I found specs at .050" for the GM Off-Road Cam 3927140.

Now I'm looking for the second design Off-Road cam specs at .050" for GM#3965754 I have seat to seat specs but they don't really reveal the true cam.

I need intake and exhaust opening and closing degrees (crank) at .050" plus lobe lift.

Thanks, David

Dave,
Got the following from an old "Chevy Power" manual. ALthough it does not have the exact numbers you are looking for, you should be able to figure them out from these figures:

duration @.010 295/301
duration @.050 249/258
intake cl 108 ATDC
exhaust cl 116 BTDC
overlap @0 tappet lift 98 deg
overlap @.010 tappet lift 72 deg
valve lash .024/.026

Hope this helps,

Bill, Thanks, I should be able to use those figures, the lobe centers are critical to doing it.

I have a buddy who is installing this cam this winter, doesn't have the cam yet though.

I am planning on a cam for my 69 Camaro vintage racer too. I like the 140 cam myself. I drove a 350 cid F5000 car with the second design cam and it seemed pretty good in that, but I don't know how it would be in the little 302.
David

FYI,
Those who are interested,
Based on the specs BillK posted, Here are the opening and closing specs for 3965754

AT .050"
IVO 16.5
IVC 52.5
EVO 65
EVC13

CENTERLINES
I 108
E 116

DUR I/E 249/258

INTAKE LOBE LIFT 330/.341
GROSS LIFT .495/.512
LASH .024"/.O26"

CAM IS AVAILABLE FROM GM
CAM IS ALSO AVAILABLE FROM MELLING PN 3965754

Thanks to Bill for providing the specs. graemlins/thumbsup.gif
David

[ 10-13-2004, 10:46 PM: Message edited by: davidpozzi ]

David,

In case you wanted to see what the 140 cam does in a side by side horsepower comparison, here is the cam test results with stock vs modified 186 cast iron heads in a DZ302.


Stock 186 - 140 Cam vs Modified 186 - 140 Cam

RPM HP TRQ HP TRQ


2000 102 269 100 263
2500 140 295 137 287
3000 176 308 171 299
3500 221 332 217 326
4000 266 350 267 350
4500 309 361 267 350
5000 345 362 317 370
5500 365 348 361 379
6000 376 329 393 375
6500 371 300 418 366
7000 357 268 429 346
7500 348 243 431 323
8000 318 209 437 306


Graeme

Graeme,
Thanks! graemlins/thumbsup.gif
That's cool!

do you know how Modified the heads were?
Was it a full port or just pocket port?
The HP seems a little low, I'd expect above 450+ if the heads had full port.
David

David,

I think those spec's may be off b/c I always thought the -754 was larger then that at .050".

Chevy's solid cams went -097(228/230), -178(242/254), -346(254/254), -140(257/270) and finally -754((262/273). And I'm not going to get into the mushroom lifter solid cam..

I say this b/c my two old copies of Chevy Power don't have all the correct cam spec's in them.

This has been mentioned before on the Boards about their published inaccuracies(Sp?) in the past..

I will check into this after work this evening and get back to you.

pdq67

How would the off-road cam work in a mild 327 ? My compression is supposed to be 10:1 with 461 camel hump heads and TRW flat tops. I am concerned because I have a 700r4 with a 2,000 stall and 4:11 gears that will be changed to 3:73's.

Theres 2 identical lines at 4000 and 4500 for the modified 186 heads. Both say 267 HP 350 FT/LBs. I think the data points from then on must be off by 500 RPM.

David,

My copy of the 6th Edition of Chevy Power lists the -754 as:

Lash = .024"I.
Lash = .026"E.
Intake Opening point = 46BTC, closing point = 92ABC.
Exhaust opening point = 93 BBC, closing point = 54 ATC.
Crankshaft duration at lash point = 318/327.
Crankshaft duration at .010" Tappet Lift = 293/302.
Crankshaft duration at .050" from Base Circle = 262/273.
Max lift w/1.5 rocker ratio = .488"/.509".
Lobe centerlines = 112.
Intake C/L from TDC = 108.
Overlap at .000" Tappet Lift = 100.
Overlap at .010" Tappet Lift = 74.
Mild racing cam for 350 and larger V-8 engines.

