3LikesHow do you adjust engine timing on nitro engines?
11-10-2008 | 12:42 PM
#93
Tech Master
Joined: Jul 2004
Posts: 1,842
From: Norway
Hi!
Very interessting the degree wheel!! Can anyone post a link to a web shop that sells and ship them outside their country. I have been looking for something like this for litterally years, i have used a cardboard with a copy of a degreewheel on, but that thiingy is just da bomb!!
Thanks for you help.
Anders
Very interessting the degree wheel!! Can anyone post a link to a web shop that sells and ship them outside their country. I have been looking for something like this for litterally years, i have used a cardboard with a copy of a degreewheel on, but that thiingy is just da bomb!!
Thanks for you help.
Anders
12-27-2008 | 05:53 AM
#95
Hi Roelof,
I think the info you are giving here is a bit too general and could lead people to mess up their engines.
First of all, you have to find out the timing of a crank, before you can decide how to modify it.
For example: a Picco .12 based crank opens very late at 40° ABDC and closes at 60° ATDC. On this kind of engine, you'll see much better results to make it open 5-10 degrees earlier, i.e. take material off the other side than in your graph.
Oh, and stay within 220° of total induction, other wise it will be hard to tune and fuel consumption will go throught the roof.
I think the info you are giving here is a bit too general and could lead people to mess up their engines.
First of all, you have to find out the timing of a crank, before you can decide how to modify it.
For example: a Picco .12 based crank opens very late at 40° ABDC and closes at 60° ATDC. On this kind of engine, you'll see much better results to make it open 5-10 degrees earlier, i.e. take material off the other side than in your graph.
Oh, and stay within 220° of total induction, other wise it will be hard to tune and fuel consumption will go throught the roof.
12-27-2008 | 08:45 AM
#96
Tech Lord
Joined: Aug 2007
Posts: 14,044
From: Holland
12-27-2008 | 08:57 AM
#97
Up to the EVO 2 is listed:
http://www.first-racing.eu/html/steuerzeiten.html
http://www.first-racing.eu/html/steuerzeiten.html
12-28-2008 | 01:59 AM
#98
Tech Elite
Joined: Aug 2001
Posts: 3,278
From: Bavaria, Germany
so your saying the picco crank, has 200 deg of duration ? i actually measured 205 deg on all 3 picco engines i have. one an IDM evo 3, a JL std, and a JL tuned. so if one was to open up the duration further to say 215 like nova based motors, would one see a big difference ? i agree the opening would have to opened up,a s there is about 10 deg difference here from the nova engines. just thinking out aloud at the moment, i am in the process of degreeing all my engines. so there is about 4 more to go . so far the plus 12-3sct has the most duration of all the engines i have checked so far.
Are you sure you are measuring correctly? How do you set the degree wheel to zero?
I measured these engines: IDM EVO3 (4 engines), LRP Spec4(3 engines), LRP Spec3, Picco EVO3 Edo, Mega ZX12 DSII (2 engines), Collari Inotech and an old Picco EVO.
I also have a few Plus 12-3 ST and SCT on record and the crank duration of the stock engines is usually 210 degrees. Is that also what you measured?
12-28-2008 | 05:40 AM
#99
Hmm, I have data of about 15 Picco based .12 engines in my little book, all engines I timed myself and the only Picco based crank that had a different timing was an old Collari engine. All the other have 200 degrees crank timing (40 -60).
Are you sure you are measuring correctly? How do you set the degree wheel to zero?
I measured these engines: IDM EVO3 (4 engines), LRP Spec4(3 engines), LRP Spec3, Picco EVO3 Edo, Mega ZX12 DSII (2 engines), Collari Inotech and an old Picco EVO.
I also have a few Plus 12-3 ST and SCT on record and the crank duration of the stock engines is usually 210 degrees. Is that also what you measured?
Are you sure you are measuring correctly? How do you set the degree wheel to zero?
I measured these engines: IDM EVO3 (4 engines), LRP Spec4(3 engines), LRP Spec3, Picco EVO3 Edo, Mega ZX12 DSII (2 engines), Collari Inotech and an old Picco EVO.
I also have a few Plus 12-3 ST and SCT on record and the crank duration of the stock engines is usually 210 degrees. Is that also what you measured?
but its cool. i am playing at the moment. so the IDM crank i opened the closing side to 212 duration. its old and had a lot of use. but if it still Idles and runs fine, then i will do to all my JL's. of course i will do a consumption test, but wont be totally acurate, as the engine is quite tired.
