Short story is the AFD is chasing CHI for flow. The CHI's flow more. More flow = more power.qwikcorty said:why do u say they are only good for 500hp with your setup? why is the chi's better for you?
do u think $3160 is a good price for these heads complete?
All sounds good for cleveland users. Just have to wait for testing to see if they work well. My guess is yes they'll work nicely anyway. I'd like to see a set firsthand to look at the port work.qwikcorty said:in their web page it says they've delevoped a 4v alloy head with 700hp flow! its in the coming soon section.
Yes, The manifold holes in the head didn't line up. The reason for this is CHI designs their heads only to take their CHI manifold. In short busted a bolt trying to get a manifold on. Too much side pressure.RevHeadRon said:but brenx didn't you have some problems with your alloy heads when you first fitted them?
Heated them up with a oxy and bent them downward. They needed to be bent downward where they run under the floor. Had to bend them as they fouled the floorpan. The reason the 4070's need to be bent is the 2V port is in a slightly different position than the 3V's port. The 3V's port is 5mm higher than stock 2V. 4V extractors 4075 hang lower from the factory, so it's not an issue.RevHeadRon said:i'm not exactly sure what you mean by bending the extractors down 10mm, how did you go about bending the extractors? where and why did you have to?
Nope, no drama's with exhaust manifold bolts etc. Yes, they accomodate for alternators/power steer/aircon etc. I run power steer myself.RevHeadRon said:ok now i get it, down at the floorpan, i thought for a second you meant like bending something up at the manifold surface, like where it bolts on or something that would be scary.
so there was no drama with the bolts for the exhaust manifolds
do the alloy heads have accomodation for alternators and powersteering pumps and stuff like that?
the reason i ask is that my father owns a T'Bucket hot rod, the motor we had built is meant to be good for 400hp with his cast heads (ported 302 heads) he wants to now upgrade to alloys he he more power, and i'm just curious if the $2000 exhausts we had made will still be useable?
I have seen a set of CHI's bolted into a '48 ute "hot rod" that had custom 4 into 1's made for stock heads. They bolted up to the heads OK as the pattern is the same, problem was because the ports are higher the backing plate (if thats what you call it) that bolts to the head now covered the spark plugs and the plug leads couldn't go on as the top of the plugs was right behind the backing plate. This would also necessitate removal of the extractors to change plugs. Therefore, custom extractors fitment to CHI's will depend on the design of the backing plate.RevHeadRon said:the reason i ask is that my father owns a T'Bucket hot rod, the motor we had built is meant to be good for 400hp with his cast heads (ported 302 heads) he wants to now upgrade to alloys he he more power, and i'm just curious if the $2000 exhausts we had made will still be useable?
Any 2V manifold will bolt up. Thats what the 2V adaptors for. Although I wouldn't recommend using a 2V manifold and adaptor. 4V manifold is better and doesn't require the adaptor. Same goes for extractors. 4V is what the heads are designed to accept. Hence when CHI did their testing they had no issues.shaynet said:CHI's are definately not a drop in and drive proposition at this stage. As Brenx experienced, most extractors will need some modification down the bottom to clear the floorpan and bolt up to the rest of your system.
Also, your inlet manifold will not bolt up to the CHI's because the inlet ports are higher up the head which makes the gap wider. CHI supply a spacer which goes accross the valley and up the inside face of the heads. This is required until their inlet manifold becomes available.