I know they're 110cc chambers, are aluminum oval ports with stainless valves and I've heard they're made for GM by Eldebrock but that's all I know. What's the flow rating, intake runner length, etc. Does anybody sell these heads as aftermarket?

My guy tells me that with a little bit of port work they'll outflow the 310cc rectangular port heads with significantly better port velocity. As far as I know, nobody carries them aftermarket. I'd look at the Brodix RR's before these, though - Mike at Wolfplace can fill you in on them and probably make you a killer deal on 'em.

EDELBROCK PERFORMER RPM-O
288 cc, 110cc chamber
2.19/1.88

LIFT INT EXH EXP
.100 70 54 54
.200 138 106 109
.300 192 132 137
.400 240 154 165
.500 263 182 191
.600 289 198 212
.700 300 213 229
.800 306 226 244


GMPP OVAL ALUM (ZZ502)
292 cc, 112cc chamber
2.25/1.88

LIFT INT EXH EXP
.100 71 58 58
.200 138 119 122
.300 193 145 156
.400 233 168 178
.500 272 189 194
.600 299 202 207
.700 318 210 213
.800 327 230 231


From Chevy High Performance, flowed on a 4.25" bore fixture.

RR ovals are only 270cc but flow alot better than both of those heads.

Thank you Mr Ty :D

Charlie,
Here are some comparisons for you,,
The Ede "Roval" & the GM heads look to be pretty much the same.
I have not flowed the GM one.

781's Mild bowl port 2.19/1,88
1 -69 / 56
2 - 158 / 102
3 - 217 / 135
4 - 254 / 161
5 - 263 / 186
6 - 274 / 209
7 - 272 / 219
==============
Perf RPM #60459 290cc Intake port 2.19x1.88 110cc chamber
"Good port"
.050 - 41/ 32
.100 - 73/ 64
.200 - 148/119
.300 - 218/149
.400 - 268/179
.500 - 304/207
.600 - 317/229
.700 - 319/245
"Bad port"
050 - 38/ 31
.100 - 74/ 64
.200 - 146/119
.300 - 218/150
.400 - 260/179
.500 - 291/207
.600 - 307/229
.700 - 302/245
================
RR OVAL 270cc port
.050 - 42/33
100 - 77/65
200 - 152/118
300 - 224/147
400 - 283/178
500 - 318/205
600 - 344/230
700 - 347/248
=============

RR Rect 290cc port CNC chamber intake only 050 - 41
100 - 80
200 - 153
300 - 227
400 - 280
500 - 319
600 - 345
700 - 352



All tests @ 28", radius inlet, no pipe, 4.530 bore.

Would those flow numbers be better when tested with the identical bore that they are going on 4.25 or 4.35 and so on? I appreciate it when you post actual test numbers, thanks.

Would those flow numbers be better when tested with the identical bore that they are going on 4.25 or 4.35 and so on? I appreciate it when you post actual test numbers, thanks.
=
Nope, they would all drop but probably by close to the same amount.
Brodix actually has two CNC chamber programs, one for the smaller bore & one for the 4.500 up stuff
I normally do testing on the 4.530 adapter for comparisons to keep them the same.
The one head that will drop the most is probably the AFR as it was designed for the big bore & also the exhaust port was designed with a pipe so the exhaust numbers will change more than most.
Some heads hardly change with a pipe but this ain't one of them,,,
Here is a test of an AFR 315 on different bores I did a while back.
Nothing changed except the bore, back to back test.
Remember, most head will not change this much.

AFR 315 CNC
4.530" ===========4.310"
..050 - 40/34 =======43.4
.100 - 78/69 ========78.1
.200 - 164/142.5 =====162.3
.300 - 247/198 ======239.5
.400 - 309/240====== 290
.500 - 350/267 ======334.4
.600 - 375/280 ======358.3
.700 - 383/283 ======374
.800 - 381/286 ======377


All tests @ 28", radius inlet, no pipe, 4.530 bore.
This is off my bench not advertised & I have had a few heads flowed by both AFR & Brodix just to "qualify" the numbers.

Mike, do you have any flow numbers on GM rectangle port heads, just for some more comparison to those above?

I don't know about the Edelbrock version of the square port head but a friend got a NHRA legal version for a new Super Stock buildup and it required a special dome that is quite a bit different than anything he had used so far. He sent the pistons off to John Armstrong in Canada to be profiled to fit the different chamber design. This head would definately not clear a regular dome as manufactured. The spark plug boss comes out into nearly the middle of the piston's dome as forged.

I don't know about the Edelbrock version of the square port head but a friend got a NHRA legal version for a new Super Stock buildup and it required a special dome that is quite a bit different than anything he had used so far. He sent the pistons off to John Armstrong in Canada to be profiled to fit the different chamber design. This head would definately not clear a regular dome as manufactured. The spark plug boss comes out into nearly the middle of the piston's dome as forged.
=
This is correct, the GM/Ede has a goofy chamber but SRP pistons now fit. They modified them a few months ago with a new part number so they fit "standard" as well as the GM/ EDE heads.

Think the dome fit problem is for the real high dome stuff though. My .210 domes fit fine with the Ede/GM heads (110CC version). But I could see where a .500+dome ht may run into trouble.

Edited 1:25PM
Just finished up the shortblock. Pistons are H693CP .030, .210 dome suitable for closed or open chamber. Have .400" top of dome to combustion chamber, .250" side of dome to spark plug boss. Think the problem will be if you use a traditional open chamber style dome. THe H693CP is really a closed chamber style with the bathtub shaped dome.

Think the dome fit problem is for the real high dome stuff though. My .210 domes fit fine with the Ede/GM heads (110CC version). But I could see where a .500+dome ht may run into trouble.

Edited 1:25PM
Just finished up the shortblock. Pistons are H693CP .030, .210 dome suitable for closed or open chamber. Have .400" top of dome to combustion chamber, .250" side of dome to spark plug boss. Think the problem will be if you use a traditional open chamber style dome. THe H693CP is really a closed chamber style with the bathtub shaped dome.
=
Again mostly correct :D
It was the open chamber domes that had the problem with the GM/EDE heads.
Both large & small domes were effected as it was at the edges of the chambers.
The new SRP's are "rolled" at the edge now so it is not an issue with the low compression (10.0 give or take) ones.
The Hi compression ones will not fit the above heads but they do have a hi compression piston specific to the GM/EDE heads
The closed chamber piston/ open chamber head stuff is something that should be checked on the smaller bore engines but most fit from 4.250 on.

THink we're saying the same thing. If you try to bolt the Ede/GM heads onto a shortblock built with traditional open chamber pistons , expect interference. I matched the GM 110CC chamber heads up against both the H692CP -030's and also a set of TRW high dome 427 closed chamber pistons I have here - no signs of interference with either set, but these are both closed chamber piston designs.