What makes the 1970 Buick 455 make so much Torque?

The heads are part of the reason for the Buick torque. However the camshaft was the other important ingredient to the torque production. I have been able to visit with Denny Manner on several occasions discusing this topic. He worked very heavily with the cams. He says, remember, we had to get the big heavy cars moving from a dead stop which required torque.

The GS Stage 1 cam and the Riviera Stage 1 cam are different. He tried the GS Stage 1 cam in the Riviera and did not like it, needed more torque. The Riviera Stage 1 cam ended up a bit smaller to make sufficient torque to get the car moving.

Intake valve closing is extremely important to making torque. However, bore, stroke, intake port velocity, heads etc all go into the equation and must be matched properly. Cams with a lot of intake duration and late closing events reduce cylinder pressure which reduces torque. This is part of the reason that the high performance cars from other manufactures use high numerical rear gears to get the cars moving.

 

This is very interesting information, thank you for taking time to write me this, very much appreciated.
I get it, everything needs to be matched to obtain the magic performance.

The reason why I'm putting in the cam specs for the original 1790 Stage 1 Buick and the cam specs of the Comp Cam that the original engine builder installed. Is because I have to wonder when part of the equation is changed, does the engine perform better or worse?

The only way I know of finding out, a Dyno test or run it at the track.

The one item that is holding back my GS is the highway geared differential (2.93 posi). When I purchased the car, it was advertised as a 3.42
differential but I found out later that was a lie. Wonder why anybody would posi a 2.93?
The Base GS 455 (which is my car) came from the factory as an open differential in 1970.

There is are differences between these two cams. The exhaust and intake duration specs are close but the lift is more on the Comp Can than the Stage 1 Cam.
Have to say, the Comp cam sounds great.

Another thing I noticed, the Stage 1 cam's Lobe separation: 115 degrees. This gives the engine more vacuum for the power brakes.
The Comp Cam is 112 degrees and just does give 15 inches of mercury, just enough for power brakes.

Original Cam specs - 1970 445 Stage 1 Engine

Cam Part# 1383853

Gross valve lift: Exh. Lift .454”

Gross Valve lift: Int. Lift .407”

Exh. Duration .340 - (@ .050) - 227

Int. Duration 316 - (@ .050) - 208

Lobe separation: 115 degrees


This is the specs for the Comp Cam that was installed in my GS 455 buy the engine builder.
Comp Cam - specs in my 1970 Buick GS 455

Gross valve lift: Exh. Lift. .496”

Gross Valve lift: Int. Lift. .478”

Duration @ .050: Exh. Duration .231

Duration @ .050: Int. Duration .218

Lobe separation: 112 degrees

Check out my Buick and listen to the Cam. I love it. Vet (Navy)

https://www.rkmotors.com/vehicles/1991/1970-buick-gs455#

 

That comp cam is a very good piece. Very similar to the TA 212. Works well with factory manifolds or headers. Makes a little more hp, not sure how tq is affected.
Most aftermarket cams that are larger than factory make a little less tq unless the compression is increased to compensate.

 

talking about more compression, the previous owner of my Buick added aftermarket pistons.

Here's what I know, BUT not the compression ratio, this is a mystery. It could be 11 to 1?

These pistons are what is in my Buick, however, I can't find any information on this particular piston design. Can't find compression Ratio. Davis, have you ever seen this piston or used this type before? I'm referring to is the piston on the left of the picture.
let me know if you know anything about this piston or where I might find information/specs on it. Thank you.


Piston on left is the Federal-Mogul hypereutectic alloy cast piston (.030 over). I have searched all over the internet for this piston, I'm sure this is an old design that is no longer continued.
The previous owner of my Buick bought this car in 2015. Don't know how soon he changed out the pistons.

I know the original engine builder and he said he installed the pistons (10.5 to 1) like the Stage 1 engine had. I'm guessing the 10.5 to 1 pistons are also aftermarket clones of the original Buick pistons. Could be the piston design on the right side of the picture below?

He built the base engine to Stage 1 specs including the larger valves. This engine has it's original intake and cast-iron headers, 750 Qjet. It's a matching numbers engine.

Unfortunately, the Qjet was damaged beyond repair, and the shop had difficulty finding another Qjet (they did find one but it was defective) so we decided to go with a Holley 750 double pumper with eclectic choke and mechanical secondaries. This carb runs very well, I'm happy with it.

On the right is a Speed Pro L2353F forged piston. Black on the skirt of the forged piston is the new anti-scuff coating.

If this piston as I suspect, is a high compression model, I hope the 510 lbs of Torque is still retained. VET (Navy)