Don Terrill’s Speed-Talk

Ron Miller wrote: ↑Sun Dec 09, 2018 6:01 pm

cpmotors wrote: ↑Sun Dec 09, 2018 4:55 pm Good info as always Larry! Although you should probably read some of the recent threads and realize a 2.055 intake valve and 1.875" header won't work in a OEM Vortec head

Pete, That would be me. I did send Larry an e-mail and he confirmed the 2.050 -1.6 was a good combo. He has never seen cracks in a head that had the 2.050 valves and bowl worked.

Larry, Thanks for the e-mail reply and info here.

You've been here even longer than me Ron, and I know Larry had posted some of this info in the past, but I probably payed more attention to it as my second valve job I ever did was on a set of Vortec heads that caused a million questions on my part. I wouldn't suggest the average guy use that size valve, but they can certainly be made to work as Meaux shows.

Those wide 118 lobe separation angles makes one ponder. Goes against most everything that one learns on the internet.

Old School wrote: ↑Mon Dec 10, 2018 12:32 am Those wide 118 lobe separation angles makes one ponder. Goes against most everything that one learns on the internet.

the Mud Track had a Plenum Vacuum Rule ... thats the main reason for the LSA=118.0 and the Rhoades Lifters,
it pulled 18.5"Hg Vacuum and i think the Track Rule is 18.0 for Small Blocks and 14.0" for Big Blocks ??
we had 3 Vacuum Gauges that Day 1=Dyno 2=local Parts Store model 3=identical Vac Gauge Make/Model as the Track Tech Guy had
so we could make sure it was Legal ... that allowed us to retard the Cam 1 more degree to = 117.0 IntCl from 116.0 and still get 18.5" Hg Vac

When we won the Race , they protested us, Wesley Roberson ( ex Engine Master Tech Guy , and ex NHRA Tech Guy ) found us completely Legal

by cpmotors » Sun Dec 09, 2018 4:55 pm
Good info as always Larry! Although you should probably read some of the recent threads and realize a 2.055 intake valve and 1.875" header won't work in a OEM Vortec head


by Ron Miller » Sun Dec 09, 2018 6:01 pm
Pete, That would be me. I did send Larry an e-mail and he confirmed the 2.050 -1.6 was a good combo.
He has never seen cracks in a head that had the 2.050 valves and bowl worked.
Larry, Thanks for the e-mail reply and info here.


by cpmotors » Sun Dec 09, 2018 10:16 pm
You've been here even longer than me Ron, and I know Larry had posted some of this info in the past, but I probably payed more attention to it as my second valve job I ever did was on a set of Vortec heads that caused a million questions on my part. I wouldn't suggest the average guy use that size valve, but they can certainly be made to work as Meaux shows.

hi Pete and Ron ,
i can't believe Guys still think Vortecs will not make more HP + run faster with 2.055/1.600 Valve combo

i have a Friend/Racer loves SBC Vortec Heads , thats all he talks about and builds
lives less than 1/2 mile from my Shop,
years ago i Posted on Speedtalk Flow+Dyno+DragStrip Data on his Race Car 355cid w/Vortecs
from 1.940/1.500 to 2.020/1.600 to 2.055/1.600
each time i installed the larger and larger Valves + Bowl-Porting , he went faster at the Dragstrip, more HP on the Dyno

now i've been giving him pointers how to Port his own Heads
he's went from 2.020/1.600 to 2.055/1.600 combos and his Race Car went faster

now if a Guy who maybe Ported 3 or 4 Pairs of Heads in his Lifetime can make a 2.055/1.600 Valve Combo Vortec
make more HP + run quicker ... WHY ?? can't the rest of the world do it ???

maxracesoftware wrote: ↑Mon Dec 10, 2018 3:01 am

Old School wrote: ↑Mon Dec 10, 2018 12:32 am Those wide 118 lobe separation angles makes one ponder. Goes against most everything that one learns on the internet.

