Govenor removal and gear ratios
- Thread starter Hollow45
- Start date
Nope!
the additional rpms will convert to additional top speed;
it's the only way to go significantly faster without ruining your clutch on day one
'sid
the additional rpms will convert to additional top speed;
it's the only way to go significantly faster without ruining your clutch on day one
'sid
JTSpeedDemon
2019 Build Off Winner!
A billet ARC flywheel and connecting rod are VERY good ideas (almost mandatory), but they are pretty pricey. You can run it ungoverned without them, but it’s not really recommended.
I need to agree to that 
ungoverned bone stock (well exhaust and air filter)
should be fairly safe even on a 420...
if you run faster than 5.5k however the billet con rod is indeed very nearly mandatory,
and the billet flywheel also becomes a better and better idea with every rpm..
within the 5k rpms I doubt it's already necessary on an engine that size,
(I wouldn't call it mandatory at all tbh)
but in order to be safe (rather safe than sorry, right?) both will buy you that extra bit of strength that might prevent fatal engine damage or worse severe injuries...
So it indeed remains to be a good idea
'sid
ungoverned bone stock (well exhaust and air filter)
should be fairly safe even on a 420...
if you run faster than 5.5k however the billet con rod is indeed very nearly mandatory,
and the billet flywheel also becomes a better and better idea with every rpm..
within the 5k rpms I doubt it's already necessary on an engine that size,
(I wouldn't call it mandatory at all tbh)
but in order to be safe (rather safe than sorry, right?) both will buy you that extra bit of strength that might prevent fatal engine damage or worse severe injuries...
So it indeed remains to be a good idea
'sid
JTSpeedDemon
2019 Build Off Winner!
Glad to hear you're erring on the side of safety.
okay.. now you got me worried slightly..
stage kits are excessively used for no reason,
and worse sometimes full of crap and inconsistent in contents.
(many stage 1 kits for example have high density valve springs, but neither a con rod nor a billet flywheel... still removing the valve float for no reason)
and it gets worse and worse..
Sooo my suggestion would be:
read and read alot! (and not on shopping pages!)
to be sure what you want and need..
IMHO a high flow airfilter and a high throughput exhaust
together with a billet conrod and flywheel is all you really want
sure with a nicely tuned carb that adds the required amount of fuel for the additional air.
(personal opinion only)
Once that does NOT fullfill your needs for a fast and powerfull enough engine,
then you might want to consider some higher compression and maybe (just maybe)
heavier valve springs..
and if THAT still does not do the trick for you it's time to think about a differnet cam,
maybe ratio rockers etc...
Do not get fooled by some "buy this and you rock"-Sets
some are crap to say the least, few downright dangerous even.
most terribly overpriced.
and at one point you've spend 700-800 bucks or more for a stinky industrial engine
with no gearbox and some lousy hp when yor the same amount or less you could've gotten a motorbike engine with gears and twice the torque and hp.
So, since we're talking 420 here and not an outlaw-friendly race engine,
but something that's for sure meant to be a hobby/fun project,
do not waste your time and money for high dollar mods.
(again.. opinion!)
just saying
'sid
stage kits are excessively used for no reason,
and worse sometimes full of crap and inconsistent in contents.
(many stage 1 kits for example have high density valve springs, but neither a con rod nor a billet flywheel... still removing the valve float for no reason)
and it gets worse and worse..
Sooo my suggestion would be:
read and read alot! (and not on shopping pages!)
to be sure what you want and need..
IMHO a high flow airfilter and a high throughput exhaust
together with a billet conrod and flywheel is all you really want
sure with a nicely tuned carb that adds the required amount of fuel for the additional air.
(personal opinion only)
Once that does NOT fullfill your needs for a fast and powerfull enough engine,
then you might want to consider some higher compression and maybe (just maybe)
heavier valve springs..
and if THAT still does not do the trick for you it's time to think about a differnet cam,
maybe ratio rockers etc...
Do not get fooled by some "buy this and you rock"-Sets
some are crap to say the least, few downright dangerous even.
most terribly overpriced.
and at one point you've spend 700-800 bucks or more for a stinky industrial engine
with no gearbox and some lousy hp when yor the same amount or less you could've gotten a motorbike engine with gears and twice the torque and hp.
