496ci revamped

That takes care of just the power brakes Grumpy.
Not the 4L80E.
Reason why the Vacuum modulator takes the place of the Line pressure control solenoid EPC.

Has to follow a smooth linear curve.
Or the Clutches will slip.

Steady predetermined line pressure rise.
Could go full line pressure.
May beat up the aluminum cases 4L80e to death.

Turbo 400 has the aftermarket REID CASE for Severe duty applications.
Constant lime pressure.
What you're saying makes sense now,
I may have not had enough vacuum to begin with.
I say this because if you're in 2nd gear
And slam it back in to 1st it hits hard
But 1st to 2nd and 2nd to 3rd and 3rd to 4th fine , I always made sure to be completely stopped (let's say at a stop sign) completely stopped then shift to first, it wasn't a big deal to me I didn't run around slamming it into first all the time.

I had transmission built as you know,
So might get some answers from the guy today as to what and how.

And that as my buddy says is hot rodding
Degreed cam, cheap procomp belt drive
Off a tooth , you line dots up it's off 10 degrees you jump one tooth on top gear
It seems to come right in, you guy's seen anything like this before?
 
What you're saying makes sense now,
I may have not had enough vacuum to begin with.
I say this because if you're in 2nd gear
And slam it back in to 1st it hits hard
But 1st to 2nd and 2nd to 3rd and 3rd to 4th fine , I always made sure to be completely stopped (let's say at a stop sign) completely stopped then shift to first, it wasn't a big deal to me I didn't run around slamming it into first all the time.

I had transmission built as you know,
So might get some answers from the guy today as to what and how.

And that as my buddy says is hot rodding
Degreed cam, cheap procomp belt drive
Off a tooth , you line dots up it's off 10 degrees you jump one tooth on top gear
It seems to come right in, you guy's seen anything like this before?
I have never worked with a Pro Comp Belt drive.
I have degrees cams in for Racers with Jesel dry setup beltdrives.
One was a Big Block Chevy.
The other was a Ford Windsor 351.
 
Found a review from jeg's
SBC but it's similar issue
I will break out calculator
Do some ciphering
 

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ProComp chinese junk needs r&d or correction every time you have to pay close attention when using catch simple problems. Many have had success many have not. Speedmaster or ProComp have mixed reviews all over the net. Eyeballed the belt drive but thought cost to fix issues it would cost.
 
ProComp chinese junk needs r&d or correction every time you have to pay close attention when using catch simple problems. Many have had success many have not. Speedmaster or ProComp have mixed reviews all over the net. Eyeballed the belt drive but thought cost to fix issues it would cost.
Oh my plan was just that.
I got a smoking deal on it $364
And was planning on making my own parts to fit step nose cam.
The back side has to be milled in a few spots as well, a few people on YouTube
Said most have to be modified because of so many block variation.

index.php

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Back to vacuum...
I'm spit balling but I wonder if I could use old mechanical fuel pump as a vacuum pump? I know we modified Hayabusa smog pumps as vacuum pump to pull vacuum on crank case to cut fog on our race bikes
 
.
Sorry I didn't get to this yesterday, but it was 107° where I live!

I did figure out a few things..... first I got the labels reversed on the graph with two plots. See below

Sim03_Crane139791_680_680_AFR315_-4°Retarded.JPG

Second is the Crane camshaft cannot be symmetrical about the opening and closing sides of the lobe
and DynoSim5 does not know how to handle that very well. The closing side takes an additional 12°
(41-29=12°) to close after the .050 lift.

I had to make a choice between the intake centerline or the valve timing events being per the cam
card, I chose the valve timing numbers. This made the intake centerline to be 115.5°, instead of the
109° called for.

