Valve train, intake manifold and header questions

Its not clear to me what valve train question you had.

One difference between the Performer & Air Gap manifolds, the Performer is heated with exhaust heat, the Air Gap doesn't have provision for that. Something to consider anyway.

If those are truly Australian heads there shall be extra material surrounding the exhaust port flanges, allowing any header to bolt up & seal around the port. So technically you could bolt any header to the heads. In general, the 2V heads, with 1.65" exhaust valves & smaller ports (smaller compared to the 4V heads) will tend to work best with smaller tube headers ... 1-3/4" OD for example.

-G

Hard to read the casting numbers in the head in your picture.

Here's a picture of the Heads from the AusFord Parts web page.

1.9:1 ratio on the rocker arms is kind of stressful on the rocker studs. You would be safer to run them with a stud girdle for durability.

You can snap the rocker arm studs with that much leverage on them.

> Crower enduro roller rockers with a 1.9 stamped on them.

Crower makes a 1.9:1 rocker for SBC applications that changes the pivot point
(backset 0.090" relative to their normal SBC enduro). Given that 2V heads
(Aussie or U.S.) peak at a relatively low lift, that's an odd choice of rocker.
Also, Crower sells the rockers in sets of 8 to be used on the intake side only.
On a head with decent exhaust flow (like a 351C-2V), a shorter exhaust ratio
(0.1 or 0.2 less) on the exhaust side generally works better. We tested and
verified that on the dyno mule 351C-4V.

It appears to me you have the Crane rocker arm guideplate conversion kit (p/n
52655-16 is for 351C but they also make another one for 429/460 BBF). This is
a bolt-on conversion that requires no machining of the cylinder heads. Crane
recommends the kit for open valve spring pressures of no more than 320 lbs.
To install the kit, you remove the stock valvetrain and chase the rocker arm
pedestal bolt holes with a 5/16" x 18 tap. Fel-Pro thread locking compound is
then used to hold the new studs in place. Curing time is approximately 6 to 8
hours. Crane recommends the top five head bolts be replaced with 1/2" x 4 1/4"
grade 8 Allen head cap screws since, with the rocker arm conversion in place,
it's almost impossible to put a socket on the original head bolts. You will
also need to check if your rocker arm pedestals are cut on a 90 degree or
dovetail angle. There is a different part number for each case. Since the
guideplates are plastic (Crane calls the material "Feflon", you can re-use the
stock, non-hardened pushrods, assuming they are the right length and up to the
spring pressure.

> They are in 2V heads that don't have a stamp in the corners so we think they
> could be the aussie 2v's.

They may also be 351M-400 heads. Larger cast-in raised numerals may be located
on the intake side at the top corners, near the valve cover rail. U.S. 351C-2V
and 351C-4V heads will usually have the raised letters. Boss 302 and 351M/400
heads may not. Aussie 2V heads may not have the numerals on the intake side
but the four that I owned have a smaller raised numeral on the exhaust side,
down low near a corner head bolt. The odd thing is that three of the Aussie
heads have a raised numeral 2 and the fourth has a raised numeral 4 (but it
still has 2V ports). I've heard of 3's in that location as well.

Note that most 351M-400 heads have a bad exhaust port. US 351C-2V and
Aussie closed chamber 2V heads have a nice smooth exhaust port. Most
(early 400 heads may be an exception) 351M-400 heads have a "potbelly"
port with the water jacket drooped down around the valve guide. You
can't grind the potbelly out because there's water inside it.

The closed chamber 2V's are from Australian 302C's (there are also open
chamber Aussie 2V heads from Aussie 351C-2V engines) and will carry an
ARD1AE casting code. The codes are located on the underside of one of the
middle intake ports and foundry marks (CC or CF for U.S. heads, GF for
Australia) are located in the rocker arm area. The Aussie closed chamber
heads I've inspected all have a sundial mark in the rocker arm area but
Steve Liebenow has inspected Aussie heads without the sundial mark.

> Is there a draw back to using the airgap if I don't turn up to the 6500 rpms
> it's rated for?

As George mentioned, the Air Gap doesn't have carb heat if that is important
to you. Also the Air Gap is substantially taller so won't fit under stock
engine screen. Other than that, the Air Gap will outperform the Performer
across the RPM range. If you want EGR (good for cruise MPG), a Holley Street
Dominator 2V has that feature, along with carb heat and will fit under a
stock engine screen. It's a single plane but in testing on a 393C with
ported Aussie 2V heads, it outperformed the RPM Air Gap from the lowest
RPM we tested (2500 RPM). However, I wouldn't expect that to be the case
on a mild 351C with unported 2V heads.

