3.5 Outboard Powerheads

[Jerry Wyss]

Time to find a new thread you guys...... sounds like you are taking us "off the subject"

I was going to stay out of this - but it appears I've been indirectly quoted.

If my comment from the other thread that I've quoted above was taken as a "get lost" - please accept my appology. It was never my intent. I was merely trying to keep that post relevant and on track as it is undoubtedly helping to raise the profile of O/B tunnel racing in Oz.....

We were just kidding when we made our comments as we left Tim,,,and I think the 3 of us knew that. It's just that some have ZERO sence of humor but so what else is new.

 

[AndyBrown]

:huh: No, I haven't even ran it yet,,,,,where's my "LOL" thing,,,There are definetly two methods

here with this "pinch in", "pinch out" thing. I happen to go along with Rod G on this,, long before

he wrote his last page on it.

TimD and many others go with the "pinch in",,,people I respect,,, it's just one of those Ford vs

Chevy things that will go on forever I suppose.

I'm sure not buying Joe's example,, there's Way too many variables "screwin'" with that one,,

there's water flyin' freakin' everywhere while runnin' one of these and Only The Drops Leaking

From The Head is Goin' down the Carb??? Get Outa Here!

Joe,

Is correct! This water leakage is why the MAC OB did not become popular after the first batch was sold. Everyone said they run like stink untill you back off and then they take a long time to get back on pipe.

When at speed water was spraying out of the OD of the Waterjacket. While at speed this water would blow past the carb with little or no effect. When the boat slowed down these small drops could easily drop into the carb and cool the combustion chamber.

Jerry, If you look at your OB engine you will see that leakage from the glow plug area can never reach the carb.

Anyway, Last year I found the water leakege problem and started supplying the MAC OB with the waterjacket O-ring....Problem sovled! It's a great engine, but not many guys were buying them because of the initial problems and of course some of the OB gurus were telling everyone that these engines did run based on the first batch problem.

That is the reason we now have them on sale..to get more of them out there so you all can see how well they do run.

On the in or out squeeze. I like the "in". Not going into why at the moment.

 

[user 115]

We were just kidding when we made our comments as we left Tim,,,and I think the 3 of us knew that. It's just that some have ZERO sence of humor but so what else is new.

And some us couldn't spell to save our life.

 

[Jerry Wyss]

We were just kidding when we made our comments as we left Tim,,,and I think the 3 of us knew that. It's just that some have ZERO sence of humor but so what else is new.

And some us couldn't spell to save our life. (Yeah, I already knew you couldn't.)

 

[Jerry Wyss]

Thanks Andy, I didn't want to quote your full post to save on bandwidth,, with Charley so close by.

I know first hand the Mac is a good performer, thats why I have one. I'll give'r a good workout and test that

"O" ring thing,, might just have to use the "pinch-in" method for that engine, will have to see.

While your reading this, the piston/rod has resisted coming off the crank pin last time I tried. I didn't force

things, I figured I might get to talk to you some day,, or did I already?

 

[AndyBrown]

Jerry,

The rod will come off....with a little force. I use an "L" allen wrench like a crowbar. Put the piston at TDC and place the short end of the allen behind the rod about half way up the rod. Put the bend of the allen against the crank for leverage. I've never hurt one doing it that way.

 

[Jerry Wyss]

Jerry,

The rod will come off....with a little force. I use an "L" allen wrench like a crowbar. Put the piston at TDC and place the short end of the allen behind the rod about half way up the rod. Put the bend of the allen against the crank for leverage. I've never hurt one doing it that way.

Good Deal, I was thinking of trying something like that at the time but there was no hurry.

Thank's a bunch!

 

[Jerry Wyss]

Since this a "powerhead" an such topic, hosted by Gene"Machine"Gillman, I feel Free to exploit it

all I want :lol:

I've picked-up the old idea of planting another powerhead on the TT lower,,, making my own

"Fronkinschteen" (that spelling is for "Charley") motor.

I was looking at the O.S.21 VZ-B V-Spec-T (car engine) or the O.S.21 VZ-M Turbo boat engine.

Obviously the crank on one of these motors is going to need a crank pin to drive the TT PTO.

I was wondering if anybody on this site has one of these motors that could give me a few

measurements. The car engine may have a problem the marine engine don't,, the front

of the crankshaft is made for a clutch but the two shafts may interchange.

And the other option is to buy the O.S. VZ-M and if it's not possible to adapt I'll just put it

in my Sport 20 "shovel". Any info would be great guy's.

Jerry

(I also found that the O.S.21RG(P)-X is a "pull-start" model) that's an "edit" Gene

 

[Slideblues]

Hey run with it Dude

Ive never ran OS so Im not up on the numbers. Always amazed on what fits what thou.

For me its been K&B, OPS, CMB, Picco, and Rossi

Gene B)

Edit! ( And no Im not biting on tha "Shovel" ) :lol: :lol: :lol:

 

[Jerry Wyss]

:lol: :lol: I got'cha wid the "shovel"

I have been lookin' aroun' at the OS'thes and it looks like all the really high performance

21 models don't have a pull start crank option,,just the RG,,which is probably stronger

than the TT to start with,,but I really wanted the "Beast" motors.

Some of those have an RPM range of 3,000 to 40,000! YeeGads

Somebody may come along that knows allot more,,,I have looked at the OFNA line

in the past and have owned an Ofna 21 before,,had it in a Kyosho 1/8 4WD Baja truck.

