how will these pars (head, cam, etc) go on LPG?

[Anonymous]

looking at picking up some parts (s/h) to put into the old XD over summer

COME racing Streetmaster cam - stg3 CLH-191
details: (i think)

Grind #CLH 191
Advertised Duration:
Intake 278 Exhaust 290
Duration @ 0.50
Intake 217 Exhaust 218
Cam lobe lift:
Intake .290 Exhaust .293
Lift @ 1.5:1
Intake .435 Exhaust .440
Lift @ 1.6:1
Intake .464 Exhaust .469
Lift @ 1.7:1
Intake .493 Exhaust .498

Lobe separation : 114

Stage3 COME racing head, flowtested to 300 hp (alloy) / set of alloy head extractors

Redline 4 bbl holley manifold / Holley 465 4bbl carb (freshly rebuilt) / rebuild XE electric dizzy

ok... so the current engine in the car atm is a 250 iron crossflow - its still healthy enough (no bad sound, oil use ~ <1 L over 5000 KM's, no smoke) - so I am not sure if I really need to rebuild it ? how will the alloy head affect the CR on the iron-head block ?
or should I just get it done anyway - maybe go for higher comp pistons @ 10:1 or somthing ?

The main issue however, is how well do you think this cam is suited to LPG - i have a impco 300A mixer etc that is currently on the car (holley 350) and it runs really well .... the car would be on gas ~ 80% of the time so its critical that the new parts help it get up and go while on gas !

will the stock fuel pump cope with this setup (for the small time its on petrol...) or will I need a bigger one ?

does the holley 465 need any modifications to run on gas (ie ... will the secondarys still open and stuff ?)

another question - should I get a new timing set for the cam, or try and get the one from the engine the cam is coming out of ?
new lifters are a definite yes ... ?


anyway... I will think up some more questions, in the mean time thanks

btw car in question = '79 XD 4spd
http://nforsa.8m.com/car/index.htm

 

[Anonymous]

The head swap might not be straightforward. I just bought an ACL Race rebuild kit for my iron x-flow, different part numbers for the cylinder head gasket from the alloy-head set. I think the water jacket openings in the iron head and block are a different shape. I would check if i was you.

Maybe ACL make a gasket that allows this swap.

Dom

 

[DYNOED250]

the alloy head goes on the iron head block no worries dont listen to any one that says it wont, if they say it wont and they think they know 250's there a tossa. One engine shop told me you couldnt do the swap this when i was building mine , ive never gone back there and i bag the crap out of them now. THE ONLY DIFFERENCE IN THE BLOCK IS THAT THE ALLOY HEAD HAS DOWLS TO LINE IT UP. just cut the top of a few old iron head long side bolts and wind them in to the deck one at the front and one at the back use them to guid the head on the block remove with vice grips and put ya head bolts in.

YOU WILL NEED FOR THE SWAP

-Head bolds, alloy head ones are all the same length cast iron ons wont fit
-Defently get a new chain and gear set. youre one will be stuffed use a rolmaster or jp set. just watch out for steel cam gears moor oilin points are required between the gear and the retaining plate for the cam, have seen a few chew that plate out
-Get a crow gear for the dist and being an xd it may still have points if so frow them out
- PUSH RODS are shorter in the cast iron head jobs only a lil bit but if youre cam is a re-ground one they wil tick like hell, but they are tapered at the end which is good, because with cams over .500 lift and with stock rockers i have found the alloy head ones rub on the back of the rocker because they are thicker near the tip, have had a few snap off.
id try and use tappered iron head ones if possible, see what ya pre ;oad is to, the les pre load on the rockers the better. if u use alloy one and with the engine on top dead see how much the rocker bolt winds in after the free play is taken up between the valve and the lifter. any more than half a turn of the rocker bolt to tighten up the rocker posts after this point u either need rocker shims, or shorted cast head push rods.

-um other than this ... hope you dont love ya holley because gas can be nasty to them, seen venturies melted, id go straight gas with an imco 425 straight gas carb, model e converter...... but duel fuel is always good. never had a 250 hottie on gas, only fuel so not sure how the cam will go should be ok, with that duration should have a slight lump, if you got an auto it will suck of the line.

