triumphs
[Top] [All Lists]

Re: Lift Throttle Backfiring

To: triumphs@Autox.Team.Net
Subject: Re: Lift Throttle Backfiring
From: Jeff Arrowsmith <jarrow@dlcwest.com>
Date: Tue, 29 Apr 1997 18:25:45 -0700
>Greetings Scions.........
>
>Does anybody else experience this "problem"? (I put that in quotes because I
>actually kind of like the effect I am about to describe).  In my slightly
>tweaked Spitfire Mk I w/ 1147 motor, when I run it up fairly high on the
>tach (not to redline, just 3,500 or 4,000 or so), then lift off the throttle
>such as coasting to a stop light or behind heavy traffic (with the car still
>in gear mind you), I get a really nice terrific fat burbling sound with a
>couple of pretty good "pops" out the tailpipe (backfires).  (Scares the hell
>out of little old ladies and dogs,  and gets smiles from college coeds so I
>don't care to fix it frankly.)
>
>Question - what causes this?  It sounds very much like some of the vintage
>race cars I have watched at various races, but I've never understood what
>causes it.  I don't think it is a "true" backfire where the charge gets
>blown back out of the carburetor (or am I wrong on this point?).  Does
>anyone else experience this?  Thoughts please,
>
>Thanks.
>Ross D. Vincenti
>64 Spitfire 4
>64 Porsche 356C Coupe

Had this problem that got so bad my 75 Spit would stall out on me. Turned
out to be "Lucas" fever.....electronic ignition failed. Replaced with Crane
box and Mallory Dual-point dist.  Haven't had that problem since then (5
years ago). I also run a 40 DCOE.........with nice results.


Jeff.A


1967 GT6 Mk1
1975 Spitfire
1975 TR6
===========================================
"Why do you own 3 Triumphs?".........because I can't afford 4!
===========================================
Rap = Disco for the 90's
=================



<Prev in Thread] Current Thread [Next in Thread>