Cam for XF



Whats the best cam to put into the XF, i have heard that a milder one will go harder in the XF than a hot one?? and where bouts in canberra is a good place to go to?
Manual Trans
I have heard from two sources that a cam of less than or equal to 280 degrees total duration, and less than or equal to 215 degrees 50 thou lift is the biggest you'd use on a manual trans XF. And both say the EEC computer still works well at this level. It's at the 180 to 200 hp level that it starts to throw a wobbly.

Auto Trans
The auto presents a problem in that the sky-high gearing of a 3-speed with 2.77:1 gives something like 18 km/h for every 1000 rpm to work against on take off. If you lower the diff ratio to a 5-speed XF 3.3 ratio of 3.23:1 you may be able to use the same cam, but even then there will be an off idle "hole" that the car will fall into with the tight stock stall converter Ford ran. Even with 250 cubes, it will loose the impulse or ability to torque out of an intersection in an urban situation. For this reason, cam grinders work out what stall ratio is needed. I'd put in a 2200-2500 rpm stall ratio coverter, 3.23:1 gears, and get a manual style cam. The stock gearing is just too tall to produce the goods at 2.77:1 when the cam is big.

My Car
My auto still runs a 2.77:1 but has the second smallest Heatseaker cam there is. It is brilliant around town, good enough for most Jap cars, even turbo ones, off line, but misses some of the mid to high end urge I'd like to have. What you want is great off idle performance, and then extra mid to top end performance. Screw this up, and it'll make you spit.

What not-to-do
An example is my old neighbour, a serious gear head. Danny had a 1963 Chevy Bel Air with a stock +30 thou 350 with the 350SS cam. There was an Edlebrock dual plane intake, twin 2.5 inch exhasts, stock THM 350 trans and converter and Firebird 8.2 inch diff with 3.08:1 gears. Wheels were 245/50 X 14's, so it did only 14.4 km/h per 1000 rpm in first, and could pull 200 km/h at 5500 rpm in top. So it wasn't high geared. We decided to rebuild after it ran a main bearing on a ConRodders club run. Danny wanted more revs and more mid range with a small loss in low -end torque, a trade-off that suited his foot-to-the boards driving style.
Well, we cahnged to a Kelford 294 degree total cam duration with 500 thou lift and around 228 degrees duration at 50 thou. The old one was around 260 or so, 450 thou and 205 or less at 50 thou. Result was a huge loss in low-end torque. It wouldn't idle at all because of the wild exhast and it was a pig to drive around town. But when the hammer came down, it just boggied like a darg car. 265 corrected hp at the rear wheels, and his other car, a 265 Charger six would pi** all over it around town without drawing attention to itself. The stock stall ratio was all wrong, and it couldn't be feathered around town. We got pinged by a speed camera about 150 metres form an intersection. The flash got him at 65 km/h in a 50 km/h zone. I'm sure if it was even 50 metres back, he wouldn't have been doing 45! A nasty slingshot car.

That's why you should avoid over-camming an auto. It will be a hairy beggar to drive, so get advise from an expert. It's easier to over cam than under cam, that's for sure!
do you guys rekon its possible to change a cam without taking the motor out?
very hard to do ?
no no aircon or anything to worry about hehe :) or powersteering...

is there a special way to get the lifters out? would have to take the head off too right?
There are long pliers and tongs used in casting foundaries which may help extract the lifters. The cast iron non-x-flows are almost impossible to do with out going to a tool maker, while the cross-flows have much more space!
Too right! Behead it.

You need a decent spread of tools, and I'd say a weekend. I would clean the valves, chambers and add new stem seals as a minimum. Prepping everything to refit will take some hours.

Don't forget to drain the coolant. :oops:

Cheers, Adam.

As for people in Canberra... Maybe talk to Wayne Whiting. I think he runs the Kaleen Service Centre Workshop.
dont forget to change the distributor drive gear.get a crow steel dg2.old gear on new cam could get ugly(been there,done that).i see crow recommend a cam no larger than the 14771 for a efi engine.
14771 specs IN.19/59 258 ADV DUR 200 .050 DUR .458"V LIFT
EX.63/19 262 ADV DUR 205 .050 DUR .470" V LIFT
POWER RANGE 1200-4000

ok guys, I have a TE cortina which I had a zk fairelane EFI 250 (same as XE) bebuilt and fitted into my corty. At the time I had the crow cam 14771 fitted, the compression lifted to apparently 10:1 comp with every thing else stock. Had a c4 auto and diff ratio. Also did the efi conversion on it also. As for performance I couldnt tell the difference from this motor and the old iron head 250 with holly 350 I had in it before. Due to problems after fitting the gas with the efi I decided to go straight gas using gas research setup, was cheaper than having to get an aftermarket computer. Since then I have changed to manual and changed the diff ratio to 2.77 with the lsd also. I have had the car dynoed and it produced 101hp at the rear, which is ok considering the diff ratio. As for the 14771 cam its ok for a daily driver but not the best if you want more performance, though I dont think a different diff ratio would have made all that much difference.
I'd stick with what you have. It's very easy to screw up a propane engine with too much duration. They don't like it, and the mixture can go out the exhast if its not set up right. Impco carbs and long duration don't go together well on heavy Falcons, but on a Cortina, it may be guite permissable. The GRA carb is better in this repect than the Impco, but the 90 degree bend before the carby manifold is a bad idea. No way to change it!

