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XC Fairmont 4.1 crossflow Cheap power upgrade ??

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Hi , we are looking at upgrading the power of our XC Fairmont wagon - it has the 4.1 straight 6 with cast iron head.  We are looking into the cost of changing head possibly to alloy from later model- DOES any one know which would bolt up?

Also we will be changing the carby to a holly 2 barrel 350 and running extractors with a larger exhaust.

 

Our aim is to use this vehicle for the 2014 camp quality escarpade , so basically we need more torque to run bigger tyres and needs to stay cheap ( within budget). any other ideas/ Help would be much appreciated.

 

 

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Ah... Xflow are a pushrod valvetrain system, changing the head will still leave you with the original cam.

 

I'm pretty confident I've read elsewhere that the alloy heads from later xflows bolt straight on.

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Alloy head C2 (easy and cheap) and a hydraulic 'towing' cam for a bash car.  TIGHE - camtech and CROW all do some great towing cams so whoever is close to you to save some freight.  You will need new lifters and it is best to fit new cam bearings to suit the cam - but if you are on a budget and don't wont to pull the motor out then bang it in and pray. 

Every new cam should be dialled in IMHO but again if budget is tight and you don't have the skills, then bang it in DOT to DOT and pray.

In a fresh motor - a nice hydraulic towing cam - decent 2 Barrel manifold (Aussiespeed only way to go) - and a set of extractors and you will have an economical - reliable package with bucket loads of torque.  Don't forget to upgrade the alternator to run all the siren - flashing lights and horns etc. 

good luck with the build and camp quality is a great cause

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Thanks ando76 sounds like a good idea, If i go to do i would say the motor will come out and we will do properly - needs to be reliable also as trip next year will be around 4000k in middle of no where :)

I will try and price up some of these parts see if i can squeeze into budget.

 

I haven't dialled in a cam before as used to working on OHC vehicles but had a quick read and all sounds pretty straight forward.

 

Would it be worth worrying about bottom end?

 

Thanks for the help.

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Alloy head C2 (easy and cheap) and a hydraulic 'towing' cam for a bash car.  TIGHE - camtech and CROW all do some great towing cams so whoever is close to you to save some freight.  You will need new lifters and it is best to fit new cam bearings to suit the cam - but if you are on a budget and don't wont to pull the motor out then bang it in and pray. 

Every new cam should be dialled in IMHO but again if budget is tight and you don't have the skills, then bang it in DOT to DOT and pray.

In a fresh motor - a nice hydraulic towing cam - decent 2 Barrel manifold (Aussiespeed only way to go) - and a set of extractors and you will have an economical - reliable package with bucket loads of torque.  Don't forget to upgrade the alternator to run all the siren - flashing lights and horns etc. 

good luck with the build and camp quality is a great cause

This is exactly what i've done in the past with great results. The only other thing i would suggest that will make a big difference is getting an aftermarket inlet manifold, the standard manifolds were a shit design and a big power killer, so even a cheapy will see excellent results.

 

Also you'll obviously be doing alot of highway k's so a long diff ratio would be best, a 2.77:1 is very economical for highway use, but a 2.92:1 will retain the long legs but also give a little bit more poke up-hills and will also benefit the torque of the new tow cam. (3.23:1 or 3.50:1 would suit the cam better again but maybe too short for your intended use.) Be sure to let the cam guys know what diff ratio you intend to use.

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Thanks ando76 sounds like a good idea, If i go to do i would say the motor will come out and we will do properly - needs to be reliable also as trip next year will be around 4000k in middle of no where :)

I will try and price up some of these parts see if i can squeeze into budget.

 

I haven't dialled in a cam before as used to working on OHC vehicles but had a quick read and all sounds pretty straight forward.

 

Would it be worth worrying about bottom end?

 

Thanks for the help.

Run a compression gauge over the bottom end, if they are pretty good and reasonably even i wouldn't worry about doing anything to it (except the cam change)

An old but healthy bottom end will have already seen 200,000kms+  and is a proven package that will easily see another 200,000kms+, Have you ever tried to kill a 250ci bottom end? Almost impossible!! The only thing that ever went wrong with Fords inline sixes were heads/head gaskets.

I'd probably go to the later electric ignition but carry a spare coil.

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If you go an electronic ignition (recommended) take a spare set of modules and a spare coil for sure.  Like Mr Mntlxd said the borrom ends are very reliable, but if it's done more than 250k I'd be re ringing and re bearing.  Thats just me.

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If the engine is out and is healthy then a set of rings $75 and bearings about $150 for king bearings is a great investment.  If the bottom end is not flogged you will get away with just a hone and some new cam bearings and surface the head. Engine Engineering in Brisbane charge about $380 for that service not including supply of cam bearings. 

 

Most shops are happy to help out good causes so you may find that they will do the machining for minimal cost.  definetly worth it and anyone with basic mechanical knowledge and a Gregory service manual can put together a 250 crossflow for this application.

As to cam dialing in have a look in my ute (ando's ute) build thread as I did a step by step in that.  Just make sure you use a quality Rollmaster double row timing gear set as the standard one is puss. 

 

with a good towing cam, aftermarket two barrel manifold, 350 holley and a set of extractors on a fresh bottom end you will have a great package.  add the xe electronic dizzy and coil and you have one reliable, torquey and fuel efficient motor that will be great for the intended application.

