Rossi Powerhead

[ZIonOB75]

Got my Rossi powerhead today, what a work of art , I am used t the K&B junk, Rossi truly makes machine work top priority and it shows in their products...just ranting cause I am used to something different.

Mike

just fiy, used the nylon lock nut and lock tight for flywheel instead of regular nut and press hard the carb when tightening it and lock tight again coz it's known for loosening during few run.

 

[topfuel443]

Ok guys... I just bought THIS and was wondering is the silver head or the gold head the newest version? I know there was some postings about this a while back, but dont remember what I saw... Rossi is the only .21 outboard Ive never messed with so I figured Id give it a try, and for the price that i got it, I figured I cant go wrong...

The gold head has four bolts right? and the silver has 5? I thought I remember readin that the silver head was the better of the two but cant be sure... Where is ole Slidey when you need him?

Gener you out there?

~James

 

[Slideblues]

Yo James

If memory serves me, the silver head was perfered over the newer gold 4 bolt head, My Rossi I got off the Dist Director in tha Nor West with mods from Mark Anderson, Believe it had a K&B air cooled car head cut down to bout 4 fins and a lil porting, Ran VERY well, Won some major races out west too. Fav pipe was a big belly Garcia or Irwin J with inverted stinger.

On my WOF she liked a mod 1640 from Mark S,

Hope this helps, Get with Mark A fer specs on what all he did to it

Gener B)

 

[Ronald van Essen]

Ok guys... I just bought THIS and was wondering is the silver head or the gold head the newest version? I know there was some postings about this a while back, but dont remember what I saw... Rossi is the only .21 outboard Ive never messed with so I figured Id give it a try, and for the price that i got it, I figured I cant go wrong...

The gold head has four bolts right? and the silver has 5? I thought I remember readin that the silver head was the better of the two but cant be sure... Where is ole Slidey when you need him?

Gener you out there?

~James

James

If you ever want a rossi goldhead, I have a brand new one, special price for you.

Ronald.

 

[legendscar24]

Ran the engine on a Leecraft set up for heat racing, with a little positive angle for speed as there was zero wind and kind of muggy air, after ten runs I finally got her up to 67mph on the GPS, seems kinda slow so I'll look for more speed this weekend.

Mike.

 

[ZIonOB75]

Ran the engine on a Leecraft set up for heat racing, with a little positive angle for speed as there was zero wind and kind of muggy air, after ten runs I finally got her up to 67mph on the GPS, seems kinda slow so I'll look for more speed this weekend.

Mike.

what a speed..i'm jealous...i think i like the GPS

 

[chriscarbon]

mike,

sounds like your doing good for a out of the box rossi. are you using a h7 prop.

thanks

chris

 

[topfuel443]

67 MPH huh?

~James

 

[waltr]

67 MPH with muggy air?

Not to shabby.Or was the GPS upsidedown for 49 :lol: :lol: :lol:

I've been sittin on a new one that Rod Geraghty went through for 2 years now.

I guess it's time to dust it off,brake it in and give it a chance. :unsure:

 

[topfuel443]

67 MPH with muggy air?

Not to shabby.Or was the GPS upsidedown for 49 :lol: :lol: :lol:

Kinda what I was thinking Walt.

~James

 

[legendscar24]

You have to remember most GPS units are inaccrate up to 3-5 miles an hour, unless you have one of the multi satellite Military versions, so actual I figure is around 60 mph. No I was not using an H7 I never really liked them all that much. The Rossi pipe makes this engine pull hard, really hard.

Mike.

 

[topfuel443]

can anyone else that has the four bolt silver head rossi 3.5 tell me if theirs came stock with a "turbo" plug style head? I just recieved the one I got from ebay and it has a turbo head. It also has four head bolts, which I found strange because I thought it was suppposed to have more than the gold head version...

~James

 

[jfm]

James, I have a silver-head Rossi OB (though it's anodized blue now). It came stock with the four bolt, turbo-plug style head.

Rod G, prepped it for me and installed one of his carbs.

John

https://www.intlwaters.com/gallery/displayimage...6&pos=-9627

 

[chriscarbon]

topfuel,

a friend bought a rossi gold head and it has the turbo plug button. i would say that the power head that you have may be a transition model (your model has the finned case and shorter crank) like the four bolt gold head. a regular head button will fit however my friend used the turbo plugs and it worked very well.

chris

 

[topfuel443]

Gotcha, thanks John. Nice looking unit. how do you like yours?

I just got finished taking this thing apart.... whoaa.... it needs some serious finessing inside. It flows about as good as Barn Door at 200 mph on the Salt Flats.

The carb definately has to go.

The head button has to go.

The ports will get matched this weekend.

The tranfers.... well...what tranfers?

Good looking piston/rod, once is gets clearanced on the big end.

Crank "looks" nice and solid, we'll see what can be done with it. PTO looks to be pretty good also.

Overall, not a bad platform to start with.

Gotta give Mr. Geraghty a call soon...

~James

Chris, Thanks for the info. I dont mind the turbo plug, but im not a fan of this current button, dont like the shape of the bowl, nor the volume. I have just what it needs though.

 

[Jerry Wyss]

Hey Top, I was wonderin' if you could give me the "bore and stroke" of your Rossi 3.5?

Also the engine bearing sizes, if you know,, maybe easier yet, just the bearing ID

sizes where they fit on the crank.

JW

 

[topfuel443]

Jerry, will do tonight, getting ready to head to dinner with the wife...

~James

 

[topfuel443]

Ok Jerry, heres what I got, dont know what Rossi claims but these are the numbers I just ran.

Bore 0.652 inches (or 16.561mm)

Stroke 0.633 inches (or 16.078mm)

Small bearing I.D. Crank size 0.275 inches (or 6.985mm (7mm)) Bearing # 607RS

Large bearing I.D. Crank size 0.5115 inches (or 12.992mm(13MM)) Bearing # ??? (havent taken it out yet)

Hope this helps. ~ James

 

[Jerry Wyss]

Thanks Top, it's hard to believe that thing is 3.5cc or under,, guess I'm not figuring right.

Anyway, does anyone know if one of these Rossi cranks be had easily? Approx cost?

Thanks,

JW

 

[chriscarbon]

jerry,

the older 6 bolt crank is longer than the new four bolt crank. three years age the older crank was approx 35.00 if memory serves me right. dave at hyperformance would have current cost & i thought he recieved some of the new ones.

chris