1. Standard Intake and exhaust port locations will fit ALL factory style intake and exhaust manifolds GUARANTEED.
2. 300cfm of airflow at just .600” lift
3. 3V combustion chamber provides the most efficient burn characteristics and detonation control on the market today.
4. All new 220+cfm “UNI” Exhaust Port will fit either 2V or 4V headers with NO port matching, and features true Standard Height Exhaust Port & bolt locations.
5. 5/8” Thick Deck for positive head gasket retention and ideal for all nitrous and blown applications.
6. Standard head bolt lengths.
7. Fully CNC machined in house.
I saw this recently as well and began wondering where this left the "185" series head.The 185 head does have a raised inlet port location and exhaust as well but it appears that the new head is at the very least able to keep up on the flowbench. Which begs the question.Does raising the entry inlet as has been done to the 185 actually translate into a better design head or does the raising have negligible effect on the outcome?Conversley do the flow numbers mean little if nothing to the actual performance of the head/s.If one where to look at raw numbers alone the new head appears to be better on paper and the advertising alongside says that it can support 600hp whereas the 185 is rated at 590 hp.
It would be interesting for john to do a comparo between these two heads.My belief is that the new head is solely aimed at those who a keen on using their existing manifolds so the changeover costs are kept to a minimum.I,m no expert on cylinder head design but i would have thought that a higher entry and smoother more gradual turn [ aka 185] would ultimately make for a more superior head.
So what is to be gained from changing from iron 2v's to alloy ? i can see a higher compression ratio and a better port design, but is that enough of a gain to warrant spending the $ ?
What is the price on these heads bare/complete ?
Member of the the Trans Pacific Moderator Tag Team
Also broader torque curve and more power using the same camshaft in most cases. I'd expect that at the very least. The main benefit would be for people that haven't got modified heads. For those that have there is increased in other areas.
Prices definately far out weigh any reason to bother modifying 2V cast iron heads.
Bare Pair $AU 2150 (inc. GST)
Complete Assembled Street Package up to .600 lift* $AU 2650 (inc. GST)
Complete Assembled Competition Package up to .600 lift** $AU 2850 (inc. GST)
Complete Assembled Competition Package up to .650 lift*** $AU 3050 (inc. GST)
I checked the site earlier today and was pretty impressed. Although I was suprised that the cast iron heads are dearer than the alloys!! Anyway, the cost of a dressed pair of alloys is an absoliute bargain when you weigh it up against parts and machine work on a pair of factory 2Vs (or 4Vs for that matter). I now have a good idea what will be sitting atop of my next engine. They will look absolutely brilliant, and performance won't be an issue.
One question but, I couldn't find chamber size on the CHI site, what are they ??
I have a set of these heads arriving in a week or so. John told me the chambers were 65 CCs but if i wanted a different size it was simply a case of asking for them.
I have a stock standard 73 cobra jet motor with 90,000 miles on it. It has dished pistons and the 65 cc heads won't give me the compression I'm going to need. John suggested reducing the chambers to minimize fitting cost but that will foul things up later on when I rebuild the bottom end. I plan on using about 11:1 compression with flat-top pistons. This will allow me to maximise quench and swirl giving me a better burn.
According to the hi-compression experts, providing I keep the areas outside my principal combustion zone less than 60 thou, my chances of eliminating pinging are increased.
For the time being I'm going to either re-ring the motor and replace the dished pistons with flat-tops or rebuild the bottom end completely with a blue print and all the goodies. Its going to depend on how things look when I go investigating. And of corse my finances.
Chamber size varies. Even different valve types will vary it. For example on mine John told me they'd be 64cc. When CC'd they were 60cc due to the valves not being concave etc. My chambers are now about 58cc as I had the heads decked but was too lazy to check. I knew the slight raise in compression wouldn't hurt. I had 11.2:1 prior (pump fuel).
if/when i buy some of these or other alloy heads would they make my new ford motorsport roller rockers scrap as they are desgined to bolt right onto std heads without machining for studs etc? as the aloys i think are allready machined
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