Ford 4.6L DOHC FR500 camshaft kit question
Posted: Mon Nov 26, 2012 7:07 pm
Anyone here have experience with the normally aspirated 4.6L DOHC Ford V8's?
I have a 1963 Thunderbird roadster clone project that uses a 1998 Lincoln Mk VIII
as a donor (engine including fuel injection, 4R70W automatic overdrive transmission,
front and rear independent suspension, brakes, rack and pinion, air conditioning
radiator, driveshaft, etc.). In stock trim, the 1963 Thunderbird is somewhat
heavier than a Lincoln Mk VIII but after all the swap parts, the Thunderbird may
come in a bit lighter than the Lincoln but it will still be at least 3800 lbs.
I've not checked the final drive ratio yet but the Mk VIII got either 3.07:1 or
3.27:1. I also need to look into the torque convertor stall speed and lock-up RPM.
Given the small displacement and weight of the vehicle, I'll likely swap out the
final drive ratio for something steeper and perhaps change the torque converter for
a higher stall speed but I'd like to get the engine running and sorted before I make
any modifications to the converter or rear end. Car is to be a street toy and will
likely never see a drag strip.
The 1998 Lincoln DOHC 4.6L uses the aluminum Teksid block, "B" DOHC heads, matching
long runner intake and was rated at 290 HP @ 5750 RPM and 295 lbs-ft @ 4500 RPM
with the dual exhaust of the LSC model. I also recently picked up:
2004 Cobra DOHC heads (complete with cams and valve train, very low mileage)
2001 Cobra intake (long runner, cut apart, ported and re-welded)
Mach 1 lid
BBK dual 62mm throttle body (probably overkill for the combo)
JBA stainless steel shorty headers
If they fit, I may pop for a set of the Mk VIII long tube headers from Kooks and I
plan to fabricate a cold air induction of some sort plus I'll need a tuner for the
1998 OBD-II EEC-V. I think the normally aspirated 2003-2004 Mach I used the same
heads and cams as the supercharged 2003-2004 Cobra Mustang. A 2004 Mach 1 was rated
at 310 hp and 335 lb·ft and the parts I have are similar except I'll have a ported
intake with larger throttle body and a better exhaust (no catalytic converters, Kooks
long tube headers, true dual exhaust with Magnaflow or similar mufflers). That leaves
camshafts. The usual upgrade is a pair of '96-'98 Cobra or '99/'01 Cobra intake cams
which have a bit more duration and are supposedly worth 15-20 HP. Cam specs from the
web:
96-98 4.6L DOHC Cobra Mustang Cam Specs:
Intake: Primary Lobe 196 duration (at .050)/ 390 lift
Secondary Lobe 206 duration (at .050)/ 390 lift
Exhaust: 196 duration / 390 lift (at .050)
99/01 4.6L DOHC Cobra Mustang Cam Specs:
Intake: 194 duration (at .050) / 392 lift
Exhaust: 194 duration (at .050)/ 390 lift
Mach 1, 03/04 Cobra, Aviator, Marauder.
Intake: 184 deg @ .050"/0.394" lift
Exhaust: 196 deg @ .050 / .394" lift
However, a local guy has a set of all four Ford Racing FR500 cams:
FR500 (M-6550-T46)
intake: 258 deg @ 0.003" (212 deg @.050), 0.472" lift
exhaust: 254 deg @ 0.003" (208 deg @.050), 0.472" lift
109 LCs (stock cams are supposedly on 114 LSA, can be altered with adjustable sprocket)
Ford claims the cams will increase power through 7000 RPM while increasing low-end torque
and retaining good street manners. A quick 'net search seems to back up that claim, at
least in lighter weight Mustangs with steeper gears. The Ford kit includes camshafts,
valves, springs, retainers and followers. The valves relocate the keeper grooves closer
to the stem tip to accommodate the longer valve springs. The followers also have a
different shape for increased clearance to the spring retainers. The seller only has the
cams. Are there any aftermarket spring packages that will accommodate the extra lift without
requiring replacement of the valves?
