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Re: Newbie Part 2

To: MG Mailing List <mgs@autox.team.net>
Subject: Re: Newbie Part 2
From: "John M. Trindle" <jtrindle@tsquare.com>
Date: Thu, 25 Jul 1996 11:36:45 -0400 (EDT)
On Wed, 24 Jul 1996, Douglas Gaither wrote:

> A) Cams- several of the catalos mention that an improved street cam will 
> increase performance AND economy.  I'm not looking for a racer, but would 
> like additional performance.  Recommendations?  And I guess with cams, go 
> lifters and other components?

Kent sells its cams in kits, with new lifters and double springs.  I've 
installed the 714 Fast Road Cam (I think that's it) and I like it.

It does reduce torque somewhat below 2000 RPM.  It definitely increases 
breathing above 4000 RPM.
 
I think you have to put increased performance and increased economy in 
separate boxes.... you may be able to increase performance without decreasing
economy too much. 

> B) No-lead head modifications- I'm certainly not wanting to use lead 
> additives.  But the kits that I find (Brit-tek and others) are around 
> $250 for valves, seats, guides, springs, gaskets, rocker shafts, bushings 
> etc.  Do I need all of that?  Would I be smarter to purchase a 
> remanufactured head with all that already in it instead of rebuilding 
> mine?

The re-man head is going to cost $500 or worse, and not include any rocker
parts.  If your head Magnafluxes out with no cracks you are better off
rebuilding it than throwing it away.  Ask your machine shop which valves
you need (probably exhaust, maybe intake).  You will need valve seats and
guides.  As for the rocker shaft and bushings, maybe they don't need
replacing. Springs come in the cam kit as I mentioned above.


> C) Carbs- Webers seem to be the choice for aftermarket carbs.  Sounds 
> like the sidedraft's are the better performers (although they may give a 
> lumpy idle), and the downdraft's that are between the sidedrafts and the 
> stock SU's.  Your thoughts?

I love my S&K carb (Weber sidedraft clone) and you shouldn't have any 
problem with it >if< you use the recommended jetting.  It's when you 
decide you need a bit more fuel in the high RPM zone because of your 
breathing mods that you can get seriously confused and screw up the 
low-end operation.  This is true of SUs as well, though.  There are more 
choices for Webers than needles available generally for SUs.  They're 
easier to mess with some settings without altering others.  They're 
self-synchronizing.

Your lumpy idle may come from the cam and advanced timing more than the 
carb itself.  Weber side-drafts don't have vacuum ports by default.  The 
S&K does, but it is venturi vacuum and won't drive the normal distributor 
vacuum advances.  I used the place in the manifold where the gulp valve 
is supposed to go, and tapped it to fit the vacuum hose.  My round-town 
gas mileage went from 16 back to 18+.

> D) Headers- "of course you'd be dull to improve your carburation and not 
> put some good breathers on".  The stock units look pretty flowing, but 
> I've been told that because they are cast iron, they are thicker and 
> therefore have restricted flow.  Is this so?  And if I put headers on, 
> should I go the extra mile and put a larger free-flow exhaust system as 
> well?  Recommendations?  Gotcha's?

Headers and freeflow exhausts tend to reduce torque in the bottom end and 
increase horsepower in the top end.  Headers made the most difference, 
closely followed by the side-draft carb.  All the other mods except cam 
were unnoticable to feel, but could be measuered.

> E) Oil pump- should I rebuild, replace, or don't worry?
> 
Replace as long as you are in there.

> F) Coil- a coil is a coil is a coil?  Are there differences between 
> brands?

Lucas Sport Coil is a good choice.  You can increase your spark gap some 
with them vs. the stock coils.
 
> G) Electronic Ignition- I don't believe that I need to put every 
> performance item that exists on my car.  But if it really does improve 
> things, I'm all for it.  Should I stick to stock?  What about the Mallory 
> distributors?  Or the electronic jobbies that fit into a distributor as 
> opposed to the external box (ala Crane).  I would assume since most 
> modern cars are equipped with electronic ignition, that it does have 
> benefits.
> 

Well, it's a trade off.  You get a hotter spark and more consistent 
timing with a breakerless ignition system.  But, you can't fix it with a 
pocket knife on the side of the road.  Be sure you have a backup for the 
breakerless system.  One of the few times I have been stranded was 
because of a module failure.  I'm running on breakers right now since the 
distributor is new, but will probably switch to electronics (with a set 
of breakers in the tool box) when things start to wear.

John M. Trindle     | TSCC-Net Host      | jtrindle@tsquare.com
T-Square Company    | ISS/FSPlan for FS5 | trindle@widomaker.com
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