TECH: Increasing CR on 73 351C

Hi. What is the best way to increase the compression ratio in my 73 Q
code? Is new pistons the best / only way to go? Any recommendations?

The first question is if increasing CR is what you really "need" to do...
Pistons is one good way,,, not knowing if you are ready for a rebore is a
PITA... Cylinder heads can do it but there are other considerations....
Increasing the compression ratio will offer up other very real
considerations in light of available gasoline quality... Artificial
aspiration is a way of theoretically increasing compression ratio.

There are a lot of very smart people on this NG... if you spell out what you
expect, what you are willing to spend (this is the most important part),
some details about the car (weight, weight bias, gearing, trans, and so on,
and so on... this ain't no little thing if you plan on being happy with your
"package").

In the FWIW department... this is some pretty old technology your dealing
with... I get to play with a small fleet of old Mopar big blocks and the
parties involved are into "nostalgia".. yes, these cars are very strong but
there are a lot of "off the shelf" new cars that can almost equal their
performance with none of the hassles...

Your question is too open ended when we consider the out of pocket expense
you will realize attaining your goal...


"Gary Vitagliano" > wrote in message
...
> Hi. What is the best way to increase the compression ratio in my 73 Q
> code? Is new pistons the best / only way to go? Any recommendations?
>

Let me be more clear. Im trying to keep the car stock as possible. The
car has original heads, ntake, carb etc. I know the 71 engine has more
HP due to the fact Ford detuned the 72 a bit and the 73 alot.

(Gary Vitagliano) wrote in news:22139-44597C15-679
@storefull-3211.bay.webtv.net:

> Hi. What is the best way to increase the compression ratio in my 73 Q
> code? Is new pistons the best / only way to go? Any recommendations?
>
>

Here's an excellent place to ask your question:

http://www.ford-trucks.com/forums/forumdisplay.php?f=54

Some very knowledgeable folks in there.

Gary Vitagliano wrote:
> Hi. What is the best way to increase the compression ratio in my 73 Q
> code? Is new pistons the best / only way to go? Any recommendations?

The cheapest way to increase compression is to bolt on a set of
Australian
cleveland heads. They are available on ebay and a lot of other places.
They have a smaller combustion chamber and an excellent intake port for
good torque.
Remember this is old technology. There are better (and more expensive)
ways
to make horsepower.

The reason for the "detuning" was because of the new concerns imposed by
unleaded gasoline... tetra-ehtyl lead was, quite possibly, one of the best
octane improvers/ detonation suppressors available. If your whole power
enhancement plan hinges on upping the compression ratio of the engine, you
are sure to be disappointed...

Additionally, the lead in the gasoline lubricated the exhaust valve seats
allowing cast iron seats and valve rotators.. another consideration when
using old technology engines.

The 351C 2V and the 351C 4V had some significant differences.... One other
salient point... after the introduction of no lead gas, the Cleveland engine
family died quite suddenly. Replaced by the 351M/400 family, which also
didn't last a significant amount of time - especially when compared to the
long lived Windsor engine family...


"Gary Vitagliano" > wrote in message
...
> Let me be more clear. Im trying to keep the car stock as possible. The
> car has original heads, ntake, carb etc. I know the 71 engine has more
> HP due to the fact Ford detuned the 72 a bit and the 73 alot.
>

Well Im open to Ideas to increase HP but the motor MUST appear stock.
Anyone use those MPG port plates? Will the aussie heads take my intake /
exaust manifolds?

(Gary Vitagliano) wrote in news:4328-445AC325-924
@storefull-3216.bay.webtv.net:

> Well Im open to Ideas to increase HP but the motor MUST appear stock.
> Anyone use those MPG port plates? Will the aussie heads take my intake /
> exaust manifolds?

Ah, you're racing it?

Gary Vitagliano wrote:
> Well Im open to Ideas to increase HP but the motor MUST appear stock.
> Anyone use those MPG port plates? Will the aussie heads take my intake /
> exaust manifolds?

They aussie heads will take your stock intake and exhause manifolds.
They look like Ford heads because they were Ford heads, in Australia.
Not quite sure of your intent here, but if you want it to appear stock,
they will work until somebody pulls a valve cover and starts looking at
part numbers.

How much HP increase? Just what the f*ck is it you want in easily identified
measures??? More bottom end grunt? top end snort? Are you after a car that
is quick or a car that is fast? You can make a car seem to have more HP with
gear ratio and suspension changes....

You must realize this.... when you modify a car, the only way to spend money
wisely is to decide on your "package"... To this end, we decide, first, our
budget... then we decide what we want to achieve.... then, we spend our
money in the best possible manner to get as close to our goal as
possible....

I am not tryng to be counterproductive.... OTOH, you haven't given us any
idea of what you want other than the appearance angle. This rules out
headers, most intakes, power adders and most carburettors.... Without a
little better idea of the goals, this thread is about to turn into a waste
of time...

FWIW, everyone wants horsepower... you can get horsepower only to find that
it was torque you were after.... Hint... There is no replacement for
displacement...


"Gary Vitagliano" > wrote in message
...
> Well Im open to Ideas to increase HP but the motor MUST appear stock.
> Anyone use those MPG port plates? Will the aussie heads take my intake /
> exaust manifolds?
>