It would lay down 4 patches of rubber 12 feet long on pavement,, it was perdy kool.

Edit: I don't think I'm in a hurry to buy the "VZ-M Turbo" as it cost's $349! and the

VZ-B V-Spec-T is $399!!!!

 

[Jerry Wyss]

Ok, I just got off the phone with Rod G. and he kinda showed me a new direction to investigate

concerning the TT Frankenstein motor idea. While talking with him I discovered that the car engine

idea might have a shortcoming in the "torque" area of the boat application.

I think the O.S. VZ-M inboard marine engine is a good candidate dimension wise for the TT PTO

but I would have to add a seperate "pin" in the crank to drive it. Also the VR-M would probably have

so much more power that it would be "snapping" flex cables all day long, which would take the fun

right outa the whole deal and I'm sitting here talkin' to myself :lol:

 

[VansRacing]

Jerry,

Getting a crank shaft made will be the clincher with the VZ-M or VZ-R engines.

This being the key part, it will have to be made by someone that can turn out a quality part and more important than that is, it has to be made from the right material and treated correctly afterwards or you will just be building a little time bomb.

I would pick the "M" over the "R" as it already has the head configuration worked out for you.

-Carl,

 

[Jerry Wyss]

Jerry,

Getting a crank shaft made will be the clincher with the VZ-M or VZ-R engines.

This being the key part, it will have to be made by someone that can turn out a quality part and more important than that is, it has to be made from the right material and treated correctly afterwards or you will just be building a little time bomb.

I would pick the "M" over the "R" as it already has the head configuration worked out for you.

-Carl,

I'd never consider having a crank made just to get a crank "pin" to drive the PTO,,,

Oh , I think you forgot that the TT has a "gearset" , so you don't need a reverse crank

like a K&B.

I could have a crank pin installed in the end of the existing crank pin

,,but if it ever came loose it would easily destroy the $350 VZ-M Turbo motor in a blink of an eye

 

[Jerry Wyss]

Well, Its for sure, I'm goin' a different dierection wid duh TT Frankenstein mod motor thingy.

Rod G. opened the door and let me outa the closet,,,Thanks Rod,, and Tim D mentioned goin'

that way too a while back. Both are really smart feller's

I just love messin' with these things,,call me weird, the guy's in Seattle do

 

[izitbrokeyet?]

here you go Jer

this one had the Hyper 8-port head, novarossi combustion chamber, and WC head, OS 4e carb had a good tuned pipe at one point but was sold with the re-tigged magic pipe....it ran strong

 

[Jerry Wyss]

IT'S ALIVE,IT'S ALIVE :lol: :lol: :lol: Man! I Just Felt Like I Was 7 An It Was Christmas!!!

Thanks For That Kev,,HaHaHa! It's Beautiful! Got The Lower All Polished Up, Beautiful

So You didn't use the the TT PTO at all I see,,,The "Hyper" is a Picco ain't it?

Man, Now That's a Real "Fronkinschteen", GOOD SHOW KEV!

 

[izitbrokeyet?]

Jer,

It's been a while since I built this one....I'm pretty sure I ended up using the TT pto ...I had to completely re-work it to fit the Hyper 8-port crankcase with a different backset and crankcase ID...I think the bolt pattern was compatible for the TT PTO frame. I'm pretty sure there are several other motors that would have workd. The Hyper was my choice given the fact that it came in a Pullstart version, and wasn't expensive to purchase. and I wouldnt need to worry about counter-drilling the crankpin B)

It ran very strong

The hyper 8-port is a cheap Korean built (maybe Tiwan) motor. It's made by a company called HoBao.

In fact...I remember that the bolt pattern on the crankcase was the same on top and rear plate as novarossi equipment B0

I remember wanting to mount a larger prop than the TT lower would allow 8)

have fun,

KB

 

[Jerry Wyss]

Awesome Stuff,,I have been lookin at several car engines, there was one site that had a car motor

and it was called "Hyper8 Picco". 'Course the car engine area is a ever changing industry of changing

names and Sponser names,, who the "H" knows what is what on any given year.

The timing in these engines was scaring me off mostly, these engines utilize a clutch so they can get

away with having some perdy radical specs in their motors. On the other hand the TT has interchangable

gears so you could probably get away with using a "pavement screamer".

Like I was saying ealier the O.S. VZ-m Turbo IB boat engine has a rear case dimensions that are

Really close and if you "could" get it adapted it would probably tear up flex cables. I'm using up

cables now a little sooner than I would like with a heavily modded Tiger powerhead.

 

[izitbrokeyet?]

Both Picco and HoBao make motors for OFNA....could be the reason it was called a Picco motor. There are several similaritys between the Hyper and italian motors in parts compatibilty, bore x stroke, crankpin, rod-length, wristpin size, etc

 

[Jerry Wyss]

I just brought this back up to tell KevinB that I ordered a Ofna Hyper .21 pull start, but it wasn't the 8 port.

I was told by a "engine brain" type person that "the amount of ports" is not the deceiding factor of better in a boat engine. I also got the Ofna "Force" 4 port engine at the same time (pull start) just

to see if one adapts better than the other. (there goes the Christmas money)no kids,hehe

The engine bore&stroke in the Ofna is a little toward the "stroker" side in comparison with the TT,,I just wanted to try it. So Kev if you can remember anymore, let me know. I got some good pics anyway.

I just did notice in the pics that I can't see a place where the PTO seperates from the case,,???

OH NO!! :lol: :huh: