[Jack Gifford]

I thought Glenn said above that he's already bought stuff to mount the SuperMag in front of the cam?

[Brian Baker]

Originally Posted by pontiac jack

I thought Glenn said above that he's already bought stuff to mount the SuperMag in front of the cam?

He was talking about the fuel pump. He could put a plug in the distributor hole and run a dual drive out front for the pump and mag, but given his tinwork is already done and painted, he may not have the room for it.

[Jack Gifford]

Originally Posted by Glenn Lever

Mallory Supermag III (purchased)... driven off the front timing cover with a dual drive (purchased)...

So Glenn said...

[Brian Baker]

Originally Posted by pontiac jack

So Glenn said...

I stand corrected. No matter, now all of you know about another Pontiac speed part that is available that you didn't know about before.

[Glenn Lever]

Ok, Question
What lift and duration on a solid roller cam that the lifter valley can survive
Duration at .050…….278 to 284?????????????????
lift……………………………640 with a 1.5 ratio rocker…………………..680 with a 1.6 rocker
Engle EX-4 grind on the intake, EX-5 on the exhaust?????????

For a Pontiac stock block (1970 Ram Air III) ,blower engine, with lifter bore brace

Blower is an 8-71, high helix, stripped, retro

Stock main bearing size (3.00), GM (2.20) rod bearing size, Light weight Nitrided Crank (70 Lbs)

Deck height 10.239 bore 4.155

Compression ratio of 10 to 10.5 to 1

Custom built Venolia pistons and aluminum rods.

Kauffman High Port heads, 64 CC, 2.200 intake, 1.750 exhaust, titanium retainers, 10 degree locks, h-11 springs. (Solid roller cam) 380 CFM port work, 1200 series Ferrrea valves. ARP High Port head stud kit. ARP Rocker arm studs and a girdle.

Looking to be able to produce 1000 HP but tune to 850.

I'm taking the dragster out tomorrow night and again this Sat.

It has been running great although have had an idle problem, but believe that has been fixed (user error)

Best run is 8.810 at 152.790 reaction time of .502

Starting tomorrow we will be working on slowing it down to a 9.000 index for NDRL racing http://www.nostalgiadragleague.com/Home.html

Looking to be able to produce 1000 HP but tune to 850

[Brian Baker]

Someone will correct me if I am wrong, but I think the rule of thumb on a roller cam and a stock block is up to 200 degrees duration at .200" lift before you'll need a lifter valley brace.

[Glenn Lever]

Originally Posted by Brian Baker

Someone will correct me if I am wrong, but I think the rule of thumb on a roller cam and a stock block is up to 200 degrees duration at .200" lift before you'll need a lifter valley brace.

.200 lift and the valves are barely open??????

I have found that the grind profiles for Engle cams are not well known, below is pulled from their grind profile list.

NEW SOLID ROLLER PROFILES FOR RACING ONLY
GRIND LIFT LIFT LIFT LIFT DURATION DURATION DURATION
NUMBER 1.7 Rocker 1.6 Rocker 1.5 Rocker @ Cam @ Lash .020" @ .050" @.200"
EX-4 .731" .688" .645" .430" 316 278 190
EX-5 .731" .688" .645" ,430" 323 284 196