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Also you'll obviously be doing alot of highway k's so a long diff ratio would be best, a 2.77:1 is very economical for highway use, but a 2.92:1 will retain the long legs but also give a little bit more poke up-hills and will also benefit the torque of the new tow cam. (3.23:1 or 3.50:1 would suit the cam better again but maybe too short for your intended use.) Be sure to let the cam guys know what diff ratio you intend to use.

Depends what box is behind the motor too as to best diff choice, if its going to be auto or 3 or 4 speed Id stay 2.77 or 2.92, but if its a 5 speed I'd switch up to a 3.23, they match up brilliantly with the 5 speed boxes, good acceleration and I can get highway fuel usage of around 10/11L/100km.

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All the advice above is great, the one thing I would change is using a C2 head, the C2 would give way too much comp on an XC bottom end, I would go the XE head or the C1 personally. The XC pistons are a flat top aren't they?

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For a cam I would go Camtech CT142-509 (especially if it is auto and 2.77). You CAN run std valve springs with this cam. You can dial it it but I'll bet you won't gain anything over just lining it up dot to dot (if the dots are out it won't be by much)

 

I doubt it needs new cam bearings, I have seen way more engines fail with new cam bearings than old ones, so I say if it doesn't need them don't change them. But check them.

 

Definitely want new rings and big end and main bearings though.

 

Pity you can't use an EFI manifold, I have tried a bunch of different ones with LPG and the std banana EFI manifold beats them all for low end grunt. I would just look for a second hand Redline off eBay for what yoy are doing.

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I wouldnt bother with it,can buy a cheap good running 302 with a auto and will drop straight in with v8 engine plates and can use the orignal tailshaft and diff.

just need to run either a twin or single exhaust (single exhaust to keep costs down single 2/ 1/4).External tranny cooler and go a bigger radiator as you will need one even if you were to hot up the old 4.1.

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When I first got my XC I did the Holley carb and exhaust upgrade to the old iron head six, it made a reasonable change but you would really want to look at a cam upgrade as the factory cam is pathetic, changing the dizzy to an electric setup helps quite a bit too, u can use the points dizzy as a trigger and install an MSD setup for some nice gains.

 

Before switching to straight gas I had the old crossflow up to 88kw's at the wheels using the following specs

 

350 Holley on a redline 2 barrel manifold with a 2 inch spacer

Pacemaker extractors into a 2.5in system

crow 14221 cam (which I found was a bit smallish but miles better than the factory cam)

regraphed XE electric dizzy

comp ratio bumped up to approx. 9.5:1 running on Pulp 98

 

It was a pretty nice setup still a bit mild but miles better than the stock setup, the bottom end was stock and only the springs were upgraded in the head.

 

If you have a bit of coin I would really consider going for an alloy head unit with a carb/cam/exhaust upgrade, much lighter, better on fuel and more potential to make power than the Iron head six

 

OR

 

U could go for an Orion engine out of an FG with a cold air intake upgrade, exhaust upgrade and a flash tune, my FG XR6 make 173 rwkws and has even surprised a few VE SS owners...especially once I started to pull away from them.

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All good advice, and to simplify, exhaust, cam, carby and compression are what make power, and are all dependent on each other. You don't just do one and expect noticeable gains. I would say 20% more power and torque are achievable without losing economy or driveability, If you match everything.

 

The 350 Holley is a classic upgrade, but not the best for economy. The 34 ADM is a better choice in that regard.

 

A "towing" cam is pretty fool-proof, with sweet idle and very useable midrange. Perfect for a tractor engine like this. Next step would be a 208/208@0.050 from Dynotec or Crow. Any bigger than this would need stiffer valve springs and better rockers. Also a bigger cam would come in later and just when it's time to boogie, the heads run out of puff. Don't skimp on the lifters. Get good quality ones and then forget about them.

 

I wouldn't touch the compression at all. Long-stroke engines don't like it, especially with mild cams.

 

Keep your 2.92 diff, as I'm finding my 3.27 a bit short with my 302. If you've got good torque, use it with tall gears, you can get away with much less gearchanges if you have longer legs.

 

Also when taking off in a manual and you have short gearing, a lot of the power is wasted accelerating the engine itself and then even more time is lost changing gears all the time.

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Don't like compression?? Based on what?

 

Not easy to explain quickly but a few things on this kind of engine all conspire to not tolerate too much compression:

- iron head

- mild cam

- long stroke/short piston dwell time

 

Iron head: why Ford went to alloy after 4 years of iron.

 

Mild cam: this has the peak torque (and cylinder pressure) right in the meat of regular cruise rpm, meaning full timing can't be used, and economy suffers.

 

Dwell time: on long stroke/ short rod engines, the piston spends less time sitting at TDC so timing is more critical and if fired too early, the piston is still coming up to the top while the mixture is being ignited. Extra compression will make the problem worse.

 

I had a straight gas 4.1 Corty and used to pull my hair out getting the timing right with the stock dizzy. Seems these engines are very fussy. In comparison, my 302C (high rod/stroke ratio) takes upwards of 40 deg at idle and runs as smooth as glass. Nevertheless I have MSD programmable now and have never looked back.

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For bush mechanics reliability, I'd stick with the iron head, and points dizzy.

The less technology in them, the better, when you're looking for parts in the middle of nowhere.

 

I'd just check the condition of the original parts - check oil pressure, radiator core/hoses, check that the distributor advance mechanisms (mechanical and vacuum) are working properly.

Use LED rotating lights/spotlights, for minimal extra load on alternator.

 

If you need extra pulling power, change the diff ratio, (but not if there's a lot of highway driving).

 

I'd go with the KISS principle, on a variety bash vehicle.

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