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Javelin_GT
AMC Addicted Joined: Feb/15/2008 Location: Colorado Status: Offline Points: 1066 |
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Posted: Jun/21/2018 at 6:29am |
This engine is going into my rally AMX build. For hill climbs and road course. Power band 3000-7000.
Right now it’s at the machine shop. Block: 343 Crank: Steel 343 3.28 stroke Rods: 6.200 Carrillo Pistons: Forged flat tops CR: 12:1 Heads: 291s with good valves and some port work Intake: Torker Carb: Modified 4150 750cfm Cam: Solid Lifter Big question is about the cam. Anyone care to comment on how it will work with the combo? This was the grind recommended by Howard’s. |
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jcisworthy
AMC Addicted Joined: Jul/23/2009 Location: North Carolina Status: Offline Points: 2805 |
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Cam will work with your rpm range.
The heads will hurt the combo some. Probalby not movine a lot of air with what you described and the CSA is probalby on the small side for turning the rpm you want. The engine will go to 7K but it will do it a lot better and make more power with more cylinder head on it.
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Specializing in dyno services, engine building, and cylinder head porting
rbjracing.com Phone Number 518-915-3203 |
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Javelin_GT
AMC Addicted Joined: Feb/15/2008 Location: Colorado Status: Offline Points: 1066 |
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What if I sent with Indy SR heads?
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jcisworthy
AMC Addicted Joined: Jul/23/2009 Location: North Carolina Status: Offline Points: 2805 |
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Edelbrock with some work or full port on the 291's is probalby best for that CID
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Specializing in dyno services, engine building, and cylinder head porting
rbjracing.com Phone Number 518-915-3203 |
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jpnjim
AMC Addicted Joined: Nov/25/2007 Location: New England Status: Offline Points: 2752 |
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Closest lobes to those that I could find in the Howards Lobe List are: Tight lash mechanical (.016" lash): Intake lobe: AF250343 293 @seat 278@.020" 250@.050" .343" lift .549"w/1.6 rockers AF250360 293 @seat 278@.020" 250@.050" .360" lift .576"w/1.6 rockers Exhaust lobe: AF256343 299 @seat 284@.020" 256@.050" .343" lift .549"w/1.6 rockers AF256367 299 @seat 284@.020" 256@.050" .367" lift .587"w/1.6 rockers ^ lifts are close, but different (one each with slightly lower, and higher than the .350"/.560" of your lobes). The "Tight Lash Mechanical" lobes aren't listed as AMC/Mopar or Ford specific lobes to take advantage of the wider lifter, but the numbers that they supply are very similar to Howards Ford Mechanical lobes, just with much less lift: Ford Mechanical Flat Lobes (.875" lifters) .018" lash: FF2503861A advertised/seat not given 278@.020" 250@.050" 167@.200" .386" lift .618"w/1.6 FF2563940A advertised/seat not given 284@.020" 256@.050" 173@.200" .394" lift .630"w/1.6 If those tight lash mechanical lobes are what's being used (maybe in a AF250350 & AF25350 not shown in my catalog), They look like great fast acting lobes when you're not looking for .600+ lift. As far as the 250 & 256 durations for your application, I'm in over my head when it comes to spec'ing race engines. I'm guessing this is strictly a race engine from the application, and compression ratio. Are you planning on race gas? Are you drilling the block for later 1/2" bolts? Just curious, I like 343 builds
Edited by jpnjim - Jun/21/2018 at 4:51pm |
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71 P-code 4spd Javelin/AMX
some Jeeps and some Fords |
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jpnjim
AMC Addicted Joined: Nov/25/2007 Location: New England Status: Offline Points: 2752 |
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One more thing, when I ordered my Howards Cam I got it from Competition Products, they occupy the same building as Howards, and it came in a ridiculously fast turn around time. They also had the best price. I had called Competition, and ordered it right through them. Mine was Hydrolic, but here's their custom solid 319992 for $169.00 I checked my cam and it was spot on.
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71 P-code 4spd Javelin/AMX
some Jeeps and some Fords |
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1982AMCConcord
AMC Addicted Joined: Jul/13/2012 Location: Kenosha, WI Status: Offline Points: 1286 |
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Howard's will also grind anything you want in house for like $150 I think... If I remember correctly... A custom grind was very reasonable.
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