RockSolidEngines billet head.

[jlebh1]

oh ok me to im also sorry if I sounded rude before to (also hot here), I know I should use better fuel.
Also after I did around 5000kms on my chopper (its the one with the billet head on it, but its a zbox engine bought it last year its been good to me) I took of the head to do a mild port and polish I looked and there was only very minor scoring on the cylinder wall, but im on my last 5L of that fuel, also I use castrol 2 stroke oil.

 

[AussieSteve]

Something to note with the billet head - my stock studs were a couple of mm too short, causing a head nut to strip.
If all studs are a similar length, I'd recommend replacing them with slightly longer ones when you fit the head.
... Steve

 

[Barbie's hubbie]

You guys kinda threw me there for a blink, then I remembered you guys are starting into summer down there. Is Nowra on the other side of the mountains form Sydney? and Jlebh1 where are you? I spent 8 days in Perth about a hundred years ago...most beautiful city I've ever been to..and I've been to a bunch! I looked at hat web site where you got your high compression head, but did'nt notice if they had a head for a 80cc grubee!

 

[AussieSteve]

You guys kinda threw me there for a blink, then I remembered you guys are starting into summer down there. Is Nowra on the other side of the mountains form Sydney? and Jlebh1 where are you? I spent 8 days in Perth about a hundred years ago...most beautiful city I've ever been to..and I've been to a bunch! I looked at that web site where you got your high compression head, but did'nt notice if they had a head for a 80cc grubee!

Yep, Summer starts in 2 days. We always seem to get a hot spell just before.
Nowra is on the coast, about 2 hours drive South of Sydney.

Everyone says Perth is pretty good. Haven't been there yet.

Is an 80cc Grubee really 80cc, or 66cc like most 80's?

Mine is a ZBox Z66, previously labelled Z80. Still a typical 66cc Chinese Happytime engine.

Someone will know, otherwise email Tony at Rock Solid Engines

... Steve

 

[jlebh1]

im in brisbane

 

[mountain80]

I would be curious as how much if any it reduces the head temperature. My stock ht head that is shaved 0.050'' runs 160 psi and averages about 240 deg F or 114 deg c at about 25 deg c. Measured with an infared temp gun riding and close to the sparkplug area fwiw.

 

[210061741]

Wow i'll have to compression test mine to see where it's at.
I got rid of .045 base gasket + Milled the head and jug.
My compression is prolly through the roof.

 

[AussieSteve]

I would be curious as how much if any it reduces the head temperature. My stock ht head that is shaved 0.050'' runs 160 psi and averages about 240 deg F or 114 deg c at about 25 deg c. Measured with an infared temp gun riding and close to the sparkplug area fwiw.

Temperature will vary with rider weight and riding style, but I'm not sure how much. I'll measure mine when I start it next. First, I need to replace the cylinder studs.
I don't have an infra-red temp gun, but I do have an accurate DMM with a temperature range and a 'K'-type thermocouple.
I know that it runs above boiling point - a wetted finger touched to the head.

I also need to do my compression test again. It's possible that the head was leaking compression last time. A stripped head nut. (135psi first test)

... Steve

 

[motorpsycho]

I really want to get one of the rock solid heads. but how much more compression will it give me on a 50 c.c. ? (already has the slant head on it now) would i need to upgrade the carb as well if i go to this head?
If i would need to upgrade to a better carb, and install longer head studs, i might just pass on the idea for now.

 

[AussieSteve]

I really want to get one of the rock solid heads. but how much more compression will it give me on a 50 c.c. ? (already has the slant head on it now) would i need to upgrade the carb as well if i go to this head?
If i would need to upgrade to a better carb, and install longer head studs, i might just pass on the idea for now.

You don't need to upgrade to a bigger carb, although it would complement the high comp head. I stuck with the stock NT carb. You might need to change your slide needle height or main jet.
I got 1000RPM extra - went from about 37kph, (5390RPM) to 44 kph, (6420RPM) and more power all through the rev range.

I don't know if the 50cc billet head will also need longer studs.
Best thing to do is ask Tony at RSE.

... Steve