The EFI manifold is worse at being able to dial in advance, due to the un-used mixture in the long intake ducts causing backfire on over-run. Advance it on the dyno, its fine, lift off on overrun through a corner or coasting to the lights, and its as rough and poppy as an early RX-7. SO THE DYNO GUYS TEND TO BACK OFF THE INITIAL TIMEING, LOOSEING POWER BUT GAINING SAFETY.

The gearing and everything needs to be just right. A few degrees too much can soften the low-end grunt a heck of a lot.

From how much horsepower to you have??:-
I don't know what I've got, but is sure more than the 115 hp at the rear wheels I got in November 1998 when my 1984 Alloy head 4.1 XE Falcon was last dyno'd. Thats around 150 ponies at the flywheel.

Spec then was 500 cfm Holley #2300 4412 carb on adaptor to stock 34 ADM Weber manifold, no extractors, LPG Impco CA 300 A1 348 cfm propane carb with 2.5 inch adaptor to sandwhich the two together. Did 23 Imperial miles to the gallon after that on the open road, a 20% improvement on the old dual fuel figures. Motor is +30 thou over with ACL shallow top pistons. Gear box is silly old BW 35 auto with 2.77:1 diff and it weighs 3165 pounds all up with full tank and no passengers.

Since then, it's had major intake work, extractors and K&N filter. Now it's much nicer around town with tyre smoking torque, and revs freely out to 5300 rpm with the stock economy cam.

Just to add:-My Falcon got the ~256 (at lash) duration Heatseaker (ex USA) grind, and I used the 2.77:1 gears and Borg Warner auto. Lp gas, and changed to the 432 cfm of Impco CA 300 carb with 500 Holley throttle body (two 43 mm throttles). Stock XE valve sizes, just a relieved intake, 12 mm thick port spacers to stop reversion, and, eventually, a NZ-made 'Heateaker' (no relation to the US brand) header with the stock XE tailpipe (47 mm internal)

I have to say the diff wasn't much of an issue. I was looking at 3.23:1 gears, but from all the calcs I did, I don't think stand-off grunt would have improved that much.

The engine produced bag-loads of torque, far in excess of any LP gas 302C or cammed petrol 351C 2V from idle to about 2700 rpm. The dynoed figure was 194 lb-ft at 2600 rpm, which is about 350 Nm installed from my calcs. Maximum power wasn't noted. But in the old days it was abot 77 hp with the stock Weber ADM and Landi-Hartog Mixer. After getting the better LPG carb, it went up to 115 rwhp, or around 153 hp installed. Then I added headers which are normally an 18% power boost on a stoker, but less when you have a restrictuve exhast like my old hump. I felt there was about 174hp, or 131 rwhp based on my (single) 16 second flat quarter mile time two-up.

See this for the information
i am thinking about changing cams i have a mild cam gives 180rwhp to a slightly bigger cam and you only seem to mention drivability with autos. does it happen to manuals? if so what is it like? as i have never driven a big cammed car. i think my cam is a 14892 as it delivers power where my dyno run showed and has the same valve lift. what sort of difference would i see if i went to say a 686 or 650? do these engiens like dual pattern cams or do you lose to much out the exhaust. and would my four barrel intake and 600 holley be enough breathing improvement over stock for these cams? sorry for all the Questions but i would love to have some quicker accelleration to stay with these new cars.

thanks Aaron
No recommendations, sorry, but some genral advise.

If its street torque, undercam. If its high rpm power, then you have a loose torque, long duration cam, and have to gear it perfectly, or be unhappy evertime a ricer runs past.

I never drove my friends 295 degree cammed 350 63 Chev, but it was auto and lost a lot of torque off the line. Badly enough for little CRX's to beat it off line. A workmate had a 2000 cc Corolla RWD which had a 312 degree cam. It was a rally car, and the owner said you don't ever wan't to drive an over cammed, over geared car with close ratios.

Other info from six cylinders guys suggests that with manual transmissions, the ratio spread is much better, you can slip the clutch and make up for the low end torque loss. The cam grinders suggestions are the key. You have to make the gas flow and compression of the cylinder head match the cam and gearing.

Dual pattern cams are there for restricted exhasts in most cases. But engine builders have there own checklist, and some are able to design engines around these cams.
Thanks Alloydave,

Just got my dizzy done at Ice Ignition, there was wear in the main shaft and lower drive gear. Had it recoed which involved replacing the lower drive gear with crow gear and a re graph to suit lpg.

Can anyone suggest a good dyno tuner in Victoria, for straight lpg.

thanks and seya