the Mud Track had a Plenum Vacuum Rule ... thats the main reason for the LSA=118.0 and the Rhoades Lifters,
it pulled 18.5"Hg Vacuum and i think the Track Rule is 18.0 for Small Blocks and 14.0" for Big Blocks ??
we had 3 Vacuum Gauges that Day 1=Dyno 2=local Parts Store model 3=identical Vac Gauge Make/Model as the Track Tech Guy had
so we could make sure it was Legal ... that allowed us to retard the Cam 1 more degree to = 117.0 IntCl from 116.0 and still get 18.5" Hg Vac

When we won the Race , they protested us, Wesley Roberson ( ex Engine Master Tech Guy , and ex NHRA Tech Guy ) found us completely Legal

by cpmotors » Sun Dec 09, 2018 4:55 pm
Good info as always Larry! Although you should probably read some of the recent threads and realize a 2.055 intake valve and 1.875" header won't work in a OEM Vortec head


by Ron Miller » Sun Dec 09, 2018 6:01 pm
Pete, That would be me. I did send Larry an e-mail and he confirmed the 2.050 -1.6 was a good combo.
He has never seen cracks in a head that had the 2.050 valves and bowl worked.
Larry, Thanks for the e-mail reply and info here.


by cpmotors » Sun Dec 09, 2018 10:16 pm
You've been here even longer than me Ron, and I know Larry had posted some of this info in the past, but I probably payed more attention to it as my second valve job I ever did was on a set of Vortec heads that caused a million questions on my part. I wouldn't suggest the average guy use that size valve, but they can certainly be made to work as Meaux shows.

hi Pete and Ron ,
i can't believe Guys still think Vortecs will not make more HP + run faster with 2.055/1.600 Valve combo

i have a Friend/Racer loves SBC Vortec Heads , thats all he talks about and builds
lives less than 1/2 mile from my Shop,
years ago i Posted on Speedtalk Flow+Dyno+DragStrip Data on his Race Car 355cid w/Vortecs
from 1.940/1.500 to 2.020/1.600 to 2.055/1.600
each time i installed the larger and larger Valves + Bowl-Porting , he went faster at the Dragstrip, more HP on the Dyno

now i've been giving him pointers how to Port his own Heads
he's went from 2.020/1.600 to 2.055/1.600 combos and his Race Car went faster

now if a Guy who maybe Ported 3 or 4 Pairs of Heads in his Lifetime can make a 2.055/1.600 Valve Combo Vortec
make more HP + run quicker ... WHY ?? can't the rest of the world do it ???

Because once a rumor like that starts, it's near impossible to get it fixed. If it's been heard, said or posted more than 3 times, it becomes dedicated fact. And then you'll have the guys who actually have never tried it, or worse yet, guys who don't even do head work will defend said lie to the death on the forums until threads get locked and all the thinkers and doers leave.

I had a conversation with EQ at pri and I told them how much I liked this casting. I told them that they cleaned up well and were responsive to light porting. I found the GM to be a bit stingy with flow gains. It is a heavy casting as well. EQ is not happy with this exhaust port as it is I offered to help out. Thanks for the thread Larry! Charlie

Old School wrote: ↑Mon Dec 10, 2018 12:32 am Those wide 118 lobe separation angles makes one ponder. Goes against most everything that one learns on the internet.

The easiest way DV explains it is lc is linked to compression ratio. The higher the compression the smaller the chamber volume to scavenge. So the smaller the overlap triangle needs to be and the wider the lc. Thanks, Charlie

The easiest way DV explains it is lc is linked to compression ratio. The higher the compression the smaller the chamber volume to scavenge. So the smaller the overlap triangle needs to be and the wider the lc. Thanks, Charlie
Servedio Cylinder Head Development
631-816-4911
9:00am - 9:00pm EST

hi Charlie ,
Yes i totally agree with you and David Vizard !

