Fordification

I can't help but feel a little disappointed with the power I'm getting out of it. Can anyone see anything in my mods that doesn't match up? I swapped fully ported heads along with the cam changed and gained nothing at the track what-so-ever. I'm running 14.7@92mph with a 3900lb truck, @ a track alt. of 3600ft.

Engine Specs: -Holley 750cfm -Edelbrock Performer RPM Intake -Crane Cam, Lift: 0.548(I),0.580(E) -Stock 1968 cylinder heads, fully ported -bored 0.015, 10.5:1 flat top hypereutectic Silvo-lite pistons -Black Jack 1-3/4" Headers

xdc351

I'm only getting into the BB's... but I hope this helps anyway.

I would say if putting a set of ported heads on makes no difference then either your cam is too small or intake too restrictive. Your top end sounds OK, so i reckon your cam is not up to the job. What grind is the cam? or exactly what specs is it?

Also what else has been done? Like tranny, stall speed, diff gears, exhaust size, etc. Any dyno tunes done? What HP does the dyno show?

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Fordification

Part Number: 343801 Grind Number: H-278-2 (REPLACES HMV-278-2)
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1963 1976 FORD-MERCURY 8 GOOD IDLE, DAILY PERFORMANCE USAGE, MILD BRACKET RACING, 3000-3400 CRUISE RPM, 9.5-10.75 COMPRESSION RATIO ADVISED. BASIC RPM 2200-5200
Engine Size Configuration
352-428 C.I. V

Valve Setting: Intake .000 Exhaust .000 HOT

Lift: Intake @Cam 3114 @Valve 548 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 3294 @Valve 580
Rocker Arm Ratio 1.76

Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 26 BTDC 72 ABDC 278 °
Exhaust 80 BBDC 30 ATDC 290 °

Spring Requirements: Triple Dual Outer Inner
Part Number 99837
Loads Closed 90 LBS @ 1.828 or 1 53/64
Open 283 LBS @ 1.268
Recommended RPM range with matching components
Minimum RPM 2200
Maximum RPM 5200
Valve Float 6500

Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 2 BTDC 40 ABDC 109 222 °
Exhaust 56 BBDC (2) BTDC 119 234 °

Although I don't know how it would effect the performance, I don't like the offset lifts. The high lift exhaust must be for restrictive systems.

Can't see the intake being restrictive because the RPM is the best FE intake available.

I have a B&M 2600 stall with 4.10s in the back. I think my exhaust maybe a little restrictive considering its 2-1/4" with 2-90 degree pinched bends. My plan is to replace it with 3" straight pipe dumped like 5 feet out with an H-pipe. No dyno runs. The hp calculator online estimates like 280hp at the wheels, taking the altitude/track time/trap speed, which I find greatly disappointing. The 'Desktop Dyno' is apparently within 5% accuracy, and it says 420hp at the flywheel.

xdc351

I reckon your cam's running out of puff long before your manifold and heads have made it to their max HP. I'd email a few cam manufactures with your specs and ask them to reccomend a cam.

Also as your in a 4wd I reckon 4.10 gears are not short enough, depending on what your tires rolling diameter is. I assumed 36" and ran through some calculators. I found your likely to sitting on your stall at all times, which is not good for your auto. I hope you are running a damn big cooler!

You'd really want to be looking at 3000RPM @ 60mph to keep things happy and it'd mean a big improvement in launch at the track. But until I know your tyre size then i'm really just guessing here!

Cheers,
Greg

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Fordification

Nope, 2wd 71 F-100 with 28" bfg's. I think your right about the cam running out even with the 580 lift. Because according to their range, it's only good to 5200, which I could have swarn was higher. My intake is good till 6500.

Fordification

Thanks for the help xdc351.

xdc351

Another thing to remember with the FE blocks is the varying displacements.

Is commonly accepted that more cubes will knock the cam's powerband a few hundred RPM lower, so If this cam is good to 5200 in a 352, is likely spent at 4800 or lower in a 390!

Thats why i'd get a custom ground cam made up to take full advantage of your displacement, stall, gears and intake. Let us know how you go!

Cheers,
Greg

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Just like a Tsunami.

Butchart

Ever heard of being over carburated, you might want to try a 650cfm carb instead of the 750cfm, the larger carbs will bog you down a bit at the lower rpm in relation to the size of engine block.

67merc

exactly, with BB you dont exactly need that much cfm, to get a lot of power, small blocks take higher cfm, because they rev higher.

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Ford Products past
1967 Mercury Montclair Breezeway 390 2bbl
1961 fairlane

Mopar products owned
1965 Chrysler New yorker
1983 Dodge Ram 250
1991 Dodge Daytona Shelby

themaninthehat

both ideas have merit. I would go with the cheaper one first, and if it doesn't work try the other. get back to me when you find out. I'm building a FE 390 right now too.