Timing effect on HP

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Discussion

Fire99

Original Poster:

9,844 posts

230 months

Tuesday 7th August 2007
quotequote all
Hi All,

not exactly the most in depth question in the world but what effect does incorrect timing have on HP outputs on an old school Chevy V8?

I run a 302 (5.0 litre) carb fed one in a boat and recently checked the timing and it was at 2 degrees instead of 8 at idle.

Will this significantly affect power output? Normal HP is 200HP

thanks people,

Nick

rev-erend

21,421 posts

285 months

Tuesday 7th August 2007
quotequote all
My guess is you will loose a few HP.

It's often retarded to a figure like this to cater for low quality fuel. Say if it was pinking.

Fire99

Original Poster:

9,844 posts

230 months

Tuesday 7th August 2007
quotequote all
rev-erend said:
My guess is you will loose a few HP.

It's often retarded to a figure like this to cater for low quality fuel. Say if it was pinking.
Thanks for that. well i tend to run it on the finest Tesco or Morrisons can deliver.. oo blimey i best worry smile
Seriously though she tends to run mostly on Shell 95 or occasionally Optimax so 8 degrees should be fine.. i would hope.
may improve bottom end response which has been rather fluffy.

GreenV8S

30,210 posts

285 months

Tuesday 7th August 2007
quotequote all
If you're saying the ignition is 6 degrees later than it should be, that sounds like a lot and will make a big difference to top end power.

Fire99

Original Poster:

9,844 posts

230 months

Wednesday 8th August 2007
quotequote all
GreenV8S said:
If you're saying the ignition is 6 degrees later than it should be, that sounds like a lot and will make a big difference to top end power.
yep thats the long n short of it. Should be advanced by 8 degress. Was advanced by 2.
Strangely, or not, idle raised by around 200rpm once the timing was set correctly.

Mr2Mike

20,143 posts

256 months

Thursday 9th August 2007
quotequote all
Fire99 said:
Strangely, or not, idle raised by around 200rpm once the timing was set correctly.
Not strange, perfectly normal for idle speed to rise as ignition is advanced.

Edited by Mr2Mike on Friday 10th August 09:24

Fire99

Original Poster:

9,844 posts

230 months

Thursday 9th August 2007
quotequote all
GreenV8S said:
If you're saying the ignition is 6 degrees later than it should be, that sounds like a lot and will make a big difference to top end power.
yep thats the long n short of it. Should be advanced by 8 degress. Was advanced by 2.
Strangely, or not, idle raised by around 200rpm once the timing was set correctly.