FE Torque Curve

[GT350Mike]

Originally Posted by blykins

Just so everyone knows....I was just ribbing on Barry. In no way was I accusing him of padding his numbers. He and I have had offline email conversations about dyno results, based on the numbers shown from other builders.

Barry is one of the builders that I can joke around with and give a hard time....some of the others are ego-centric.

For a moment, I thought this was going to get really interesting. Glad to see a little friendly rivalry.

BTW Brent, thanks for the clutch/slave cylinder info!

[blykins]

Mike, it's good to do a little poking every now and again, but at the end of the day, we're all trying to feed our families. I have a good bit of respect for Barry, and I would hope that he would reciprocate that.

Dwight, Undy had it.....hot oil with cold water makes a noticeable difference in horsepower.

[blykins]

Originally Posted by blykins

I wish that statement could be made for all applications...but it can't.

Had a flat on the way home yesterday, so that put me behind the rest of the evening...didn't really have time to expound.

But here's my thoughts on this:

You don't cruise at 3000-3500. You cruise at 1800-2500. Dynos generally won't pull down that far, so if you're wanting a good realistic view of what's going on as you're going 60-70 mph down the highway, I don't think it would be easy or prudent to go there.

If I were an independent dyno operator, I would decline at someone's request to pull it down that far, even if I were able to. As I mentioned earlier, you don't always know what the compression ratio is, what the cam is, what the timing is, etc. You get an engine pushing 11:1 with a short cam, too much total timing, and a quick curve, and I think it would be rattle city if you tried to lug it at wide open throttle at low rpms.

A pull from 3500 will tell you everything you need to know, unless you're building an engine for your RV or dump truck.

[DanEC]

Originally Posted by blykins

A pull from 3500 will tell you everything you need to know, unless you're building an engine for your RV or dump truck.

I wish I had had the presence of mind to request a recorded pull from 3500 on my motor. I still think it's likely the chart recorder left a little peak torque back of 4200 rpm. With 9:1 compression and a fairly mild build I don't think it would have stressed it.

[blykins]

Well, keep in mind that it's just a number. A dyno sheet is a necessary evil....

Again, not saying anything about any other builder, but you could probably bring your engine to me or Barry and the numbers would be slightly different.

[GRUF78]

Gents,

For reference, the data for the dyno runs on my motor were logged starting at 3000 RPM. Motor is a 482 FE, pump gas, 38 degrees timing in by 3500, custom Hyd roller cam, Aluminum "F" heads, 10.75 to 1 compression, 780 Holley BV Carb, Vintage Sidewinder intake, Stock distributor.

At 3000 RPM, the motor made 569 Ft-lbs of Torque and 324 HP.

At 4100 RPM, it made 601 Ft-lbs and 468 HP

At 6000 RPM, it made 520 ft-lbs and 594 HP

Pretty strong in my Cobra.

GRUFF

[blykins]

That would be pretty strong in a school bus.

[GRUF78]

Amen....

[AL427SBF]

Originally Posted by blykins

Had a flat on the way home yesterday, so that put me behind the rest of the evening...didn't really have time to expound.

But here's my thoughts on this:

You don't cruise at 3000-3500. You cruise at 1800-2500. Dynos generally won't pull down that far, so if you're wanting a good realistic view of what's going on as you're going 60-70 mph down the highway, I don't think it would be easy or prudent to go there.

If I were an independent dyno operator, I would decline at someone's request to pull it down that far, even if I were able to. As I mentioned earlier, you don't always know what the compression ratio is, what the cam is, what the timing is, etc. You get an engine pushing 11:1 with a short cam, too much total timing, and a quick curve, and I think it would be rattle city if you tried to lug it at wide open throttle at low rpms.

A pull from 3500 will tell you everything you need to know, unless you're building an engine for your RV or dump truck.

I guess we'll agree to disagree. Not all engine dyno's are created equal, nor are the latest chassis dyno's. Fortunately for me I'll have access to a Dynapack 4000 that bolts right up to the hubs and can provide a full load via calibrated EMF at any RPM you want. These guys are local and will be doing mine when the times comes, the vette vid shows just how clean a setup it actually is.
Dyno Services | Goodies Speed Shop - San Jose CA

[blykins]

It doesn't have anything at all to do with the dyno....it has everything to do with the engine.

Still not sure why WOT data is necessary for off-idle performance....

[Gaz64]

Originally Posted by DanEC

I had Keith Craft build my 428 stroker more for torque than raw horsepower. I witnessed the dyno pulls but didn't really sit down and closely study the dyno data until later. The recorder didn't start recording until 4200 rpm and based on everything, I always assumed that was well above the torque peak - which I figured was down somewhere in the 3600 rpm area.

I finally got curious enough to email Tony at Keith Craft and ask if they had any additional data in their file that recorded the max torque and peak rpm. He advised that the recorder starts recording when the motor hits the torque peak - indicating peak torque was at the 4100/4200 area.

I'm having a problem believing this motor's torque peak is at 4200 rpm especially with max power at 5300 rpm. What would you think?

Originally Posted by ERA Chas

I question several other things.
The heading 'A/F Ratio' is listing fuel pressure which is fine but the actual A/F Ratio would be valuable.
I think the BSFC is a bit high for these days but then I see the motor struggles to make more than 50% V/E.
Dan can you post some particulars in the motor's parts list? A 'torque' build should not have a lot of overlap or duration...

I'd want another dyno run without conflicting figures like that.

A/F ratio in the sixes is certainly wrong, and VE in the fiftys?

[ERA Chas]

Originally Posted by Gaz64

I'd want another dyno run without conflicting figures like that.

A/F ratio in the sixes is certainly wrong, and VE in the fiftys?

I think it was mentioned that it was dyno'd with one carb only on a dual plane. dual quad intake-accounting for A/F and VE being 50% readings. I just don't know why KC would dyno that way...
I don't know if it would read that way. And the dyno sheet does not show the test configuration of the engine.

[Bob In Ct]

I know I'm really anal about this stuff but Torque is measured in LB-FT not FT-LBS (a measure of work). Stop looking at your Craftsman torque wrench (which has it incorrect) and start looking at car ads or the charts shown on this post.

Bob