here is the whole list
NEW SOLID ROLLER PROFILES FOR RACING ONLY
GRIND LIFT LIFT LIFT LIFT DURATION DURATION DURATION
NUMBER 1.7 Rocker 1.6 Rocker 1.5 Rocker @ Cam @ Lash .020" @ .050" @.200"
JR-69 .674" .632" .421" 287 252 173
JR-70 .677" .635" .423" 293 259 179
JR-71 .678" .636" .424" 296 260
JR-72 .682" .639" .426" 302 268 186
DG-256 .686" .644" .429" 292 256 175
DG-262 .688" .645" .430" 300 262 180
DG-266 .686" .644" .429" 302 266 182
DG-272 .710" .666" .444" 306 272 192
HTR-272 .722" .677" .451" 305 272 188
HTR-280 .723" .678" .452" 312 280 195
HTR-288 .723" .678" .452" 316 283 197
L-760 .680" .640" .600" .400" 298 260 174
L-764 .680" .640" .600" .400" 300 264 177
L-768 .697" .656" .615" .410" 302 268 178
L-772 .697" .656" .615" .410" 310 272 183
EX-1 .695" .654" .614" .409" 301 260 175
EX-2 .712" .670" .629" .419" 305 269 180
EX-3 .729" .686" .644" .429" 312 272 184
EX-4 .731" .688" .645" .430" 316 278 190
EX-5 .731" .688" .645" ,430" 323 284 196
EX-6 .726" .683" .641" .427" 328 290 197
HO-290 .782" .736" .690" .460" 329 290 205
HO-294 .782" .736" .690" .460" 334" 297 206
HO-304 .789" .742" .696" .464" 340 304 210
HO-310 .789" .742" .696" .464" 310 216
GA-280 .800" .750" .500" 280
GA-286 .800" .750" .500" 318 286 199

[johnta1]

That's 200º duration at .200" lift.

That 1st cam listed is 190º at .200" lift.
(all of them except for the last 4 or so are less than 200º duration.

[Glenn Lever]

Originally Posted by johnta1

That's 200º duration at .200" lift.

That 1st cam listed is 190º at .200" lift.
(all of them except for the last 4 or so are less than 200º duration.

Ok, I get the table, 190 degres at .200

What does that mean?

[BruceWilkie]

If you already have the lifter bore brace, dont sweat much over the duration at .200" cam lift.

With any roller cam its the actual ramp rise rate that affects the amount of side loading on the lifter bores. All rollers will impart side loading.

Flat tappet cams do not impart side loads on the lifter bores. To do so would require the edge of lifter to "dig" into the cam.

A blower motor, especially one with high flow rate heads does not need a radical duration camshaft. It will like a lift range that compliments the flow curve.

IMO a good flat tappet with hi ratio rockers and good valvesprings should be able meet/exceed your HP goals.

Its also my opinion that if you can eliminate a high stress in a stock block and still meet your HP goals, then eliminate that stress.
A flat tappet may be a wise choice for that reason alone. Hydraulic rollers have modest ramp rates and could work with your plan if you really dont think you can live with a flat tappet.

I have a flat tappet cam(max lift rate type) in a road race Pontiac that has lived just fine for 2 seasons and is now in a back up motor. (It was replaced with a bigger version of same series lobes to compliment other changes) I would have no worries about these lobe designs "living" in your application. These lobe types combined with hi ratio rockers can give near roller action at the valve.

Your lifter bore brace, if its the full valley brace, is still useful for block stiffness.

Feel free to contact me if I can be of assistance.

[Glenn Lever]

Originally Posted by BruceWilkie

If you already have the lifter bore brace, dont sweat much over the duration at .200" cam lift.

With any roller cam its the actual ramp rise rate that affects the amount of side loading on the lifter bores. All rollers will impart side loading.

Flat tappet cams do not impart side loads on the lifter bores. To do so would require the edge of lifter to "dig" into the cam.

A blower motor, especially one with high flow rate heads does not need a radical duration camshaft. It will like a lift range that compliments the flow curve.

IMO a good flat tappet with hi ratio rockers and good valvesprings should be able meet/exceed your HP goals.

Its also my opinion that if you can eliminate a high stress in a stock block and still meet your HP goals, then eliminate that stress.
A flat tappet may be a wise choice for that reason alone. Hydraulic rollers have modest ramp rates and could work with your plan if you really dont think you can live with a flat tappet.

I have a flat tappet cam(max lift rate type) in a road race Pontiac that has lived just fine for 2 seasons and is now in a back up motor. (It was replaced with a bigger version of same series lobes to compliment other changes) I would have no worries about these lobe designs "living" in your application. These lobe types combined with hi ratio rockers can give near roller action at the valve.

Your lifter bore brace, if its the full valley brace, is still useful for block stiffness.

Feel free to contact me if I can be of assistance.

