U.S 200/250 vs 250 x-flow camshaft

I am trying to rebuild an 82 alloy head 250 x-flow in the USA. Parts are very difficult to locate by application due to the fact that the engine was never used in the US market, therefore it is not listed in any parts store books. Can anyone tell me if the camshaft and or lifters for a U.S. 200/250 is the same as the alloy head Aussie 250 x-flow. Would also like any information on the timing chain and gears. Aftermarket manufacturer name and part numbers for the gears and timing chain would help me to match them up.

Dave

The Aussie cam is exactly the same as the US 200/250 cam bar the different phasing of the inner most lobes (cylinders 3 and 4 have no exhast valves side by side in the centre, unlike the non-crossflow US engines.)

The timing chain and gears are a halfbread, which are different. Others know better than I. The camshaft is physically spaced the same as the US 250, but uses 200-style gears, with a different chain. This was an upgrade due to the increased leverage of the heavier valve gear they had.


All lifters come in two types, and the Aussie ones are the same as Clevland ones.

Pushrods, I have no idea which ones are the same. They are quite long.

Dave, I considered myself too slow to tackle this one last time. But it looks as though maybe I was wrong. Crane or Comp sell crossflow cams - I have seen them listed. Personal preference would see me recommend

(local maker) but this may not be time/cost-convenient for you.

Check this for grind specs: http://www.crowcams.com.au/templates/Ca ... flow.shtml

Timing sets: Rollmaster CS6-188-250 or JP 5980 (equivalent). Both about $120 Aussie plus post.

If you want (got P/Pal?), I can purchase and mail these bits ASAP, at actual parts/post cost (see my b!tch elsewhere 'bout losing my shirt on this stuff). It's time to get that motor going.

Cheers, Adam.

Thanks for the input and part numbers.
Adam, I have set a target date of February to get the engine installed and running. That is the 1 year anniversary of when I snapped a timing chain that bound up and broke a hole through the water jacket and into #1 cylinder disintegrating the piston and the engine.
I have already looked at the Crow site on the internet. I will most likely go with one of their cams.
I need some help in deciding which cam best suits my vehicle. Vehicle weight 3200 lbs. AOD4 gearbox, 4.00:1 rear axle. Also need the ablility to tow a trailer of 1600lbs. Not looking for a race cam, just a good low-midrange torque builder.
Dave

What I do is benchmark another known combination which works, and then henpeck the heck out of my choice.

Looking at the weight of your van, you can benchmark it to a similar 4-stage auto Australian Falcon sedan, and see what practical limits there camshafts were taken to.

What I do is suss out the likely power of the engine, the peak rpm at peak power, the maximum revs the engine can handle, and then gear it for an optimised 1/4 mile time in third gear, reving to the maximum rpm limit, not in top gear. Top is used for cruising. I also add 400 pounds to make it more realistic. To do these calcs, all I need is the tire size (P185S14 I've assumed).

I won't go into all the calculations, but with just a stock 130 hp cross-flow reving to 3600 rpm for peak power, and 4800 rpm for peak rpm, in your 3200 pounder with two people, it will do a 17.7 second standing quarter at 77 mph. This means the ideal gear ratio is actually 4.56:1 reving to 4800 rpm, or 3.45:1 reving to 3600 rpm. In practice, your 4.00:1 diff is about perfect for 4200 rpm upshifts, just over the peak power mark! This is what both car development engineers and drag racers look for.

As the engine gets 'cammed up' the diff ratio needs to rise numerically to allow the engine to hit the sweet spot in the rev range. With most modern cams, you can leave the gearing unaltered untill you start loosing low-end torque. Some cams produce better power and torque eveywhere, but as soon as you go 20 degrees over the stock cams 'at lash' duration, you have a high probability of a low-end torque loss. You must avoid this.


Stick with a sub 270 degree cam, and don't change the diff gears. This will give you very usable intermediate ratios, for a great launch and pick-up, plus a lopeing top gear that cruises at 60 mph with only 2200 rpm on the engine. Just where maximum torque sets in.


