I have a saito .91 I would like to get more power out of, does anyone know any good engine mods like AB does for rc car engines? Thank you all very much. Jason

This question comes up on here every few months and is typically asked by car type guys

The best answer is to sell your 91 and buy a bigger Saito. The Saito 115 has all the same external dimensions as the 91 and about the same weight.

The Saito 100 and 125 have the same external size as each other but the power is different.

OK, thank you W8 because I ended up going with the TF at-6 and want some more speed out of it, I will do what you suggest. Thank you W8 you are always very helpful. I appreciate it greatly.

The problem with hopping up an engine if you cannot do it yourself, is the cost. It is cheaper to buy a bigger engine.

Modified engines are not common in the R/C plane world except maybe for competition events.

We have so many more choices than the car guys, no one bothers with modified engines.

If you are looking for something to replace that saito .91 with a similar size engine, the YS 1.10 is the way to go. The YS is supercharged and fuel injected, very powerful, WOooo HOoooo..........

I do my own modding and have modified alot of engines. Twostrokes are easy to modify for more power but the fourstrokes are not that easy to hop up. On my fourstrokes all I do is to drill out the outlet of the muffler some, and remove a headshim or two and reset the valve gaps. This does not give very much power increase, only maybe 100-300 rpm. More can actually be had by experimenting with different fuels. I do this mostly because I like to fiddle with my engines and I want them to perform their best

If you need more power then a given fourstroke can provide it is best to get a bigger one.

The Saito 100 is great as a hop up engine in the 90 size because it weighs only 600 grams and most other .91 fourstrokes weigh 640 grams

w8ye has, as usual, hit the nail on the head. The old axam "There is no substitute for cubic inches" applies. The only exception (IMO) is if one is possessed of the the combination of interest and expertise to make the "hop-up project" a worthy venture on it's owm merits even if the finar result does not live up to expectation.

Whatever you do, enjoy!

jess

Well I made a OS 52 out of a OS 48 and have used the engine for three years. I also have three other OS 52's and there's no difference in the way the four engines run.

However it would have been cheaper to have bought a OS 52 at a swap meet than to convert the OS 48. Now all I have left of the 48 is the crankshaft, crankcase, & bare head.

The guy that has access to a machine shop and milled down the crankcases on his Saito engines to increase the compression ratios made out OK. It didn't cost him anything.

It surprises me that some enterprising individual hasn't offered a set of custom camshafts for various model glow four-strokes. Who would buy them? The folks that have transitioned from R/C cars to R/C airplanes. Years ago, the car crowd didn't bat an eye when paying $700 for a handful of upgrade parts.

A friend that owns a hobbyshop in NJ tells me that airplane guys are a bunch of cheapskates. He changed his shop from selling mostly R/C airplane stuff to catering to the R/C ground guys. I can see his point.


Ed Cregger

Jacked...if you're not already doing so, you could try running 30% nitro Heli fuel...that'll give you several hundred more r.p.m.

Same over here ed.Lhs is 80% cars and the rest is bits and pieces for planes and trains.If you get served within ten minutes you count yourself lucky because the counter is four rows deep with excited car owners in a rush to part with some big bucks for all kinds of go faster parts.Then i get to the front holding a two dollar clevis i was lucky to find

The ultimate playground for modified model airplane engines was always control line speed. Of course that's all two stroke.

jess

I just don't think there is much demand for modified four strokes. You can buy a larger engine without any problem. If there were popular competition classes where displacement was limited and engine mods were allowed, there might be demand. I could see some demand the old time pattern event(I forget what it's called specifically) with displacement limits set to 15cc, but maybe the currently available engines are satisfactory, or mods are not allowed. I think there is more power hidden in most engines, but people are reluctant to take rotary tool to a 300USD engine. I've seen a few mods for increasing power in four strokes. I've done a few mods but nothing specifically to increase power at this point. I'm going to try a few in the spring.

If a car engine quits or breaks, the car stops. If an airplane engine quits in the air, the model's fate is very dependent on the pilots ability to land. Some can land any deadstick at their feet, some lock up and crash every time.