possible bad news

87IrocTim · Member Joined: 10 Jan 2006 Posts: 448 16836.12 points

i think it will be very practical and kick up my numbers quite nicely. that price does seem abnormally low, but shit im not complaining.

artinla · Posted: Wed May 24, 2006 11:46 pm Post subject:

I know that these aren't assembled, but this is also a great deal considering the CNC port work alone would normally cost this much. The flow numbers are pretty good.

http://cgi.ebay.com/ebaymotors/CNC-ALUMINUM-HEADS-CAMARO-SB-CHEVY-SBC-350-383-400-RP_W0QQcmdZViewItemQQcategoryZ33617QQitemZ8037883357

Aerosmith · Posted: Thu May 25, 2006 8:23 am Post subject:

Just my opinion, but those $899 complete heads are waaay too small for what you have. Depending on your future plans, I would set 180cc as a bottom end and 215cc as a top if you are going to get serious. There are going to be proponents of alum vs iron and different opinions on port size and shape. do some reserch before you spend your money.
Pay attention to angle vs straight plug because some headers won't fit angled. On assembled heads make sure you know what you need as far as spring pressure, you will ruin your valve train with too much or too little pressure. Also check around (other bulletin boards) and ask about peoples experience with different brands of heads, just because it's "CNC'd" doesn't mean it is a good head..all cnc means is that someone ported a head and they used it as a model for a computer program to cut a million exact copies. You could cnc a turd, it wouldn't make it anymore than an exact copy of the parent turd.
Doesn't mean that it can't be good and inexpensive at the same time, just reserch before you buy. Chances are this will be the biggest single purchase you make for your engine, make it wisely.

87IrocTim · Member Joined: 10 Jan 2006 Posts: 448 16836.12 points

your exaclty right which is one of the reasons of why im here. I thought 160cc seemed a little small too but i would be still way improving what i am coming from. i would probably be most comfertable with 180cc runners. ill keep looking and asking around definitely, this will probalby be going down during fall and throughout the winter.

artinla · Posted: Thu May 25, 2006 8:29 pm Post subject:

For a 305, the 180's would be appropriate. For a 350 I agree that you might want to think about 190's or 200's.

As for the CNC'ed heads that I linked above, the flow numbers are good and I have personal experience with the pro-comp castings. I am not saying that they are the best, but they are pretty damn good for chinese (they say australian, I say BS) castings. However, if the porting was of no concern, I would buy the sportsman II's or a set of AFR 195's because they flow best out of the box with only slight massaging.

87IrocTim · Member Joined: 10 Jan 2006 Posts: 448 16836.12 points

my worries with the sportsman II's is because they are iron, if i got the 64cc chambers would i be risking some problems with compression? the car is strictly 93 gas because of issues with the new ethanol.

af2 · Posted: Fri May 26, 2006 5:19 pm Post subject:

87IrocTim · Member Joined: 10 Jan 2006 Posts: 448 16836.12 points

im gonna have to take your word for it.

af2 · Posted: Fri May 26, 2006 6:43 pm Post subject:

SMOKEmUP · Posted: Fri May 26, 2006 11:13 pm Post subject:

The larger volume, the bigger cross sectional area of the cylinder head. The bigger the cross sectional area the slower the velocity. The goal is try to optimize the velocity to point where the volumetric efficiency peaks. This is usually around 0.6 mach.