Author Topic: Misprinted Cam Card  (Read 3172 times)

Offline jeremy.farlow

  • Frequent Member
  • **
  • Posts: 255
  • Newbie
Misprinted Cam Card
« on: June 11, 2020, 08:21:27 AM »
I plan to call Comp Cams for clarification this morning, but I’m coming up against a weird one: the numbers on the card that came with my cam DO NOT WORK!!?!?

I’m not sure what’s wrong... my initial guess is that intake opening should be 33 • BTDC, not 3 degrees. 
That jives, better, with the 266 degrees of duration. Still leaves 20 degrees unaccounted for...
Numerically speaking the exhaust seems to have the same problem. 46 + 180 + 6 = 232, not 276.

I got so frustrated yesterday I had to walk away from it. I’m gonna start again this morning with the standard timing marks and see if maybe I was missing something.

Just wondered if anyone has had an issue with their cam card being misprinted.




Jeremy

Offline ehjorten

  • Senior Member
  • ****
  • Posts: 1198
Re: Misprinted Cam Card
« Reply #1 on: June 11, 2020, 10:20:09 AM »
I've got you covered Jeremy...just give me a few minutes and I can post the numbers for you!
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline ehjorten

  • Senior Member
  • ****
  • Posts: 1198
Re: Misprinted Cam Card
« Reply #2 on: June 11, 2020, 10:28:33 AM »
Here you go!  Looks like the same as the card though. 46+180-6=220 & -3+180+33=210. Those are valve events at 0.05" Lift.


« Last Edit: June 11, 2020, 10:37:35 AM by ehjorten »
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline ehjorten

  • Senior Member
  • ****
  • Posts: 1198
Re: Misprinted Cam Card
« Reply #3 on: June 11, 2020, 11:16:38 AM »
If you want to give me the numbers for your ICON pistons and AFR Heads, plus how far in the hole your pistons are, I could give you a peak into what the torque and power curve might look like!

ICON 9983  -15 cc dome? 0.06" or 0.070" over?
Standard 9.8" Deck or 10.2" Tall Deck?
AFR P/N? Heads
« Last Edit: June 11, 2020, 11:41:12 AM by ehjorten »
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline jeremy.farlow

  • Frequent Member
  • **
  • Posts: 255
  • Newbie
Re: Misprinted Cam Card
« Reply #4 on: June 11, 2020, 12:05:22 PM »
I got the cam timing figured out. The intake opens, @ 0.050” closer to 1 degree BTDC, but all the other valve events are as advertised. I never got the FULL advertised 0.2850 on the intake so I’m guessing I didn’t get the dial indicator fully in line.

As of right now I’m happy with where and how things are happening, from a valve event perspective.



Jeremy

Offline jeremy.farlow

  • Frequent Member
  • **
  • Posts: 255
  • Newbie
Re: Misprinted Cam Card
« Reply #5 on: June 11, 2020, 12:16:15 PM »
The pistons are 23.00cc domes.
AFR heads are oval port Oval V2 heads 112cc chambers.
I’m using a 0.050” compressed Cometic multi-layer steel head gasket.
Bores are 4.310/0.060” over.

I’m fairly certain it’s a short deck block:

I’m dead at 9” off the crank. Add .80” to get to crank center and I imagine it’s a short deck block. The block was skimmed, but not decked. Just cylinders bored and align-bored.
As far as pistons “in the holes”... they’re not really:

Some crown projects:

I’m interested to see what you come up with. I’ll check back in a couple hours, lemme know if there’s any other info I can provide.
The compression calculator I used indicated almost 11:1 for compression.
I hope I’m not stuck looking for Av-Gas in the heat of summer.



Jeremy

Offline ehjorten

  • Senior Member
  • ****
  • Posts: 1198
Re: Misprinted Cam Card
« Reply #6 on: June 11, 2020, 01:42:29 PM »
What AFR heads?  265 cc ports (AFR P/N 3610-1) with 112 cc chambers, or 290 cc ports (AFR P/N: 3640) with 112 cc chambers?

Also...what ratio rockers...1.7 stock?

Assume you are running 6.135" Rods?
« Last Edit: June 11, 2020, 02:24:06 PM by ehjorten »
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline jeremy.farlow

  • Frequent Member
  • **
  • Posts: 255
  • Newbie
Re: Misprinted Cam Card
« Reply #7 on: June 11, 2020, 02:30:21 PM »
I want to say they’re 290 cc intakes, but I’m not finding that info readily.

1.7:1 Comp magnum rockers

Stroker crank, so rods are 6.385” long.


Jeremy

Offline ehjorten

  • Senior Member
  • ****
  • Posts: 1198
Re: Misprinted Cam Card
« Reply #8 on: June 11, 2020, 02:47:39 PM »
Here is your engine with 265 AFR heads. 488 HP @ 4,500 RPM & 656 Torque @ 2,500 RPM (At the Flywheel) / 415 HP & 557 Torque (At the Wheel)
Had to make some assumptions, but shouldn't be way off.

