My Phantom Experience.

[DAMIEN1307]

You in the big O Impulse?

Yes he is, Its right on his profile when you hover your mouse cursor over his avatar picture...lol.

 

[ImpulseRocket]

Reeds are for low and mid mainly on our engines, an do nothing for the top end. An as that 9000rpm plus, is a bit high for rpms on a CG bottom end, if you want it to last. I'm thinking they went with reeds to get more bottom end. A chain saw has no bottom end at all. They are designed to rev up and stay there while cutting. I'm a fan of reeds, because of the low end and mid they add. We can build a high rpm screamer all day with a CG, but they don't last long. If I make my own P85 from scratch, I'd be concentrating on producing more down low in the normal CG rpms range. I can see where you are talking about the wide intake, and that can be a huge issue. Especially if there is no bevel and when rpms begin to rise. Easy as pie to have the intake make love to a ring. lol

Oh, I know the reeds help. Combine the Stihl saw transfer design with a reed setup and you get one ridiculously torquey little engine. I was never saying they didn't help, just that they could probably go without and still be rather impressive.

As for the RPM's, I wouldn't want to push past 9000 anyway, and the Phantom doesn't really need to. I've watched one gentlemen rip up to 9100 with nothing more than the SHA clone carburetor with ease, although he did say it was starting to run out of steam by that point. I don't want a high RPM screamer, even if the bottom end could handle it. Revs make the heat issue worse. That's actually one reason I want to try and stick with the OZ style reed and maybe upgrade to the VM18. The Bofeng carb is, in my opinion, a bit too small for the Phantom, but I don't want or need a PWK21 or other too-big carb and larger reed block on it. That's also why I didn't go crazy with the port work and just did very mild things to adjust for losing a base gasket, and instead aimed for more compression. Top end power can be fun, but mid range power is where the most fun happens. Especially with my large self on a bicycle. I need that grunt lol.

You in the big O Impulse? I'm up in the area you hear on the news weekly, you know where they like to go pop pop at each other. When you hear it on the news, I heard it while it was happening lol. Just north Ames ave.

If you are, we should get together and figure this bad boy out.

I do indeed live in Omaha. Grew up in Benson, currently live South Central area off of L street. More than willing to meet up at some point.

 

[ImpulseRocket]

I'm going to have to hold one of them jugs in my hands, to see what I can do. Might have to be a case induction engine for best reed capability. I'm curious to what the guys that have blown up the needle bearing updated engine have ran in oil ratio too.

bicycle-engines states a break in ratio of 20:1 and now a post break-in of 24:1. This is their new recommendation now that people have been breaking pistons even after the wrist pin bearing situation was remedied. It's a BS band-aid fix to a problem that isn't oil related. Most guys are running the standard 32:1, a few 40:1 and are doing just fine. The issue isn't the oil, it's the piston and the ports.

 

[weefek]

bicycle-engines states a break in ratio of 20:1 and now a post break-in of 24:1. This is their new recommendation now that people have been breaking pistons even after the wrist pin bearing situation was remedied. It's a BS band-aid fix to a problem that isn't oil related. Most guys are running the standard 32:1, a few 40:1 and are doing just fine. The issue isn't the oil, it's the piston and the ports.

If they are so terrible in other ways why would you listen to them w/ regards to oil ratio let alone anything else?

 

[ImpulseRocket]

If they are so terrible in other ways why would you listen to them w/ regards to oil ratio let alone anything else?

I'm not going to, other than the break in ratio, that has remained the same lol. I think anybody with even a mild background in mechanics or engines can see it for what it is. I wouldn't call the Phantom itself terrible either. Flawed, sure. Flaws that can be worked around, but it isn't a bad design, just badly executed by people that don't want to take another financial hit by admitting they made a mistake with the main piece of the motor that is unique - the cylinder and piston. Heck, realistically just the piston. Everybody that has installed an aftermarket MS460 or 380 piston has so far, to my knowledge, not had a piston break or ring snag. Why? As I mentioned before in this thread the ring pins are just slightly further away from one another when compared to the Phantom piston. That is literally the main reason I went and bought one and windowed it myself.

Food for thought.

 

[Karl Snarl]

Oh, I know the reeds help. Combine the Stihl saw transfer design with a reed setup and you get one ridiculously torquey little engine. I was never saying they didn't help, just that they could probably go without and still be rather impressive.