Read and understood. More thinking needed.

I will use the valley brace however I go.

It is a full valley brace from Kaufman racing

[Brian Baker]

To remove all doubt, when you degree the cam, measure how much duration is there from .200" lift opening to .200" lift closing...if it's 200 degrees or more, the lifter bore brace is needed.

[Glenn Lever]

Originally Posted by Brian Baker

To remove all doubt, when you degree the cam, measure how much duration is there from .200" lift opening to .200" lift closing...if it's 200 degrees or more, the lifter bore brace is needed.

Lifter bore brace is going in no matter what. It sounds like, from the responces above I am fine.

Thanks a ton.

[Brian Baker]

Good choice...installing a roller cam for me would be an automatic decision to install the brace, regardless of the cam specs.

I suer would like to see you bring that car to Norwalk in August.

[Glenn Lever]

Originally Posted by Brian Baker

Good choice...installing a roller cam for me would be an automatic decision to install the brace, regardless of the cam specs.

I suer would like to see you bring that car to Norwalk in August.

It is not out of the question yet.

I'm just starting to get it dialed in.

What kind of racing is it Index, ET, Heads up (no fast enough for that).

[Brian Baker]

Norwalk is all bracket racing, save for the class set aside for the fastest 4 door cars on the property and the heads up class for door cars. Your FED might make a good candidate for the quick 16 class.

[rumair]

if you've got the fed dialed in and running consistently in the high 8's then i'd say enter the q-16. that would give you a chance to see how good you are on the tree against some very experienced and fast bracket racers.

[Glenn Lever]

Progress has been slow but there has been progress.

I'm currently looking for the crankshaft hub and pulley and am only finding kits. Any help?

I do not want a kit at the moment as the blower is a retro blower and will have to be moved back with an adapter plate yet to be built. Becuase of that I do not know the length of the snout for the blower.

Below is a list of parts bought and on hand

Engine: 400 Pontiac ram air III block 1970
Deck 10.240
Stroke 4.000
Head Gasket 4.200 Bore/ .043 Thick
Forged four bolt main caps
Moon Front Timing Chain Cover for dual drive for Mag and Pump
Scraper
Kauffman lifter valley brace

Enderle front Offset dual drive

Intake Modified BDS Blower Intake

Ignition Mallory Super III Magneto

Crankshaft RPM-455A400C 4340
light weight (70 pounds)
Forged
Nitrided
Pontiac 400 3.00 Main 4.00 stroke GM Rod Journals

Blower Littlefield 8-71
high helix
stripped
retro
Bird Catcher
injector hat

Proposed Engle Roller cam
SOLID ROLLER PROFILE
GRIND LIFT LIFT LIFT LIFT DURATION DURATION DURATION
NUMBER 1.7 Rocker 1.6 Rocker 1.5 Rocker @ Cam @ Lash .020" @ .050" @.200"
EX-4 .731" .688" .645" .430" 316 278 190
EX-5 .731" .688" .645" ,430" 323 284 196

Custom built Venolia pistons and aluminum rods.
Pistons: 4.155 Bore
.990 Pin/Supply Pins & Spiro Locks
2.200 intake notch/ 1.750 Exhaust notch
15cc Dish Includes Valve Notches
10.5 Comp. for Blown Alcohal
1.605 Compression Distance
Aluminum Rods:
Big Block Chevy Big End and Pin Bore
2.200/2.325 Bore .990
6.635 Center – Center
-.010 Aluminum

Kauffman heads High Port
64 CC,
2.200 intake, 1.750 exhaust,
titanium retainers,
10 degree locks,
h-11 springs. (Solid roller cam)
380 CFM port work,
1200 series Ferrrea valves.
ARP High Port head stud kit.
ARP Rocker arm studs and a girdle.

[Jack Gifford]

Steve Barcak will sell you a crank hub. Pulley should be available by scrounging.

[Glenn Lever]

Originally Posted by pontiac jack

Steve Barcak will sell you a crank hub. Pulley should be available by scrounging.

Thanks, I will e-mail him.