R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro On-Road

Like Tree2Likes
Reply
 
Thread Tools Search this Thread
Old 06-27-2014, 01:25 AM   #601
Tech Master
 
Join Date: Apr 2011
Posts: 1,080
Trader Rating: 14 (94%+)
Default

Quote:
Originally Posted by dan_vector View Post
1. The Alu bell wears extremely quickly if your clutch isn't setup perfectly. If you have a lot of slip then you will ruin the Alu bell in a few seconds. Your friend is partially right in that the Alu bell is quite sensitive to needing accurate clutch setup. If your not 100% happy with clutch setup then stick to the steel bells for now. The wear inside your current bell is not good and contributing to the issue you are having with bogging. Change it for a steel bell before continuing.

2. What end float and end play are you running? Make sure it's 0.6mm and 0.1mm. Below 0.6 will cause bogging. It's difficult to say how many turns in to set the adj nut because the setting various clutch to clutch engine to engine but start with 10mm down from the end of the crankshaft and then tune it from there.

I doubt your broken conrod is totally attributable to a bogging clutch however you will see higher engine temps if the clutch is either bogging or slipping. My advice is to recheck your engine settings as well before continuing on a new engine as it's likely the piston/sleeve/head/main bearing is toast when the rod breaks...
Dan,
I've been recently using 0.5-0.6mm clutch gap... So that's the problem I guess? I've been told to use 0.5mm though. What the heck?!
The preload turns shouldn't matter that much at this point. I've tried different turns anyways.
The engine temp was 240-290F but I really didn't care much about it.
I'm currently using STEEL bell. The aluminum bell I mentioned is in my bag. So you're saying the thread inside the bell shouldn't be there, right? Is it supposed to be smooth on surface just like steel bell?
__________________
Capricorn LAB C03
snuvet75 is offline   Reply With Quote
Old 06-27-2014, 01:32 AM   #602
M7H
Tech Elite
 
M7H's Avatar
 
Join Date: Dec 2004
Location: The Netherlands
Posts: 2,193
Default

Quote:
Originally Posted by dan_vector View Post
It's difficult to say how many turns in to set the adj nut because the setting varies clutch to clutch engine to engine but start with 10mm down from the end of the crankshaft and then tune it from there.
Everytime I assembly my clutch, I just fully screw in the clutch spring, until it's fully compressed, and then unscrew the nut 1.5 turns, (360 + 180 degrees) this combined with a gap of 0.7mm, gives you a (near) perfect clutch, which only might need a slight readjustment. But be sure, the flyweights rotate freely, without a lot of binding, over the flywheels pins. If they don't I unscrew the nut a bit more, run the car, and readjust when parts loosen up.

I also advice everybody who is doing clutch maintenance, that before unscrewing the clutch nut, first fully tighten it, and note the exact number of turns. Then later, when assembling the clutch, with the same parts, just tighten it full again, and unscrew with the same amount of turns, it's that simple.
__________________
Serpent

Last edited by M7H; 06-27-2014 at 03:17 AM.
M7H is offline   Reply With Quote
Old 06-27-2014, 01:34 AM   #603
Tech Master
 
Join Date: Apr 2011
Posts: 1,080
Trader Rating: 14 (94%+)
Default

Why does 0.5mm clutch gap give bogging anyway?
__________________
Capricorn LAB C03
snuvet75 is offline   Reply With Quote
Old 06-27-2014, 01:39 AM   #604
M7H
Tech Elite
 
M7H's Avatar
 
Join Date: Dec 2004
Location: The Netherlands
Posts: 2,193
Default

Quote:
Originally Posted by snuvet75 View Post
So you're saying the thread inside the bell shouldn't be there, right? Is it supposed to be smooth on surface just like steel bell?
The ALU bell, will get scratched on the inside, it will not be smooth, don't bother about that. But I do think you should only use it for qualifying, because it will not last long enough for a main final.
__________________
Serpent
M7H is offline   Reply With Quote
Old 06-27-2014, 02:01 AM   #605
Tech Elite
 
Join Date: Oct 2013
Posts: 3,274
Trader Rating: 23 (100%+)
Default

I agree the alu bell does indeed get scratched up and isn't smooth like the steel bell but deep grooves on the drive face isn't ok in my opinion. I don't run the alu bell as it just doesn't last long enough and to me the benefits are too small to matter to me.

There are many ways that people reach the ideal clutch setup but I do like M7H's method of adjusting the spring tension and will be giving it a go.

The 0.5 end float will cause bogging because it doesn't give the shoe enough room to engage at the right RPM. It makes it engage too early and then to compensate you tighten down the adj nut further which makes it engage later but not hard enough and it then slips.

