Fiat 128 - ignition advance

Competition engines and ancillaries - general discussion
Post Reply
philippe74
Posts: 39
Joined: October 27th, 2009, 9:10 am
Location: Annecy - France
Contact:

Fiat 128 - ignition advance

Post by philippe74 »

Hello

I finished my latest car, it's an Fiat 128 3P.
I will use it in the french hillclimb championship for historical races,in group 2.
In France the name VHC ( véhicules historiques de compétition). I would like to have your opinion about ignition advance.
///////
I got few informations about it, but I would like to compare with your suggestions.
First, you have to know that I have to keep standard ignition system ( due to FIA regulation)
Volumetric ratio is 10.6, engine is prepared for high rev's (maxi: 9000 RPM)

Informations I got from a pilot in Italy is to adjust to:
max: 28° at 4000 RPM ..Otherwise, ther would be a big risk for the pistons ( which are forged)
It's seems realistic ...
What are your comments ?

Philippe74

PS: if somebody needs more infos about this engine to give an answer ...no problem
James Bowen
Posts: 90
Joined: June 23rd, 2006, 8:17 pm
Location: Brighton, UK.
Contact:

Re: Fiat 128 - ignition advance

Post by James Bowen »

Phillippe,

My 1500cc Fiat SOHC engine which has forged pistons, and comp. ratio of 10.8:1 revs to 7,500 rpm, has 30 deg max advance. There was no more power to be had from more advance, and only slightly more at 30 than at 28 degs. ( I mean fractions ) The engine has about 28 degs by 4,250 rpm. Swinging the ignition on a fully open throttle did not seem to affect power readings much at all.

Hope his helps,

Regards, James Bowen
philippe74
Posts: 39
Joined: October 27th, 2009, 9:10 am
Location: Annecy - France
Contact:

Re: Fiat 128 - ignition advance

Post by philippe74 »

Thanks James

I forgot to say that my car is a 1300 cm³
Anyway, it seems to reach this 28° value ...is OK

Regards

Philippe
Attachments
A view of piston + conrod
A view of piston + conrod
bloc jaune fini (2).JPG (67.49 KiB) Viewed 7078 times
philippe74
Posts: 39
Joined: October 27th, 2009, 9:10 am
Location: Annecy - France
Contact:

Re: Fiat 128 - ignition advance

Post by philippe74 »

Hi

Impossible to obtain 28° at 4000 RPM and also a correct advance at iddle speed !! My engine at 1000-1500 rpm knock and stop
If I want to start engine easily, I have to increase a little bit advance, but after I have approx. 30 to 31 ° at 4000 RPM

Do you think it could be due to the springs ? may be they are too soft ?

is it possible to find new springs ?

Regards

Philippe
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: Fiat 128 - ignition advance

Post by Guy Croft »

Could be a problem with the contact breaker setting in the distributor.

G
philippe74
Posts: 39
Joined: October 27th, 2009, 9:10 am
Location: Annecy - France
Contact:

Re: Fiat 128 - ignition advance

Post by philippe74 »

Guy Croft wrote:Could be a problem with the contact breaker setting in the distributor.

G
OK ... I will have a look

thanks

Philippe
Post Reply

Who is online

Users browsing this forum: No registered users and 34 guests