Also : nice Porting on the EQ Heads !!!
......what Valve Sizes you went with ??

i wish the Mud Truck Class Rules allowed us to Port the Heads
but they only allow us to very creative with Cutters/Blades ... but absolutely no grinding/blending the ridges left by the various Cutters,
no Port matching of Heads or Manifold , ETC

maxracesoftware wrote: ↑Mon Dec 10, 2018 2:44 pm

The easiest way DV explains it is lc is linked to compression ratio. The higher the compression the smaller the chamber volume to scavenge. So the smaller the overlap triangle needs to be and the wider the lc. Thanks, Charlie
Servedio Cylinder Head Development
631-816-4911
9:00am - 9:00pm EST

hi Charlie ,
Yes i totally agree with you and David Vizard !

Also : nice Porting on the EQ Heads !!!
......what Valve Sizes you went with ??

i wish the Mud Truck Class Rules allowed us to Port the Heads
but they only allow us to very creative with Cutters/Blades ... but absolutely no grinding/blending the ridges left by the various Cutters,
no Port matching of Heads or Manifold , ETC

Technically isn't a CNC just a creative cutter?

maxracesoftware wrote: ↑Mon Dec 10, 2018 2:44 pm

The easiest way DV explains it is lc is linked to compression ratio. The higher the compression the smaller the chamber volume to scavenge. So the smaller the overlap triangle needs to be and the wider the lc. Thanks, Charlie
Servedio Cylinder Head Development
631-816-4911
9:00am - 9:00pm EST

hi Charlie ,
Yes i totally agree with you and David Vizard !

Also : nice Porting on the EQ Heads !!!
......what Valve Sizes you went with ??

i wish the Mud Truck Class Rules allowed us to Port the Heads
but they only allow us to very creative with Cutters/Blades ... but absolutely no grinding/blending the ridges left by the various Cutters,
no Port matching of Heads or Manifold , ETC

Thank you Larry, you made my whole day! That was 45 minute clean up at DV's shop with a 2.02" 1.6" valve job. Flows @ .7" 275cfm just before the ssr let go and nearly 200cfm on the exhaust. It was to show Marvin how to tune them up for a hot street 355.

In regard ..

The easiest way DV explains it is lc is linked to compression ratio. The higher the compression the smaller the chamber volume to scavenge. So the smaller the overlap triangle needs to be and the wider the lc. Thanks, Charlie

But 118 lsa is going quite a ways past the recommendations in DV formula for that aspect.. Not saying the results aren't real nice, just that its not totally explained by the compression ratio /lsa.. 118 lsa installed slightly retarded is so different from most recommendations you usually hear that it makes me wonder. Do you have any dyno numbers from the lower rpm range 3000-5000 ? Does it fall off real fast or drop unusually low anywhere in comparison the usual alternate cam choices?

I have used all the vortecs at one time or another. Currently EQ.. I have been running wider and wider lsa each time with decent results. Never beyond 113 lsa though. The vortecs "seemed" to like that more so than some other heads. Sorry no dyno #s , just curious.

by ClassAct » Mon Dec 10, 2018 8:49 am

Because once a rumor like that starts, it's near impossible to get it fixed.
If it's been heard, said or posted more than 3 times, it becomes dedicated fact.

And then you'll have the guys who actually have never tried it,
or worse yet, guys who don't even do head work will defend said lie to the death on the forums
until threads get locked and all the thinkers and doers leave.

very True what you Posted !!!

" so sad " .... as President Trump is often quoted

Looking at it on the "bright-side of things"
We can win more Race Events if others keep thinking
a Vortec Head cannot make any more HP with any Valve Combos
larger than 1.940/1.500 or 2.020/1.600


That reminds of when i was at an old Cajun Mechanic's Shop in late '60s ,
using his Hydraulic Lift Jacks to raise my 1968 SS Chevlle 396/375 4-speed Car
up enough to install a pair of new Headers , taking off the GM cast manifolds.

He said these very memorable words to me :
"You think you are smarter than GM" ??
"If GM wanted it that way ,
they would have made it that way"

needless to say , he frowned pretty much when i cranked it up with Open Headers

by GARY C » Mon Dec 10, 2018 3:08 pm
Technically isn't a CNC just a creative cutter?

Yes , that's basically what it ends up at the Valve Job area !

Larry

Just for curiosity sake, when were these dyno runs made on these different build configurations?

