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Author Topic: Bulldog Customs Turbo Enfield Twin Project  (Read 1510 times)

armando_chavez

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Re: Bulldog Customs Turbo Enfield Twin Project
« Reply #30 on: October 31, 2013, 09:12:19 PM »
scotty j you are awesome if you do that

High On Octane

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Re: Bulldog Customs Turbo Enfield Twin Project
« Reply #31 on: November 02, 2013, 01:48:02 PM »
Just a personal not to myself, but feel free to check it out.  Pretty cool read.  I just learned there is a HUGE difference between static compression and dynamic compression.  I mean, I always knew there was a difference, but I never realized how much timing has an effect on overall dynamic compression.  Very helpful information.

http://www.hotrod.com/pitstop/hrdp_0706_pitstop_compression/

Scottie
Bulldog Kustoms - Denver, CO
Specializing In Kustom Paint

The Blackhawk
1958 Enfield/Indian 711cc Twin

Building The 1st Ever Ace Performance
Enfield Twin Full Race Heads

ace.cafe

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Re: Bulldog Customs Turbo Enfield Twin Project
« Reply #32 on: November 02, 2013, 02:54:55 PM »
Yes,  this is a very important matter for engine builders who are working with different cam timing.
We set the dynamic compression for all of our builds. We calculate it for each build because it is also affected by the atmospheric pressure at your elevation.

So briefly,  the later that you close the intake valve, and the higher in elevation above sea level you are, the higher the dome(static compression) you need to run to get your desired cylinder pressure amount. This is because the later the intake valve closes, there is less remaining swept distance left in the compression stroke to make compression. So, you need to squeeze it harder. Similarly, in a high altitude like Denver, the air is thinner than at sea level, so you need to squeeze that harder too.

This can become an issue because the bigger the piston dome is, the heavier the piston is,  and it can be a limiting factor in how high the engine can rev before it comes apart in a very exciting way.

I am very well-versed in calculating all this stuff. It's every day fare for me.
Let me know if you need help.
« Last Edit: November 02, 2013, 03:03:27 PM by ace.cafe »
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High On Octane

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Re: Bulldog Customs Turbo Enfield Twin Project
« Reply #33 on: November 03, 2013, 07:28:32 PM »
Thanks for the chat Tom!  You really filled my gaps of lack of information.  I'm ready to start taking this build to the next level.  :D  And if I ever make it out to Tennessee we'll have to get together for some beers.

Scottie
Bulldog Kustoms - Denver, CO
Specializing In Kustom Paint

The Blackhawk
1958 Enfield/Indian 711cc Twin

Building The 1st Ever Ace Performance
Enfield Twin Full Race Heads