The best carb is the Weber ADM 2-bbl that comes stock with it, but a Holley #2300 500 cfm will work very, very well with this combination too.

Sorry about the delay in responding, Dave. Seemed to get sidetracked whenever I logged on.

Based on your comments, plus XECUTE's calcs, I would suggest Crow's 14602 cam. They actually spec this with anti-pump lifters, but you can try either (I would start with the cheap regular chilled cast iron ones). You need hi-po retainers off a Cleveland or similar (easy to find), and stronger single springs (either Crow or check assembled height for other interchanges; should be Clevo).

The AOD is not a direct bolt-up to the Oz block. Are you planning a tweak to fit?

Adam.

I don't have the specs here in front of me, but I think the 14602 is very close to the stock EFI cam spec, but with just a bit more lift. I think the EFI cam may ahve a bit more duration on the intake; I'll verify tonight when I can get to my manual.

If it is similar, it should be a nice cam. I am currently running the EFI cam in my car and it idles well and pulls hard to over 5000 rpm.

You will need the Oz timng chain and gears. The US sets are different. You'll find that the Oz crank has the same diameter snout as a 200, but the chain is a different length.

As far as lifters, any lifter for a small bock Ford will work. US 200/250 lifters will not, since they lack the oil-thru capability you need for the crossflow.

SBF springs and retainers also fit, but check the diameter and installed seat height. I used a set of Crane springs for a 5.0 and they work well. Don't go crazy on seat pressure. Stock spec springs will work fine for your application.

What are you using for an intake? The stock 2bbl manifold with 34 ADM seems small for a 250, IMO.

What are you using for an intake? The stock 2bbl manifold with 34 ADM seems small for a 250, IMO.

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Jack, with any modification at all, and even in stock form, the Weber 34 is too small. Its very economical, but it requires a return line and a special fuel pump. So if you want a Holley or Autolite with the Holley base, you'll have to go to the post I've done on Holley carbs for XE/XF's. Its a little bit of work, but I promise you for the small fuel economy penalty, you'll get a massive increase in performance.

I have a philosphy that undercarbing is the right thing for most people. Accept power addicts like us. Depends how far you wanna go. If its just fuel economy, the too small Weber 32/36 and 34ADM are wonderful carbs. But 125 to 130 hp is it. Anything over this, the venturi size is too small. Just a cam alone will push any 250 way up in power. A Weber 38 would be the most simple bolt on upgrade, but its rather rare and expensive compared to the 500 Holley. And it still uses the Weber linkage, whic won't work with the next item I gonna talk on.

The AOD is not a direct bolt-up to the Oz block. Are you planning a tweak to fit?

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Its very hard to make an AOD fit the Weber kickdown linkage, let alone fit a 4 bolt Aussie block. I'd say it won't work at all unless you spend a long time sorting the throttle valve linkage, and then use the plate adaptor for the crank and bellhousing that I've made up. I'll send some pictures once I've got my ftp site running.

But the main idea should be getting it running within your budget. If you have to do things to an elitist, aspirational level, you'll be longer getting it done. I know, I am one of those people! That's why I'm not driving behind an AOD'd 250 at the moment. It's been a year since I first PM'd Jack on this site to see what the going modifications are to make an Aussie 250 work in front of an AOD, and if it were simple bolt up, I would have done it already. Back then, my Falcon had a BW auto and a Holley 500.

I can vouch for the Holley 500, but not for the AOD conversion. Meantime, I'd look at the manual 3+od SROD or later O/D Toploader. There are enough people to help get the Aussie bellhosing if it suits you. Otherwise, I can send you my diagrams or an adaptor to suit the AOD. The only thing is the automatic trans forces you to adapt the V8 starter and 250 US flywheel. The header tube form the exhast needs to be bent down to clear it. If you use a tubing Perry, Genie or Pacemarker header for a cross-flow, you have to modify it to clear. An AOD won't allow the stock starter position to be maintained.

Best sum-up I can say is the one from the Ford Dunedin parts guys (counter wally). I asked him to check his inventory for a 250 C4 bellhousing, thinking they were the same as the US ones. After going through all the reasons why I wanted to know, he aked "do you know more than the Ford Motor Company?" This is the issue. Each modification needs to be thought through.