Newold1 wrote: ↑Mon Dec 10, 2018 5:36 pm Larry

Just for curiosity sake, when were these dyno runs made on these different build configurations?

its a mix of the last 4 or 5 years of various Mud Truck SBC361cid Vortec Builds/Dyno tests
Sorry i don't have more Pictures , lately not taking as many Pictures as i used to

i'm Dyno testing a BBF Ford Mud Truck Engine this Wednesday if you are interested in that Engine
i'll take a lot of Pics ... let me know ?

gottago wrote: ↑Mon Dec 10, 2018 5:12 pm In regard ..

The easiest way DV explains it is lc is linked to compression ratio. The higher the compression the smaller the chamber volume to scavenge. So the smaller the overlap triangle needs to be and the wider the lc. Thanks, Charlie

But 118 lsa is going quite a ways past the recommendations in DV formula for that aspect.. Not saying the results aren't real nice, just that its not totally explained by the compression ratio /lsa.. 118 lsa installed slightly retarded is so different from most recommendations you usually hear that it makes me wonder. Do you have any dyno numbers from the lower rpm range 3000-5000 ? Does it fall off real fast or drop unusually low anywhere in comparison the usual alternate cam choices?

I have used all the vortecs at one time or another. Currently EQ.. I have been running wider and wider lsa each time with decent results. Never beyond 113 lsa though. The vortecs "seemed" to like that more so than some other heads. Sorry no dyno #s , just curious.

i agree with the previous Post as it was stated,
but i do not agree 100% with DV LSA formula

Do you have any dyno numbers from the lower rpm range 3000-5000 ?
Does it fall off real fast or drop unusually low anywhere in comparison the usual alternate cam choices?

I have used all the vortecs at one time or another. Currently EQ..
I have been running wider and wider lsa each time with decent results.
Never beyond 113 lsa though. The vortecs "seemed" to like that more so than some other heads. Sorry no dyno #s , just curious.

these Dyno tests are the only time we made Dyno Pulls
befow 5000 RPM starting point :

He runs a 5000+ Stall Converter in the Mud Truck

we only started this Dyno Pull this low in RPM
because it had only 10.8:1 CR ( along with Q16 Gas )
so no chance of harming the engine at all


SBC Mud Truck
4.030x3.480=355.2 CID
ProMaxx Vortec Heads 2.055/1.600
Edelbrock Vortec Super Victor
Q16 Race Gas
10.8:1 CR
CompCams 5980/5985 118 251/247 .363/.363 118 Centers 116.5 CL
1.52 Roller Tip Steel Rockers
38 BTDC
LAT 20/50 Breakin Oil
Custom Kickout Oil Pan 10 Qts Oil


unmilled ProMaxx Heads
Peak TQ = 433.3 at 4800 RPM
Peak HP = 476.4 at 6500 RPM


So this is the smallest Cubic Inch Mud Truck engine we ever built/Dyno tested
i think it did really great for only 10.8:1 Compression Ratio , all things considered
476.4 Peak HP / 355.2 CID = 1.341216216 HP/CID Ratio


525.9 Peak HP = best Engine Combo at 361.5 CID
-476.4 Peak HP at 355.2 CID 10.8:1 CR
------------------
49.5 Peak HP difference


Compared to one of our best Engine Combos :
1.341216216 HP/CID Ratio x 361.5 cid = 484.8

so about 484.8 Peak HP if it were 361.5 CID engine size

then Angle-Mill the Heads 0.000-0.085" for almost 12.5:1 CR
12.5 - 10.8 = gain 1.7 points in Compression Ratio

then go from Q16 Race Gas to higher HP C45 Race Gas

then go from 1.52 Rocker Ratios to 1.72 Rocker Ratios

then lighter LAT Race Oil from LAT 20/50 Breakin Oil

and it should end up around 526 Peak HP

Note : CompCams 5980/5985 118 251/247 .363/.363 118 Centers 116.5 CL
Cam was on 116.5 IntCL and had 118.0=LSA
still made a lot of Torque

Larry
Are these all running a true HYD flat lifter?
Have you experimented with different preloads or are you your running them lashed?
Cheers James