Don Terrill’s Speed-Talk

vortecpro wrote: A 427 that makes 600 HP @ 6200 RPM
A 427 that makes 600 HP @ 7100 RPM

Nobody has yet mentioned the shape of the torque curve?

How would you build those 2 engines?
The first one.....drop the CR and ad a pair of small turbos. With low boost you might see those numbers?
The 2nd one......high CR, a hot cam and big breathing .


Which would be quicker?
Boost wins.

vortecpro wrote:
Pretty simple isn't it.........Its always about moving the power UP

I'd rather make more hp than make same hp but move peak hp rpm up

The easy way is to consider the most efficient transmission which is a 100% efficient cvt. keeps the engine at peak hp at all times which maximises torque to rear wheels at all times and thus maximises the propulsion forward at all times.

Doesnt seem anywhere close to your math? so.................

Digger quote:

It's simple

Hp=tq x rpm / 5252 rearrange the equation

Tq = hp x 5252 / rpm

Exactly as digger wrote.
It's all math.

600 hp at 6,800 rpm and 526 lb-ft of torque at 4,800 rpm

600 HP at 6800 RPM = 463.41 TQ
526 lb/ft at 4800 = 480.73 HP



HP-TQ Calc

Yea Bob i agree with what you said, and have come to the conclusion that you have to have great cylinder heads to accomplish that, that being a greater distance between peak tq. and peak H.P. ?? Thanks Mark

I've always said a good engine is a good engine. Some people say you need XX for a heavy car, but YY for a light car. I've always believed the trick was gearing, convertor to match the engine, and car. I'd never really thought about RPM but it makes sense the screamer would go faster, assuming proper gearing ect.

Someone mentioned big truck diesels and torque earlier. Let's compare a DD13 Detroit diesel to a comparable 800ish cubic inch race engine. (I don't think the turbo "really" matters, just power) The DD13 has 470 horsepower and 1650 pounds of torque. An 800ish cubic inch race engine could have something like 3 times the horsepower, and 2/3s as much torque. (guessing) Properly geared ect I suspect the race engine would get the 80,000 pound load up the hill quicker. However, the 2000 rpm diesel with similar cubic inches will last a million or more miles.

vortecpro wrote:I'am going to ask the same question I asked on the Chevelle forum.


"Which engine is faster down a dragstrip and why"




A 427 that makes 600 HP @ 6200 RPM
A 427 that makes 600 HP @ 7100 RPM

?

Absolutely and without doubt the 427 making 600 hp at 6200.

I will explain when I return from down under next week.

DV

David Vizard wrote:

vortecpro wrote:I'am going to ask the same question I asked on the Chevelle forum.


"Which engine is faster down a dragstrip and why"




A 427 that makes 600 HP @ 6200 RPM
A 427 that makes 600 HP @ 7100 RPM

?

Absolutely and without doubt the 427 making 600 hp at 6200.

I will explain when I return from down under next week.

DV

You going kangaroo boxing?

vortecpro wrote:I'am going to ask the same question I asked on the Chevelle forum.


"Which engine is faster down a dragstrip and why"




A 427 that makes 600 HP @ 6200 RPM
A 427 that makes 600 HP @ 7100 RPM

?

So, did it blow up about like this over there?

I'm still half expecting someone to say that it depends on the rod length...

ptuomov wrote:I'm still half expecting someone to say that it depends on the rod length...

probably the one with the 8.1" rod

Ptuomov------laughing my butt off!!

ptuomov wrote:I'm still half expecting someone to say that it depends on the rod length...

no no no ,,, I smell a rat ... ITS THE OIL !

David Vizard wrote:

vortecpro wrote:I'am going to ask the same question I asked on the Chevelle forum.


"Which engine is faster down a dragstrip and why"




A 427 that makes 600 HP @ 6200 RPM
A 427 that makes 600 HP @ 7100 RPM

?

Absolutely and without doubt the 427 making 600 hp at 6200.

I will explain when I return from down under next week.

DV

David

Can you use those red letters in your post when you explain, I really like those. Be safe.

I said on page 1 the 6200 rpm engine would be faster. Look forward to what DV has to say.