496ci revamped

a properly designed and built performance engine thats used as transportation occasionally and occasionally street driven, is,
going to be assembled from a slightly different set of components than a true race engine , that will be normally disassembled,
and carefully re-assembled after a race or at least every few months.
this does non necessitate a huge reduction in over all power, but it will generally result in,
an engine built with DURABILITY taking a higher priority, over getting the last potentially available peak rpm horse power ,
and the difference in performance potential is generally minimal if both engines are properly designed.
with current tech, and suspension and tires, performance can be significantly enhanced, without a huge power penalty , especially with added nitrous
example, my 1968 corvette, with a 13.7:1 compression 496 BBC,
ran a 10.25 second 1/4 mile time at 135 mph, but I drove it on the street regularly.
back in the mid 1970s that was respectable performance, but keep in mind Sunoco 260 was available as pump gas,
and the corvette tended to draw un-wanted attention with the way it looked.
my 1968 corvette with a big block 496, running SUNOCO 260 and crower injection, it looked vaguely like this picture,when I even tried alcohol for a short time,
mine was Burgundy and a chrome bumper corvette of course
that required a quick disconnect fuel cell, so I could quickly swap fuel tanks,
I had a 15 gallon fuel cell in the corvette, filed with METHANOL, and a quart of MMO, and a jury rigged 5 gallon fuel can, filled with 115 octane gas and a pint of MMO, we carried separately , too the track,
with the proper quick connect connectors to run the car from for a few minutes ,
before we parked it for any length of time to reduce the chances of corrosion.
78CrowerFI-1.jpg

http://garage.grumpysperformance.com/index.php?threads/build-a-496-stroker-bbc.101/#post-15067
It was the 1971 Hemi Cuda Dana 60.
4-link drag rear.
Real drag gears.
Young could shift a Muncie 4 lighting fast.
CROWER IR. MAX VE.
You had a Real Race cam too.
 
Hi guy, what's your thoughts on this cam in my 496ci, it appears to be setup for my EFI.
Grumpy I knew you said something about a few more degrees of cam timing vs my other cam

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Hi guy, what's your thoughts on this cam in my 496ci, it appears to be setup for my EFI.
Grumpy I knew you said something about a few more degrees of cam timing vs my other cam
Bigger is not always better.
You have a matched drivetrain system now.

It looks Ok.
Best to use an engine Simulation.
I have old Desk Top Dyno 2000.

Rick has the latest and greatest Desk Top Dyno 5 or something I recall.

I really like Isky Cams.
Grumpy prefers Crane.
Both perform close we have found on another thread last year this time.
Similar rated profile cams.
But Isky had a slight edge.
 
The Midrange punch is real important in steel bodied Musclecars weighing 3400-4200 lbs typical .
Don't want to lose it.
 
The Midrange punch is real important in steel bodied Musclecars weighing 3400-4200 lbs typical .
Don't want to lose it.
Did my little dyno simulator I have on my phone, and I think I will stick with what I have. It's missing leading , on two different things one is spring weight
Cam card says 130 seat pressure to 320
On the nose.
But you dig in deeper on cam spec's on edelbrock it's saying 175 seat pressure and 420 on the nose.
: 2 they advertise it as 723 hp but that's on a 555ci

And why would it say single spring only ?
I would think 130 lbs and 320 lbs would be the same weather you have 1 spring or 3 springs.
 
Did my little dyno simulator I have on my phone, and I think I will stick with what I have. It's missing leading , on two different things one is spring weight
Cam card says 130 seat pressure to 320
On the nose.
But you dig in deeper on cam spec's on edelbrock it's saying 175 seat pressure and 420 on the nose.
: 2 they advertise it as 723 hp but that's on a 555ci

And why would it say single spring only ?
I would think 130 lbs and 320 lbs would be the same weather you have 1 spring or 3 springs.
Ok.

Eddy cams in Pontiacs with Eddy Heads...
Heads are capable of near 900 Hp NHRA Super Stock layout.
On TA forum guys run 15s -13's.

So I am not sold on Eddy Cams.
 
Im not a fan of edelbrock cams, I've heard too many people bitch after using one,
but the timing and lift would be in the ball park, in a 496 BBC if your intending on racing the truck/car
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Cam card says 130 seat pressure to 320 on the nose.
But you dig in deeper on cam spec's on edelbrock it's saying 175 seat pressure and 420 on the nose.
: 2 they advertise it as 723 hp but that's on a 555ci

And why would it say single spring only ?
I would think 130 lbs and 320 lbs would be the same weather you have 1 spring or 3 springs.

