Lawrie. What is the duration of your cam at .050 and what is the lobe center
separation? Advertised duration is useful, but duration at .050 is more useful
for comparing one cam to another, and separation will tell us a good bit about
its behavior at low revs Thanks, John.
Lawrie Alexander wrote:
> Dennis,
>
> As Kelvin said in his note, anything with more than 280 degrees duration is
> going to give you problems around town. We sell a regrind that has greater
> than stock lift and 272 degrees duration. It gives a noticeable boost in
> mid-range power (3,000 to 5,000 r.p.m.) while still permitting an 850 r.p.m.
> smooth idle. It also does not impair the car's ability to pass the CA
> emissions test. (In fact, one of my friends in the MG club has one in his
> 78B which also has an empty catalytic converter and yet it still passes!) I
> have one of these cams in my "sleeper" 77B and there aren't many cars in our
> club that can keep up with me when I press the little pedal a bit harder
> than usual. The only requirement in fitting it is that the block be relieved
> for exhaust valve clearance (as all the 18V blocks were anyway), and the cam
> must be degreed for No. 1 inlet valve fully open at 105 degrees a.t.d.c.
> Actually, this usually just entails setting the marks on the timing gears to
> the usual position, then advancing the cam gear one tooth,
>
> This cam costs $95 and we need a rebuildable core in exchange. We also have
> the same grind for MGAs (with the tach gear) and for other cars. We've used
> it very successfully in MGCs, and a variety of Triumph engines.
>
> Lawrie
> British Sportscar Center
>
> -----Original Message-----
> From: DENNIS COX <djc@appsig.com>
> To: Lawrie Alexander <Lawrie@britcars.com>
> Cc: Carl French <cfrench@cybertours.com>; mgs@autox.team.net
> <mgs@autox.team.net>
> Date: Tuesday, November 30, 1999 9:07 AM
> Subject: Re: 2 Litre
>
> >Hi Lawrie
> >
> >This message brought up the subject of cams. And you mention the use of
> >a mild street cam. This is where I have some confusion. I've looked at
> >cams from various grinders and they seem to be sold by specification.
> >What I mean is they have 160, 170, 180 and even 190 or greater duration
> >cams with various lifts. Terms like "mild", "1/4" and 1/2 race etc. are
> >not mentioned. What do you consider a mild cam? What criteria do you
> >use in selecting a cam? Like when you would use a 170 duration and when
> >would you use a 180 duration cam. What would be the "hottest" cam that
> >can be used before you start to have to modify the head, intake and
> >exhaust. I know a lot can be said on this subject but I would like to
> >hear from experience on using different cams.
> >
> >Thanx
> >
> >Dennis
> >67 MGB
> >
> >Lawrie Alexander wrote:
> >>
> >> Carl...........
> >>
> >> I know the old saying, "there's no substitute for cubic inches", but I
> have
> >> never been impressed with the 2-litre MGBs I've experienced. I know of
> three
> >> in my locality at the moment and not one of them is quicker than my
> 40-thou
> >> overbored BGT! My biggest objection is that, with the added capacity, you
> >> have a need to remove more heat from the engine - and many folk already
> >> complain that Bs don't cool well - plus you have the attendant risk of
> >> cylinder wall warpage from having removed extra metal that the factory
> >> thought was necessary to support and cool the cylinders. Then you have
> the
> >> need to change the carb needles and springs (to what? who really knows?),
> or
> >> even fit 1-3/4" carbs (again, what needles are best?) to make the most
> of
> >> the added displacement.
> >>
> >> So, my two cents (or does that long paragraph constitute a nickel's
> worth?)
> >> says go 40 over and fit a mild street cam, and know that you'll be able
> to
> >> get the carbs right and have a powerful, trouble-free motor.
> >>
> >> Lawrie
> >> (willing to race any 2-liter B with either my BGT or my 77 roadster!)
> >>
> >> -----Original Message-----
> >> From: Carl French <cfrench@cybertours.com>
> >> To: mgs@autox.team.net <mgs@autox.team.net>
> >> Cc: bfrench@nh.ultranet.com <bfrench@nh.ultranet.com>; info@britbits.com
> >> <info@britbits.com>
> >> Date: Monday, November 29, 1999 7:17 PM
> >> Subject: 2 Litre
> >>
> >> >I have been offered a set of never used 2 litre pistons for my
> >> >rebuild, they would be free from a friend. I have a 67B with the
> >> >original motor from what I can tell. What would you say are the risks of
> >> >trashing the block? Other thoughts? Lawrie?
> >> >Carl French
> >> >
> >
|