02-16-2009 | 08:19 AM
#100
Tech Rookie
Joined: Feb 2009
Posts: 3
From: Florida
Ignition timing is done by headshims and glowplug.
Lower compression will give a later ignition
colder plug will give a later ignition.
(by the way: less nitro will give a later ignition as well)
later = more rpm but less power
sooner = more power but les rpm and a hotter engine....
Colder plug with higher compression will keep the timing the same but the higher compression will give more power, the colder plug can give an unstable engine....
Porttiming can be changed mechanical.
Higher ports by grinding the ports out
Higher ports can also be made by adding a modified headshim under the edge of the sleeve
lower ports can only be made by taking off some material from under the edge of the sleeve.
Higher exhaust will give more rpm but lower power, lower exhaust will give more power but les rpm. Widening the exhaust will give more rpm without affecting the power.
Take care with positioning of the sleeve that you change the headshims as well.
Changing crankshaft timing can do a lot to get more power or more rpm, it can only be done by grinding,
Lower compression will give a later ignition
colder plug will give a later ignition.
(by the way: less nitro will give a later ignition as well)
later = more rpm but less power
sooner = more power but les rpm and a hotter engine....
Colder plug with higher compression will keep the timing the same but the higher compression will give more power, the colder plug can give an unstable engine....
Porttiming can be changed mechanical.
Higher ports by grinding the ports out
Higher ports can also be made by adding a modified headshim under the edge of the sleeve
lower ports can only be made by taking off some material from under the edge of the sleeve.
Higher exhaust will give more rpm but lower power, lower exhaust will give more power but les rpm. Widening the exhaust will give more rpm without affecting the power.
Take care with positioning of the sleeve that you change the headshims as well.
Changing crankshaft timing can do a lot to get more power or more rpm, it can only be done by grinding,
later = more rpm but less power
sooner = more power but les rpm and a hotter engine
Less percentage nitro is easier to burn than more nitro.
In your statement above concering more or less RPM, nitro content has nothing to do with top RPM,
the pipe design and pipe length controls top RPM
Hope this helps
moby
02-16-2009 | 10:00 AM
#101
I believe you have this statement backwards, [B]((by the way: less nitro will give a later ignition as well)
later = more rpm but less power
sooner = more power but les rpm and a hotter engine
Less percentage nitro is easier to burn than more nitro.
In your statement above concering more or less RPM, nitro content has nothing to do with top RPM,
the pipe design and pipe length controls top RPM
Hope this helps
moby
later = more rpm but less power
sooner = more power but les rpm and a hotter engine
Less percentage nitro is easier to burn than more nitro.
In your statement above concering more or less RPM, nitro content has nothing to do with top RPM,
the pipe design and pipe length controls top RPM
Hope this helps
moby
02-16-2009 | 10:46 AM
#102
Tech Lord
Joined: Aug 2007
Posts: 14,044
From: Holland
In reality more nitro does give more room to find a good setting. With a (to) low nitro content finding the spot for maximum performance is very small and it is easy to go to lean, with more nitro it is easy to stay on the rich side and still to have power and speed.
More nitro will give a better acceleration what will give a fraction higher topspeed on the end of the straight, it can make a 5 to 8 km/h difference. More nitro will also give more power what you can use to gain more topspead with a faster gearing.....
More nitro will give a better acceleration what will give a fraction higher topspeed on the end of the straight, it can make a 5 to 8 km/h difference. More nitro will also give more power what you can use to gain more topspead with a faster gearing.....
04-08-2009 | 06:18 PM
#103
Tech Apprentice
Joined: Aug 2008
Posts: 64
From: Tennessee
Sing-grooves, I have tested is and I am amazed...
http://www.somender-singh.com/
My JP Eagle.
It is shown that the combustion is more spread on the piston and did give a better performance. The question is what is legal to modify....
As I told here before the cranktiming can do a lot, but if it is not alowed to modifi the crankshaft and they do inspections you can always alter the cranktiming by modifying the crankcase in the hole under the carburator, they will never inspect that
http://www.somender-singh.com/
My JP Eagle.
It is shown that the combustion is more spread on the piston and did give a better performance. The question is what is legal to modify....
As I told here before the cranktiming can do a lot, but if it is not alowed to modifi the crankshaft and they do inspections you can always alter the cranktiming by modifying the crankcase in the hole under the carburator, they will never inspect that
