installing headers on a 73 brave with 318

Started by angrybreadbox73, May 23, 2009, 09:26 PM

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angrybreadbox73

has anyone put headers on a brave with a 318 if so what kind of headers and brand also how well did they fit oh and did ya get
more power and mpg
soo many bagos so little time

Oz

Because of the smaller size of a 318 vs 440 and it's component layout, adding headers to a 318 doesn't present the crippling issues in comparison.  However, if you install headers, you must carefully look at all the surrounding components in relation to air space between them and the headers, i.e. fuel lines, brake lines, & wiring.  Use the Message search to see what serious potential problems may occur if these things are not taken into consideration.

In addition, slapping on an set of headers won't do diddly except screw up things unless you modify the rest of the fuel delivery system.

Simply put, more air out + more air in = more horse power.  But, since you are pulling tons of weight, don't expect any insignificant fuel economy increase.  You will not see any fuel mileage improvement except over thousands of miles of travel, and only if you increase the air intake to match the increased exhaust flow.

There is a balance.  If you increase exhaust flow without increasing intake, you will burn rich, wasting fuel & fouling plugs.  Your carb, as well as your exhaust system should be modified to create a balanced intatke/exhaust flow.  

Otherwise, you will be just wasting your money.

RVs are not performance vehicles.  They are very heavy and the gains made at big expense by adding headers alone are not even noticeable.  Using the the stock manifolds with increased diameter single exhaust or dual exhaust plus minor jetting changes will create the same effect, for less money and you won't have the blistering heat increase caused by headers.

Do a message search.  The results are 90% base on the 440 engine, but you'll get real good idea of what I'm talking about and you won't find anything which supports the justification for this modification.

For availability and cost of headers, check Jegs and Summit Racing (links are in the Tech section).  But, be certain that you will need to include either the heat wrap (which voids the warranty) or price the ceramic coated headers.
1969 D22, 2 x 1974 D24 Indians, 1977 27' Itasca

angrybreadbox73

yeah i did the search and it seems when using headers the problem of heat radiation arises
dosent look like a clearance issue tho but like u say gotta get the more air in and out witch means dump the
tiny 2bbl and get a 4 bbl intake and carb with true duals and headers and i may have to make some heat sheilds aor use mfgr approved wrap
soo many bagos so little time

Oz

The good thing is, with the 318, the plug wires and such aren't located in between the exhaust manifold tubes like a 440 and you have more air space around it because it's smaller, giving you that better air flow and more room to work with.

Good pre-planning and making any needed adjustments in wire routing or heat shielding should work out well for you.

Don't forget to let us know how it works out!  And, you can create a photo album of what you've done too so others can learn from it.

A follow up on performance and economy changes would be super too.
1969 D22, 2 x 1974 D24 Indians, 1977 27' Itasca