Shop A is asking $3500
Shop B is asking $3600
Shop C is asking $3550
If all you based your head purchase off of was flow numbers, which set of heads would you buy and why? Keep in mind, you have no idea they are all the same set of heads. This is the first time I have been able to make a comparison between three bench's and I find these numbers very interesting. One mans 374 is another mans 364. One mans 41 is another mans 66!
I don't think any of us would know..most of what we buy is from what that person reputation is, and that's the problem. You have no idea what
your getting. There's so many variable's that they can easily say..this is
off that is wrong and that's why your not running the numbers.
Over the past 10 years..I've probably had heads done by everyone
in the Pontiac coummnity..Butler...KRE..RRE and have had the opportunity
to flow one against the other on the same bench..same day. I figure that's how you learn..most of it came from helping/doing motors for friends
almost for free.
After seeing this..I won't buy heads from either of them again. The ports were totally inconsistent from port to port. The best set believe it or not
was RRE..they were suppose to be CNC ported..they weren't. At the time
I was doing two motors for friends...they were exactly the same combination carb to pan. But two totally different cars.
They both agreed to use both their sets of heads for the dyno test to see which heads were actually better. We dyno the motor with the only changes being made where the heads...KRE heads frist then swap to RRE heads..when we put on the RRE heads..it made 75 more HP!
We where blown away. They ague between the two of them which heads
was the better set of heads. Of course I knew because we flowed both heads
same day same bench.
But that motor was going in a back halve car and the RRE heads went
in a stock suspention car. The back halve car was my old car. He was running 10.30's with the motor I built..which was a 462 with ported R-Air
1V heads... they only flowed 265 cfm. It ran 10.30's with a Torker 1 intake and a two inch spacer to a dominator.
He went with KRE's whole top halve..Victor intake port match to there heads and the cam they pick. I think he spent a total of $4500.00 for every thing. it was suppose to be granteed to run 9.80's - 9.90's all he
wanted was to run in the 9's..wanted that 9 second time slip. The best
it would ever run is 10.10's...LOL So he pick up 2 tenths over the r-air
1V heads....LOL while others pick up 5 tenths over R-Air 1V heads
We heard every excuse in the book..the car had 4:56 gears...they said
nope...you need to go to a 4:10 gear...So I ran it though Perfomance Teands sim...I have both the Engine Dyno and Drag Race Dyno. What
it told me was with the gear change the car would lose 1 tenth...sure
enough it did. Then came more excuses...but finally Mike who was very interested in the out come..said hey lets put my head on..and see what
happens. My thorey it wasn't making enough power so it needed the 4:56
With out changing out the 4:10 we bolted Mike's heads on..frist pass
it went 10.00 the best past of the day was 9.80 I foget how much mph
it pick up...but I think it went from 126 mph to 132 mph..don't really
Get this KRE's head flow better the RRE heads..not by much..I think
10-15 cfm more...But RRE ports were with in 5% of each other..where
KRE were all over the place..some 20 cfm less then other ports. What
we did find though..the R-Air heads had a 62 cc chamber KRE's had
72 cc chamber.. So while they where off I had them cut down. I thought
to myself..well there's the problem.
We put them back on..and he pick up 1 full tenth..and ran a 10.00
so yeah I can agree with you and Dan..flow numbers aren't every thing.
But when I use flow numbers I'm asuming that the heads have good
ports. It's easy to see how they sell heads base on flow numbers. You
learn the hard way about flow numbers.