 

[xctasy]

Q.ok... so the current engine in the car atm is a 250 iron crossflow - its still healthy enough (no bad sound, oil use ~ <1 L over 5000 KM's, no smoke) - so I am not sure if I really need to rebuild it ? how will the alloy head affect the CR on the iron-head block ?
or should I just get it done anyway - maybe go for higher comp pistons @ 10:1 or somthing ?

A. Point 1.

Chamber cc's are similar, and any alloy head can go to higher CR's without detonation than any cast iron head. Use the CR COME recomends.

Point 2.

the alloy head goes on the iron head block no worries dont listen to any one that says it wont, if they say it wont and they think they know 250's there a tossa.

:roll: Okay, then I'll just say the two location pins, minor gallery changes, head gasket part number and different block casting number was just Ford wasting money....You can slap an alloy head right on there, but the termal stress and scuffing of the alloy heads under high pressures are well known. Honda and Ford made those changes for a reason.

Go do a conversion if you like, but make sure you soak the bolts in oil, and trial fit the bolts to 30% of the full clamping pressure first five times to break the sticky friction which stops the bolts clamping the head, then follow the gasket makers installation practice. Fords' bolt specification isn't as good as it could be.

Q.The main issue however, is how well do you think this cam is suited to LPG - i have a impco 300A mixer etc that is currently on the car (holley 350) and it runs really well .... the car would be on gas ~ 80% of the time so its critical that the new parts help it get up and go while on gas !

A. Point 1

I agree with DYNOED250. The cam is going to be a plonker off line, unless you find a way of lowering the overall gearing, at the expense of highway mileage. There is no way to get extra power without loosing low-end grunt unless you Turbo or supercharge, so get a 3.23:1 or 3.45:1, or 3.5:1 diff off a Ute (Some XA-XB's got 3.5:1 options, most XD-XF 3.3's have 3.23:1, XG XR6's have 3.45:1 LSD'S). An auto always needs a 2200 to 2500 rpm stall convertor, not the 1600-1800 item they cam with. With 3.23:1 gears, a convertor, and a rebuilt BW 40 from an XF, or preferably a six cylinder C4 from an XA/B/C/D, then you'd get a fairly good launch.

A close ratio 5-speed manual, with 3.45-3.5:1 gears would be perfect for a cammed up streeter.

Point 2: The cam choice with an LP Gas engine isn't such an issue as long as the engine can build vaccum and engine speed off line. The Impco 300 carb can't hang out with really wild cams, because its gas valve is super sensitive. I think there is too much exhast duration, and only Sam B from COME can tell you what works for gassers. LP Gas is light, and can go right out the exhast if the duration on the exhast valves is 10 to 20 degrees higher at valve lash. I'm a little nervous, and personally wouldn't use that cam. However, there are no bad cams, just engines that don't suit. At the milder level (this isn't a screamer cam, but it's as high as you can go an still remain practical) "if it breads power on petrol, then it shouldn't be to bad on propane".


Q.will the stock fuel pump cope with this setup (for the small time its on petrol...) or will I need a bigger one ?

A. Should be okay, but there is a severe risk of fuel leaking into the sump if it perishes any internals. The gasoline is not going anywhere when its on LP Gas, and it once happened to my old mechanical pump. Not nice to have a sump full of stale petrol, and freeking dangerous. My advice is to get a brand spanker from Ford, or check Addo's posts. He mentioned that Aussie petrol pumps are in some cases V8 hybrids with bits from the Windsor/Cleveland family. The extra benzene we have in todays gas isn't friendly to the internals, so fix before it breaks.

Q.does the holley 465 need any modifications to run on gas (ie ... will the secondarys still open and stuff ?)

A. No worries as long as the mixer is remote mounted. If you chop the hood, the CA 300 can go right over the 465 or 350 carb, but the main stud that bolts the thing down must be strong, and not foul the air horn in any way. There is no cooling without gasoline, so there is a risk of something melting unless you retard the ignition back from the factory setting. This can cause a lean backfire, which can blow the diaphram out of the 300 carb, perhaps melting the Holley. It's never happened to me, but it can if you don't have an expert check the advance.

Q.another question - should I get a new timing set for the cam, or try and get the one from the engine the cam is coming out of ?
new lifters are a definite yes ... ?

A.YES, NO, YES, for the reasons DYNOED250 said.

