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So what really sets one engine make/model apart from another?

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So what really sets one engine make/model apart from another?

Old 02-07-2016, 01:08 PM
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1QwkSport2.5r
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From what I've read, another modder said the Piccos have 20-25 degrees of blowdown, but do better with 30-35 degrees. He went on to say moving the blowdown up that high requires modifications to the exhaust port in the case to match the ports in the liner. I don't recall any mention of whether the crank or transfer/boost port timing is changed or not. I have to mount it up in my test stand fixture and degree it to see what it has to start with. I do this with many of the engines I buy, and keep a record of it so I have a baseline of what the engine is at to start with. My plan is to run a 086/9886 pipe and a short conical header (41015). It's going into a heavy truck that I just want brutal power in. I understand the Picco already has a strong bottom end, so I'd like to bump the top up a little if it needs it. The truck goes about 38mph with a Mach 427, I'd like to see if it will do a bit better than that - maybe 45mph? and still wheelie if I want it to. My SH .28 truck wheelies on command, but isn't all that fast (tops about the same speed as the Mach 427 truck) likely due to the pipe acting like a rev limiter.

The conrod will not come off the crankpin. The way it looks, I don't how on earth they put this together with the piston and rod installed as an assembled unit. The rod only comes about halfway off the crankpin.

Heres the link I was talking about: http://www.rctech.net/forum/nitro-of...engines-2.html

Last edited by 1QwkSport2.5r; 02-07-2016 at 01:14 PM.
Old 02-07-2016, 01:36 PM
  #77  
Nitrovein
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I didn't read through the whole page, can do so tomorrow.
The thing is, if you run a short manifold the puls has shorter way to travel, so the exhaust duration might be where it needs to be.
A pipe that slows it down might be a way to go also, the conical manifold should slow it down and the longer length delays it further.
But I don't know how long the onroad manifold are and how they behave, so I really couldn't say...
Old 02-07-2016, 02:22 PM
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Originally Posted by Nitrovein
I didn't read through the whole page, can do so tomorrow.
The thing is, if you run a short manifold the puls has shorter way to travel, so the exhaust duration might be where it needs to be.
A pipe that slows it down might be a way to go also, the conical manifold should slow it down and the longer length delays it further.
But I don't know how long the onroad manifold are and how they behave, so I really couldn't say...
Nobody seems to know how long those conical manifolds are. Generally, the higher the powerband desired, the shorter the pipe. This is how full wave tuned pipes work. Lower load/faster rpm = shorter pipe and higher exhaust timing. Higher load/lower rpm = longer pipe/shorter exhaust timing. If I have an engine with a strong bottom end already and maybe a little anemic on top, I'd want to adjust the top end to be stronger which would likely require a shorter pipe (as a system).

If I was made of money, I'd order one of every popular pipe and all the different manifolds and go to town with testing. Unfortunately I don't have that kind of resource (money), so I'm trying to determine through this thread what's the best case scenario and start with that. I've been tempted to even cut the stock LST header (and take a small chunk out each time) and test it out. That's how full wave pipes are tuned, I don't see how it wouldn't work with a car header.

This is what I get for trying to put a fancy engine in a MT and make it go fast. Nobody does this because everyone is brushless happy. I like my nitro MTs and will always have one or two. They come with a better challenge that I much prefer.
Old 02-07-2016, 02:51 PM
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There is often an misconception that it's the length that's the key to what rpm it will make power, it's volume and area's of the pipe that will give you the length. But sure, the last fine tuning is done with different length.

I might have an onroad manifold I could measure, but that's a Hipex manifold.

Picco 2046 pipe (the new in-line) might be a good candidate regarding pipes. I guess Neal could have tested that one. http://www.absolutehobbyz.com/RC-Con..._p_505098.html

Last edited by Nitrovein; 02-07-2016 at 02:53 PM.
Old 02-07-2016, 03:01 PM
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Originally Posted by Nitrovein
There is often an misconception that it's the length that's the key to what rpm it will make power, it's volume and area's of the pipe that will give you the length. But sure, the last fine tuning is done with different length.