That's just what my book say's. It's kinda funny the way they spell it out.....

pdq67

PS., W/B/R lists their PN WG-989 as 323/257 for the intake & 329/270 for the exhaust, 112/108, .493"/.512", lash at .022"/.024", timing at .050 = 19BTC/58ABC & 70BBC/20ATC.

Here are the specs Melling sent me:
Int opens 21btc int closes 61abc
Exh opens 71bbc exh closes 22atc
Int lift is .341
Exh lift is .357
Int center line is 108
Exh center line is 116

Technical Manager
Cal Rydjord
2620 Saradan Drive
Jackson, MI 49202
Phone: 517-787-8172
E-mail: technical@melling.com

I asked for specs at .050".
David

[ 10-14-2004, 09:03 AM: Message edited by: davidpozzi ]

IF the duration and lobe ctrs are correct above, the following must be the valve event timing:

IVO 23
IVC 59
EVO 72.5
EVC 20.5

LOBE SEPARATION 112

The cam is 4 deg advanced this way.


It looks like the IVO/IVC EVO/EVC specs he gave me were at two deg advanced, but the centerlines should be 110/114 in that case.
David

tjs69,
Those cams need 11 to 12.5 to 1 compression plus peak hp in a 327 looks to be around 7000 with torque coming on fair at 3000 and very good torque at 3500 in a 327.

I had a similar but slightly different cam in my 67 Camaro, with 11 to 1, I used a Crower X19-F and it liked to rev to 7000, had lots of torque from 2500rpm's up, ran strong from 3000 up.

You might look at Crower 00320
rpm range would be 2000 to 6500 strong torque at 3000.
more torque than the 040 cam but less top end.
Lift .458/.468
duration 230/236
Int ctr 108
ex ctr 116
lobe sep 112.

I'm no expert on cams, so don't take this as an dependable recomendation.
David

pdq67,
The 754 cam has more lift but faster ramps than the 140 cam.
Here is some cam data I found on the net.

Chevrolet Factory Cam Specs by part number
Part # Lifter type--duration at .050 In/ex--Lift in/ex--centerline--description
Small Blocks
3849346 Mechanical - 254/254 - .484/.484 - 114 - 327 365HP& Z-28 302
3863151 Hyd. - 221/221-.447/.447-114 - 327-350HP, L79
3896929 Hyd. - 195/202 - .390/.410 - 112 - 327 300 HP
3896962 Hyd. - 222/222 - .450/.460 - 114 - 350 L-46, L-82
3927140 Mechanical - 257/269 - .493/.512 - 112 - Off Road
3965724 Mechanical - 262/273 - .488/.509 - 112 - 2nd design road race, short track
3972178 ?
3972182 Mechanical - 242/254 - .459/.485 - 116 - 70 LT1 360 & 370HP, 71 LT 330 HP
10134334 Hyd. Roller - 235/235 - .480/.480 - 114 - 350ZZZ and ZZ2 Crate Motor
10185071 Hyd. Roller - 208/221 - .474/.474 - 112 - 350 345, ZZ3&4 Crate Motor
10224241 Hyd. Roller - - 92-94 GenII, LT1, 350
10243779 Hyd. Roller - - 94-96 Gen II, L99 265 V-8
12353914 Hyd. - 180/194 - .378/.401 - - GM Crane Lo speed Hi torque
12353915 Hyd. - 194/204 - .401/.423 - 104 - GM Crane street
12353916 Hyd. - 204/214 - .423/.446 - 110 - GM Crane 305-350 street legal 50 states
12353917 Hyd. - 204/214 - .420/.441 - 112 - GM Crane nan-emissions vehicles & off road
12353918 Hyd. - 214/224 - .442/.465 - 112 - GM Crane marine & off road
12353923 Hyd. - 224/234 - .465/.448 - 114 - GM Crane off road
12364050 ?
12364051 ?
12364052 ?
12364053 ?
12364054 ?
12370845 Hyd. Roller - 214/224 - .488/.509 - 112 - Off Road, lobe for mech fuel pump
12370846 Hyd. Roller - 222/230 - .509/.528 - 112 - Off Road, lobe for mech fuel pump
12370847 Hyd. Roller - 232/242 - .539/.558 - 112 - Off Road, lobe for mech fuel pump
12551142 Hyd. Roller - 203/210 - .476/.480 - 115.5 - 96 350 LT4 w1.6 roller rockers
12551705 Hyd. Roller - 201/208 - .447/.459 - 112 - 95-96 Gen II, LT1, w center dowel pin
14088843 Hyd. - 202/206 - .403/.415 - 115 - 305 HO, 83-86
14093643 Hyd. Roller - 202/206 - .403/.415 - 115 - 87 350 Corvette, IROC Camaro
24502476 Hyd. - 121/220 - .435/.460 - 112.5 - 350 300 crate motor
24502586 Hyd. Roller - 218/228 - .525/.525 - - 96 LT4 H.O.T. crate motor, use with 1.6 roller rockers
NA Hyd. Roller - 202/210 - .472/.478 - 111 - 97 Gen III LS1 Corvette 350 uses 1.7 roller rockers

