Question on cams !
If a cam is added to an engine what "must" also be changed ? Parts that is,
ie header, carbs, dizzy ?
-----Original Message-----
From: nikolai jaremka [mailto:njaremka@yahoo.com]
Sent: Tuesday, November 02, 1999 8:16 AM
To: spitfires@autox.team.net
Subject: Re: Cams
that first cam (from spitbits) looks like the one i got from
BPNW. it came with a spec sheet that said it had a power band
starting around 2200rpm. i am very happy with it, and it gave a
noticable increase over stock with no other improvements to the
engine or exhaust or intake. since then, i've changed part
piece-meal to determine what made an improvement and what
didn't. i guess what i'm saying is that it made good
improvements to the spitfire without taking anything away from
it's streetability. also, i can get an even idle at as low as
800rpm. (i was told it would have to be at 1000rpm to be nice
and smooth)
--- "Bowen, Patrick A" <PABowen@sar.med.navy.mil> wrote:
>
> I am getting to the point in my restoration where I need to
> select my cam.
> I have a good stock cam, but since I am making other mods, I
> would like to
> add to this. I currently am running a 1500 engine, with high
> compression
> pistons, weber DGV, and header, oh and no emissions gear
> (since I am
> ignoring any and all emission laws anyhow, don't let those
> enter the
> conversation). I want a good streetable spit, but with some
> power. I don't
> mind having to take idle up to 1000 or 1200 rpm if that is
> required. I
> spoke to Nigel at Spitbits and he recommeded his cam that has
> the following
> specs. he said its power was from 3000 to 6500 I believe.
>
> .415 intake lift 272deg duration
> .400 exhaust lift 270 deg duration
> with the intake timing being 22 - 70
> and the exhaust timing being 62 -28
>
> and here are Ted Shumachers specs from his web page.
>
> B .409" 280 degrees 3500-6000 Good mid-range $110
> TSI275-4 .425" 275 degrees 3000-6500 Flat power curve $125
> A-6 .391" 288 degrees 4000-7000 Marginal for street $140
> A-8 .465" 290 degrees 4500-7500 Race only $140
> TSI298-4 .485" 298 degrees 4500-8000 Race only $140
>
> What is all this information I am looking at and what is the
> list
> recommendation for a cam? what will I get with each of these
> cams. Or
> should I just keep a stock cam?
>
> Patrick Bowen
> '79 Spitfire
> Jacksonville FL
>
=====
nikolai jaremka
72 spitfire mkIV
east aurora, new york
|