« Last Edit: June 11, 2020, 02:50:31 PM by ehjorten »
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline jeremy.farlow

  • Frequent Member
  • **
  • Posts: 255
  • Newbie
Re: Misprinted Cam Card
« Reply #9 on: June 11, 2020, 03:05:29 PM »
Pretty healthy.
I’m planning on setting the rev-limiter to 5500 RPM or so... and realistically with the torque output the engine should make it’s doubtful I’ll ever turn it that fast, but... wondering what your program says the HP would likely be at 5500 RPM.

Cool program and THANK YOU.

Initially I had planned to break in and tune on the dyno, more for the controlled environment than actually tuning to the ragged edge, but COVID is likely gonna prevent me doing so as I’m pretty much out of money. Nice to have an idea of what to expect.


Thanks again.



Jeremy

Offline ehjorten

  • Senior Member
  • ****
  • Posts: 1198
Re: Misprinted Cam Card
« Reply #10 on: June 11, 2020, 03:21:01 PM »
Program says 415 HP at the flywheel and 353 HP at the wheel at 5,500 RPM
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline jeremy.farlow

  • Frequent Member
  • **
  • Posts: 255
  • Newbie
Re: Misprinted Cam Card
« Reply #11 on: June 11, 2020, 04:05:33 PM »
So peak HP comes in at 4500 RPM. Sounds perfect for a truck motor.

Thanks again.



Jeremy

Offline ehjorten

  • Senior Member
  • ****
  • Posts: 1198
Re: Misprinted Cam Card
« Reply #12 on: June 11, 2020, 06:40:18 PM »
Might want to think about retarding that cam a few degrees if you find you are having to run too high of octane fuel.  With the information that I put in, the 11.16:1 compression ratio and Seat timing for IVC the dynamic compression ratio is getting up there.  If you retard the cam say 4° you gain about 18 HP and move the HP Peak up to about 5,000 RPM and only lose about 7 lb.ft. of torque.  This brings your dynamic compression ratio down some.  It still seems a little high, but there is a lot of theory in there and your aluminum heads help to pull heat out of the combustion chamber.  Something to think about once you find how it runs.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline jeremy.farlow

  • Frequent Member
  • **
  • Posts: 255
  • Newbie
Re: Misprinted Cam Card
« Reply #13 on: June 11, 2020, 08:27:36 PM »
Whelp... I’m not finding myself... anywhere. I’ve been in uncharted territories for about the last three months. With this truck... and every time I walk out my front door. Strange times these... I’ve built engines before. This one is both the easiest and most complex all at the same time. Too many different options.

Regarding this engine... I started expecting a 119cc combustion chamber. See my other posts for the full story. I settled WAY UP with the AFR heads... Originally I had planned on a better>mediocre head with 119cc chambers. AFR didn’t have that option. Right, wrong or ugly, my outlook is that under 10.5:1 is low compression, better is high compression. I’m now building, in my mind, a HIGH compression engine. That wasn’t my plan.

My reciprocal assembly with a 119cc head kept me under my threshold. AFR’s 112 cc chambers put me in high compression territory. Roll with the punches.

Honestly, the most surprising thing about your model is that torque tapers off so quickly.
HP= (Ft-Lbs X RPM)/3553

When I asked you earlier about peak HP at more revs I really expected a bigger number. In all my previous experience it’s about making the engine safely rev higher. Keep the valves from floating, keep peak piston speed under 6000 ft./minute.

Typically speaking you achieve that with oversquare architecture. I didn’t want a stroker motor initially. Early on I was contemplating a 427... mostly to keep a WAY oversqaure layout. A big block version of the original Trans-Am 305. Rev it until the valves float

I’ve done the compression ratio calculator SO MANY TIMES, lately. You mentioned that you made assumptions. The bore on my head gaskets is 4.3250” I couldn’t find a MLS gasket in 4.310 bore, 0.050” compressed. The calculators I’ve used indicate that my combo will be just under 11:1. I don’t know how that will change the calculus.

As I said... it’s still a high-compression engine no matter what. Just maybe not as high compression as what it seems I’m building.

The quarantinis are working. If above made sense I’m doing well... I’m putting the phone away now because anything that comes now isn’t gonna be coherent.


Y’all be safe and stay healthy out there.



Jeremy

Offline ehjorten

  • Senior Member
  • ****
  • Posts: 1198
Re: Misprinted Cam Card
« Reply #14 on: June 11, 2020, 08:46:55 PM »
Well...I made assumptions about the intake manifold and the Edelbrock Pro Flo you are putting on it. The Exhaust headers I assumed large tube with mufflers no cat.  I did use 265 cc AFR and got the flow values off of their website.  The cam I have in my Cam library.  Will be curious to see how it turns out.

I have built several engines.  My most recent one is a 2004 LQ4 6.0 l and I stuck with the stock cam and ran all the numbers.  I got very close to the posted curves from GM.  I wanted a torque motor for my 1991 V3500 Crew Cab and all of the "torque" cams seemed to not make that much of a difference and they fell on their face at higher RPMs.  Seems all those thousands of hours of GM engineers did pretty good. Putting headers on and tuning we will see how close my simulation comes to the real thing, but it isn't done yet.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6