Al the hackmeister has well publicised the issues with AOD's. I'm inclined to think Jacks idea on using a GM thm 200 or 700 auto overdrive is a good one. Whatever the course of action, tell us, and everyone can get to see the shop diagram.

The neat thing about this site is that you can get others to help do the engineering work, and that can be crossed checked so there is no chance of getting told BS.

If you wan't help, PM or e-mail me, and I'll post the info I've got on the AOD.

To all,
I will try and answer some of your questions.
The engine I purchased has the stock intake and 2bbl 34ADM carb. Lots of pollution stuff that will all be removed. No required pollution controls in the state of Texas for this year vehicle. Exhaust that came with the engine is a cast iron manifold.

I think the information all of you provided makes the Crow 14602 cam a good choice. Good driveability with a boost in power. If I read the posts correctly Jack stated that the valve springs, retainers, and lifters can all be purchased as US 5.0 stock items. Jack is this a correct statement?

I would really prefer the AOD trans for the highway cruising capability and the good low end that they provide. It is not uncommon for me to get on the Interstate highway and drive 75-80 mph for eight hours, stopping only to fuel up or get something to eat.

I am not trying to build a super fast vehicle. You have to remember the original drive train in this vehicle was a 170cid, 95hp, with a Dagenham (weak and awkward shifting) 4spd with a 1:1 final drive gear. At 70mph it ran out of power and was spooling up some high rpms.

Dave

Thanks for the input and part numbers.
Adam, I have set a target date of February to get the engine installed and running. That is the 1 year anniversary of when I snapped a timing chain that bound up and broke a hole through the water jacket and into #1 cylinder disintegrating the piston and the engine.

Click to expand...

:roll:

To Dave and everybody who has followed the Oz I6 to American transmission adaptor sticky.

I've almost got that AOD to Aussie I6 adaptor ready.

My close work mate has swapped companies last month, and this has created no end of trouble for me. He and I have built some good stuff together in my work contracting. Down here in the South Pacific, you have to scratch build everything, or pay th going rate!

Anyway, just so everone is aware, I was to have the adaptor tested in my mates XC Falcon last Feb, and packaged for air freighting.

Dave, thankyou for pre-paying, and sending me those good bolts as per the specification I gave you.

I don't see myself as an importer of bits to the US. This is to help you out, and get you guys making great cruiser I6's. I really appreciate your gesture of faith in my adaptor, Dave.

I won't let you down, buddy.

Crow Cams have superseded the 14602 cam to a 14221
specs
VALVE TIMING ADV DUR .050 DUR VALVE LIFT
IN.26/60 266 205 .472
EX.66/25 271 209 .485
POWER RANGE 1400-4200
improves throttle response .good highway cam for mild or stock engines
Use lifter ht900(VL35) or ht900r(VL67RH) antipump .industry standard part numbers in most places.
ADDO,s onto it with the JP5980 timing set .This has a billet steel cam sprocket ,double rolon chain , multi-keyways.Seperate chains are available
aussie use a 3dr52 chain USA use a 3dr50 ...2 links shorter.
Get a new distributor gear to match camshaft either a CROW DG2 (suits 0.490"shaft) or the DG2A suits points ignition (0.530"shaft)
Pushrods use CROW PR317 for standard steel replacement 9.682" long
big end bearings p/n 6B2150 STD/010/020/030/040
main bearings p/n 7m2158 std/010/020/030/040
cam bearings p/n 4c5826std
head gasket set p/n dh100 alloy head 1980-85
bottom gasket set p/n ep633 rope rear main
bottom gasket set p/n ep340
oil pump p/n JP9438 std volume
oil pump hi-vol jp9436 high volume
you will need an aussie oil pump drive if yours is buggered USA drives are
10mm to short -can cut down 351c drive but will leave 1 unhardened end.
Water pumps can vary from model to model ,is yours going to run a viscous fan or fixed? any other numbers you need ?

cheer Dave