LPG Carbs:

1.Stock Impco CA 300 carbs flow to 218 hp as an A1 (fits 2-bbl Weber or Holley). Suits dual fuel or straight gas.
2. CA 300 A5's are 270 HP but rather hard to find (Same as a 300, but has a different gas body inside. Hard to tell the difference).
(432 cfm verses 348 cfm)
3.CA 425, which is a 460 cfm, 287 hp carb which fits a 4-bbl Holley. Suits either dual fuel or straight gas.

Carby Base (Throttle Body):

The stock Sydney Alternative Fuels/ABER Weber ADM adaptor is not a great design for a hi-po engine. It uses the Weber throttle body with a alloy adaptor, not dual fuel.

Converter:

The L-series converter cannot sustain any more than 250 hp, the E-seires can flow 325 hp.

Vaccum Lock-off:
VFF30's can flow 325 hp, no worries. If duel fuel, get a Century electric lock-off, or so you Impco agent.

Adaptors (This is dual fuel):

It can have either the REMOTE MOUNT, natural gas goose neck which puts the 300 upside down over the power steering or over the exhast. No issues with space. The only option for dual fuel on a Falcon, unless you chop the hood. Impco carbs are just too big to mount on the existing carb to preserve dual fuel.

Adaptors (LP Gas dedicated only):

In a Falcon XD or XE, there is only 188mm of space from the base of a Holley or Weber manifold, to the underside of the bonnet. If you mount the CA 300 on top of the still working Holley, there is no space unless you get a hood scoop, which is technically a defect item (illegal in most states).What DYNOED250 says about the venturis melting is a valid point, it can happen. The carb must be fully empty, and with warm propane zooming past at 200 feet per second, it's possible to melt things, espeically if it back-fires on over run. A 425 Impco is much nicer, it is shallower than the CA 300 on an intake manifold.

 

[Anonymous]

I understand the motivation of working with what you've got. I'm usually pro any mod that saves time and money.

The scuffing effect of alloy expanding and contracting at different rates can cause a cylinder head gasket to to wear out. The cylinder head effectively rubs the gasket, its like its getting a fine sanding. I have seen 2 that were paper thin which eventually caused failure, 1 on an XE and 1 on an EA. This doesn't happen immediately of course. Both examples were on the wrong side of 200, 000km.

The difference between the iron and alloy head block is not so much the placing of the water jackets, it's the shape. As long as you use dowels as suggested and the gasket you use seals head and block there is no reason to have short term relaibility problems.

Alloy head engines are now very cheap. The advantage of having the samller boss for the electronic dizzy in the alloy head block makes the cost of another engine worthwhile in my opinion. (some early XD's with iron heads had the samller boss which Is what i'm running.

I have only stuck with the cast iron head because i found a cast exhaust manifold for a split housing TO4 and garret v band wastegate. if i had one for an alloy head I wouldn't have a second thought about going alloy.

 

[DYNOED250]

if u do decide to re-build the motor, id get an acl larry perkins engine re-build kit , u get pistons for the 200 rods, all gaskets, acl race series head gaskets, all bearings , the got mine for 500.

i got the dowl pins machined into the deck of my 76 da block, and i had 2 brass bushes machined into my distrubutor. one at the top which is there any hows, and had one machined down the botom., got rid of all movement in shaft.


* sorry bout getting model e and l converters mixed up was very late at night when i posted that :>

 

[Anonymous]

thanks guys - given me a lot to think about - i think

hmmm, I dont really want to change the diff ratio because I like the decent rpm's at 110 - 120 km's - (it has a 2.92:1 in it), so it seems the cam might be a little bit too big still has to be drivable in city traffic also
hmmmm. not sure what to do now hehe

so, the alloy head -> iron block is dooable, but not really reccomended?
how severe is the head gasket wearing issue? the old car needs to be fairly reliable!

I do have a XD alloy head engine ('82) but its completely shot, probably rebuildable - but I would prefer to put the stuff onto the working XD because im a cheapass uni student

i had an idea the 300A was good for 300 hp sounds like I was wrong. The guy who sold it to me (the mixer was $ 360 new i think?) said it was reccomended for 308's etc. if its only 218 HP this should still be enough I think? ( hopefully! )

im not sure how the 300A is setup - space is fairly tight, have a look at the pic (link) in the first post - will the same setup co-exist with the 465 ?

arrrgh... see the maximum I really want to spend on this whole caper is ~ $ 1000 or as close as I can get - that leaves about 350 or so to play with after I buy the parts (gaskets, timing set, lifters, etc) ... might be cutting it a bit close now I think about it

thanks for all the feedback so far - i will let you know what happens with it

 

[xctasy]

The key to any good car with a cam is the gearing. If you can get the gearing right, then COME will tell you what gearing is needed to make the cam work.

