Dyno Results

[BSB67]

"...We found duration greater than 245-degrees at .050-inch killed the low-end torque curve. Worse yet, the motor wouldn't make any more power upstairs with the big cam."

That's a bit of a generanization, considering that the 0.050 number at the valve can be quite different between a hydraulic and solid, the lsa matters, and maybe the exhaust lobe too. But certainly Andy has been down this path and has had some success.

 

[rumblefish360]

Ops

 

[Sweet5ltr]

That's a bit of a generalization, considering that the 0.050 number at the valve can be quite different between a hydraulic and solid, the lsa matters, and maybe the exhaust lobe too. But certainly Andy has been down this path and has had some success.

Completely agree. Andy has two articles, that one and the Lobology article where he tested 4-5 different camshafts with manifolds.

 

[rumblefish360]

I look forward to both of you guys dyno tests of this subject.

 

[Sweet5ltr]

I look forward to both of you guys dyno tests of this subject.

Not sure what you mean, there are plenty of tests, engines are air pumps, what happens to a Chevrolet with manifolds is similar to a Ford or Chrysler. There is always a significant loss, normally over 20-HP regardless of the build. Hopefully the loss is minimal!

 

[ksurfer2]

My goal was never to build a max effort motor, I wanted the end result to be a motor that looked stock and makes gobs of power and be reliable. With those goals, I think the engine builder nailed it! I realize that manifolds are costing me power, but I am ok with that to maintain the stock look. If in the future, I want to step up the power, adding headers can be done easily.

 

[rumblefish360]

Not sure what you mean, there are plenty of tests, engines are air pumps, what happens to a Chevrolet with manifolds is similar to a Ford or Chrysler. There is always a significant loss, normally over 20-HP regardless of the build. Hopefully the loss is minimal!

To that I do not disagree or argue.

That's a bit of a generanization, considering that the 0.050 number at the valve can be quite different between a hydraulic and solid, the lsa matters, and maybe the exhaust lobe too. But certainly Andy has been down this path and has had some success.

To this, I look forward to the tests you have done proving and showing.

 

[PRHeads]

I’ll post it again, since the gist of my post seemed to be totally missed......

I’ll be curious to hear your impressions about how you like that cam with exhaust manifolds and full exhaust on the motor.

While I definitely feel that cam is leaving power on the table, with the motor being used with exhaust manifolds as opposed to headers, my post was about how happy the OP will be with the drivability of the car, using that cam without headers........ not about how much power the motor made.

 

[PRHeads]

Curious as to what your selection would have been and why?

Knowing the motor was going to be used in the car with exhaust manifolds, I would have used a cam that provided less of an opportunity for residual exhaust gasses to back flow into the intake port during the overlap period.

It’s very possible(maybe even probable) that a cam I would select to use with manifolds could have resulted in less power than the 23-602-9 cam.......... if both cams had been tested with headers installed on the motor.

 

[BSB67]

To that I do not disagree or argue.

To this, I look forward to the tests you have done proving and showing.

I do have quite a bit of experience and data regarding this. However, it seems a bit off track from the OPs intended discussion, and apologize to the OP for any part that I had in that.

 

[rumblefish360]

I do have quite a bit of experience and data regarding this. However, it seems a bit off track from the OPs intended discussion, and apologize to the OP for any part that I had in that.

Maybe so, but since you brought it up, what did you find. Still looking forward to your results.

 

[Hemirunner]

Knowing the motor was going to be used in the car with exhaust manifolds, I would have used a cam that provided less of an opportunity for residual exhaust gasses to back flow into the intake port during the overlap period.

It’s very possible(maybe even probable) that a cam I would select to use with manifolds could have resulted in less power than the 23-602-9 cam.......... with both being tested with headers installed on the motor.

I don’t have a ton of experience trying to maximize exhaust limited combos but I would think the original cams would be an indication of what’s needed having a 115 lsa and limited overlap.

 

[rumblefish360]

The way they did things and the reasons behind what they did were for the “Passenger ride quality” rather than for the hot rodding and racers aspect of power output.

Customers by far and large want a smooth running and quite car.

 

[moper]

I'm a little suspect of the results, given the stock heads and that camshaft. Even with dyno headers and probably external water and fuel. Big test is when it's in the car running. I wouldn't go out and change gears just yet either.

 

[Hemirunner]

I'm a little suspect of the results, given the stock heads and that camshaft. Even with dyno headers and probably external water and fuel. Big test is when it's in the car running. I wouldn't go out and change gears just yet either.

What I read said Edelbrock heads and he didn’t know all the details so... maybe they’re ported?

 

[moper]

There could be several things involved making things look a certain way. As long as the owner's happy it doesn't matter. Dyno's just a tool, and if it's not tested in the configuration it's being run in it's not going to be accurate anyway.

 

[IQ52]

Comp Cams 23-602-9

243/[email protected], 107lsa

I’ll be curious to hear your impressions about how you like that cam with exhaust manifolds and full exhaust on the motor.

Frankly, I wouldn’t expect that cam to be a very good match for exhaust manifold use.

I’ll post it again, since the gist of my post seemed to be totally missed......



While I definitely feel that cam is leaving power on the table, with the motor being used with exhaust manifolds as opposed to headers, my post was about how happy the OP will be with the drivability of the car, using that cam without headers........ not about how much power the motor made.

Knowing the motor was going to be used in the car with exhaust manifolds, I would have used a cam that provided less of an opportunity for residual exhaust gasses to back flow into the intake port during the overlap period.

It’s very possible(maybe even probable) that a cam I would select to use with manifolds could have resulted in less power than the 23-602-9 cam.......... if both cams had been tested with headers installed on the motor.

Is anybody listening to the man?

 

[IQ52]

Alright, I'll say it and be the bad guy. I'm glad the owner is happy. I feel a little bit sick to my stomach. I don't think the people who built the engine know what the heck they are doing.

But don't listen to me, I've quit building engines.

 

[Hemirunner]

Is anybody listening to the man?

Yes, he would most likely have a cam with less duration on a wider lsa that would make less power on the dyno but would likely loose less hp due to the exhaust manifolds and result in greater drive ability and a happier customer? Lol

 

[PRHeads]

Yes, he would most likely have a cam with less duration on a wider lsa that would make less power on the dyno but would likely loose less hp due to the exhaust manifolds and result in greater drive ability and a happier customer? Lol

That about sums it up.

But, after the customer/owner of the motor in this thread gets the car back, if he’s happy with the power and the way it drives, it’s somewhat of a moot point.

However....... if he’s not....... it’s cam change time.