> Which headers would be best on these heads?

I ran Larry Stock's Hedman headers when I ran Aussie 2V heads. They had
1 3/4" primaries and a 2 1/4" collector. If the heads are really Aussie 2V,
the flange will seal against 4V heads (U.S. 2V heads may need some gasket
trickery to seal). Remember it's the ANSA mufflers that are the biggest
HP loss on the engine (50 HP loss on a 400 HP 351C dyno verified).

Dan Jones

Sorry that I didn't ask a good question. I guess I was wondering what the advantages to such lift would be and why someone would choose something like this when the company makes ford kits up to 1.8? The previous owner claims there is also a cam in there but didn't know which one. If you were choosing a cam for these rockers which one would you pick?

Now if the heads turn out to be the 351M heads, is there disadvantages or advantages to these vs. the other 2V heads that are out there?

With a 2.25" collector on the headers, did you run 2.25" exhaust pipe also or did you increase it to 2.5? I was thinking of doing a 2.5" exhaust system over the winter.

Thanks for all the great information. Its really appreciated. I'm still trying to learn all this stuff so thanks again.

Probably what is in there cam wise is a hydraulic lifter, 280 advertised duration, 224 or so at .050, moderate overlap, maybe 62 degrees.

Gives a rump rump muscle car sound, idles decent, peaks around 6000 rpm.

Lift is probably somewhere between .500 and .525 with 1.72:1 ratio rocker arms.

Installing 1.90 rocker arms gives you more valve lift without changing any of the other timing events.

With that ratio you increased the valve lift a little over 10%. So if there was a .525 lift, it's now at .5799". That's the reason the arms were changed, for more lift.

Even with the "good" Aussie 2v heads, a cam with that much lift is wasted. They top out pretty much around .500 lift.

All they are doing is making more valve train wear needlessly.

I'd change them to the stock ratio and sell those rockers on ebay. Someone will be interested in them.

It would be interesting to find out if the heads had port work done to them. With any 2v heads that would be a plus.

The 2v heads aren't my favorite. You can clearly see a car that has them, on a road course (race track) from a distance trailing the pack or noticeably down on power.

In a strictly street car, unquestionably they crispen the throttle BUT at the expense of the top end.

There are enough people using them in autocross or even circle track racing to show that they can support somewhere around 450hp with nice torque, so they definitely are not garbage at all, but they take a good deal of port work to make them acceptable. Out of the box, they are not.

They are just items never intended as high performance parts from a bi-gone era. There are so many better compromises available now in heads for the Cleveland.

I'd leave the cam in there and just change the intake and rocker arms UNLESS I was going to change the heads too. Then that's a different story and there are other considerations to make a viable package with complimentary components.

It all depends on how you see the nature of your Pantera and what you want to use it for. No one here can make those decisions and build it for you.

here's how to ID an Aussie cylinder head while on the car

http://351cleveland.wetpaint.c...rd+Aussie+302C+Heads

quote:

Originally posted by 4V & Proud:
here's how to ID an Aussie cylinder head while on the car

http://351cleveland.wetpaint.c...rd+Aussie+302C+Heads

Interesting, the sliced Aussie pic is mine originally... Still have the pieces somewhere.

thanks for all the great info. Under further investigation, it appears that I have the Aussie 302C heads due to the 3 scallops on the heads. It also appears to have some extra large intake ports. So with the new valve train and ported heads there seems to be quite a bit of potential here. The car had a performer 4V intake on it and I have a performer 2V to install. The 4V intake appears to be port matched to the heads, and the 2V is straight out of the box. I'm thinking of installing the 2V intake until I can figure out how to seal the fuel injector bungs that have been welded onto it. I don't necessarily want to weld them closed in case I decide to revisit the FI world again.
Fun stuff thanks again. I'll try to remember pics tomorrow.

what old fuel injection system were you using and why do you want to go to a carb now?

I'm not sure of the injector brand, but the ecu was from TEC. It was so old that my tuner's oldest software was still too new to interface with my computer. When we contacted TEC, they were optimistic at first but quickly were less than helpful. I then started to have some fuel issues where the car was unreliable so instead of upgrading the ecu, I thought I'd return the car to a more original state.
I have not totally abandoned the idea of EFI but for the time being I'm going with the proven reliability.......