High power sport engine
 

How much would you guys pay for a normal sport engine like a OS 55 that has been Modded to turn a 11x7 at 14,500 or say a Gp 42 that will turn a 9x8 at 16,500-17,000 and is only 9 ounces?

I am just wondering i see a couple of guys offer ported cylinders for the car guys and want to see if others would like a bit more power from normal sport engines.

RE: High power sport engine
 

Get'cha a JETT engine.

RE: High power sport engine
 

Hi!
Those figures are just not possible!

RE: High power sport engine
 

Yes they easily attained. thats why I was wondering if anyone would pay a little more for more than normal power out of sport engines.

maybe i will make a few engines and then sell them to see if any takers.

RE: High power sport engine
 

The .55 AX will do it. I have cracked 14K in stock form using an 11-7 APC/ 15% nitro/ 8.5 Macs pipe. It was peaky and had a useless mid range (rich). This is to be expected with a "peak" set-up. I get about 13, 600 using a Macs 10cc Quiet pipe. a little less top end but a useable mid range. I believe that with some additional exhaust duration, 14k+ with a user friendly pipe set up like the 10cc quiet pipe is possible, and it would be a viable power plant for classic pattern aircraft.

-Robert

RE: High power sport engine
 

KLX the 55 with a jett muffler and some timing and carb mods it does really well on the 11x7. we have got them up to 15,000 on the 11x7 but they will only last about two seasons this way. 14,500 though and they last a long time. You do have to change bearings out even bone stock ones.

RE: High power sport engine
 

Yup. The stock bearings did not last long, and the replacements (Boca "High Performance" 52100 steel) are about done. Sorry, no hard data on hours.

I've beat up on that engine pretty hard, it is now semi-retired. It is turning a 12/6 with the stock muffler in it's current usage.

RE: High power sport engine
 

The OS 55 AX and a Macs 8.5 Quiet pipe will turn an APC 11X7 at 13,900 rpm backed off peak on 15%. Need a bit more? 14,300 off peak using 30% and an OS #10 or K&B HP glow plug.
Is 400 rpm worth it? That's up to you. I either case you best get stainless bearings from RC Bearings if you want it to live a while if it's pushed this hard.

Could a port job yield more power? Absolutely, but there may be some cost like idle-ability, transition, fuel efficiency, and engine life. A skilled craftsman may get away with porting nickle plated liner......... most of the time.

RE: High power sport engine
 

Actually the ones we have done idle just like normal and transition very well. I have a Avistar 53 that took some time but got it to turn a 10x7 at 17,300.

most of the 46-55's burn about one ounce a minute on the Jett pipe. we set them up to run these levels on 5% nitro also.

RE: High power sport engine
 

S.S. bearings are not even as durable as Std bearing's since the rockwell hardness of 440 strainless is quite a bit less than conventional bearing steel. S.S bearing handle corrosion better, that's it. A quality Polyamide retained standard steel bearing is allthat is required.

RE: High power sport engine
 

Hi!
Like the Swiss WIB C4 bearings used in Nelson engines!

RE: High power sport engine
 

I would be interested in the GP 42 piston and sleeve turning your numbers. How much are we talking?

RE: High power sport engine
 

would have to do the whole engine its just not a piston and sleeve. the carb, crank, case, piston and sleeve all need work. once done though make a great engine under 12 ounces with the jett muffler.
Shoot me a email and we can work through the Details.

RE: High power sport engine
 

If I need the performance I just dig out a Rossi .53 five port. No sense buying a expensive sport engine and the having it mod'd to run faster.
If I needed more performance I would go with a Jett engine but I suppose since they have the VP modified Rossi engines there is a market out there that exists for OS 55AX engine modified. I would be concerned with how well the nickle plating on the cylinder holds up to higher performance levels of stress. The Rossi engines still use real chrome in their ABC engines.
Anyway I wish you good luck in your endeavors, it sounds interesting,

Now if you have made some real ABC cylinder and piston combos for the 55AX, that would be really neat. I can see lots of people being interested in that.

