place. the cooling cap looked like a can on top covering every thing including the plug.

The revs where over the top. with lots of nitro to boot.

The sound out of this eng was like a top fuel dragster.

Every thing I have bin doing in the opposite direction.

Was a very impressive display of burning nitro.

I can say this is not for the first timers or the faint of heart.

Way to go Stan the eng man.

David

I knew that had to be the work of Stan by the time I finished reading your fourth line.

 

[simen gjørstad]

When you run so high compression an large amount of nitro, do you have the ignition under control?

When i try that i just end up with destroying pistion and head because of detonation.

Is the trick to give the engine enormous mounts of fuel?

 

[BigChuck]

I saw a littel of the outer side of the spectrum this weekend at the race.

High compression ,clearance as tight as can go and not hit the head with a cooling cap separate from the button and clamp used to hold the button in place. the cooling cap looked like a can on top covering every thing including the plug.

The revs where over the top. with lots of nitro to boot.

The sound out of this eng was like a top fuel dragster.

Every thing I have bin doing in the opposite direction.

Was a very impressive display of burning nitro.

I can say this is not for the first timers or the faint of heart.

Way to go Stan the eng man.

David

David was that with Stan 60 mono of his F Boat...? 2nd is what you are talking about for the jacket area the as the Grannis Heads....???

 

[dwilfong]

I saw a littel of the outer side of the spectrum this weekend at the race.

High compression ,clearance as tight as can go and not hit the head with a cooling cap separate from the button and clamp used to hold the button in place. the cooling cap looked like a can on top covering every thing including the plug.

The revs where over the top. with lots of nitro to boot.

The sound out of this eng was like a top fuel dragster.

Every thing I have bin doing in the opposite direction.

Was a very impressive display of burning nitro.

I can say this is not for the first timers or the faint of heart.

Way to go Stan the eng man.

David

David was that with Stan 60 mono of his F Boat...? 2nd is what you are talking about for the jacket area the as the Grannis Heads....???

67 boat.

I have a Grannis cap and it is a pain in the you know what. the cap over the plug falls off all the time then you have to make a new one.

The button and top clamp look like what I make but smaller. then there is a cap that looks like a spray can cap that fits over the whole top of the eng.

With a stud and a thumb screw to hold it down.

 

[BigChuck]

Ok...Saw the system when he was here. As for the RPM...well I have heard that before also..But Stan is "The MAN" Sr & Jr.!!!

Remember trying to catch Stan when he had a white "challenge.."

Food for thought David..............Make the trip to the Nhra Race when they come back to FL. Great things is you can talk to any Crew Cheif if you are willing to wait for them. They know how to burn NITRO!!!