Crawford Billet Power Blocks

[nelsmar]

Originally Posted by gramicci101

That good, huh?

I cut my finger on the clamp on the sound tube and bled all over the donor car.

[gramicci101]

Don't wash it with hot water, the blood will set.

Or maybe that's clothing. Either way, all bleeding stops eventually.

[Luis_GT]

Originally Posted by Sojhinn

As a physics teacher I really appreciate this explanation.

As a Civil engineer... I hate dynamics...

[Dipstik-sportech]

Originally Posted by nelsmar

I cut my finger on the clamp on the sound tube and bled all over the donor car.

Hydrogen peroxide for cleaning and a band aid for the boo boo lol

The Frozen North

[nelsmar]

Originally Posted by Dipstik-sportech

Hydrogen peroxide for cleaning and a band aid for the boo boo lol

The Frozen North

I just held a rag around it while @Ninjin magically happened to show up and help me finish the install.

Oh and btw we finished hours ago.

[fa5tco]

Originally Posted by nelsmar

I just held a rag around it while @Ninjin magically happened to show up and help me finish the install.

Oh and btw we finished hours ago.

good god man! tellllllll ussssssssss

[Dimman]

Originally Posted by FrsDuke

Did you fall asleep during lecture? He said the compression wave can move at mach1.0 but no material breaks the sound barrier. His post was just to clear up the guy claiming sonic booms from flow velocity at the valves. I'm not making a claim about the validity of your statement only that it is not a correction of gov's.

The gas flow issue comes from the difference between mean and instantaneous flow. While some people calculate a mean supersonic velocity depending on valve lift, the overall flow can increase because of the way the pressures change at valve lift isn't linear. So a calculated supersonic flow rate isn't actually supersonic through the whole event.

This is why some people talk about supersonic flow while others say un-possible.

The waves are the priority, though.

[nelsmar]

Originally Posted by fa5tco

good god man! tellllllll ussssssssss

Oh right. Maybe I should stop teasing everyone who has been texting me. Was late returning the car. I'll make a thread that is actually on topic when I get home. But they worked. sustained most of the gains through tune.

[FrsDuke]

Originally Posted by nelsmar

sustained most of the gains through tune.

That is a less than exciting teaser...

[mike the snake]

Now it's been properly Christened with blood.

Originally Posted by nelsmar

I cut my finger on the clamp on the sound tube and bled all over the donor car.

[governor]

Originally Posted by Dimman

I'm not 100% certain on the gas itself (there is often talk of sonic choking if velocity gets to high) leaving breaking breaks the sound barrier, but there is a wave produced that travels at the local speed of sound. The wave is what is used to increase gas speed and flow by modifying the pressure differential across the valves. It's timing, sign and effective strength are affected by the tubing cross section, distance traveled, gas density etc... which is what part of header and intake tuning is about. You want a high pressure positive wave at the intake as it opens and a low pressure negative wave at the exhaust when it opens.

This is why you sometimes see headers "shift" power up or down the rpm range, with a bump at high rpm. The higher rpm bump is typically from flow improvement, whereas the shift is from acoustic changes.

I did a quick search and found a thesis that affirms that through a valve it is possible to go from subsonic through to transonic and then to supersonic but there are some disclaimers in the text as well. http://www.diva-portal.org/smash/get...FULLTEXT01.pdf entitled 'Simulations of Compressible Flows Associated with Internal Combustion Engines'. Jump to Section 8.1 for a summary.

In my previous post I was considering the average flows and choking through the system and neglected to mention what was happening at the valve. Across the valve there will be a pressure reduction followed by a pressure recovery. In this area potential energy is converted to kinetic energy and then back to potential energy again. However, order to maintain supersonic speeds after the pressure recovery zone a very precise geometry is required. This was the point I wanted to make and perhaps misinterpreted what the original post I quoted was referring to.

-gov

[StormTrooper]

Originally Posted by nelsmar

Oh right. Maybe I should stop teasing everyone who has been texting me. Was late returning the car. I'll make a thread that is actually on topic when I get home. But they worked. sustained most of the gains through tune.

Very curious to see the details... Also what happens when you add headers as well.

[nelsmar]

Originally Posted by StormTrooper

Very curious to see the details... Also what happens when you add headers as well.

http://www.ft86club.com/forums/showthread.php?p=1635741

I will be updating the post w/ header gains as well.

Enjoy guys! The gains were matching up with the other third party test & Crawford. This looks like a legitimate product!

[cslntuee]

Originally Posted by Turdinator

Thank you for the photos. I like how you can't really see them.

I wonder if the grimmspeed strut bar would still fit. Do you know how tall the blocks are?

HI,

I plan to order Grimmspeed strut bar.
Do you think this block can fit with Grimmspeed strut bar?
The block height is 35.8 mm from the thread.
Thanks a lot.