You must be looking at 2 different cam spec cards. Or whoever typed up what you are looking at entered the info WRONG.
120/320 are spring pressures for hydraulic flat tappet camshafts. 175/420 pounds would be used with roller camshafts.
 
You must be looking at 2 different cam spec cards. Or whoever typed up what you are looking at entered the info WRONG.
120/320 are spring pressures for hydraulic flat tappet camshafts. 175/420 pounds would be used with roller camshafts.
Same cam, just wanted to point out my confusion
One cam card one jegs or summit.
Then when you dig around on edelbrock
You can find the one I marked up
2264 and 2263 are same cam 2264 is step nose. But it lists both cams with same spring rates
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yes a very common problem, theres a great deal of erroneous info even posted by various vendors
it always helps too call and talk with the various tech departments to get their ideas on cam design and matching valve spring clearances and load rates

The following recommendations are from Erson Cams. If you have questions, you can reach their tech department at 800-641-7920.

Hydraulic Flat Tappet Camshaft: 110 lbs Seat pressure/250-280 lbs open pressure

Solid Flat Tappet Camshaft: 130 lbs Seat Pressure/300-325 lbs open pressure

Hydraulic Roller Camshaft: 130-140 lbs Seat Pressure/300- 355 lbs open pressure

Solid Roller Camshaft: (Minimum Safe Pressures DEPEND ON SEVERAL FACTORS)

Up to .600˝ valve lift: 200-235 lbs Seat Pressure/600 lbs open pressure

Over .600˝ valve lift: 250-280 lbs Seat pressure /100 lbs pressure for every .100˝ of valve lift


http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/

http://garage.grumpysperformance.com/index.php?threads/valve-train-clearances-and-problems.528/

http://garage.grumpysperformance.co...-the-extra-cost-vs-a-flat-tappet-design.3802/
 
Im not a fan of edelbrock cams, I've heard too many people bitch after using one,
but the timing and lift would be in the ball park, in a 496 BBC if your intending on racing the truck/car
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So Grumpy any reason why it says single spring only? Just curious, I mentioned this to my brother in law he wasn't sure why, but said it's better to have two , if one breaks the other will some what hold valve up so it doesn't drop down and destroy your engine.
Any thoughts on why.
 
New cam

Howards 120666-112+4
Lift .640 .640

Int 243 exh 249@.05 overlap @.05 22

Int opens @40° close @ 76°
Ex opens @ 87° close @ 35°

72° of overlap
Advertised duration intake 296 exhaust 302
About as big as I can get and still pull vacuum for EFI I'm at 11" to 12" now
Will be about 9" or 10"
8" is minimum
I'm trying to get it to 6300
Falls flat at 6100 with old cam
Talked to three cam manufacturers today
With all three said not enough duration
At 236 243 to get it to rev up

Race car street car
You think it's enough cam Grumpy to get 6300?
 
Int 243 exh 249@.05 overlap @.05 22
vs the older 236 243 should add the extra 300-500 rpm
 
New cam

Howards 120666-112+4
Lift .640 .640

Int 243 exh 249@.05 overlap @.05 22

Int opens @40° close @ 76°
Ex opens @ 87° close @ 35°

72° of overlap
Advertised duration intake 296 exhaust 302
About as big as I can get and still pull vacuum for EFI I'm at 11" to 12" now
Will be about 9" or 10"
8" is minimum
I'm trying to get it to 6300
Falls flat at 6100 with old cam
Talked to three cam manufacturers today
With all three said not enough duration
At 236 243 to get it to rev up

Race car street car
You think it's enough cam Grumpy to get 6300?
W
New cam

Howards 120666-112+4
Lift .640 .640

Int 243 exh 249@.05 overlap @.05 22

Int opens @40° close @ 76°
Ex opens @ 87° close @ 35°

72° of overlap
Advertised duration intake 296 exhaust 302
About as big as I can get and still pull vacuum for EFI I'm at 11" to 12" now
Will be about 9" or 10"
8" is minimum
I'm trying to get it to 6300
Falls flat at 6100 with old cam
Talked to three cam manufacturers today
With all three said not enough duration
At 236 243 to get it to rev up

Race car street car
You think it's enough cam Grumpy to get 6300?
What is the LCA on your old cam ?
What headers do you have again ?
496 Is like a Pontiac 455.
4.25 vs 4.21 inch strokes.
More cubed 496 and more to fill and scavange.
Seems like an exhaust issue.
Big Chevies love 5.000 inch collectors.
No exhaust.
5 inch exhaust Dumps or custom 5 inch .
 
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