For a mostly stock(bigger cam,carb,intake) engine, will the 2v heads or the Aussie heads really make much or any of a difference over the 4v heads? What should I expect to pay for a set of Aussie heads?
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Aussie heads WILL make a difference, for nothing else because they will boost your compression ratio significantly. Having much smaller combustion chambers, you can expect perhaps a couple of points higher compression, although you'd have to calculate the exact number based on your engine.
The least I've seen for Aussie heads is $350 the pair, requiring everything. Getting a set that has been rebuilt and is ready to bolt on may be $1500, and depending on what else you have done (porting, etc) can be much more. Prices tend to vary GREATLY for the same thing, so it pays to shop around.
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Charlie McCall
1985 DeTomaso Pantera GT5-S #9375
"Raising Pantera Awareness across Europe"
http://briefcase.yahoo.com/gt5s_1985
The least I've seen for Aussie heads is $350 the pair, requiring everything. Getting a set that has been rebuilt and is ready to bolt on may be $1500, and depending on what else you have done (porting, etc) can be much more. Prices tend to vary GREATLY for the same thing, so it pays to shop around.
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Charlie McCall
1985 DeTomaso Pantera GT5-S #9375
"Raising Pantera Awareness across Europe"
http://briefcase.yahoo.com/gt5s_1985
Be aware that this is a simple question with a book-length answer. Before deciding to change cylinder heads on your car, first ask yourself what you expect from your Pantera, which in well-tuned almost-stock form, will equal or exceed 150 mph while out-handling & out-braking any same-year 'other-make' car on the road, and still get 20 mpg. All a changed- head can do is give you more of the same (except gas mileage). OK- once you decide that you do want 'more', you have 5 choices in no particular order:
1)-Aussie 2V closed-chamber heads
2)- U.S. 1970-71 4-V closed chamber heads
3)- 2-V open-chamber heads (which may come from Australia but are virtually the same as U.S. truck heads available in wrecking yards for $25 each)
4)- U.S. 4-V open-chamber heads (all 351-C engines '72-up)
5)- aluminum 'SVO' racing heads of nine different varieties.
All the above heads have at least one good point and one or more bad points. As mentioned, the open-chamber 2V heads are very cheap, while aluminum racing heads may cost up to $4000 to get them bolted to a running engine. The old saying is, "Speed costs money; how much you got says how fast you'll go!" This was only a brief summary. I suggest you search the archives here and on the DeTomaso Forum for 'Cylinder Heads'. Bring a comfortable chair and a bottle of water....
1)-Aussie 2V closed-chamber heads
2)- U.S. 1970-71 4-V closed chamber heads
3)- 2-V open-chamber heads (which may come from Australia but are virtually the same as U.S. truck heads available in wrecking yards for $25 each)
4)- U.S. 4-V open-chamber heads (all 351-C engines '72-up)
5)- aluminum 'SVO' racing heads of nine different varieties.
All the above heads have at least one good point and one or more bad points. As mentioned, the open-chamber 2V heads are very cheap, while aluminum racing heads may cost up to $4000 to get them bolted to a running engine. The old saying is, "Speed costs money; how much you got says how fast you'll go!" This was only a brief summary. I suggest you search the archives here and on the DeTomaso Forum for 'Cylinder Heads'. Bring a comfortable chair and a bottle of water....
That was'nt even much more than a chapter Jack. I was hoping for more from you.........
So I'll take the liberty if i may to quote Pat Ganahl on the subject:".....Ford had learned by then that cylinder hds. make an engine.And short of an all out hemi-head, the Clevelands are just about the ultimate in factory production configerations.....the Cleveland head is the ultimate refinement of the 'poly-angle" chamber design as well as the ultimate in " bigger is bettter" thinking for portsize and shape....they're all good......" - this from his very readable Ford Performance Book,-going on to point out the superiorities of the 351C over the Chevy he goes on to say that; " ..for anything short of Pro Stock compition, you cant improve on the performance of the 4V hds.(porting & polishing is actually discouraged).."
As an aside,I spent many months tracking down the right heads for my purposes,(finishing up a Gr4 replica)and eventually had to buy a complete motor just to get the heads;4V closed-chambered (62.4cc).I was determined to find a set of these ellusive beauties having read Pat Ganahl's lyrical description of them; ".....the quence- chamber is so named because it tends to actually extinguish the flame-front as it travels to the corners of the chanber because the quence area remains relatively cool.This helps reduce detonation or "pinging" in the cylinder.." and a greater advantage even than that, he mentions later ; ".....creates turbulence in the chamber, which improves mixing of air & feul,especially at lower rpms. This in turn yeilds more complete combustion and greater low- and mid range torque....."
The other great advantage of course over the Chevy is the equal length runner intakes compared to the Chevy 's un-equal length, siamised intakes...( At a Cobra Shoot-Out day here recently I was astonishde to see only 2 out of the over 30 Cobra's there had Ford power...........) Enjoy, tai
So I'll take the liberty if i may to quote Pat Ganahl on the subject:".....Ford had learned by then that cylinder hds. make an engine.And short of an all out hemi-head, the Clevelands are just about the ultimate in factory production configerations.....the Cleveland head is the ultimate refinement of the 'poly-angle" chamber design as well as the ultimate in " bigger is bettter" thinking for portsize and shape....they're all good......" - this from his very readable Ford Performance Book,-going on to point out the superiorities of the 351C over the Chevy he goes on to say that; " ..for anything short of Pro Stock compition, you cant improve on the performance of the 4V hds.(porting & polishing is actually discouraged).."
As an aside,I spent many months tracking down the right heads for my purposes,(finishing up a Gr4 replica)and eventually had to buy a complete motor just to get the heads;4V closed-chambered (62.4cc).I was determined to find a set of these ellusive beauties having read Pat Ganahl's lyrical description of them; ".....the quence- chamber is so named because it tends to actually extinguish the flame-front as it travels to the corners of the chanber because the quence area remains relatively cool.This helps reduce detonation or "pinging" in the cylinder.." and a greater advantage even than that, he mentions later ; ".....creates turbulence in the chamber, which improves mixing of air & feul,especially at lower rpms. This in turn yeilds more complete combustion and greater low- and mid range torque....."
The other great advantage of course over the Chevy is the equal length runner intakes compared to the Chevy 's un-equal length, siamised intakes...( At a Cobra Shoot-Out day here recently I was astonishde to see only 2 out of the over 30 Cobra's there had Ford power...........) Enjoy, tai
Throttle man e-mail me I may know of a set . ontherdagain@usa.com
Tai, if you wish to get deeper into the subject of closed-chamber heads, I'll give you another reference book: 'Racing Engine Preparation' by Waddell Wilson of NASCAR fame (Steve Smith Autosports, publisher). In it, Wilson talks about 'posting' Boss heads, to keep the combustion chambers from flexing and reversing water flow through the engine at high revs.... In the April POCA newsletter, I sawed apart 3 cracked Cleveland heads and wrote an article on the coring, cooling mods and a pictorial of the miserable oil drain-back holes we have to deal with. I also showed the effect of such 'posting' supports and the somewhat controversial subject of adding air-bleeds to the back of 351-C heads to prevent spot-overheating.