Give me your best GUESS.

[TomO]

Well Guys, the racing season is over and I the dream of building a 409 is back on center stage in my mind. Don’t laugh – I cant help it BUT, I am playing around with a dyno program and need to know if the head flow numbers that I am using are in the “ball park”. I will probably have to use a set of ported/large valve 333 truck heads on my dream engine. Please take a look at the default flow numbers that my dyno program uses and give me a guess if either is close to a set of reworked 333 heads. Info is in 25.0” H20.

Option #1
Lift int cfm exh cfm
.200 119 87
.300 157 104
.400 190 111
.500 196 117
.550 196 117

Option #2
Lift int cfm exh cfm
.200 130 101
.300 177 133
.400 217 153
.500 239 164
.550 242 164

I realize that the dyno program is a huge guesstament. I am using it to compare cams/compression ratios/stroke and look for trends that might lead me to make a better choice when it comes time to actually build the engine and the rest of the drive line. Of course I will confer with the experts, but I would like to play a little and see what I come up with.


TomO

 

[Va348]

Hi Tom


Does anyone near you have a flow bench? If they do, take a head, Intake to them and flow it that way,Those programs are very close if you do that way. Perf trends is about the best one out there at a good price. Put a clay radius around carb pad holes.

If you do not have a flow bench close I would use # 2 and take 10- 15% off for intake manifold , If you are using Perf trends put # 2 on heads then coff eff on intake of 1.5 or 2. no more. Are you doing a 348 or 409 Do Not automatic put big Valve in. Its not allways the best way to go.

IF You can flow intake and head together Its worth it. IF not try use eng. stock cam spec. and comp ratio and adj head flow untill it maches factory spec. TQ&HP would prob come out close.

If you need any help let me know.

Dale

 

[raymar58409]

dyno program

If you are using dyno 2000 simulator as I have, one thing I found is that it seems like the actual set-up we run in our late model engine comes out pretty close to the dyno. However when I let it choose what it considers to be an ideal cam it goes the wrong way, way wrong, it could be I'm doibng something wrong. When I get a chance I'm gonna play with it some more. We know what our heads flow and I'll try it the way you are doing it and see how the floww numbers come out. Never really tried it that way as we always knew our actual flow numbers. I'll let ya know what I find.

Happy T'day

Ray

 

[tripowerguy]

Hey Raymar You asked about the 58's up by Joplin, I got 2nd hand info that he wants to sell the whole works for $9000. The thing is that there is not a running car in the bunch. To much money for parts and not end up with a running car. Roy

 

[raymar58409]

Tripower, Thanks for the info.

Ray