Hello Guy,
I’m coming back to the reading of the chapter concerning the CR in your first book (p22).
I calculated the effective CR for a camshaft opening up to 81° ABDC (GC stage 3), I found an effective stroke of 59 mm and so an effective swept volume of 330 cc (bore=84.4mm).
If I consider your yardstick CR = 9.5:1, I obtain an equivalent static CR of 14:1
Because you recommend for 98 octane gasoline and FI a CR of 12:1, what is it possible to do?
Rise the CR up to 14:1 to “stick” to the yardstick ? Is there pistons allowing this number ? What are the consequence in term of robustness ?
Keep a lower CR to the detriment of performance (??) ? …
Once again I thank you for your lighting on this subject.
Robert
Compression ratio (effective/static/yardstick)
-
- Posts: 86
- Joined: August 20th, 2006, 8:17 am
- Location: France
- Contact:
-
- Site Admin
- Posts: 5039
- Joined: June 18th, 2006, 9:31 am
- Location: Bedford, UK
- Contact:
-
- Posts: 86
- Joined: August 20th, 2006, 8:17 am
- Location: France
- Contact:
-
- Site Admin
- Posts: 5039
- Joined: June 18th, 2006, 9:31 am
- Location: Bedford, UK
- Contact:
Re: Compression ratio (effective/static/yardstick)
Ok - forget the calcs. You would be wasting your time in my exp going over appr 11/1 because the 8V TC burn rate suffers so much.
I know this from bsfc readouts on dyno test.
GC
I know this from bsfc readouts on dyno test.
GC
Guy Croft, owner
-
- Posts: 86
- Joined: August 20th, 2006, 8:17 am
- Location: France
- Contact:
Re: Compression ratio (effective/static/yardstick)
Hello Guy,
In other words you mean that 11:1 is enough for any cams in the TC engine ?
Robert
In other words you mean that 11:1 is enough for any cams in the TC engine ?
Robert
GC_131
-
- Site Admin
- Posts: 5039
- Joined: June 18th, 2006, 9:31 am
- Location: Bedford, UK
- Contact:
Who is online
Users browsing this forum: No registered users and 14 guests