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RHS MA-X 20300 REAL flow numbers #1101340
10/25/11 11:37 AM
10/25/11 11:37 AM
Joined: Dec 2008
Posts: 37
Pittsburgh Pa
b5fish73 Offline OP
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b5fish73  Offline OP
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Pittsburgh Pa
I decided to go with RHS magnum heads for my 408 build based upon flow numbers Ive been reading about. I know I'm probably going to get a lot of flack about the bench I had them done on being conservative, but take of it what you may. RHS 20300 cut for 2.02 intake with stock exhaust valves, ported and by Toth Performance in Eau Claire PA. I think these numbers are more realistic of what the heads actually are. These are very nice heads, I've just been reading too much about them being more than what they really are.
As Cast 1.92int -- Ported 2.02int
---- Int----Exh----Int----Exh
.100 67.4 - 62.2 - - 72.6 - 64.7
.200 115.1 - 111.6 - 133.6 - 113.1
.300 163.0 - 151.2 - 188.6 - 156.2
.400 190.2 -172.5 - 230.0 - 188.1
.500 205.2 - 178.4 - 248.1 - 190.2
.600 212.0 - 178.9 - 257.5 - 193.0
.700 ------ ------ - 261.1- -----

6887704-MopartsFlow.pdf (142 downloads)
Last edited by B5Fish73; 10/25/11 12:01 PM.
Re: RHS MA-X 20300 REAL flow numbers [Re: b5fish73] #1101341
10/25/11 11:39 AM
10/25/11 11:39 AM
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Posts: 9,146
Now - Port Orange,Fla. Former...
MIKES_DUSTER Offline
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MIKES_DUSTER  Offline
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Nice numbers but I think someone like Brian from IMM could get them up.

Re: RHS MA-X 20300 REAL flow numbers [Re: MIKES_DUSTER] #1101342
10/25/11 11:45 AM
10/25/11 11:45 AM
Joined: Aug 2004
Posts: 2,128
sweden
S
sshemi Offline
top fuel
sshemi  Offline
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sweden
I got mine to 298 cfm with a 2.055 int valve at 0,515 lift but they are dead after that

Re: RHS MA-X 20300 REAL flow numbers [Re: sshemi] #1101343
10/25/11 11:49 AM
10/25/11 11:49 AM
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Branson, Mo.
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joedust451 Offline
super gas
joedust451  Offline
super gas
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Branson, Mo.
I think Brian got his in the 270s with the 2.02 valve, & there was a bit left in it.


75 Duster, 451 10.87 @ 123.58 NA 97 Z28 6sp., 12.01 @ 115 on a 100 shot 71 Swinger. 360 magnum. 12.58 @ 105 78 cutlass, 469 BBC. 12.70 @ 108 on street tires. http://www.youtube.com/watch?v=Z2kqNmMfheU
Re: RHS MA-X 20300 REAL flow numbers [Re: joedust451] #1101344
10/25/11 12:07 PM
10/25/11 12:07 PM
Joined: Dec 2008
Posts: 37
Pittsburgh Pa
b5fish73 Offline OP
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b5fish73  Offline OP
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Posts: 37
Pittsburgh Pa
I agree. I have a lot left in these heads, I had them matched to my cam rather than trying to get the absolute most out of them. Ive been seeing a few flow charts from some reputable resellers claiming 252 cfm on the intake at .500 lift with a stock 1.92 valve. Just want to make sure everyone is comparing apples to apples when looking at stock numbers. Again, dont get me wrong, these are great heads... I just dont want anyone to think that these are more than what they really are.

Re: RHS MA-X 20300 REAL flow numbers [Re: b5fish73] #1101345
10/25/11 12:31 PM
10/25/11 12:31 PM
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Posts: 5,484
SoCal
Brian Hafliger Offline
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Brian Hafliger  Offline
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On my bench an OOTB RHS head with a stock 1.92 valve goes 244-246 cfm from .500 to .600 lift. That's it.
Once we do the 2.02 valve and blend they will flow on my bench, mid to high 260's @ .500 and high 260's to low 270's @ .550 lift.

My basic porting get them in the 280's @ .500 and 290's @ .600 lift.
Brian


Brian Hafliger
Re: RHS MA-X 20300 REAL flow numbers [Re: Brian Hafliger] #1101346
10/25/11 07:32 PM
10/25/11 07:32 PM
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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joedust451 Offline
super gas
joedust451  Offline
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Branson, Mo.
Quote:

On my bench an OOTB RHS head with a stock 1.92 valve goes 244-246 cfm from .500 to .600 lift. That's it.





I agree, & the way my mild 360 magnum performed i was very pleased with them OOTB.


75 Duster, 451 10.87 @ 123.58 NA 97 Z28 6sp., 12.01 @ 115 on a 100 shot 71 Swinger. 360 magnum. 12.58 @ 105 78 cutlass, 469 BBC. 12.70 @ 108 on street tires. http://www.youtube.com/watch?v=Z2kqNmMfheU
Re: RHS MA-X 20300 REAL flow numbers [Re: joedust451] #1101347
10/28/11 03:43 PM
10/28/11 03:43 PM
Joined: Dec 2008
Posts: 37
Pittsburgh Pa
b5fish73 Offline OP
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b5fish73  Offline OP
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Pittsburgh Pa
If youre seeing 244-246 ootb and im seeing 205 ootb at .500, then my heads may be doing alot better than the 250 range ported from the bench I had mine on.

Re: RHS MA-X 20300 REAL flow numbers [Re: b5fish73] #1101348
10/28/11 07:05 PM
10/28/11 07:05 PM
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Posts: 5,484
SoCal
Brian Hafliger Offline
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Brian Hafliger  Offline
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SoCal
Quote:

If youre seeing 244-246 ootb and im seeing 205 ootb at .500, then my heads may be doing alot better than the 250 range ported from the bench I had mine on.




Most likely however that's very low flow #'s so I'd look for something wrong...JMO!


Brian Hafliger
Re: RHS MA-X 20300 REAL flow numbers [Re: Brian Hafliger] #1101349
10/28/11 08:13 PM
10/28/11 08:13 PM
Joined: Nov 2004
Posts: 3,544
Syracuse,NY
CompWedgeEngines Offline
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CompWedgeEngines  Offline
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Syracuse,NY
As Brian says, if your getting 205 on those heads, you have a serious problem. Is this a " known" flow bench?


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