Originally Posted by
TripleDeucer
So, are you working the Saito's over yourself? I have a 1.80 that I don't use much because it likes to kick the prop loose. Would your mods help my engine? Do you work on other peoples engines, like mine?
LOL just for fits & giggles I tried running the high compression 180 on glow ignition. It was an evil prop spitting monster. Absolutely psychotic! But, the engine was designed to be CDI only.
On any Saito about 100 or above, CDI will soon pay for itself in fuel savings. Fuel economy improves by about 25% when the same glow fuel is employed with CDI. Max RPM usually improves by 200-300 RPM. On my FA200Ti fuel economy improved by 70% but I didn’t see an improvement in HP.
My prototype FA180HC was made from an FA150 case that has a .055” shorter deck. I had to use a .020” spacer to keep the piston crown/head clearance acceptable so a net reduction in compression height of about .035 is maximum. The FA150 case also required a lot of clearance work that will not be necessary W/a 180 case. On an FA180 case the proper compression height can either be accomplished by milling the case deck .035” W/the stock FA180 piston, or use an FG57 or FG84 piston & reduce the deck by .020”. (The FG57 & FG84 pistons have .016” taller compression height.)
Just using the FG57/FG84 piston W/CDI would make a significant improvement bringing CR up to about 11:1 & it wouldn’t require valve notch clearance work or deck machining.
Here is a thread about the FA180HC prototype.http://www.rcgroups.com/forums/showthread.php?t=1754616
Here is another thread that documents HP & fuel consumption. http://www.rcgroups.com/forums/showthread.php?t=1769449
Finally here is a video clip of the FA180HC CDI engine before I ported the intake manifold & employed the 12mm FA220 Big Bore carburetor. (The induction improvements added 400 RPM @ WOT) http://www.youtube.com/watch?v=5xaiAR8Yelc
As you can see in the video, CDI makes a huge improvement in idle, hand starting & transition as well as the HP & fuel economy gains.
If you would like me to work on your engine RM me for a phone # & we could discuss it. A CH-Ignitions CDI will run a $150 installed & tuned. Depending on which way you want to go, either 11:1 or up to 13:1, the engine work would run from $75 to $125 respectively plus shipping/insurance. That would include a new piston & ring. If I use your piston & reduce the deck .035", the 13:1 combo would be $90.
Last edited by SrTelemaster150; 01-30-2014 at 06:59 PM.