I might have an onroad manifold I could measure, but that's a Hipex manifold.

Picco 2046 pipe (the new in-line) might be a good candidate regarding pipes. I guess Neal could have tested that one. http://www.absolutehobbyz.com/RC-Con..._p_505098.html
I found a new Dynamite hard anodized 086 on eBay for $37. That will be my first test pipe. The other pipe I'll obtain later will be a 9886SS. Neal says the 9886 is the bees knees, and I believe it. I'll try that one later this summer when I get the Legend 28-8 for the other LST.

FWIW, the stock LST manifold is 110mm long basically measuring the length along the inside of the header against the outer wall. Not the most accurate, so figure there's maybe +/- 10mm on that maybe. Neal says the LST manifold is too long and recommended a short conical manifold.

Last edited by 1QwkSport2.5r; 02-07-2016 at 03:25 PM. Reason: Fixed typo
Old 02-08-2016, 01:49 AM
  #81  
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Use a zip tie to measure the length of the manifold. Measure only the tube, not flanges, and the center of the tube.
Not inside or outside radius.

I believe he's right about the 9886, also 110mm is very long.
Old 02-08-2016, 02:23 AM
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I found Truggy pipe for .28 engines, I have no idea how they work, maybe Neal has tested one...(?)
The price is right; http://www.worldchampionproducts.com...pma280002.html

Do you know what rpm you need the engine to turn?

The onroad manifold I got measure about 45mm, it's from Hipex.
I'm not sure on how the pipe is mounted, but remember that Picco has an angled outlet. The "normal" offroad manifold is easy to tweak, but I doubt it's possible with an onroad manifold.
Old 02-08-2016, 03:48 AM
  #83  
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Originally Posted by Nitrovein
Use a zip tie to measure the length of the manifold. Measure only the tube, not flanges, and the center of the tube.
Not inside or outside radius.

I believe he's right about the 9886, also 110mm is very long.
I remeasured. Wire is yellow in the pic. 100mm. Best I can get.


Originally Posted by Nitrovein
I found Truggy pipe for .28 engines, I have no idea how they work, maybe Neal has tested one...(?)
The price is right; http://www.worldchampionproducts.com...pma280002.html

Do you know what rpm you need the engine to turn?

The onroad manifold I got measure about 45mm, it's from Hipex.
I'm not sure on how the pipe is mounted, but remember that Picco has an angled outlet. The "normal" offroad manifold is easy to tweak, but I doubt it's possible with an onroad manifold.
I don't have a specific number in mind. Just want crazy strong power and as fast as it'll rev. I need to use an on-road manifold because of the engine layout. Most buggies and truggies have the engine mounted with the exhaust to the rear of the truck. The LST truck has the engine mounted with the exhaust is facing to the left of the truck looking at it from the rear. The header needs to come off the engine, drop some, and make a 90 degree bend to mate with the pipe.

The pipe you linked to costs almost the same as the Novarossi 9886.
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Last edited by 1QwkSport2.5r; 02-08-2016 at 03:51 AM.
Old 02-08-2016, 04:25 AM
  #84  
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100mm should be pretty close from that picture, maybe a little less as it's not centered on the top, it should have been on the right side there, but that's impossible without cutting it.

I think one problem is that the engine is going to need to breathe through a slightly small manifold for the size.
So I would absolutely run a conical manifold and try to see if it's possible to remove edges or anything other restrictive.

