Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

Stroker kits

07GTS

Well-Known Member
Joined
Sep 8, 2013
Messages
4,957
Reaction score
6,513
Points
113
Location
Australia
Members Ride
VEGTS BUILT BLOWN E85
You can use a little overlap on PD but you shift the EVC and IVO closer to the EVO event. Boost bleed off is not as much of a concern as some think.
Also most cam companies run way too much lift on the exhaust lobes.
yea u can use a little overlap but the way that works is as soon as the intake valve is cracked and exhaust is open it goes straight out as the intake valve has pressure on it just waiting to flow in, BUT overlap with the PD blower will increase torque lower in the rpm if u want that but then limits it up top,
may last cam had massive torque that peaked at 3800rpm (5 deg overlap at .050 or 57 deg at .006) and then fell off fast but HP kept going up till 6700rpm, what a wider LSA does too is flatten the torque curve and place more up top so i want to use all that torque i had at 3800 and push it further up so it can be multiplied into HP, can also use a little overlap to send some fuel over the exhaust valve to help cool it, and less overlap can also help with knock resistance as it dosnt disrupt the intake charge with left over exhaust,
yea exhaust lift with the smaller valve just isnt needed past a curtain point it does nothing, better to have a longer duration and lower lift then the intake, worst part about building an engine is hoping all the parts u choose work together when its done
 

shane_3800

Well-Known Member
Joined
Aug 13, 2011
Messages
4,187
Reaction score
1,753
Points
113
Age
35
Location
places
Members Ride
vr commo
yea u can use a little overlap but the way that works is as soon as the intake valve is cracked and exhaust is open it goes straight out as the intake valve has pressure on it just waiting to flow in, BUT overlap with the PD blower will increase torque lower in the rpm if u want that but then limits it up top,
may last cam had massive torque that peaked at 3800rpm (5 deg overlap at .050 or 57 deg at .006) and then fell off fast but HP kept going up till 6700rpm, what a wider LSA does too is flatten the torque curve and place more up top so i want to use all that torque i had at 3800 and push it further up so it can be multiplied into HP, can also use a little overlap to send some fuel over the exhaust valve to help cool it, and less overlap can also help with knock resistance as it dosnt disrupt the intake charge with left over exhaust,
yea exhaust lift with the smaller valve just isnt needed past a curtain point it does nothing, better to have a longer duration and lower lift then the intake, worst part about building an engine is hoping all the parts u choose work together when its done

If you want 0 or negative overlap you'll be better off with a short rod ratio. The longer the rod ratio the more overlap you can get away with the better because the flow through the chamber cools it with overlap. With a short rod ratio you have less dwell and therefore less heat build up. With long ratios the dwell increases and more overlap is essential to cool the chamber off.

Tony Knight told me he uses Engine Analyser Pro and he has dynoed builds to less than 5% of the program so it's a starting point to select the correct parts.
 

07GTS

Well-Known Member
Joined
Sep 8, 2013
Messages
4,957
Reaction score
6,513
Points
113
Location
Australia
Members Ride
VEGTS BUILT BLOWN E85
If you want 0 or negative overlap you'll be better off with a short rod ratio. The longer the rod ratio the more overlap you can get away with the better because the flow through the chamber cools it with overlap. With a short rod ratio you have less dwell and therefore less heat build up. With long ratios the dwell increases and more overlap is essential to cool the chamber off.

Tony Knight told me he uses Engine Analyser Pro and he has dynoed builds to less than 5% of the program so it's a starting point to select the correct parts.
i got the dynosim6 program myself seems ok with a nice graph layout and data if u want and ive set it up to suit my old build with known dyno figures so ill find out how far off it is when the new engine gets going, also have that pipemax which is good for data
 

shane_3800

Well-Known Member
Joined
Aug 13, 2011
Messages
4,187
Reaction score
1,753
Points
113
Age
35
Location
places
Members Ride
vr commo
i got the dynosim6 program myself seems ok with a nice graph layout and data if u want and ive set it up to suit my old build with known dyno figures so ill find out how far off it is when the new engine gets going, also have that pipemax which is good for data

Is it engine dyno data? If not the drive train adds too much noise in to make a reliable assessment.
 

07GTS

Well-Known Member
Joined
Sep 8, 2013
Messages
4,957
Reaction score
6,513
Points
113
Location
Australia
Members Ride
VEGTS BUILT BLOWN E85
Is it engine dyno data? If not the drive train adds too much noise in to make a reliable assessment.
yea my data is vehicle dyno and the program has a variable loss to drivetrain so its all a bit of a guess really
 

Redline457

Active Member
Joined
Jan 31, 2017
Messages
312
Reaction score
248
Points
43
Location
Melbourne
Members Ride
VF1 6.6 Litre Stroker SSVR A6
Hi guys, well I bit the bullet and had the motor rebuilt with a stroker kit, picked it up Thursday , only done a couple of short drives due to lockdown, really happy with it so far and no more f@#*ing piston slap
 

daves8

Well-Known Member
Joined
Feb 15, 2006
Messages
1,014
Reaction score
340
Points
83
Age
43
Location
Sydney
Members Ride
2015 VF Calais V 6.0 | 2013 VF Calais V V6 Wagon
Hi guys, well I bit the bullet and had the motor rebuilt with a stroker kit, picked it up Thursday , only done a couple of short drives due to lockdown, really happy with it so far and no more f@#*ing piston slap
What specs did you end up with? Cam? Heads?

what power?

how does it drive now compared to stock?
 

Redline457

Active Member
Joined
Jan 31, 2017
Messages
312
Reaction score
248
Points
43
Location
Melbourne
Members Ride
VF1 6.6 Litre Stroker SSVR A6
Block honed 0.010” for a 4.010” bore, 4” stroke gives 402ci (6.6L) CP forged pistons and H beam rods, fully balanced rotating assembly, Higgins heads, same cam as noted earlier in the thread plus the usual new replacement parts , oil pump , valve springs etc , these kits are more about extra torque than top end kw’s it drives much like before behaves very nicely in traffic, will go on a freeway country run after lockdown ends
 
Top