0.6mm start with a new shoe results in ~0.7mm after the initial bedding in run.
__________________
Serpent Viper 977e, Serpent Project 4x, Serpent 811T-TE Truggy, Serpent 811e 2.1, Serpent SRX2-MH, Serpent SRX-2 RM, Serpent SRX-4, Serpent F110-SF2, Serpent F180, Serpent 748 Natrix WC, Serpent Cobra GT 3.0, Serpent SRX8, Serpent S811 2.2, Baja 5B Flux, Atomic AMZ 1/27th, Schumacher GT12 SS.
Sanwa, Ielasi Tuned Novarossi Racing Engines, Tekin, Hobbywing, Muchmore.
dan_vector is offline   Reply With Quote
Old 06-27-2014, 02:48 AM   #606
M7H
Tech Elite
 
M7H's Avatar
 
Join Date: Dec 2004
Location: The Netherlands
Posts: 2,193
Default

Quote:
Originally Posted by dan_vector View Post
There are many ways that people reach the ideal clutch setup but I do like M7H's method of adjusting the spring tension and will be giving it a go.
It works perfect, and once tried, you will always do it like this, it's very easy.
The only time I actually measure something in my clutch, is for the gap, and I use a tool for that ( http://serpent.com/product/190538/ )
Also for the end play, I keep on adding 0.1mm shims, until it binds, and then remove 0.1mm

Quote:
The 0.5 end float will cause bogging because it doesn't give the shoe enough room to engage at the right RPM. It makes it engage too early and then to compensate you tighten down the adj nut further which makes it engage later but not hard enough and it then slips.


Quote:
0.6mm start with a new shoe results in ~0.7mm after the initial bedding in run.
__________________
Serpent

Last edited by M7H; 06-27-2014 at 03:16 AM.
M7H is offline   Reply With Quote
Old 06-27-2014, 07:19 AM   #607
Tech Initiate
 
Join Date: May 2014
Location: UK
Posts: 35
Default

Just got myself a used 977 and setting it up. At the rear downstops are set to 8mm and I have 10mm ride height with 73mm rear tyre diameter. But cannot adjust the ride height any lower as the shock adjusting nut is already fully unwound up to the cap with the standard long rear springs. Is this normal ?
The only way I can see of obtaining a lower ride height adjustment is to fit shorter springs to the rear ?
8thracer is offline   Reply With Quote
Old 06-27-2014, 09:35 AM   #608
Tech Elite
 
gearhead_22's Avatar
 
Join Date: May 2006
Location: Philly
Posts: 2,445
Trader Rating: 9 (100%+)
Send a message via AIM to gearhead_22
Default

Quote:
Originally Posted by 8thracer View Post
Just got myself a used 977 and setting it up. At the rear downstops are set to 8mm and I have 10mm ride height with 73mm rear tyre diameter. But cannot adjust the ride height any lower as the shock adjusting nut is already fully unwound up to the cap with the standard long rear springs. Is this normal ?
The only way I can see of obtaining a lower ride height adjustment is to fit shorter springs to the rear ?
do you have the top of the shock mounted in the lowest hole of the shock tower. also you can lengthen the shock shaft by turning out the bottom of the shock.
__________________
serpent 977WC-novarossi-748TQ
serpent S120 LTR-S411 4X-F110 fs2
serpent America/Ashford Hobby/skyrocket racing
Juwan Hunter http://rccarworld.com/............ serpent.com
Track director at RCCW.
gearhead_22 is offline   Reply With Quote
Old 06-27-2014, 09:48 AM   #609
Tech Regular
 
djiewie's Avatar
 
Join Date: Aug 2010
Posts: 433
Default

Quote:
Originally Posted by 8thracer View Post
Just got myself a used 977 and setting it up. At the rear downstops are set to 8mm and I have 10mm ride height with 73mm rear tyre diameter. But cannot adjust the ride height any lower as the shock adjusting nut is already fully unwound up to the cap with the standard long rear springs. Is this normal ?
The only way I can see of obtaining a lower ride height adjustment is to fit shorter springs to the rear ?
Shorter springs is an option, but there are longer and shorter ballends to put on the shockshaft. This will help you. Other solution is lower rideheight.
djiewie is offline   Reply With Quote
Old 06-27-2014, 10:00 AM   #610
Tech Initiate
 