Do the 55AX engines hold up well with only 4 head screws holding the head on when modified for higher performance? I would think they needed 6 screws at the minimum, but what do I know, the 4 screws seem to work Ok for the most part in the engines. I saw that some other engine brands like SuperTigre are only using 4 screws too.

RE: High power sport engine
 

Well, based on what I saw today, I'm not super impressed. Airraptors 46FX modified turned an APC 9x7 at 17,000rpm on the 3rd run on 5% nitro 20% oil. Ran my TT 46 pro right after and got 16,500rpm on the same prop, plug, and fuel. The TT hasn't run much this year, last summer I was getting 16,800rpm on the very same prop, plug, and fuel.

Considering the amount of work done to this engine to get this result, it's not worth doing IMO. I could make up the rpm difference with more nitro. I'm sure if I ran the dickens out of it I may have seen better results. Maybe.

RE: High power sport engine
 

Did you buy an engine from Airraptor or his engine guru?

RE: High power sport engine
 

He sent me a modded engine to test out. I was considering having one modified. I wasn't in perfect zen or something because I didn't get the result I expected.

RE: High power sport engine
 

"I would be concerned with how well the nickle plating on the cylinder holds up to higher performance levels of stress. The Rossi engines still use real chrome in their ABC engines." I always wondered about this too and thought it would be fairly easy to strip the plating and do a proper copper-nickel-chrome job after porting a stock liner. I believe the liners are brass in most OS motors. They would have to be lapped after a kiss with the hone on the liner. It would be better if OS would just make them right from the start. They charge enough for them, and had a lot of returns over the years. I am sure this service would be worthwhile for someone to do.

RE: High power sport engine
 

The moneymaker would be (for the OS Enthusiast) to buy magnum/asp 46 piston and liners which are true abc and install them in the OS engine and sell the OS piston and liners on eBay. Then you could do all sorts of port work and never need to worry about the plating peeling.

RE: High power sport engine
 

Okey, I understand it isn't Airraptor that makes the mods (but his engine guru) and I have seen some rather ridiculous rpm claims in other threads too. Good to know that the earth is still round and will stay that way...

RE: High power sport engine
 

It almost sounds like the ASP/Magnum is a better base engine to start with.  I am happy with the gains on my little guys.  If the liners need to be turned down to fit on the OS motors or something, it would be easier than boring the case.  I haven't seen one, but it already fits on the Magnum so it seems like the ASP Magnum is the better animal to start with and just fine tune it.(change carb parts head shapes etc.)  Or get the Jett or Fora or something else for about the same money if you are paying someone to do the mods.

RE: High power sport engine
 

As with anything, I probably didn't do something right. I am not sure if the sun was in line with Venus or if my chÃ* was at peace or not. 17k flat on a 9x7 APC. I got 16,500 with my bone stock TT 46 pro.

RE: High power sport engine
 

west eurotech 52v1 high power sport engine.
http://www.westonuk.co.uk/westonuk2_021.htm

RE: High power sport engine
 

Yes i dont know why that engine i sent him didnt run well for him. before i sent the 46 it did spin a APC 9x8 at 17,300 on 10% fuel. it hadnt ran in a couple of years so when i ran it the bearing or something could have gone bad or the liner peeled on it as it was a 46 with many hours on it.

Yes my engine goy does most of the work yet i am learning from him also.

I do know Mr Cox has been a non believer from the start if not a hater lol but i have seen all the results as he runs engines every day at the field. all he does is work on the engines then brings to the field to test and re do till the numbers are achieved.

a new engine will be going to 1QWK soon. ; )

RE: High power sport engine
 

If you are wanting to sell some of your modded engines why not just get a camera and put up some videos? Nowadays anyone anywhere who sells anything has a picture or video of it available at a mouse click.

I had actually asked you in a post a few months ago for some video, not to disprove you....but if you have the engine doing that I would enjoy and be motivated by seeing it! I think you said maybe in a week or so, but I've never seen the link? I've seen a lot of your reported #'s and I would think with some simple 30 second videos of the engines running backing them up you would have people waiting in line.

If you are running the engines anyway how hard is it to push the button on a camera?

You are kinda asking people "How much would you pay for this?" And they ask "Can I look at it?" and.......... Todd