Here is the 140 cam info in more detail, this is from crane who sells a copy of it:

Part Number: 968821 Grind Number: 3927140
Engine Identification:
Start Yr. End Yr. Make Cyl Description
Engine Size Configuration

Valve Setting: Intake .024 Exhaust .026 HOT
Lift: Intake @Cam 3286 @Valve 493 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 3412 @Valve 512
Rocker Arm Ratio 1.5
Cam Timing: TAPPET @--
Lift: Opens Closes ADV Duration
Intake -- BTDC -- ABDC °
Exhaust -- BBDC -- ATDC °
Spring Requirements: Triple Dual Outer Inner
Part Number 99893
Loads Closed 120 LBS @ 1.875 or 1 7/8
Open 296 LBS @ 1.415
Recommended RPM range with matching components
Minimum RPM 4200
Maximum RPM 7000
Valve Float 7500
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 20.5 BTDC 56.5 ABDC 108 257 °
Exhaust 70.5 BBDC 18.5 ATDC 116 269 °


CENTERLINE
INT 108
EXH 116

LOBE SEP 112

David,

You might check Midwest Motorsports for good inexpensive, roundy-round valve springs...

I got a set of .600" lift kit to go with my "264/246", 108/108, .468"/.468"net lift PAW el-cheapo "aggressive" solid cam for my 283 motor just for the fun of it!! He, He!! Sucker should rpm to the moon!!!

Springs are Elgin PN ELG RV1943X. I figure they will handle any solid cam that is anywhere near streetable!!

My -601 heads had Exhaust valve rotators so I had to go taller springs to get rid of them b/c I didn't want to run THAT thick a rotator eliminator is all..

pdq67

PS., and GM say's the -142 spring will, (quote), "extend the rpm range of all Chevrolet mechanical tappet street performance cams", whatever that means??

Thanks for your input David!! I have looked at the specs on that Crower cam before and I liked what I saw! I didn't think I had enough compression for the off-road cams. Most people compare 327's to 350's ,but I don't think they should with cams. Just my opinion. Thanks again.

All that means is that a longer stroked motor makes a cam appear smaller then a shorter stroked motor if rod length is held constant..

This is b/c the piston is very slightly farther down in the hole at the point of the intake valve closing point so it traps more charge like a smaller cam would...

LCA and ICA stuff move the power points and shapes of the curves sorta deal to fine tune everything if you look at your motor from a "combination" view point..

Isn't this fun??? At least, it's a hoot to me...

pdq67

TJS69,
I would do a DCR computation on it and see what the dynamic compression is with your compression ratio.

I think the DCR would be near 7.5 to 1.
Cranking compression around 180 psi.
I think you'd have 400hp @6000, but with better flowing ports, closer to 450 hp @6500 is possible.

There might be a better cam around but this one is close, a better choice than the 140 for your compression I think.