Join Date: May 2014
Location: UK
Posts: 35
Default

Quote:
Originally Posted by gearhead_22 View Post
do you have the top of the shock mounted in the lowest hole of the shock tower. also you can lengthen the shock shaft by turning out the bottom of the shock.
I've got it on the mid hole and have lengthened the shock shaft from 8.5mm to 12.5mm by unscrewing the bottom ball joint BUT that made no difference as I say because you are limited by the bottom wishbone movement with the 8mm downstop setting so anything you do to the shock off the car is negated by the fact that it returns to the same position once re-attached. If I lower the downstop value to 4 or 5 mm then that will allow more adjustment in the shock adjuster nut but that is going against all the setups ive seen for this car ?
8thracer is offline   Reply With Quote
Old 06-27-2014, 10:08 AM   #611
Tech Initiate
 
Join Date: May 2014
Location: UK
Posts: 35
Default

Quote:
Originally Posted by djiewie View Post
Shorter springs is an option, but there are longer and shorter ballends to put on the shockshaft. This will help you. Other solution is lower rideheight.
I suspect a ballend with a lower spring seating position maybe the answer or an older 966 shock perhaps ? Didn't understand the last part of the answer, as my quest is how to Lower the rideheight with the adjuster nut already backed off to the maximum ? so 10mm at the rear is the lowest I can achieve at the moment.

Obviously sounds as though its not a problem encountered to anyone else running the car ? which leads me to suspect there maybe something not correct with the build of my car's rear suspension perhaps ?
8thracer is offline   Reply With Quote
Old 06-27-2014, 10:12 AM   #612
Tech Regular
 
djiewie's Avatar
 
Join Date: Aug 2010
Posts: 433
Default

Quote:
Originally Posted by 8thracer View Post
I suspect a ballend with a lower spring seating position maybe the answer or an older 966 shock perhaps ? Didn't understand the last part of the answer, as my quest is how to Lower the rideheight with the adjuster nut already backed off to the maximum ? so 10mm at the rear is the lowest I can achieve at the moment.

Obviously sounds as though its not a problem encountered to anyone else running the car ? which leads me to suspect there maybe something not correct with the build of my car's rear suspension perhaps ?
Picture/ maybe.

I use 9mm rideheight with 75 tire at the rear on bumpy tracks. On smooth tracks 8mm. looks like you need the short ballends. compare the front shock ball ends with the rear, are they different?
djiewie is offline   Reply With Quote
Old 06-27-2014, 10:37 AM   #613
Tech Initiate
 
Join Date: May 2014
Location: UK
Posts: 35
Default

Quote:
Originally Posted by djiewie View Post
Picture/ maybe.

I use 9mm rideheight with 75 tire at the rear on bumpy tracks. On smooth tracks 8mm. looks like you need the short ballends. compare the front shock ball ends with the rear, are they different?
Unable to post an image as I get a pop up telling me I haven't done enough messages here yet to be able to link an attachment.
But yes the rear ball ends are longer ones than the fronts.
8thracer is offline   Reply With Quote
Old 06-27-2014, 10:51 AM   #614
Tech Initiate
 
Join Date: May 2014
Location: UK
Posts: 35
Default

Just tried a front shock (short) ball end on the rear and that wont work correctly as all that does is lift the lower rear wishbone up as it doesn't allow enough shock length. The spring seating position is the same on both.
8thracer is offline   Reply With Quote
Old 06-27-2014, 11:15 AM   #615
Tech Elite
 
Join Date: Oct 2013
Posts: 3,274
Trader Rating: 23 (100%+)
Default

How long are the rear springs? They should be 27mm long if you have Serpent springs on the car (fronts are 23mm)... Also make sure you have the alu (or carbon) lower shock mount extension plate fitted. You should easily be able to have a lot less than 10mm on 73mm rear tyres. I can get less than 10mm with 76mm rear tyres and my 977 is totally stock.

Best thing to do is recheck the rear entire shock package and mountings to the manual. If you don't have the manual you can download it from the Serpent site.
__________________
Serpent Viper 977e, Serpent Project 4x, Serpent 811T-TE Truggy, Serpent 811e 2.1, Serpent SRX2-MH, Serpent SRX-2 RM, Serpent SRX-4, Serpent F110-SF2, Serpent F180, Serpent 748 Natrix WC, Serpent Cobra GT 3.0, Serpent SRX8, Serpent S811 2.2, Baja 5B Flux, Atomic AMZ 1/27th, Schumacher GT12 SS.
Sanwa, Ielasi Tuned Novarossi Racing Engines, Tekin, Hobbywing, Muchmore.
dan_vector is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
2013 FLORIDA WINTERNATS DATES jrice Nitro On-Road 288 10-02-2013 12:09 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:07 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net