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B1 BS vs Edelbrock Performer RPM vs 440 Source Stealth

  
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B1 BS vs Edelbrock Performer RPM vs 440 Source Stealth

 
IQ52 IQ52
Guru | Posts: 860 | Joined: 06/10
Posted: 03/16/12
07:18 AM

I wish I could afford to buy a B1 BS head to test but the bare unported version lists for $1008.43/ea and the bare CNC ported heads list for $1674.04/ea, so I pulled the flow figures from their website.

The ported flow figures for the Stealth and Edelbrock heads were taken from heads ported in our shop yesterday.

.......B1 BS stock...CNC ported...Stealth stock...Ported...RPM stock...ported

.100"......NA..........NA..................67................71.............71..........73
.200".....145.........145................142..............153...........155.........152
.300".....204.........214................205..............217...........205.........216
.400".....249.........267................240..............265...........252.........265
.500".....284.........305................255..............301...........275.........301
.600".....294.........337................267..............331...........286.........333
.700".....295.........348................268..............344...........287.........350

While this will not change the course of the world's orbit, it does go to show that the RPM and Stealth heads are pretty equal and far better than anyone may have suspected.  

451Mopar 451Mopar
User | Posts: 220 | Joined: 07/10
Posted: 03/16/12
08:04 PM

The B1 BS heads flow pretty close to the RPM heads.  When they came out, in the early 1990's the closest competitor head was the Mopar Stage VI, which flowed even worse out of the box. There was also the Indy 440-1C, the aluminum 440-1, and the Stage V Hemi conversion head.  The 440 SR, and Edelbrock RPM were not on the market till several years later.  

Budnicks Budnicks
Guru | Posts: 1497 | Joined: 08/10
Posted: 03/17/12
03:08 PM

I thought the Indy-B1-BS heads were better than that, it's been a long time though... How come you din't list, the RPM's Ported the E-Street or the Victor's Stock & Ported...LOL... IQ52 I'm just busting your chops, yanking your chain, pulling your leg, thanks for the posting, it's always good information to know... Man your getting a great stock of sample porting heads...  
"Fill Your Library Before You Fill Your Garage" Good Luck  "Budnicks"

451Mopar 451Mopar
User | Posts: 220 | Joined: 07/10
Posted: 03/18/12
09:27 PM

Question for IQ52?  What bore size do you use when flowing heads?  Also, do you modify the port entry?  I'm asking because I have flow numbers on my B-1 BS heads and the 440 Source Stealths, and the flow numbers seem a bit lower than I expected?
The flow sheet says the bore size used when flowing the heads was only 4.30"?
Intake....B1 BS Koffels Stage1.....Stealth mild porting
.100".......80........................82
.200"......145.......................157
.300"......194.......................221
.400"......235.......................260
.500"......265.......................278
.600"......279.......................283
.700"......291.......................289
.800"......293.......................289

Exhaust...B1 BS Koffels Stage1.....Stealth mild porting
.100".......72........................81
.200"......111.......................127
.300"......140.......................151
.400"......155.......................174
.500"......187.......................190
.600"......200.......................200
.700"......219.......................211
.800"......228.......................215  

IQ52 IQ52
Guru | Posts: 860 | Joined: 06/10
Posted: 03/19/12
07:54 AM

The last post on the second page of the 440 Source Stealth Heads thread that I just bumped, has flows for the Stealth with the stock port window and the second column is with a port window modified to be between stock and Max Wedge in height but still the stock width. The first page will give box stock Stealth flows and slightly ported flows from our bench, on stock intake windows.

My flowbench is something I received from my father when he died. He never left anything stock. It has a 4.25" bore, that in the last 3/4" he opened to 4.375". Last night was the first time I ever measured it. The bore never made any difference to me because I was always measuring my increases on the same heads on our bench. I may have done a dis-service by comparing the Brodix website flows to our bench. But in the past, our bench has been very consistant on stock flows listed by websites on box stock heads.

Hope this information helps.  

451Mopar 451Mopar
User | Posts: 220 | Joined: 07/10
Posted: 03/19/12
05:34 PM

I was just curious because your unported B1 b/s heads were showing higher flow than what my stage1 ported heads were?  I did find it interesting that my mild port job on the stealth heads out flow my b1 b/s heads below 0.600" lift.  

IQ52 IQ52
Guru | Posts: 860 | Joined: 06/10
Posted: 03/20/12
07:33 AM

I have no idea what stage1 ported means to whoever did the stage1 porting. After having been ported, it seems odd to me that those heads aren't flowing more than they are with the 2.20" intake valve vs the Stealth 2.14 intake.  

451Mopar 451Mopar
User | Posts: 220 | Joined: 07/10
Posted: 03/20/12
09:43 PM

The stage1 is what Koffels calls it.  I thought it was just basic port cleanup, but the bowls are ported a bit around the valve guides and seats?  When I had the heads rebuild we installed 2.25" Manely severe duty valves.  Could the larger valve reduce flow?  

IQ52 IQ52
Guru | Posts: 860 | Joined: 06/10
Posted: 03/21/12
08:28 AM

The wrong valves for the seat, throat and port can really ruin the flow. Here is an example.

I was sent a 1st generation 1955 hemi cylinder head that had been previously ported and had a 2.10" intake valve. The owner wanted to know if we could get the head to flow better.

The first thing to do was test the head as delivered to us.

The results.

.100....73 cfm
.200...146
.300...203
.400...234
.500...250
.600...267
.700...283

Then we backcut the valve and redid the seat.

.100....68 cfm
.200...144
.300...211
.400...251
.500...280
.600...299
.700...306

But just looking at the head told us the VALVE WAS TOO BIG for the seat and throat. So the only thing we did was install a 2.05" intake valve and grind an appropriate seat. Smaller valve, but look at the flows!

.100....86 +13 cfm gain from 1st test with larger valve
.200...160 +14
.300...221 +18
.400...253 +19
.500...280 +30
.600...301 +34
.700...313 +30

We continued the research and this head now flows in excess of 360 cfm.  

Budnicks Budnicks
Guru | Posts: 1497 | Joined: 08/10
Posted: 03/21/12
04:37 PM

Damn that's impressive change for sure, an excess of 77cfm improvement over what they originally brought you...  
"Fill Your Library Before You Fill Your Garage" Good Luck  "Budnicks"

IQ52 IQ52
Guru | Posts: 860 | Joined: 06/10
Posted: 03/28/12
05:22 AM

We finally did some exhaust flow tests on the Edelbrock Performer RPM 440 head.

1st column, stock exhaust flows as claimed by Edelbrock.
2nd column, box stock flows as tested no tube.
3rd column, box stock flows w/ 2" tube.
4th column, ported w/ 2" tube.


.100".......70.......59.......61......65
.200".....126.....108.....117.....151
.300".....160.....151.....165.....192
.400".....188.....176.....198.....229
.500".....206.....190.....221.....253
.600".....217.....197.....234.....271
.700".....223.....203.....243.....283  

Budnicks Budnicks
Guru | Posts: 1497 | Joined: 08/10
Posted: 03/28/12
12:46 PM

Wow what a difference with the 2" tube &/or w/2" tube ported, I wonder what/why the difference in your "the box stock" & "claimed", what the big discrepancy is...  
"Fill Your Library Before You Fill Your Garage" Good Luck  "Budnicks"