Having learned from so many of you here (and on FABO), I felt obligated to share how things worked out with my long-rod build.
The original writeup & more pics can be found HERE. Sound-clip & even more pictures are HERE.

This long-rod 225 slant-6 rebuild (now @ 231 CID & 3.8L) uses the 198 engine connecting rods to facilitate the use of better sealing and lighter weight pistons & valvetrain components as well as mods to create a performance street cruiser (not a red-light racer). Emphasis was on producing high air velocity through the intake tract, reducing parasitic power loss throughout, and lightening the reciprocating mass where budget allows - with all these stealthy mods hidden behind an otherwise plain-wrapper engine.

In all, it worked out great! Pulls strong from about 1,500 and rides in the powerband nearly forever. With cable throttle control and an Edelbrock AVS2 carb, the tip-in is instantaneous and almost feels like it's injected. That said, the build was designed for deeper gears - which are planned in the springtime with an 8.25" differential swap (have it - from '74 Dart Sport) with 3:07 ratio (Jeep) gears. This will pick up the slack from off-idle and balance the powerband range.

All said, I'm stoked with the results. Very drivable, quite a lumpy cam at idle (while pulling 10.5 Hg of vacuum) and pulls strong - with a balanced chassis. It's not a package for everyone - but works for me...


Comments are welcome :)

Induction
• Spectre Perf. #98881 14" 180-degree dual-inlet, aluminum air cleaner assembly. To make this work, you need to use the base from Edelbrock #1221.
• Edelbrock carburetor #1901 Thunder AVS-2 @ 500CFM w/electric choke. Running mostly on the primaries.
• Offenhauser #5270 four-barrel manifold - modified for water-heating under the carb baseplate. Saves several pounds from OE. [vintage part]
• Remflex #6008 carbon intake/exhaust gasket
• Attaching studs have been replaced with same-size parts from McMaster-Carr #94358A270 with an allen-head recess. Nuts are mil-spec flex-top locknuts #99638A300.
• Lokar throttle #XTC1000HT & kickdown #KD2904HT60 cables with bracket #SRK4000 replace mechanical linkage

Cylinder Head
• Street pocket-ported bowls and short-turn radiused - with the goal of increasing air velocity but not volume. Otherwise just cleaned things up
• Elgin supplied Ford 289 intake (#I-1670 @ 1.78") & exhaust (#E-1669 @ 1.45") valves. Oversized in slant-6 terms - and with a smaller diameter stem (5/16 vs 3/8), with positive seals and further modified with a back-cut.
• Street performance valve/seat angles
• K-motion #K-800 valve springs. Used only the outer spring resulting in 110/280 pressure - to match the cam specs.
• Comp-Cams valve spring locks & retainers
• Hand-fitted rockers & spacers
• Rockers are OE and only required cleaning to ensure oil-flow
• Endurotec #AS0193 BigBore cylinder head gasket

Block
• Line honed + new cam & crank bearings
• Deck was just kissed for gasket seating without much material removal
• Bored to 3.445" to match pistons, bringing the displacement from 225-CID/3.7L to 231/3.8L
• Wiseco #PTS536A45 forged pistons. Installed using press-pin option for endurance. Static compression = 9.6:1 (91 pump-gas)
• Wiseco piston rings #8750XX [1/16, 1/16, 3/16]
• Chrysler connecting rods from 198-CID slant-6 - which are longer than 225 rods. The essence of a long-rod rebuild!
• ARP connecting rod bolts from a Pontiac SD-455 engine [yeah, they fit!]
• NOS oil pump #2808507 - standard pressure & volume
• Chamfer on the #1 crank bearing for proper timing chain oiling
• Chamfer on the lifter bores to increase oil pooling at the top of the lifter
• Crankshaft oil holes chamfered & journals polished
• Oregon Cam Grinding's #346 camshaft was custom profiled to use Ferrea's lightweight .904" lifters which require a custom ramp angle.
• Cam Specs: duration @ .050 234/228, Lobe Separation 106, Valve Lift .476/.479
• Ferrea lightweight tool-steel mechanical lifters #LF1004 [66-grams each]
• CompCams pushrods #2497864-12
• True-roller timing chain - custom set through Elgin using the chain & crank sprocket from 440/426 Hemi mated to their HP cam sprocket for the slant-6
• Specta Premium #SP1051MP fuel pump delivering 4-6PSI @ 30-GPH [ample supply]
• Felpro and Mahle gaskets
• Driven GP-1 15W-40 Synthetic Blend High Performance Oil with Baldwin #BT216 filter (integral standpipe). The oil has a lot of ZDDP for use with flat tappet engines and runs super clean.

Ignition
• OE alternator - rebuilt to factory specs @ 50-AMP
• HiRev-7500 electronic ignition module [from Rick Ehrenberg]
• NGK Iridium spark plugs #97382 - which draw fewer AMPs to fire than other plug types
• NGK spark plug wires #6716122
• Rebuilt and custom-curved (Sun) distributor from [USER=33547]@halifaxhops[/USER]
• Pertronix #40011 Flame-Thrower coil, selected for its quick saturation which helps deliver more torque at lower RPMs.
• Mini-starter [from R Ehrenberg] which draws significantly less amperage and startup than the OE. It also saves several pounds.
• New ignition/engine wiring harness #HU226A from YearOne was installed to ensure continuity and full-system reliability.