Neal has experience with these engines, he could probably give you more hands-on experience.
But I can give you my take on it, but in that case I will do so in a PM.
Old 02-08-2016, 05:35 AM
  #85  
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The Picco 28 is fairly stout in stock form.....I would caution against modifying the ports of the engine as it is most likely you will end up losing power or creating a very lopsided powerband..without the use of a dyno it would be very difficult to make effective changes that would result in better overall performance, much better to stick to the basics like compression, crank timing and overall sleeve timing... silicone ramping a crank is a bad idea unless your filling an already existing cavity ( some Nova 21 have a back drilled cavity ) .... you cannot push mixture and any shaping you do to the outer wall of the flowpath will only behave like a obstruction and create even more separation of the incoming mixture... Much better to leave the outside radius natural and work on shortening the inside radius , the mixture will follow the shortest path naturally anyways ....
Old 02-08-2016, 05:42 AM
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to date I have dyno tested somewhere in the range of 100 different tuned pipes...pretty much everything I can get my hands on I will test...... overall the Novarossi 9886 is the king of pipes on almost every single engine I have tested....the very odd time another pipe edges it out or comes close, but for 98% of nitro big blocks that 9886 is the pipe you want .. It has fantastic power across the entire powerband, bottom, mid and top.....it is not just a top end pipe, far from it...At one time it was a very popular pipe for racing but EFFRA created a 3 chamber pipe rule about 10 years ago and 9886 become obsolete...But the reality is its a great all around pipe , mix and match with different manifolds to alter its personality and its pretty much a guaranteed good to go pipe on every big block money can buy bar none..... The Dynamite 086 is fairly close and the OFNA 086 is something else completely............ The Nova 9853 is 98% the same pipe, on some dyno tests the graphs were spot on identical and on some other engines the 9886 slightly outperformed it........ I know on the ground the 9886 tends to have a little more peak then the 9853, or at least the exhaust note sounds like it has..............
Old 02-08-2016, 06:38 AM
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One would think that someone could make a new pipe that perform like the 9886 even with 3 chamber, seems to be a hard nut to crack.

Looking at dyno runs I agree that the 9853 appear the same, but looking at the drawing on them they appear very different.
There are many way to get the same results it appears.

Do you (Neal) know if the P3 .28 as small in the crank case as the P7 Evo2?
I remember gaining a lot from mods in the crank case on those, and even after that it responded very well to larger crank bore.
Old 02-08-2016, 07:09 AM
  #88  
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Good stuff fellas. I'll keep it all in mind. If (a big if right now) I chose to have this Picco modified, is it absolutely necessary to run it in the process or can the proper mods be done and send it back unrun?

Nitrovein - it appears the measuring device wasn't centered in that picture, but it's just the camera angle. It was about as close to center as I could get it. It's a fairly long header, but to clear the chassis and starter mechanism, it kinda has to be. Using a shorter manifold is gonna put the pipe at a goofy angle, but there isn't much of a choice I don't think. Is this cylindrical Losi header gonna kill the powerband *that* much?
Old 02-08-2016, 07:21 AM
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Originally Posted by 1QwkSport2.5r
Nitrovein - it appears the measuring device wasn't centered in that picture, but it's just the camera angle. It was about as close to center as I could get it. It's a fairly long header, but to clear the chassis and starter mechanism, it kinda has to be. Using a shorter manifold is gonna put the pipe at a goofy angle, but there isn't much of a choice I don't think. Is this cylindrical Losi header gonna kill the powerband *that* much?
I meant that you should have a view from the right to see the center of the bend at the top.

According to my quick math the extra length should shift the power between 5-6000 rpm compared to a short manifold.
Measure the stock manifold and see, but my guess is that it's 12mm all the way.
I like the Novarossi manifolds as there is enough meat left on the bone to enlarge it.
With stock timing and long manifold you will have a lot of bottom end at least.
Old 02-08-2016, 07:27 AM
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Ok I've been sitting back and reading what you guys are talking about and since I'm thinking of getting a novarossi legend soon for my mmt xtm mammoth...

Currently I'm running a brand new 24.7 xtm hpi savage header and some no name pipe.....I have yet checked my mph but it's pretty fast..Can get a slight wheelie for such a big truck..