Remember Sams chant. There are no wrong cams, just wrong engine combos. I'd look for an earlier US import Top loader or SR 4-speed (ex 1982 5.0 Mustang )with an over driven fourth (2.95:1 1st, 1.69:1 second, 1.00:1 3rd, 0.70:1 forth. These should be drop ins. Or get a 5-speed. Then you could run a demon 3.7:1 diff off a Cortina six.


Talk it over with the supplier. If you focus on what you need, you'll get a really good result, without breaking the bank.

As for the carb, a 300 is the only game in town for dual fuel. Use what you have, and there should be no issues on petrol. Save up for an A5 300a mixer. They are around. 270 hp will be ample!

 

[Anonymous]

I am curious about the cam you are proposing to use and am still thinking about using it myself for a few good reasons (I have a manual). The 2V suffers a bit from the bigger inlet port size low down in the rpm and the LSA on this cam at 114 would help maintain the critical vacume (especially in a 2V ) and the gas speed at lower rpm (they say that it can be used with a near stock converter?) while still having a decent duration at 217 218 / 50. Also the LSA would help the HP peak come in at higher rpm and be maintained longer without dropping off sharply, so I would be very curious to see where its peak HP came in at, in a 250 Cortina. The downside is that it might not be quite as sharp and responsive through the midrange.
If I go ahead and use it I think Ill get it dynoed. Im Always after something a bit different. It will be a couple of months away yet.
Let me know how it goes if you decide to use it.

 

[Anonymous]

Execute
Tried to send a personal e-mail to you via this forum and e-mail failed x2. Thanks for the inquiry things are well with both of us.
Cheers Mate.
Regards Tim

 

[xctasy]

Sweet Tim.

Hey xd6pac, that's a cool Falcon. My first driving lesson was in some power board Falcon XC and XD's, and the XD was a lot quicker because of the 100 kg weight saving, or more like 123 kgs with an alloy head. The guys I know with V8's seam to be wishing they'd not gone Cleveland because of the expense of finding good core engine blocks and parts. The six is a sound economic decision that if modified right, is more reliable, longer lasting, and quicker on the street.

That alloy head swap again. Just repeating what I said. I don't think there is much of an issue with gasket faliure if you ensure the bolts are clamped in a fully lubricated state, with five tightenings to 30 to 50% of the final torque figure, then the regular torque up. If the cast iron block is done already, then I'd say check with a machinist on how to go about rebating the two cylinder head bolts falcrums for the 13 mm split dowels that are used to hold the head down. Jack hasn't used them on his 200 US block with alloy head. If it lookes to hard, you could skip it, but a propane engine is more likely to blow a head gasket than straight petrol, because of the heat in the chamber. Perhaps that was Fords main reason for going to the dowels. Certainly use the alloy head gasket with any alloy head. It marks where the galleries and dowels go. Galleries shouldn't be an issue.

Backlash or Aussie7mains may have other ideas. These guys have had years of service work on Fords in Taxi service and performance applications, where as I've just been lucky enough to see the aftermarth of LP gas torchtowns and peoples stuff ups. (Some my own )

Keep on with the planning, and then proceed. We have a saying in the Roading industry. Pi**-Poor Planning breeds Pi**-Poor Results. You look to be ahead of the 8-ball already.

 

[Anonymous]

Dynoed 250.
Where do you purchase the re-build kits as mentioned in above. $500 for pistons to fit the 200 rods and everything else supplied is a great bargain.
My kit 250 2V was nearly that much with cheap $170 hypertech standard pistons. The cheapest I have priced the ACL pistons for the 200 rods was $380 with rings. Are they ACL and do they come with the lower comp dished piston they make.
Thanks Tim.

 

[Anonymous]

Sorry Mate, you did say ACL. I guess I could get them from any ACL supplier. Greatly appreciate the info.
Cheers