ST G51 CL ABC piston / sleeve sets Photos

[RandySmith]

Hi Brian
This is what the sleeves should be and look like, I sent the timing numbers to you before, I can send the angle info to you also.
I think the pictures will explain it.

The sleeve on the right is a 51 size, It has 2 smaller boost ports with a hard angle upwards, these aim just in front of, and just to the sides of the glow plug center.the boost port in the 51 will be about 510 thou wide with a .110 (tenth of inch) bar in the middle.
 
The second  photo shows the angle upwards of the ports

The third photo shows the ports from looking on the inside

The 4th pic is a closer look at the  boost ports,

The  main ports should be angled upwards at 30 degrees

As far as timing goes use 124 intake  135 exhaust, you can open all intake ports at the same time or drop the boost ports by 4 degrees, there will be no noticeable difference , this will make the 51 like an Aero Tiger, and it will do a nice 4/2 or a wet 2, or a strong 4 cycle, this will make for a very versatile setup.

Sleeve taper is important, I can talk with you about that.

Another thing that is very important is the sleeve top diameter, ST made several size sleeve thickness on top, and bore sizes in the heads, so some heads will not go down over the top of the sleeve, you will need to get measurements of these parts.


Randy

[RandySmith]

You can email me with any other questions Randyaero  @  Msn.com

Randy

[Brian Gardner]

Magic, thanks Randy. All input is good. We want something that is user friendly & works for everyone.

Brian

You can email me with any other questions Randyaero  @  Msn.com

Randy

[Bob Reeves]

This is really cool, thank you Randy for sharing info that I am sure took time to assemble.

[Randy Cuberly]

Terriffic!  Thanks for your input input into this project Randy.  That should make a REAL Stunt engine out of the 51!

Gotta have one!

Randy Cuberly

[RandySmith]

The P/S shown will work very well with the high compression head that ST made, if you hollow the head out reducing compression, it will also kill off power, that is not needed with these, so I would suggest if you make heads , make the like the ST or my PA  High compression Hemi head. Running the low compression version can be done but it will need a larger venturie, and ran in a 2/4 mode only.
The setup will also be best with a true venturie.  Set up at a number 13 to number 16 drill size. My setup to start with would be this P/S with a number 14 size true venturie, stock head, with 1 or 2 head shims only. R/C hot t-bolt and 10% nitro 22% oil, at least 50% synthetic, I would use 75 to 80 % of the oil synthetic.

Randy

[Brian Gardner]

Thanks Randy. The optional heads won't be fully hemied out. Just a slight increase to chamber size, not like the 46 & 60. They needed it due to the increase in port area as they don't have the ring bridges per the original liners.

[Brian Gardner]

Randy, does that mean you want to be added to the list?

Brian

Terriffic!  Thanks for your input input into this project Randy.  That should make a REAL Stunt engine out of the 51!

Gotta have one!

Randy Cuberly

[Randy Cuberly]

Randy, does that mean you want to be added to the list?

Brian

Absolutely!   However I want to use the stock head.

Thanks Randy Cuberly

[RandySmith]

I have 3 St G-51 , I am taking apart now, I will post info on the  diameters as soon as I get these, on the  head  and  top of the  sleeves

Randy

[EddyR]

When I last ordered rings for my two CL version 51's Frank mentioned that some Italian and China motors may have different size pistons. I had one of each and they were identical in every way. My motors are about 10 years old. They were poor runners untill I stoped using the factory supplied tall venturi. I moved the needle down to the case and then they ran normal with 11/4 -11/5 props . One is turning 12/5 in 70 ounce Bearcat.
Ed

[RandySmith]

When I last ordered rings for my two CL version 51's Frank mentioned that some Italian and China motors may have different size pistons. I had one of each and they were identical in every way. My motors are about 10 years old. They were poor runners untill I stoped using the factory supplied tall venturi. I moved the needle down to the case and then they ran normal with 11/4 -11/5 props . One is turning 12/5 in 70 ounce Bearcat.
Ed

Hi Ed

They made, basically the same motor in a ST G-49 , that maybe where the size difference in bore comes from
Setup right, they are as powerful as a ST-60, and many of my customers used the Bolly 12.5 x 5 on ones I did for them, I had one in my SIG Magnum as a test plane, and that is the setup I used, Bolly 12.5 x 5  10% nitro 23% oil, ran a strong 4/2, with short 2 cycle beeps across the top of manouvers.
The G49 could be made to run well also

Randy

[Bill Little]

I agree with Randy, when set up right, they are as strong as a ST .60.  One flew my original SV11 as good as any ST .60, it was 64 oz.

BIG Bear
RNMM/AMM

[Brian Gardner]

Thanks Randy, I've tracked down an extra engine to measure up too. So between all our measurements we should have a good sample of measurements.

I have 3 St G-51 , I am taking apart now, I will post info on the  diameters as soon as I get these, on the  head  and  top of the  sleeves

Randy

[RandySmith]

Hi Brian

Make the top of the sleeve no larger than 1.138  and that should cover you
If your going to cover the top of the sleeve with the head you will make, it needs to be at least 1.144
If you have found different in your measures please let me know if you have one more out of this range

Regards
Randy

[Brian Gardner]

Thanks Randy, that corresponds with the two engines I've measured up. Most appreciated.