CraneVsHowardsCamTiming.JPG

.
 
somethings very wrong with the soft ware , and the predicted torque curve plots!
Ive built too many similar 489-496-502 BBC and used similar cams to both listed, examples,
the difference should be about a 30ft lbs loss in off idle torque and about a 35-45 hp gain,
in the difference with the crane roller cam vs the howards cam timing.

neither cam would post well below 350 ft lbs at 3000 rpm or anything close to that low. and
both curves should look far closer to this one you originally posted
theres got to be some data thats input incorrectly, or the soft wares not accurate

index.php


look heres an actual dyno print out of a similar 496 oval port bbc
tony_005.jpg


heres a different 496 BBC

36628_n.jpg

51420_n.jpg



heres a third 496 BBC example

496 BBC 876hp
Thought some of you guys would like to see this.

496 BBC
280/290 799/775 lift, 113 LSA
13.5-1 compression
Milodon oil pan
2927 ported manifold
Stock 1050 HP carb
Massaged 335 AFR's cylinder heads
Titanium Valves
dyno9496-1.jpg

http://www.speierracingheads.com/

related build info
notice not one build of a 496 BBC has a similar off idle lack of torque

https://www.hotrod.com/articles/0806phr-chevy-496-big-block-engine-build/

http://www.superchevy.com/how-to/project-cars/sucp-0312-496-street-bruiser/

http://www.superchevy.com/how-to/project-cars/sucp-0901-496-chevy-big-block-build/

http://www.superchevy.com/how-to/engines-drivetrain/1005chp-496ci-engine-build/

http://www.superchevy.com/how-to/en...estech-performance-496-chevy-big-block-build/

http://garage.grumpysperformance.com/index.php?threads/lunati-496-bbc-engine-build-up.1420/

https://www.hotrod.com/articles/big-block-chevy-engine-build/

http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/
 
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somethings very wrong with the soft ware , and the predicted torque curve plots!
Ive built too many similar 489-496-502 BBC and used similar cams to both listed, examples,
the difference should be about a 30ft lbs loss in off idle torque and about a 35-45 hp gain,
in the difference with the crane roller cam vs the howards cam timing.

neither cam would post well below 350 ft lbs at 3000 rpm or anything close to that low. and
both curves should look far closer to this one you originally posted
theres got to be some data thats input incorrectly, or the soft wares not accurate

index.php


look heres an actual dyno print out of a similar 496 oval port bbc
tony_005.jpg


heres a different 496 BBC

36628_n.jpg

51420_n.jpg



heres a third 496 BBC example

496 BBC 876hp
Thought some of you guys would like to see this.

496 BBC
280/290 799/775 lift, 113 LSA
13.5-1 compression
Milodon oil pan
2927 ported manifold
Stock 1050 HP carb
Massaged 335 AFR's cylinder heads
Titanium Valves
dyno9496-1.jpg

http://www.speierracingheads.com/

related build info
notice not one build of a 496 BBC has a similar off idle lack of torque

https://www.hotrod.com/articles/0806phr-chevy-496-big-block-engine-build/

http://www.superchevy.com/how-to/project-cars/sucp-0312-496-street-bruiser/

http://www.superchevy.com/how-to/project-cars/sucp-0901-496-chevy-big-block-build/

http://www.superchevy.com/how-to/engines-drivetrain/1005chp-496ci-engine-build/

http://www.superchevy.com/how-to/en...estech-performance-496-chevy-big-block-build/

https://www.hotrod.com/articles/big-block-chevy-engine-build/
Here's what my phone app came up with ,
I did one of your cams to Grumpy
Bad thing is it has no curve
 
It does seem odd torque is so low below 3000 rpm for such a Large Ci. Engine.
496 BBC.

Unless it's factual to the computer because of the Induction system and exhaust in place.
 
have you considered the Electron Controller for the tarnsmission and vacuum pump for the brakes or hydroboos system
I have build 4l80e and i did have to drop line pressure so it wont bang the gears in cruise speeds
Also transco vacuum modulator can bee adjusted
 
have you considered the Electron Controller for the tarnsmission and vacuum pump for the brakes or hydroboos system
I have build 4l80e and i did have to drop line pressure so it wont bang the gears in cruise speeds
Also transco vacuum modulator can bee adjusted
Looking at a 2800 3200 lock up converter
At the moment, same place I got transmission $600
 
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