Crower specs:
Cam 00320
ADV DUR: 264/270
.050 DUR 230/236
LIFT: .450/.468
LOBE LIFT: .305/.312
LASH: .022/.024

IVO 7 IVC 43
EVO 54 EVC 2.0 ATDC

LOBE SEP 112
INT/EXH CTRS 108/116
David

[ 10-15-2004, 08:26 PM: Message edited by: davidpozzi ]

I see the specs are allready in here . I have a phase iii solid cam in a 60 over 350 with 76 cc heads .200 dome pistons Holley strip dominator intake 780 Holley with headers . the engine is ignorant runns like a scalded dog lol . i have a 3500 converter 4.56 rear fun fun lol :hurray::yes: Oh yea in a 1972 Monte Carlo :noway:ps little sluggish under 2500 rpm

Guys I agree the numbers in David's post #4 appear to actually be for the -140 first design cam. Those are the numbers of my 140 replacement from Mahle/Clevite and the one I installed in the motor before this one. Their site at:

www.clevite.com

has a wealth of information on all the performance cams. It's more than a little difficult to migrate through their site, so if you start with the camshaft catalogue here:

http://www.clevite.com/pubspdfs/4-200-05.pdf

and scroll down to page 142 that's where the real meat and potatoes of the cam chart is. It's still difficult unless you know most of the numbers or already know the Clevite part number for the cam you are looking for, but the numbers are there for the first design off road cam under part number 229-1622. Which by the way GM no longer makes, but still offers in their performance catalogue. If you order it you'll recieve the Crane blueprint series grind from GM Performance.

The Mahle site has tons of info on all the cams including .050 duration, valve timing events @.050, lash, lobe centerlines, lift, gross lift @ 0 lash, SAE overlap, and SAE duration for many replacement grinds of the cams you are discussing. It's a great site, give it a try.

And to answer the gentlemens question regarding using the -140 in a 10:1 motor I agree the DCR would be too low. GM recommended a minimum of 12:1 SCR for this cam, although many found their way into 11:1 motors. It worked well in a 12.5:1 331 and in 12.5:1 302's, however I never used it in a motor with less compression than that myself.

Dave

Thanks Dave for chiming in b/c I was just going to ask where you were!

pdq67

Delta cams also makes a 2nd design off road cam, I ran way back in the early to mid 80's I think we advanced it 3 degrees for drag racing applacation that was a neet motor with T 400 TCI 4500 stall 5.38 gears 29.0 tall tires,ran 12.50's @ 110 mph if I remember correctly ,I am no motor guy but to read and follow you guys is neet I think I was shifting at 6,800 ,and we figured 425 hp 10.8to 1 comp. 492 heads 700 double pumper .thanks for letting me add ,Have a great Thanksgiving

Thanks Jerome, you have a great Thanksgiving too. I also love talking this stuff.

Paul I tried not to chime in on a -140 topic, but couldn't help myself. Did you ever find any specs for the 334096 110 lobe center or 094 108 lobe center cams that Smokey recommended for his intake? I'm assuming they are a Chevrolet grind because the SY1 prototype Yunick submitted carried Chevrolet part number 5237751 before GM killed it. This was all going to be trans am stuff, so I'm pretty sure Smokey was using Chevrolet grinds with it. Just wondering if the shorter, straight runners and smaller torque box plenum really called for a different grind from the first or second off road cams. I've got to assume he tried them before coming up with the 096 and 094 cams, curious how their numbers compare but can't find anything on them.

Either way right now the plan now is to run this SY1 with another -140 and 1.7 rockers, last one carried 1.6, but 46 less cubes.

Dave,

I never did find anything on those two cams for you??

Try here....

http://www.geocities.com/MotorCity/Downs/3000/cmspec.html

and here....

http://www.crateenginedepot.com/store/SB_camshaft_chart.html

But I don't think they show up??

Sorry,

From the two numbers, it would appear they followed or came before the old -097 cam, but I figure it would be way too small unless those two kept the same overall design, but went way higher on lift??

You know, tight centers and tight lash.... But way higher lifts..

pdq67

Thanks Paul. I agree with your comments. It's possible on the higher lift, especially since Yunick liked using 1.7 rockers that would boost the lift quickly, but he doesn't mention using 1.7s in the paperwork. I may give Wayne Guinn a call and see if he's run into this. If I learn anything I'll let you know.

If you look at the second page Yunick's recommending some pretty serious header primary and collector diameters for the SY1 so I'd like to get the details on those two cams to see how far off of the first and second design off road cams they are.