newbie with an xf

[Anonymous]

Just brought myself a 87 xf falcon its 4.1 carby

was wondering what i could do to get a bit more hp out of it

got some 3-2-1 extractors for and going to put a decent exshaust on

but other than that i would love some advice on mods to the engine, dont want to spend mega bucks

by the way this is a awesome site

 

[xctasy]

Taranaki! Good one!

The rules are exhast, carb, then maybee a cam. Any cam change on a Ford requires a total engine rebuild becasue the stock components aren't designed for a high lift cam. Low tension rings and the engine is general isn't designed to go past 4500 rpm. Thats 300 rpom down on the XE, and 800 rpm down on what the old XD iron head engines used to get away with.


XF's are very prone to detonation with todays fuels, and you have to check out the whole package very specifically to make it work well. However, there are no major electronics to deal with if you change to an XE ignition set up.

You can get to the 196 hp mark if you follow Dick Johnston SVO spec.

Use a good set of headers, thats a 18% power boost, 12% economy improvement. Use the best exhast you can make. An XF is an absolute dog to get a great exhast system on because the Watts linkage and spare wheel well and plastic fuel tank prevent a preferable dual exhast system being set up. And don't listen to any one else a dual system is the the only option to make it sweet on the street.

Copy the EB XR6 exhast layout. It had a great extractor set, four mufflers, twin exhasts to the diff, and then one pipe past the axle. Becasue you don't run a catalyist exhast, then you should run a basic dual outlet header (extractor). Then grab quite small pipes say from an XA-XD V8 exhast system with two good big 2.125" glass pack mufflers (resonators) at the front, and mount them backwards so the serations are not facing into the air steam. You then mount two good mufflers in the 2.5 inch range which flow at least 200 cfm each at 10" flow pressure at the back. You then group both into one big single 63.5mm internal diameter pipe at the back. This is basically what the XR6's first ran. The backpressure and sound is then times nicer than the silly big singles everyone else runs. If you have money, you can copy WasaIII X pipe set-up. A balance pipe lowers the tone, and stopes it sounding like a Cessna air plane at 1500 to 2500 rpm. Very important these days with poloce getting edgy over noise.

Once the exhast is sorted, you can then go for broke on a good intake. For my money, I'd get a Cain 4-bbl manifold and import a 4180 Holley carb off a 1984 to 1988 351 4-bbl V8, or a 5.0 HO Mustang. It's a brilliant carb, and is compatable with the stock Carter fuel pump becasue it has a return line. Its rated at above 600 cfm, and fits all the emissions bits.

Remove the stock XF EST computer, and run a reconditioned XD or XE Bosch duraspark with a the right module for the transmission


Then go buy a Kelford cam which has a single pattern, hydraulic 280 degree, 215 degrees lift at 50 thou duration figures.

Take the head off, and upgrade the valve springs, pushrods and lifters and rockers, sled fulcrums, new collets, re cut valves. Re-profile the combustion chambers to the XE set-up, which means removing the high swirl ramp around the intake valve.

If the engine needs a rebore, then do the whole engine, with good rod bolts, good pistons and preped stock rods.

Don't go over 5000 rpm, and you'll have at least well over 200 ponies.

If you use the stock Borg Warner, have it rebuilt with EA clutch pack, and track down a looser coverter of about 2000 stall rpm.

If you have access to a 4 or 5-speed, amke sure you get all the gear of the donar xe or XF 4.1 vehcile. 3.3 4 or 5-speeds will get killed under the load. Toyota Hilux or Supra 5-speeds need the right gear ratios and clutch to work on the aftermarket bellhousings.


Your ideal gear ratio is most likely a 3.45:1 limited slip EB to EL XR6 diff, but the stock 2.77:1 open wheeler will be okay until you source one.

Everyone says just wack an OHC in it, but unless you have a good package from a wrecked vehcile, your better off doing the mods I've suggested in little dribs and drabs.

Simple, Small mods = Sucessfull.

Deano

 

[Anonymous]

They should rename u the professer your knowledge of all things ford is massive.
Very happy that you could spare some time to help out a fellow ford fan and will be definitly be using some of your ideas

Thanks

 

[DYNOED250]

Just a few things.... EB xr6's never ran twin exhausts :> and they ran a CAST iron exhaust manifold same as other falcon.. Evry thing else seems spot on..

Having spendt the cash on a serious 250 build up before, if iwas u id simply get running gear from a XG manual 4.0 falcon ute, and transfer evey thing over.. you ont look back

 

[Anonymous]

mines an 3 speed auto i dunno if i wanna do a converison just yet
column change is cool it'll do 4 now

 

[2nd.gunman]

i believe xecute is refering to the ED XR6 sprint.

 

[xctasy]

Of course, Dynoed 250 is right on.

The XG XR6 ute engine, exhast and all the bits would be perfect for an XF falcon, but in NZ, XR6 utes are super rare. And an 93 to 96 XG with the stock 148 kw 4.0 would be trashed within and inch of its life by now. There are lots of little parts that make the XG 4.0 ute a great car, but everything has to be there to ensure you've got the factory 148 kW. Unless our newbie can find the bits, he can at least add some hot-up gear to his stock engine and get some extra ponies.




DYNOED250 is also bang on about the stock EB never having got tubing headers. Apparently, they are only worth 3 killer watts and cause under bonnet heat on OHC engine bays.

Copy the EB XR6 exhast layout. It had a great extractor set, four mufflers, twin exhasts to the diff, and then one pipe past the axle.

Scratch four mufflers, it only had three.


My bad.

The exhast is indeed single from the cast iron header, then it runs to only one resonator, then a twin pipe set-up with big mufflers, then back to one 63.5 mm pipe, Watts linkage, fuel tank and a single catalytic converter prevent a proper dual exhast all the way through.

The EF got the a better spec six with an extra 3.5 kw. I can't remember if it had tube headers or not.

What has been established is that considerable time was spent making certain the exhast had low back pressure, could be fitted okay, and didn't resonate. This is just what the aftermarket is doing wrong today with Falcon i6 and Commodore V6 exhasts. The big gun single set-ups sound awfull, resonate, and have quite a lot of backpressure.

When the EL GT came out, they dropped the back pressure to about 4.7 kPa, or well under 1 psi at full revs. It sounded great, and from what we see from BMW M3's and the American Falcon and Mustang owners, a dual exhast of the right size makes a six sound sweet.