Ignition Only

[Axel Rietschin]

----- Original Message -----
From: "Bruce Plecan" <nacelp at bright.net>
To: <diy_efi at diy-efi.org>
Sent: Thursday, November 09, 2000 7:31 AM
Subject: Re: Ignition Only

> > I was not aware of this potential issue and I don't believe it happens
in
> > practice.
>
> OK, we're clear that your beleifs can over rule what does happen.

Well, my beliefs on the matter are based on solid personal experience and
experiences of other people I'm familiar with or aware of.

> > First, why only at high rpm when you have the most spark advance
> > thus the less fresh gases in the cylinder, if any at all?
>
> The worst example of this is a turbo motor where you might be running 17d
of
> timing.   With too high of overlap cam this can be a major problem.

You don't want radical cams on turbo engines. What you need actually is a
very reasonable cam that works well at low rpm, before your turbo starts to
blow and where your engine is sluggish because of the low compression ratio.

Anyway, how much lift do you have at 17 BTDC on a typical turbo cam? I don't
believe you are going to ignite anything with 360 degrees of advance. The
spark easily jumps the gap precisely because the ambiant density is low.

Anyway - as I said already - if it's really a problem, go for one coil per
cylinder. This will help you reach higher rpm with higher compression and
higher boost than a conventional distributor-based system. Cost should be no
object if the engine is such extreme.

--Axel


----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org