The guys with the Hemi 99's have you ever had the heads flowed?

Do all the newer 4.900 99's use the 2.560 intake valve?

Thanks

580cfm was a good number awhile ago,, now its probably 600-620

2.560 was the std valve size back awhile ago aswell,, but i know things are bigger now

Well they do not use the 99 Hemi any longer. They have a new symetrical port head these days. FWIW my 99 uses a 2.55x6.830 valve. As for flow 570-90 seems typical.

My heads are Nickens circa 2002-03 and go 590 @ 1.060 with a 2.540 intake. They have a D-shaped intake port.

I just read something about that over pon Allpar, but they didn't have any pictures. Does it still have the layout like the 99 HEMI or is it different? Does anyone have any pics? Per Allpar it sounds like they will be using both heads for the 2012 season.

Are the numbers that were given max flow at past an inch lift or??

They are now a true symetical head. Not asyemtrical like the older stuff. On other words more like a DRCE(GM) head. Saw the new head at SEMA. The valve layout is diiferent in other owrds. They are IEIEIEIE, Not IeeIIeeI like the 99 head is. If anyone wants I can take pics of my stuff.

I for one would like to see it. Dave

Sort of off topic, but what bolt pattern is on the back of the blocks? Is it the GM pattern or Mopar?

How many different versions of these heads have they made and what are the differances. I had read some thing about rocker stands (1,2,or 3) bolt. Is the head bolt pattern the same? How about bore spacing? Just trying to learn more about these motors. Thanks for any info.

Well the 99 Hemi no longer exists really. There were revisions made in 06 and that head is seems to be referred to as an 06 Hemi. As for the rocker hold donw I beieve it is 2 and four bolt stuff. Four bolt being the newer pieces. I believe that was a fairly early pon change. BUt dont quote meon this stuff but it is what I have been told. Spoke to Joe Jolly and Rick Water this past week about the heads and this is what I recall. Now they have gone to the symetrical stuff for this coming season.

MR 340,
The skirted blocks have a BB Mopar bellhousing pattern. The newest block is non skirted and I dont think it is the same bell pattern. On the skirted blocks you have the option of using the Mopar starter or the Hemi 99 specific starter. Just need to have the correct ring gear tooth count for the starter you are using.

Other than skirted and nonskirted blocks are there diferences. Different headbolt pattern,cam height,newer desigin,etc.Sorry for the hyjak but this has been bugging me for awhile.

I think there was was 7 and 9 cam bearing options, the later having the extra cam bearing journals. Could someone verify this?

I also find it interesting that they have gone away from the mirrored port layout and to the symmetrical port. Was the mirrored layout a fad?

There are five and nine cam bearing blocks. The first blocks were skirted five cam bearing and used Jesel Dogbone lifters. They had bosses cast in and machined for the guide hardware. The second version is skirted five cam bearing but uses keyway lifters. Third is skirted nine cam bearing for keyway lifters. The most recent is non skirted nine cam bearing and keyway lifters. The first three versions had 60mm cam tunnels. The newest is 70 or 75mm, not positive. They found they needed the nine cam bearing deal once they really started spinning them.(9500 plus rpm). Also remember the heads are rough castings when the teams get them so dont assume that any piston will work with any head. The builders all have different ideas on valve angle and placement. Here are the flow #s from my Nickens heads.
Intake Exhaust
.100 75 58
.200 159 127
.300 263 182
.400 348 218
.500 437 253
.600 492 304
.700 533 326
.800 558 337
.900 573 345
1.00 586 354
1.06 590 356
This was on a Superflow 600 flow bench,4.625 bore adapter,2 1/4 pipe .600 and up on exhaust. 2.540 intake, 1.800 exhaust. As stated in my other post they are from Nickens program circa 2002-2003. Also I think they are going to the symmetrical port layout to separate the exhaust ports and provide better distribution in the intake. Just my thoughts.

Not sure how pretty they are but here goes. These are Schumacher heads that from what I understand were Jeg's last set, who knows though.