Is a 2.05 valve worth putting in a Vortec head

[1980RS]

Got a set of new 2.05 and 1.6 Manley valves for free and I am wondering if they are worth the effort to put in a Vortec head. I know some here have done this, what performance gains did you get from going to the larger valves.

[Mark O'Neal]

Depends on what rpm you're intending to turn. Below about 6K you won't see anything.

[Ken_Parkman]

Had a guy bring me a set to check after he put in bigger valves. Kicked the crap out of the flow, drove it into short side separation and killed the high lift numbers. He got the flow back and better after a lot of work and ultimately the thing worked quite well.

[PRH]

The way I look at Vortecs and the intake valve size is........
The bigger the valve, the more porting it will take to get the turbulence situation under control.

[maxracesoftware]

Got a set of new 2.05 and 1.6 Manley valves for free and I am wondering if they are worth the effort to put in a Vortec head. I know some here have done this, what performance gains did you get from going to the larger valves.

i've Ported a bunch of Vortec Heads , the 2.055/1.600 always makes more HP
same thing if you only Bowl-Ported them
and same results if you were only allowed a creative 6 Angle Valve Job without any other work/grinding


Post on Vortec SBC Heads link :
viewtopic.php?f=1&t=55602

by Mark O'Neal » Thu Sep 09, 2021 1:18 pm

Depends on what rpm you're intending to turn. Below about 6K you won't see anything.

all my Dyno tests + Dragstrip results show HP gains going to 2.055/1.600 Valve Combos
"if" the Vortecs are Ported "correctly" , they make more HP ... even under 6000 RPM no problem !

[steve cowan]

Got a set of new 2.05 and 1.6 Manley valves for free and I am wondering if they are worth the effort to put in a Vortec head. I know some here have done this, what performance gains did you get from going to the larger valves.

i've Ported a bunch of Vortec Heads , the 2.055/1.600 always makes more HP
same thing if you only Bowl-Ported them
and same results if you were only allowed a creative 6 Angle Valve Job without any other work/grinding


Post on Vortec SBC Heads link :
viewtopic.php?f=1&t=55602

by Mark O'Neal » Thu Sep 09, 2021 1:18 pm

Depends on what rpm you're intending to turn. Below about 6K you won't see anything.

all my Dyno tests + Dragstrip results show HP gains going to 2.055/1.600 Valve Combos
"if" the Vortecs are Ported "correctly" , they make more HP ... even under 6000 RPM no problem !

larry,
i enjoy reading all your threads and post so thank you-
i have a question -
does the CFM/IN2 stay nearly the same when increasing valve size / reworking port ??
i see on your pipemax information AVG air speed around 280 ft/sec,will a vortec head still respond if SSR local velocity is 400 ft/sec on the floor??
last question- i have trouble getting good geometry with a 1.7 rocker on SBC dart heads as an example-any tips.
thanks in advance

[steve cowan]

Got a set of new 2.05 and 1.6 Manley valves for free and I am wondering if they are worth the effort to put in a Vortec head. I know some here have done this, what performance gains did you get from going to the larger valves.

i've Ported a bunch of Vortec Heads , the 2.055/1.600 always makes more HP
same thing if you only Bowl-Ported them
and same results if you were only allowed a creative 6 Angle Valve Job without any other work/grinding


Post on Vortec SBC Heads link :
viewtopic.php?f=1&t=55602

by Mark O'Neal » Thu Sep 09, 2021 1:18 pm

Depends on what rpm you're intending to turn. Below about 6K you won't see anything.

all my Dyno tests + Dragstrip results show HP gains going to 2.055/1.600 Valve Combos
"if" the Vortecs are Ported "correctly" , they make more HP ... even under 6000 RPM no problem !

larry,
i enjoy reading all your threads and post so thank you-
i have a question -
does the CFM/IN2 stay nearly the same when increasing valve size / reworking port ??
i see on your pipemax information AVG air speed around 280 ft/sec,will a vortec head still respond if SSR local velocity is 400 ft/sec on the floor??
last question- i have trouble getting good geometry with a 1.7 rocker on SBC dart heads as an example-any tips.
thanks in advance

[maxracesoftware]

by steve cowan » Mon Sep 13, 2021 2:36 am
larry,
i enjoy reading all your threads and post so thank you-
i have a question -
does the CFM/IN2 stay nearly the same when increasing valve size / reworking port ??
i see on your pipemax information AVG air speed around 280 ft/sec,will a vortec head still respond if SSR local velocity is 400 ft/sec on the floor??
last question- i have trouble getting good geometry with a 1.7 rocker on SBC dart heads as an example-any tips.
thanks in advance

CFM/IN2 stays nearly the same , depends if you do more aggressive Porting when going to larger 2.055 Valve ( from 1.94 or 2.02 )
it will be less , if you do not !

