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Old 12-02-2014, 06:06 PM   #1
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Default Decided to practice porting and polishing engine parts. Tell me how I did.

I'm trying to find a way to get a little more power out of a .18 engine that isn't practical to upgrade, and I remembered reading an article about porting and polishing nitro engines, so I dug out the article and grabbed some worn-out parts to practice on. Pictures follow; before is on the left, after is on the right.

Conrod beveling and polishing


Cylinder sleeve porting and polishing


I dug a little too deep on one of the guide channels and changed the shape of the inner port surface, but that's what practicing is for. Anyway, the alteration is on the lower edge of the port, so it shouldn't affect timing even if I were going to use this cylinder sleeve again.

Comments? Suggestions?
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Old 12-02-2014, 06:10 PM   #2
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Also, are there any mods that are specifically better-suited to improving low-end torque?
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Old 12-02-2014, 06:19 PM   #3
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All the port massaging usually adds to the top end of the motor. If you need low end power, youll find the best results with a tuned pipe.
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Old 12-02-2014, 06:59 PM   #4
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Default porting

check out ( section 8 racing ) on facebook the profile picture is a modded sleeve . there is some really good pictures and information on the page. if you are into porting you will like the pictures trust me.
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Old 12-02-2014, 07:08 PM   #5
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I imagine the rods would have to be polished to ensure there werent any micro-abrasions that could lead to premature failure but that is pure speculation on my part since I have messed with anything like this.
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Old 12-02-2014, 07:30 PM   #6
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Quote:
Originally Posted by Hoese37 View Post
All the port massaging usually adds to the top end of the motor. If you need low end power, youll find the best results with a tuned pipe.
In that case, which qualities should a tuned-pipe have to give an engine more low-end torque without making it suffocate in its own exhaust fumes at high RPM? Currently the engine just uses a hollow-can pipe.
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Old 12-02-2014, 07:36 PM   #7
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Quote:
Originally Posted by madweazl View Post
I imagine the rods would have to be polished to ensure there werent any micro-abrasions that could lead to premature failure but that is pure speculation on my part since I have messed with anything like this.
The conrod is polished, just not to a mirror-shine. There are machining marks from the original manufacture that are more prominent than the marks I left after beveling, so I don't think it will lead to premature failure.
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Old 12-02-2014, 07:44 PM   #8
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you see some gains with this and it looks good. On the cut you went too deep make sure you use a diamond file on the chrome and get all burrs and sharp edges off so it doesnt scratch the piston.

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Old 12-03-2014, 12:16 AM   #9
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Well, those were just practice parts; the only part that will ever be used is the conrod, because it isn't worn-out already. While I may bevel the conrods on my other engines to reduce turbulence, the only engine I have that runs at top speed for extended periods is my Picco .08, so I think I'll test the porting on that engine first. Of course, that's the smallest engine too, so that makes it all the more important to get the cut depth just-right.

In fact, I decided to do that this evening, once I found a finer diamond-grinder in my Dremel toolbox. Here's the results:



As of right now I know the engine still runs, but that's all I know. First of all, it's too late to take the little buggy for a drive, and second, my engines HATE the synthetic machine oil I use when rebuilding them, and they're an incredible pain to get started the first couple times after a rebuild. I really need to find a rebuild oil that's more-compatible with nitro fuel oil.

I've read stories where people have ported their engines and then promptly blew them up from over-revving. I'm happy with how fast the Picco .08 goes already, so if I get more RPMs out of this mod, I might just take advantage of the opportunity to tune it richer to keep the engine better-lubricated.
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Old 12-03-2014, 12:59 AM   #10
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This is a very good engine rebuild oil. Also for after-run if you will. It has a very high capilary-effect (sp?) and diggs in everywhere. Been using it for many years

http://tamiya-color.com/shop/en/8182...ent-spray.html
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Old 12-03-2014, 01:50 AM   #11
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Does it come in a non-spray format? I do my rebuilds in a carpeted apartment bedroom, I'd much rather drip the oil where it needs to go.
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Old 12-03-2014, 03:06 AM   #12
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Not that I know of. But its no problem regulating the flow, at least when using the included straw.
Looks like its out of production now? I bought a few cans some years ago, so I havent had to buy one for a long time.
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Old 12-03-2014, 06:02 AM   #13
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Just buy some nitro engine after run oil. Works great for reassembling a nitro engine with no ill side effects when starting after a rebuild.
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Old 12-03-2014, 09:50 AM   #14
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How much have you modded that piston? It is very important that the piston covers the exhaustport completly when the piston is at TDC.
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Old 12-03-2014, 11:48 AM   #15
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Quote:
Originally Posted by Micah78 View Post
Just buy some nitro engine after run oil. Works great for reassembling a nitro engine with no ill side effects when starting after a rebuild.
I was wondering if after-run oil would work. Thanks for confirming.
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