Since my engine faces different than the lst the dynamite header and pipe will be a direct drop in...now can I use that on my 24.7? Till I save up for the legend?
Old 02-08-2016, 08:11 AM
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Originally Posted by Nitrovein
I meant that you should have a view from the right to see the center of the bend at the top.

According to my quick math the extra length should shift the power between 5-6000 rpm compared to a short manifold.
Measure the stock manifold and see, but my guess is that it's 12mm all the way.
I like the Novarossi manifolds as there is enough meat left on the bone to enlarge it.
With stock timing and long manifold you will have a lot of bottom end at least.
Any of the engines I've run in these trucks, there's never been a shortness of low-end power. Even the lowly Mach 427 will wheelie sometimes. The SH .28 will wheelie effortlessly. I have the transmission output gears flipped which adds a tooth on the output (tiny bit faster) and I have new bevel gears for the LST brushless conversion which adds 2 or 3 teeth to the output which should make it faster on top and make it wheelie a bit less. Clutch and spur gear options are pretty limited on these trucks, but I'll be shifting that around a little bit as well as I do have a couple options to lower the spur tooth count a few teeth on the high gear. With an engine that already has a good bottom, I want to tune the engine to open up a bit better on top and still have enough bottom end to get the pig moving. The truck weighs about 13 pounds as it sits and the SH .28 throws it around like a rag doll with just the trans gear flip mod.. I can only imagine how she'll do with a few extra teeth in the trans and a more stout engine/pipe setup. Now if the damn snow would melt so I can get the beast out and run it....
Old 02-09-2016, 08:49 AM
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Did you find time to measure the diameter of the stock manifold?
I doubt that it would work very well anyhow, but for sake of asking...
Old 02-09-2016, 12:05 PM
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Originally Posted by Nitrovein
Did you find time to measure the diameter of the stock manifold?
I doubt that it would work very well anyhow, but for sake of asking...
I haven't gotten to it yet. I was going to do it tonight after work.
Old 02-09-2016, 01:17 PM
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The stock LST header is 13.5mm I.D. at both ends.
Old 02-09-2016, 02:06 PM
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That's not to bad, but it's still way to long...
Trying to go around it in the engine will give por results, but if it's the only way, you can at least improve some.
Old 02-09-2016, 04:36 PM
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Originally Posted by Nitrovein
That's not to bad, but it's still way to long...
Trying to go around it in the engine will give por results, but if it's the only way, you can at least improve some.
I'll try a short conical header from Nova to start with. Worst case scenario I need to get a medium length header if the shorty doesn't fit.
Old 02-10-2016, 04:52 AM
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i would get the medium onroad conical...... the 41032 that I know dynoes well is 18 mm long with the widest point being 15mm.......the onroad manifolds look much shorter then ofroad...........

http://www.novarossi.it/2012/index.p...ad/3-5-cc.html
Old 02-10-2016, 07:10 AM
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Originally Posted by supertib
i would get the medium onroad conical...... the 41032 that I know dynoes well is 18 mm long with the widest point being 15mm.......the onroad manifolds look much shorter then ofroad...........

http://www.novarossi.it/2012/index.p...ad/3-5-cc.html
Okay. I'll look at the 41016 then. That's the medium on-road one.

18mm long? That's damn short. 1/5th the length of my stock header; granted its a buggy header, but still. That's short.
Old 02-10-2016, 07:17 AM
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http://www.novarossi.it/2012/index.p...-5-4-66cc.html

I think I misprinted LOL

there is no way it is 18 mm LOL......

Last edited by supertib; 02-10-2016 at 07:19 AM.
Old 02-10-2016, 07:20 AM
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Originally Posted by 1QwkSport2.5r
Okay. I'll look at the 41016 then. That's the medium on-road one.

18mm long? That's damn short. 1/5th the length of my stock header; granted its a buggy header, but still. That's short.

I am wrong...there is no way its 18 mm....

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