PipeMax 3.98 version and lower had 280 FPS as Default,
i changed it to 285 FPS default in v4.00 to 4.70 versions

an included simulation File w/PipeMax v4.70 installation is David Vizard's Vortec Head Dyno test :
350_Vortec_Vizards_Sledgehammer_6200RPM_447HP__4400RPM_445TQ__355cid.PMW

Both the Intake and Exhaust Port Volumes + CSA correlated to 280 FPS Avg Port velocities ( just the way it happened to come out )

and 400 FPS on Floor's Apex .... your pretty close to what i see with my Pitot Probe
i see 411 to as high as 440 FPS , it depends if i Port the Vortecs or i'm Flow testing someone else who Ported their own Vortec Heads
most of the time , even if the Flow stalls above 0.500" Lift or higher ,
the Vortec Headed engines i've Dynoed so far , not too affected by Flow Stall, as those Engines are 355cid to 383cid
sometimes a 406cid , and 6500 RPM and lower , some with Dual-Plane Manifolds,
none of them turning high enough RPM with higher Lift Cams to make Flow Stall problems show up !

on the 1.70:1 Rocker Ratios , i offset milled Rocker Stud holes and installed stainless solid Nut-Serts that had little Green epoxy pellets
for CompCams BBC 1.70 stamped-style roller tip Rockers to make everything work out correctly .
Mud Track Rules were : " stamped-style Rocker with a Roller tip" , but Rules did not state it had to be only SBC Rockers
As far as Geometry .. i worry more about Pushrod Sweep side of Fulcrum Point than Valve side
but i try to get both sides perfect !
Pushrod Sweep is where TQ and HP gains are to be gained or lost ,
and Valve side is where Guide wear and tear are to be reduced by proper Geometry !

[1980RS]

Got a set of new 2.05 and 1.6 Manley valves for free and I am wondering if they are worth the effort to put in a Vortec head. I know some here have done this, what performance gains did you get from going to the larger valves.

i've Ported a bunch of Vortec Heads , the 2.055/1.600 always makes more HP
same thing if you only Bowl-Ported them
and same results if you were only allowed a creative 6 Angle Valve Job without any other work/grinding


Post on Vortec SBC Heads link :
viewtopic.php?f=1&t=55602

by Mark O'Neal » Thu Sep 09, 2021 1:18 pm

Depends on what rpm you're intending to turn. Below about 6K you won't see anything.

all my Dyno tests + Dragstrip results show HP gains going to 2.055/1.600 Valve Combos
"if" the Vortecs are Ported "correctly" , they make more HP ... even under 6000 RPM no problem !

Thank you for your input, much aprriciated.

[steve cowan]

by steve cowan » Mon Sep 13, 2021 2:36 am
larry,
i enjoy reading all your threads and post so thank you-
i have a question -
does the CFM/IN2 stay nearly the same when increasing valve size / reworking port ??
i see on your pipemax information AVG air speed around 280 ft/sec,will a vortec head still respond if SSR local velocity is 400 ft/sec on the floor??
last question- i have trouble getting good geometry with a 1.7 rocker on SBC dart heads as an example-any tips.
thanks in advance

CFM/IN2 stays nearly the same , depends if you do more agressive Porting when going to larger 2.055 Valve ( from 1.94 or 2.02 )
it will be less , if you do not !

PipeMax 3.98 version and lower had 280 FPS as Default,
i changed it to 285 FPS default in v4.00 to 4.70 versions

an included simulation File w/PipeMax v4.70 installation is David Vizard's Vortec Head Dyno test :
350_Vortec_Vizards_Sledgehammer_6200RPM_447HP__4400RPM_445TQ__355cid.PMW

Both the Intake and Exhaust Port Volumes + CSA correlated to 280 FPS Avg Port velocities ( just the way it happened to come out )

and 400 FPS on Floor's Apex .... your pretty close to what i see with my Pitot Probe
i see 411 to as high as 440 FPS , it depends if i Port the Vortecs or i'm Flow testing someone else who Ported their own Vortec Heads
most of the time , even if the Flow stalls above 0.500" Lift or higher ,
the Vortec Headed engines i've Dynoed so far , not too affected by Flow Stall, as those Engines are 355cid to 383cid
sometimes a 406cid , and 6500 RPM and lower , some with Dual-Plane Manifolds,
none of them turning high enough RPM with higher Lift Cams to make Flow Stall problems show up !

on the 1.70:1 Rocker Ratios , i offset milled Rocker Stud holes and installed stainless solid Nut-Serts that had little Green epoxy pellets
for CompCams BBC 1.70 stamped-style roller tip Rockers to make everything work out correctly .
Mud Track Rules were : " stamped-style Rocker with a Roller tip" , but Rules did not state it had to be only SBC Rockers
As far as Geometry .. i worry more about Pushrod Sweep side of Fulcrum Point than Valve side
but i try to get both sides perfect !
Pushrod Sweep is where TQ and HP gains are to be gained or lost ,
and Valve side is where Guide wear and tear are to be reduced by proper Geometry !

Great information as usual Larry,thank you very much.
I have read where guys change the intake valve and throat bigger without going to the effort of sizing the rest of the head,then they say the head flows
better and makes more power...????