Thanks,
Dan Jones
I have a 1963 Thunderbird roadster clone project that uses a 1998 Lincoln Mk VIII
as a donor (engine including fuel injection, 4R70W automatic overdrive transmission,
front and rear independent suspension, brakes, rack and pinion, air conditioning
radiator, driveshaft, etc.). In stock trim, the 1963 Thunderbird is somewhat
heavier than a Lincoln Mk VIII but after all the swap parts, the Thunderbird may
come in a bit lighter than the Lincoln but it will still be at least 3800 lbs.
I've not checked the final drive ratio yet but the Mk VIII got either 3.07:1 or
3.27:1. I also need to look into the torque convertor stall speed and lock-up RPM.
Given the small displacement and weight of the vehicle, I'll likely swap out the
final drive ratio for something steeper and perhaps change the torque converter for
a higher stall speed but I'd like to get the engine running and sorted before I make
any modifications to the converter or rear end. Car is to be a street toy and will
likely never see a drag strip.
The 1998 Lincoln DOHC 4.6L uses the aluminum Teksid block, "B" DOHC heads, matching
long runner intake and was rated at 290 HP @ 5750 RPM and 295 lbs-ft @ 4500 RPM
with the dual exhaust of the LSC model. I also recently picked up:
2004 Cobra DOHC heads (complete with cams and valve train, very low mileage)
2001 Cobra intake (long runner, cut apart, ported and re-welded)
Mach 1 lid
BBK dual 62mm throttle body (probably overkill for the combo)
JBA stainless steel shorty headers
If they fit, I may pop for a set of the Mk VIII long tube headers from Kooks and I
plan to fabricate a cold air induction of some sort plus I'll need a tuner for the
1998 OBD-II EEC-V. I think the normally aspirated 2003-2004 Mach I used the same
heads and cams as the supercharged 2003-2004 Cobra Mustang. A 2004 Mach 1 was rated
at 310 hp and 335 lb·ft and the parts I have are similar except I'll have a ported
intake with larger throttle body and a better exhaust (no catalytic converters, Kooks
long tube headers, true dual exhaust with Magnaflow or similar mufflers). That leaves
camshafts. The usual upgrade is a pair of '96-'98 Cobra or '99/'01 Cobra intake cams
which have a bit more duration and are supposedly worth 15-20 HP. Cam specs from the
web:
96-98 4.6L DOHC Cobra Mustang Cam Specs:
Intake: Primary Lobe 196 duration (at .050)/ 390 lift
Secondary Lobe 206 duration (at .050)/ 390 lift
Exhaust: 196 duration / 390 lift (at .050)
99/01 4.6L DOHC Cobra Mustang Cam Specs:
Intake: 194 duration (at .050) / 392 lift
Exhaust: 194 duration (at .050)/ 390 lift
Mach 1, 03/04 Cobra, Aviator, Marauder.
Intake: 184 deg @ .050"/0.394" lift
Exhaust: 196 deg @ .050 / .394" lift
However, a local guy has a set of all four Ford Racing FR500 cams:
FR500 (M-6550-T46)
intake: 258 deg @ 0.003" (212 deg @.050), 0.472" lift
exhaust: 254 deg @ 0.003" (208 deg @.050), 0.472" lift
109 LCs (stock cams are supposedly on 114 LSA, can be altered with adjustable sprocket)
Ford claims the cams will increase power through 7000 RPM while increasing low-end torque
and retaining good street manners. A quick 'net search seems to back up that claim, at
least in lighter weight Mustangs with steeper gears. The Ford kit includes camshafts,
valves, springs, retainers and followers. The valves relocate the keeper grooves closer
to the stem tip to accommodate the longer valve springs. The followers also have a
different shape for increased clearance to the spring retainers. The seller only has the
cams. Are there any aftermarket spring packages that will accommodate the extra lift without
requiring replacement of the valves?
Thanks,
Dan Jones