New Converter, Different Shift Points?

[1320racer]

Originally Posted by S/ST 3040

The engine is +.060" 340 w/9.24:1 compression, OEM 596 castings w/1.88" IN valve, roller cam, Victor 340 manifold and Holley 950 carburetor.

so based on this, I stated this in post #6 without knowing anything about his cam...

Originally Posted by 1320racer

you have an engine combo that maybe makes 500+HP and 400+ ft/lbs. torque at probably around 5000 RPM.

knowing that anybody today can put together a 1.5HP/cu.in bracket type engine with out of the box parts. Well I was wrong. The OP has somehow manage to throw this engine together using these junk heads that don't flow 200cfm and the way wrong cam he chose resulting in an engine that only makes about 1 HP/cu.in. not to mention that the 8700 RPM he's buzzing this grenade to is ~ 2500 RPM past peak HP!

As I stated previously, his current cam is about 40 degrees too big at .050 and we have no clue to how much lift or the LSA. Installing the right cam with ~40 degrees less duration at .050 will make ~ 100 more ft./lbs torque at peak and ~ 60 more HP at peak and peak RPM will be lowered by ~300. This engine will require a shift point of ~ 6200, a converter that flashes to ~ 5000 RPM and be geared to trap ~ 6800 RPM. More importantly it will accelerate his 2600 lb. bucket of bolts quicker and faster than it's current performance!

[S/ST 3040]

Originally Posted by 1320racer

so based on this, I stated this in post #6 without knowing anything about his cam...



knowing that anybody today can put together a 1.5HP/cu.in bracket type engine with out of the box parts. Well I was wrong. The OP has somehow manage to throw this engine together using these junk heads that don't flow 200cfm and the way wrong cam he chose resulting in an engine that only makes about 1 HP/cu.in. not to mention that the 8700 RPM he's buzzing this grenade to is ~ 2500 RPM past peak HP!

As I stated previously, his current cam is about 40 degrees too big at .050 and we have no clue to how much lift or the LSA. Installing the right cam with ~40 degrees less duration at .050 will make ~ 100 more ft./lbs torque at peak and ~ 60 more HP at peak and peak RPM will be lowered by ~300. This engine will require a shift point of ~ 6200, a converter that flashes to ~ 5000 RPM and be geared to trap ~ 6800 RPM. More importantly it will accelerate his 2600 lb. bucket of bolts quicker and faster than it's current performance!

I understand cylinder pressure and what components affect it but, I can't figure volumetric efficiency or dynamic compression. I understand what you are trying to tell me but, I do know this..........a N/A 340 will not run better, if it's geared to cross the finish line at 6800 RPM. That would be like switching to a 4.30 gear with my current 31.2" tire just to match 135 MPH. No Way. We have turned the post from shift points to torque converters to camshafts........and I'm completely OK with that. I'm learning! I'm even looking into a different car to try to build a super stocker.





Just guessing, I'm going to say peak HP is about 7000 RPM and Peak TQ probably 5400 RPM.

[1320racer]

Originally Posted by S/ST 3040

a N/A 340 will not run better, if it's geared to cross the finish line at 6800 RPM. That would be like switching to a 4.30 gear with my current 31.2" tire just to match 135 MPH. No Way.

You couldn't be more wrong! That additional 2000 RPM you are buzzing in the lights does NOTHING to quicken your ET and is the bomb ticking!!

[S/ST 3040]

Originally Posted by 1320racer

You couldn't be more wrong! That additional 2000 RPM you are buzzing in the lights does NOTHING to quicken your ET and is the bomb ticking!!

The additional 2000 RPM is a by-product of the loose converter and gearing the car to 60' and 330'. The tighter converter has knocked a couple hundred RPM off the the top end.


So, you are trying to tell me, in order to utilize a camshaft of 270º+ @ .050", I need to add 500-800 lbs. to my car to make it work? Because, that's what I'm seeing is pretty common.
I'm sure if 240º @ .050" camshaft ran harder at my weight, I really have a hard time thinking it wouldn't work better at 3100. 3300?


At the same time, you are saying, if I knock 40º out of my cam, use a 4800-5000 stall converter and switch to a 4.30 gear with my current 31.2" tire, it will 60' better than a 1.266?


If it helps, just forget about it being a "bracket car". The bomb ticks under the hood of every race car.

[1320racer]

those that need help the most, like it the least and those that ask for advice don't want advice at all, rather conformation of what they have already decided.

[S/ST 3040]

Originally Posted by 1320racer

those that need help the most, like it the least and those that ask for advice don't want advice at all, rather conformation of what they have already decided.

I've found that to be true, in most instances.


I have entertained, making some changes to the engine/car from reading the information contained in this thread. All is not lost.


I do keep track of what doesn't work though. This is not my first engine. It won't be me last.