Hi Tenderfoot.
thanks a lot for liking my thread.
About RB kits-my Piston/sleeve sets are using on RB X12 and so far people are very happy.
I have never tryed PS12 in RRR, so can't answer on this question, but at this point seems like BRB sets in Novarossi cases are much stronger, but in the mean time we are working to improve power- PS12 is very strong egine, but it is required different type of tunning ( very sensative to head shiimming) and we are working to make it more easier to tune.
Edward

tenderfoot57:
PS12 will fit V1R/RR/RR EVO and RRR with enlarge of engine mount holes on the chassis. you will need to widen ~<0.5mm to each mounting holes since PS12 with stock engine mount, the mounting holes are 1mm wider than novarossi or os TR base engine.
Another modification needed on Kyosho V1R/RR/RR Evo: If you use kyosho optional left side belt tensioner + support or from other company with same style, you will need to dremel off material on the tensoner since PS12 will sit 1 mm to the left than other engine.

By the way the carb will clear the upper deck of the chassis without any modification on V1RR EVO with stock or lower engine mount. On V1R/RR with lower engine mount, you are require to dremel the upper deck and support to clear throttle movement this modification is require even with nova/Os tr engine.

TG777:
Any new tuning tricks on PS12? Is there anyway to make PS12 milder? I have chew thru 2 set of spurs and 1 set of pinion after 3 gallons of fuel thru PS12.
Lee

Hi Lee.
Yes, there is trick-shim the deck by0.15mm higher it will be softer
Edward

Hi Ed,

What is the recommended head clearance for running your BRB set.....after taking the engine aparts.....found 4 copper shims !!!!! Far too many in my opinion, two 0.2mm and 2 0.1mm !!!!

Got a funny feeling that the nova rossi piston not gonna last long !!!!!

Have you sorted out your paypal account yet as i want to order asap ? Gonna needs 2 set of 2.1cc BRB and 1 set of 3.5cc BRB...and do you do the piston and con rod alone coz i gonna need a couple of them as well !!!

Thanks

philip

Edward tells me you need 0.028" or so head clearance.

Thanks...got to convert that back to mm !!!!

Hey Phillip.
Yes 0.6 mm head shimming is way to much, we are ususaly running 0.4 mm in hot days and 0.3 cold days.
I am not sure if Novarossi piston will work at all, it has different expention rate properties and it containing a lot of less Si, so it will not last as long as original.
I reserved that sets for you already, but paypal still hanging. I hope will fix it within a couple of days.
Edward

Hi Corey.
That was for 21 set and Phillip is running 12.
I sent you PM and didn't get answer-any news?
Edward

Ed you got pm

Thanks for the info Boner.

Ed, I am still quite interested in your engine. Please let me know what steps are required to aquire one of your products.

Tenderfoot.

Ed, I found that measuring the head clearance using the solder wire method indentation is quite high using stock 0.3 mm shim on a NovaMax and a RR12L5 casing. I found that without any shims under the button head, the head clearance is already 0.5 mm which is more than enough I think... I might be wrong. Using 25% nitro with 7tf turbo plug. Is this normal?

Since the head clearance can differ from one crankcase case to another and therefore shim info cannot be used, what should be the correct head clearance for the .12 BRB piston sleeve?

the easiest way I've found to measure head clearance is to use a very tiny piece of modeling clay- just as with full size engines.

With the head removed, lay a tiny piece of clay on the top of the piston near the cylinder wall. Assemble the engine and roll it over only once.

Remove the head and carefully remove the clay from the piston. I've found if you put oil on the head button, this will be very easy as it will not stick to the head.

Now cut the clay in half with a razor blade, and measure the thickness with a micrometer or calipers.

I know solder is relatively soft, but clay surely will not damage anything in your delicate engine.

Hi D.
I don't have any Novamax or RR12L so realy can't tell you from my personal expirience with them, but Chris does and everywhere we use the same echnics-cold days bellow +15 C-0.3 mm shims and over +15-0.4 mm. In genearal speaking the head volume is most important thing and the mean time we don't want to forget about squish band as well. I use 0.16-0.18 cc head volume and if in some cases squish band clearance will go over 0.45 mm I will fix the head bottom on lathe.
But particulary speaking about BRB-the good starting point is 0.3-0.4 mm. Also one of the most important thing is to listen engine-if it is overshimmed you will feel los of power if it is overcompressed-it sound like engine doesn't want to brease. Sound of engine can tell you a lot.
Edward

I agree with you there Ed. Just giving out some information here from what I've experienced. At first I had my engine with 0.3 mm shim. I noticed that it didn't have punch in the 1st speed but when 2nd speed kicks in, it had loads of power. It was like an off on tap ! I measured my head clearance with the 0.3 mm shim and it was 0.8 mm !

So I took out the 0.3 mm shim and ran it as is. With 0.5 mm head clearance (approx 0.02"), I had to richen the low end a little (about 1 full turn) but power was everywhere ! Engine had a stable idle and it did not overheat. Top end was also excellent.

But then again, doing that gave problems to my conrod. Found that out because the engine felt sluggish after a few tanks. I thought my main bearing was a gonna but it turned out that the conrod bushing was already giving a lot more play than it should. It's the same conrod I used for breaking in and I guess after about 1 gallon or so, it's time to change the conrod. More so after experiencing more compression...

Thanks for the tip cdelong.