Welcome to My Inline
300-6 Page
This Information Deals with my experiences
in building up my 1983 300-6 Engine. My engine is rated at 120bhp
@ 3200rpm and 251ft. lbs. @ 1600rpm . But I should say used to
be rated at. The information that I have been gathering on the net (BBS's)
has been telling me with what I have added I should be pushing around 232bhp
@ 4000 rpm and 343ft. lbs. @ 2000rpm. This page will show you what
I put into my engine to make it GO!
First off I will start with the tired old block
and head (275,000 miles young). After tear down and clean up I brought
the block to the local machine shop and had it punched .030 over and had
.020 decked off the block. I Also had them polish the crankshaft. I ordered
new .030 over pistons (Badger P.N. 722) from a 82 and older 300-6 (adds
.5 to the compression ratio). I had the Machine shop shave .010 off the
head to true it up. By installing the 82' pistons my compression ratio
went from 8.4/1 to 8.9/1 and then after adding in the decking and shaving
I ended up with a 9.2/1 compression ratio, perfect for a daily driver!
Next up was a new camshaft and accessories, for
that I chose Comp Cams 260H high energy cam shaft (P.N. 66-237-4). This
cam has a 260* duration at .050 lift and a .447 lift on both intake and
exhaust. For lifters I used Comp Cams high energy hydraulic lifters, and
for the push rods, yes you guessed it, Comp Cams high energy push rods.
The nice people at Comp Cams told me I could run stock springs with this
cam, but since my engine had so many miles the recommended there part #903-12
springs (a little stiffer than stock.)
Since My head was nonadjustable from the factory,
I decided to cheat and make it adjustable so I didn't have to buy new,
.060 shorter, push rods. I tightened the rocker arm bolt down enough the
get the recommended .030 pre load on the lifter, then I just double nut
it so it wouldn't come loose (A friend of my Dads used to race 300-6's
and he never had a problem doing this). Other Cylinder head work included
polishing the intake and exhaust runners and gasket matching the ports.
The HP and Torque stated above don't include the Polish and Porting done
to the head, and I don't know how much Oomph.... to add to those stats.
I also did a good 3 angle valve job on the seats.
As for the Intake I bought a Offenhauser 360* dual
plain intake from a friend for $50, he decided to build a 351W up for his
truck. Sitting on top of this intake is a Holley 450 CFM 4bbl 4160 series
carburetor which I bought from another friend for $50 off his Slant-6 Mopar.
From what I hear from other people the Holley 390 CFM is a better choice
for this engine but I don't have the money to buy one now. As for the Exhaust
I tossed the single manifold in favor for a set of split headers. I don't know what brand they are but I picked them up for $40 buck so I figured I couldn't go wrong. And to quite down the exhaust I tossed in a pair of Dynomax super turbos with 2.25" pipe size. It isn't overly
loud, but boy does it turn heads. It sounds a little higher pitched that
V-8's, but it sounds more powerful.
I used to run the quarter Mile in 19.8 seconds @
62 MPH (at the track) but with the newer, better rebuild I have pushed
it to 16.7 @ 78 MPH (stop watch and Speedometer with a measured quarter
mile on the highway by my house, the track don't open till May) all thanks
to 93% more HORSEPOWER! and 37%
more TORQUE! I just can't wait to get my Bronco on A Chassis
Dyno (about a 3 hour drive from my house) I hope to break 200hp and 300ft.lbs.
@ the rear wheels (more bragging rights for my 6cyl). And to help aid the
goal of 200/300 I'm going to run synthetic 80-90w in the rear end and 4
speed tranny, and synthetic ATF in the 208-transfer case. And who knows
how much more I'll gain when I put 3:50 gears front and rear instead of
the measly 3:08's
Here is a list of companies
that make performance parts for Ford 240-300 inline 6's
-Offenhauser (intake manifolds, and linkages)
-Comp Cams (a wide selection of cams, and valve train parts) www.compcams.com
-Crane Cams (valve train products and ignitions) www.cranecams.com
-Holley (Carbs, Ignition, and fuel pumps) www.holley.com
-Hooker Header (headers, mufflers, and tips)
-Clifford Performance (everything your 6cyl could need) www.cliffordperformance.com
-MSD Ignitions (performance ignitions, coils, and wires) www.msdignition.com
There are quite a few more but these
are the ones I have dealed with, and recommend.
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