XD Falcon Project

[Anonymous]

Hey,

Currently, my XD is a fully standard 250 with iron head accept for a 350 holley, extractors and exhaust. I am planning on changing the iron head to an alloy head XE with XF valve sizes and megatork springs, etc and what goes with it. I am also considering changing the cam to a 14771 crow cam (200, 205 at .05). I'm expecting this to give me maybe another 20 or so horses without affecting the low down torque considerably. I would like to upgrade to EFI if possible, i have looked at an XE EFI as they are the most simple, and i believe the trouble will lie with having to change the fuel tank for the fuel pump which will be a bitch because the XD's have the spare tire sitting down in the boot rather than on the side for the XE's. How hard is this conversion and would the XE cpu handle the change?

 

[xctasy]

I'd go the brain dead XE CPU if you wish. Its upstream air vane is old had, but it doesn't have any trouble hacking 180 hp or so. Just don't expect it to like 200 hp without injector alterations.

The tank possibly isn't such an issue. The tank is plastic. Pehaps the XE tank bits can be made to bolt in from the top where the sender is if you can duplicate a stilling basin for the fuel pickup.The other option is having a boiler maker tig weld up an alloytank in similiar dimensions. Then the wheel and everything can sit in the stock position.

The swap to the XE floor plan is a no-goer, its all differnent from the rear seat frame back to the rear bumper. It cost Ford Oz 33% of the cost of the whole 1979 103 million dollar budget to re-do the rear sheet metal and suspension to fit the tyre upright. And all they gained was 65 mm of trunk depth, and even then it was still too shallow! And no space for an extra exhast set up.

Just be glad a leaf sprung XD can handle twin exhasts, unlike all later Falcons. I think a Falcon isn't a Falcon without a set of huge GTHO-style howitzers scaring tailgaters...

 

[Anonymous]

What about the CPU mapping etc, do you think just take to a garage to do that sorta thing. If i go for injector changes, or bigger valves would 200 hp be possible or would the cpu be inadequate. If this is so would i be better sticking to the 350 holley carb?

 

[xctasy]

The is no EPROM in a Bosch LEII sytem, as far as I'm aware. You'd possibly steal a BMW 3.2 (pre 86 735i/635Csi) CPU but its all old technology and expensive. Your held at gun point by your abilities to intimadate some IT guru into doing something for a few dollars, I'm sorry.

Any Aussie company can give you an upgrade using an aftermarket unit for a fee. It'$ ju$t a matter of dollar$. :roll:

The 350 cfm 2-bbl won't give you any more ponies than a stock Weber ADM 34. It's a 125 hp carb, maybee 155 hp if you've got a wilder cam running on the raggard edge. A 500 cfm 2-bbl carb can give 170 hp, and maybee 220 hp if you have a screamer cam and are prepared to sacrifice streetable tractorbility.

The EFI/alloy head set-up is the one to go for if you aren't going to tax it with too much power. People forget that a 250 is one of the most strangled engines around, and any cam, carb and or header alteration will unplug it to well over 180 hp without even trying.

Save up for an aftermarket kit EFI CPU, but in the meantime use a PN4412 #2300 500 Holley 2-bbl carb with 68 to 69 jets, 8.5 power valve, and leave the 350 Holley alone.

 

[Anonymous]

Cam
If you want to keep it more simple you could put a bigger two barrel or a small 4 bbl on it (with redline manifold for Iron head). Then you wouldnt be limmited with your cam choice (assuming yours is manual). If you went just a tad more with the Duration than you intend (around 210 or 212 at 50, 110-112 LSA) you would barely notice (if at all) the loss of low rpm torque with a good gain in power between 4000 and 4500 (still low) when you wanted to give it some curry. by doing this you could free up "another" 25 hp, it would still be a "grunty" cam and you could stay under 3000 FPS. Ive got a 204 at 50 110 LSA and its pulls up short of 4500rpm.

 

[Anonymous]

What brands are there for aftermarket CPU's and how much is some of the cheaper ones. I take it they would run comfortably with the rest of the XE EFI system. Also i've heard you blokes talk about exhaust port dividers. I thought you only used them on the old motors where the middle two cylinders used the same port. But from reading some reports exhaust port dividers are used on every port to basically give two exhaust ports per cylinder in an attempt to increase exhaust velocity. However i would of thought that this would restrict exhaust rather than help it, and if it did increase exhaust velocity then it would reduce back pressure, decreasing scavenging and therefore decreasing low end torque

 

[Anonymous]

You dont need them on an Iron head Crossflow. If anything you might want to restrict the large size of the inlet 40mm from what I hear 42mm for 2V. Its OK up high in the rpm but not Ideal for low rpm power. This is where the alloy head crossflows are better if you want a low rpm performer.