Home | Register | Quick Links | FAQ | Donate | Contact |
Indiana Open Wheel
> Indiana Open Wheel Forum
>
Question For Engine Guys
|
Thread Tools |
4/6/18, 6:34 PM |
#1
Question For Engine Guys
|
||
Senior Member
Join Date: Jan 2014 Posts: 542 |
When someone says they have a “12 headed engine” what specifically does that mean?Are the valves on a 12 degree angle from the deck or head? Just something I’ve always wondered. Thanks in advance.
|
||
|
4/6/18, 8:55 PM |
#2
Re: Question For Engine Guys
|
||
Member
Join Date: Sep 2007 Posts: 187 |
Refers to Brodix -12 heads. They had a progression of heads from -8's on up as technology progressed in the 80's and 90's. -12 heads are a 15 degree valve angle. They also have a 12 x 12 head that is a 12 degree valve angle. They can be had with a variety of spark plug angles and port sizes. I'm sure someone will chime in with more details than I can give.
|
||
|
4/6/18, 9:00 PM | #3 | ||
Senior Member
Join Date: Dec 2007 Posts: 2,020 |
Stock sbc are 23 degrees meaning the valves are inclined upward from the axis of the cyl bore 23 degrees. So yes a 12 degree head has them angled 12 degrees. Hypothetically if the valves were 0 degree they would be parallel to the bore.
Don't confuse this with brodix's -12 head. Idk why or how they came up with that but they've had -8,-10.11 & 12 among others. I believe the -12 was among their first to deviate from 23 degree and I think they were 15 |
||
|
4/6/18, 11:21 PM |
#4
Re: Question For Engine Guys
|
|
Senior Member
Join Date: Aug 2014 Posts: 1,921 |
Whats the advantage of angled valves?.... & please don't just say "better breathing"
|
|
|
4/6/18, 11:24 PM |
#5
Re: Question For Engine Guys
|
||
Senior Member
Join Date: Aug 2014 Posts: 1,921 |
Quote:
|
||
|
4/6/18, 11:37 PM | #6 | |
Member
Join Date: Nov 2012 Posts: 71 |
Stands the valve up more ( 15* compared to 23*) which gives a straighter "runner" for the air to flow through and helps with air speed I believe. 23* heads have what is known as a short turn radius caused by the angle of the intake runner being laid over more.
_________________________________________________
Last edited by THS; 4/7/18 at 12:56 AM. |
|
|
4/6/18, 11:55 PM |
#7
Re: Question For Engine Guys
|
|
Senior Member
Join Date: Aug 2014 Posts: 1,921 |
I wonder why Chevy didn't design valves like that to begin with?
|
|
|
4/7/18, 12:32 AM | #8 | ||
Member
Join Date: Nov 2012 Posts: 71 |
I believe technology has just evolved. The LS style heads stand the valves up also compared to the old small block chevy heads which were 23*
|
||
|
4/7/18, 6:04 AM | #9 | |
Senior Member
Join Date: Dec 2007 Posts: 2,020 |
||
|
4/7/18, 6:07 AM | #10 | |
Senior Member
Join Date: Dec 2007 Posts: 2,020 |
||
|
Indiana Open Wheel
> Indiana Open Wheel Forum
>
Question For Engine Guys
|