So, since we're talking 420 here and not an outlaw-friendly race engine,
but something that's for sure meant to be a hobby/fun project,
do not waste your time and money for high dollar mods.
(again.. opinion!)
just saying
'sid
So I bought an air intake with a new jet, and a header.
Q1: do I need to use heavier springs to prevent valve float with the addition of an intake and exhaust (Governed)?
Q2: since I am saving up for a flywheel and rod, would it make sense to remove the govenor and limit the engine to 5k rpm with the accelerator screw in order to take full advantage of the air intake and exhaust along with the increased rpm with govenor removal? I would attempt to do this by monitoring an rpm gauge while adjusting the accelerator screw/throttle limiter.
Q3: Would I see any improvement by installing the air intake jet and exhaust with the govenor in place?
Q1: do I need to use heavier springs to prevent valve float with the addition of an intake and exhaust (Governed)?
Q2: since I am saving up for a flywheel and rod, would it make sense to remove the govenor and limit the engine to 5k rpm with the accelerator screw in order to take full advantage of the air intake and exhaust along with the increased rpm with govenor removal? I would attempt to do this by monitoring an rpm gauge while adjusting the accelerator screw/throttle limiter.
Q3: Would I see any improvement by installing the air intake jet and exhaust with the govenor in place?
A1: NO! you never need to prevent valve float.. it's working for you, not against you as long as you do not have a billet conrod and flywheel!
Also: throughput has NOTHING to do with valve float, valve float is strictly an rpms caused effect,
and the rpms should be kept well below 6k (5k is what we generally consider safe w/o billet internals)
A2: yes removing the governor is already feasible,
again it raises the the rpms up to valve float (usually 5-5.5k rpms)
Actually no real need to limit the throttle.
but monitoring the rpms and limiting the throttle might add a bit of safety in that regard
(no load rpms are usually much higher than loaded rpms, and free revving you could potentially exceed the limit by accident (say a jumped off chain)
A3: yes but not by much tbh.. the engine would be a tad snappier, and might give you a slight hint of additional torque.. nothing too noteworthy however.
the amount of air allowed in and out the engine by the airfilter and exhaust are usually metered so that the engine revs rather freely in it's goverend max rpm (3600-ish rpms)
The true potential of higher throughput only really shows at higher rpms (hence after the governor removal)
So for now: if you have the airfilter and exhaust and maybe a bigger carb jet...
install both and remove the governor, do not touch the valve springs.
you gain a bit more rpms and more fun and as long as you stay below 5500 rpms say,
you have essentially the a safe stage 1 conversion.
Once you get conrod and flywheel installed you can also install the valve springs, maybe a thinner head gasket a yet bigger jet and (thanks to advanced timing of the billet flywheel) you enter the realms of stage 2.
'sid
Also: throughput has NOTHING to do with valve float, valve float is strictly an rpms caused effect,
and the rpms should be kept well below 6k (5k is what we generally consider safe w/o billet internals)
A2: yes removing the governor is already feasible,
again it raises the the rpms up to valve float (usually 5-5.5k rpms)
Actually no real need to limit the throttle.
but monitoring the rpms and limiting the throttle might add a bit of safety in that regard
(no load rpms are usually much higher than loaded rpms, and free revving you could potentially exceed the limit by accident (say a jumped off chain)
A3: yes but not by much tbh.. the engine would be a tad snappier, and might give you a slight hint of additional torque.. nothing too noteworthy however.
the amount of air allowed in and out the engine by the airfilter and exhaust are usually metered so that the engine revs rather freely in it's goverend max rpm (3600-ish rpms)
The true potential of higher throughput only really shows at higher rpms (hence after the governor removal)
So for now: if you have the airfilter and exhaust and maybe a bigger carb jet...
install both and remove the governor, do not touch the valve springs.
you gain a bit more rpms and more fun and as long as you stay below 5500 rpms say,
you have essentially the a safe stage 1 conversion.
Once you get conrod and flywheel installed you can also install the valve springs, maybe a thinner head gasket a yet bigger jet and (thanks to advanced timing of the billet flywheel) you enter the realms of stage 2.
'sid