Cooling
• Unbelievably - still running the stock radiator! Although, I doubt I'll be that lucky in the summer - so I'm on the hunt for an upgrade.
• 195F SuperStat Thermostat #STA45359
• 16-LB cap #10231
• Recovery Tank (soon)

Transmission
• Torqueflite 904 has been rebuilt & upfitted with HD internals including steels & frictions
• TransGo #TF1 reprograming kit installed
• Custom 2800 RPM stall high-efficiency torque converter with 9.5" impeller & turbine, Torrington bearings, 7/16" ARP #240-7302 bolts, and 4130 chrome moly steel drive hub & spline insert - by Edge Racing Converters
• Flexplate is from a 440 #200-1040 from 440source
• AFT+4 fluid

Performance estimations are 235-HP & 280-Ft/Lbs. torque [conservatively] I wanted to dyno it at the shop - but with more custom parts and labor than expected (which is always expected), I ran out of budget. I'll chassis-dyno it someday...

Special mentions are due to @my68barracuda @halifaxhops @slantsixdan, @RustyRatRod Doug Dutra, Duster Idiot, Slantzilla, Dart270, Charlie_S, Greg Ondayko, Joshie225, Dart270, Rick Covalt, CNC-Dude, and many more for directly or indirectly educating me on the ways of the Slant (my apologies for any omissions).

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

Fantastic! Questions. Were the long rods simply chosen so that a different piston could be used, or is there some mechanical advantage to the longer rods? Why forged pistons? Do your pistons come to the top of the deck now? My proposed build is a 1985 truck engine. The 198 rods won't fit my engine will they?

Very cool! Glad you are enjoying it. Looks like a very well balanced package.

Slant on,
Lou

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Home of Slant6-powered fun machines

Congratulations on getting it going!

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Official Cookie and Mater Tormentor.

Nice work and great results.
I always liked the performance increase that comes out of a long rod 225.
DD

Thank you all for the kind words!

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

1. Were the long rods simply chosen so that a different piston could be used, or is there some mechanical advantage to the longer rods?
_____A. Selected to enable a shorter compression-height piston without having to mill the head & block much. The chosen piston also has a bunch of mechanical advantages. Also, part of the decision was simply to address the build from a different and less-common direction. I'll add, that I looked for nearly two-years for a perfect doner set and was very lucky that mine were all in great shape. These are very difficult to find at a good price. I think I paid (negotiated) $225 for mine - and they arrived with pistons attached which gave me a glimpse at the condition of the doner engine (bonus!).
2. Why forged pistons?
_____A. Stronger, lighter, better ring-package, better heat control (sealing), dry-film anti-friction coating already applied, valve pockets already cut... lots of reasons for these. All that, and the manufacturer has a long history of doing things right.
3. Do your pistons come to the top of the deck now?
_____A. My pistons stood up .007 in the hole. Crushed thickness of Mahle or Felpro gaskets didn't leave enough space for our comfort, but the Endurotec BigBore gasket was a tad thicker when fully compressed which gave me plenty of cushion without much penalty in compression.
4. My proposed build is a 1985 truck engine. The 198 rods won't fit my engine will they?
_____A. The 198 rods only fit Forged cranks - yours is cast if I recall, so this is not an option. But... aftermarket rods are available and might fit your journals. Someone with more knowledge of your engine than I can lend you some advice/direction.

Good luck with your build!

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

What is the weight comparison on the fererra Lifters to say a standard lifter or an OE Dumbbell Lifter?

Do you have apart # for those Lifters?


Thanks,

Greg

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http://www.youtube.com/hyperpack

Greg, the weight of the OE dumbbell lifter from my engine was 103g (clean), which is a 37g (36%) weight savings. I don't have a solid-side lifter to compare but my notes say the range was between 91-110g, but I did not differentiate styles.

The lifter is #LF1004, which I believe is now a special-order-only part, but it used to be listed for immediate availability on their website. I think I may have posted it here or on FABO a few years ago.

Hope that helps you!
-C

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'68 Barracuda - taking advice on increasing street torque, power, & road handling. Click To See It

How fast do you feel comfortable spinning it?

Thank you,
Much Appreciated!

Greg

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http://www.youtube.com/hyperpack

Do we know how much that performance increase is over a standard rod engine. Or is it more of, it has less stresses internally. Just wondering.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

I used to believe there was a performance advantage when I ran mine. Now that I have run a fairly stock standard rod motor for awhile I am not sure.

I could do a fairly equal test by putting my long rod motor in the car and running it I guess.

David Reher of Reher-Morrison has said "The only important thing about rods is that the bolts are tight.".

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Official Cookie and Mater Tormentor.

A lot have fallen into the hype of longer rods being some magic pill that creates tons of HP. David Reher had an awesome article in print where he also said, "Of the 50 things that benefit you from longer rods in an engine, a gain in HP is #51!" They also increased rod length in the same engine during a round of engine development, where they ended up increasing the rod length over 3/4" of an inch, in .050" increments. And made the statement above and this one. " The only thing the rod has in common with the piston is it simply connects the piston to the crank!"

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There's no such thing as too much cam....only not enough engine!

as csheehy said "Selected to enable a shorter compression-height piston without having to mill the head & block much." ...

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/6 Dodge Charger 69
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