As for the RPM's, I wouldn't want to push past 9000 anyway, and the Phantom doesn't really need to. I've watched one gentlemen rip up to 9100 with nothing more than the SHA clone carburetor with ease, although he did say it was starting to run out of steam by that point. I don't want a high RPM screamer, even if the bottom end could handle it. Revs make the heat issue worse. That's actually one reason I want to try and stick with the OZ style reed and maybe upgrade to the VM18. The Bofeng carb is, in my opinion, a bit too small for the Phantom, but I don't want or need a PWK21 or other too-big carb and larger reed block on it. That's also why I didn't go crazy with the port work and just did very mild things to adjust for losing a base gasket, and instead aimed for more compression. Top end power can be fun, but mid range power is where the most fun happens. Especially with my large self on a bicycle. I need that grunt lol.

I do indeed live in Omaha. Grew up in Benson, currently live South Central area off of L street. More than willing to meet up at some point.

Try, I know this is shocking, but try a saw carb. lol. Way better than anything else for our motors, and seeing as the p85 is a saw engine, I'd think it would work quite well. An rwj-4b with a no return conversion kit should be spot on for that cc range.

 

[ImpulseRocket]

Try, I know this is shocking, but try a saw carb. lol. Way better than anything else for our motors, and seeing as the p85 is a saw engine, I'd think it would work quite well. An rwj-4b with a no return conversion kit should be spot on for that cc range.

I did consider that actually. I am not too familiar with the conversion stuff for the saw carbs on these motors yet so I stuck with something I have more experience working with, good ol' slide carbs. Especially tuning Mikuni VM carburetors, I can do that in my sleep. I actually already have a VM18-144 waiting for me to get my bike finished and break in completed. I can buy a 23mm adapter for an OZ reed that fits the VM-18 perfectly and I don't have to deal with too much extra muss and fuss.

I have considered building a second phantom engine off to the side. That might be a good place to do more setup/experimentation. Not sure if I want to do another Phantom though. I was considering something else just to keep things interesting. Maybe a Minarelli, or maybe something worse like one of those "110" motors with the straight walled transfer ports as something to mess around with just because I can. Like I said in the first post... I am weird lol.

 

[Karl Snarl]

I did consider that actually. I am not too familiar with the conversion stuff for the saw carbs on these motors yet so I stuck with something I have more experience working with, good ol' slide carbs. Especially tuning Mikuni VM carburetors, I can do that in my sleep. I actually already have a VM18-144 waiting for me to get my bike finished and break in completed. I can buy a 23mm adapter for an OZ reed that fits the VM-18 perfectly and I don't have to deal with too much extra muss and fuss.

I have considered building a second phantom engine off to the side. That might be a good place to do more setup/experimentation. Not sure if I want to do another Phantom though. I was considering something else just to keep things interesting. Maybe a Minarelli, or maybe something worse like one of those "110" motors with the straight walled transfer ports as something to mess around with just because I can. Like I said in the first post... I am weird lol.

Really easy to set up. An you can also just buy an adaptor ( will have to widen the screw holes for 40mm intake) and slap it on.

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[ImpulseRocket]

Really easy to set up. An you can also just buy an adaptor ( will have to widen the screw holes for 40mm intake) and slap it on.

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Huh, I never came across that in my whole time searching. Now I kind of want to try my reedless Phantom using that adapter with a Saw carb and air filter for a nice compact and simple setup. The Phantom intake port is closer to round than rectangular, so it would probably port match very well to that adapter.

 

[Karl Snarl]

Huh, I never came across that in my whole time searching. Now I kind of want to try my reedless Phantom using that adapter with a Saw carb and air filter for a nice compact and simple setup. The Phantom intake port is closer to round than rectangular, so it would probably port match very well to that adapter.

You will have to widen the screw holes just slightly to make it work if the intake is larger than 38mm spacing. It's easy though. I just run a drill bit through it on one side( outside of each hole), and it's enough. You will have to have your own gaskets though, for carb side and intake side. @mark20 here can make any gasket but the head gaskets, if you can give him a pic and measurements. I've bought a ton of gaskets off him. He made me my funky weed eater gaskets, and they work better than what I can buy anywhere else. I have a bunch of base, and intake gaskets made by him. Good work and he stands by his work.

PS, those adaptors are so sweet!!! and I was elated when I finally found them.


Now I think of it, you might have seen me mobbing around our area on one of my MB. Iol, I mob up on Sorensen quite often. I ride to the tobacco hut on Ames too. lol