Two things...
If you want to get any performance out of a late model B you must recurve or
swap out your distributor. In your case, it appears that you have the high
compression head with the closed design combustion chamber. The late model
distributor brings in advance gradually topping out at something like 4 or
4.5 grand rpm at about 25 degrees. I don't have the specs in front of me
here but you get the idea. This was done for emissions. You want an advance
curve more like an older B which comes in quick topping out at about 2500
with a total of 12 -15 degrees. Since you seem like the performance kinda
guy with too much time and money (aren't we all), I would suggest the
mallory electronic ignition distributor and performance coil. It's the same
as the dual point distributor you see in vicky brit but it has a mallory
unilite electronic ignition unit in it instead of points. Available from
Summit, it was cheaper than buying the dual point from vicky brit and is
more reliable IMHO. The total mechanical and vacuum advance are adjustable
and you can always swap springs to change the rate of advance. Which brings
me to why you cannot just change the springs in your stock distributor (been
there done that) You will be able to get the mechanical set properly but you
cannot swap out the vacuum advance unit for one with less advance. You will
be cursed with part throttle ping. If you need to hook up the vacuum advance
your best bet would be to not fiddle with the stock unit. You could put in
an older stock unit or I believe there is some company in England that
recurves older stock for performance. Seven Enterprises sells them. Aldon I
think is the name of the distributor company.
As for the cam... It can really complement other performance mods but I
wouldn't go swapping out your stock cam unless you knew there was something
wrong with it or you feel like shelling out cash for lifters, cam,
adjustable cam gear, and pressing out and reinstalling new cam bearings.
Makes more sense to do it when you rebuild or have to do other engine work.
You can not just slip it out and slide in a new one. You should degree the
cam and do a bunch of other things which would require removing the engine.
Changing the late model emissions cam will improve things a bit but I would
wait. Changing the distributor will improve power by providing a more
optimal timing of spark at all rpms and conditions.
My basic goal is to return the engine to it's pre emissions state and modify
with a few performance parts. I have an 80 B with the Mallory unilite
distributor and performance coil, Crane cam, high compression pistons on a
late model head which was skimmed 9:1 with a DGV K&N combo. Sound familiar?
Email if you want specifics. How did the OD come out? Got mine in and I love
it!
Christopher Reichle
creichle@nsc.msmail.miami.edu
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From: mgs-owner
To: mgs
Subject: Cams and Distributors
Date: Monday,February 10,1997 1:32PM
I have some questions that I think/hope will stimulate a lot of
activity. My pride and joy is a 77B. It is a bit bastardized, but here
are the particulars:
Stock engine from a 79B, with an early (pre-smog head)
Weber DGV Carb
Early cast-iron manifold into a "standard" exhaust - no cat.
Stock Distributor fitted with Crane/Allison ignition, stock coil.
Now the questions. I want a little more pep. It's not bad down low,
but still peters out above 4000 r.p.m or so. I have been advised that
the way to acheive my ends is to swap the cam, and the distributor.
Since the engine is coming out for a tranny swap, I thought that this is
the time to consider this.
I have been told (?) that the stock cam in post '72 cars is suspect, due
to "soft metal" which results in premature wear. Anyone out there
support this? Is there a way to determine cam wear w/o removing the
cam?
Will a high performance distributor help by itself, or is it a
negligable gain w/o a cam swap?
Just how much difficulty is there is swapping the cam with the engine in
the car (should my funds be too limited to do everything at this time, I
may consider it later - but I really don't want to pull the engine
again!)
Any and all opinions are welcomed!
Best Regards
Chris Delling
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