I just though this would be some interesting information for some of you.

I sold my CNC-ported stock heads (52 cc chambers) and ordered some AFR 210's (68 cc chambers) to lower my compression in preparation for more boost, and for more flow.

It has been shown in several comparisons that Thunder Racing's flowbench typically reads about 10 cfm lower than everyone elses.

They recently flowed a set of Race Ready AFR 190's and were disappointed with a reading of only 233 cfm peak, when they're advertised to flow 260+.

My Race Ready 210's came in today and I was pleasantly surprised to see that they flowed as follows:

Lift In. Ex.
.200 129 104
.300 183 144
.400 230 177
.500 264 198
.600 270 209
.700 278 215

I was very happy with the exhaust port, thinking that the 200+ cfm would be great for the supercharged setup.

Mike

 

are you sure that those numbers are right i checked their site and got these #s

lift/int/ex
.200/135/112
.300/197/145
.400/245/185
.500/273/205
.600/282/215
.700/285/220

these are for the 210 race ready lt4s

 

I do not believe AFR numbers are anywhere CLOSE to reality, especially on the Street heads.

I have a set of AFR 190's that have been ported by three porters at a tremendous cost and though the last one got CLOSE to the 'Race' numbers, none of the flow results previously were ever close to the advertised numbers.

They currently are

.500 257 / 199
.600 278 / 216

Note - I asked that the exhaust side be worked on for my blower as well.

The Street numbers form AFR are
.500 260 / 190
.600 264 / 195

and Race

.500 264 / 195
.600 276 / 208

After the SECOND porting the numbers (flowed on the bench of the third porter) were
.500 241 / 192
.600 251 / 201

Basically this suggested to me that the AFR 'Street' numbers are a little........generous.

 

enjoy the heads Mike I am gonna get another set of afr's myself for my new motor (they havent let me down yet) With good porting skills they can really flow well. I have had a few shops work on mine and have been very suprised with the gains that can be had. I just wish i could have tested the 220's with the turbo system on but the new owner of these will be very happy as he has my complete setup now.

Steven

 

wow something isn't right there...i'd be complaining to someone about those heads

 

Since we had seen such poor results with the 190's, I was surprised to see the 210's come so close to their advertised numbers. I think that, in general, the larger heads better match the advertised numbers. Thunder Racing had previously flowed some Competition Ported 210's that did 290 out of the box (advertised 297), so all of the 210's they tested did well and all of the 190's did poorly.

In a side-by-side comparison, the 210 Race Ready's have more CNC porting done than the 190 Race Ready's. In the 210, the port appears to be completely CNC'd. But in the 190's, the entrance is CNC'd, the throat is untouched, and the bowl appears to be hand-ported. Maybe the fact that the 210's cost more plays into this(?).

Mike

 

Well it is a long story and I agree that after all the time and money spent on them - i bought them AFTER the second porters work - the results are ........modest. The only thing I can suggest is that the third and final flowbench is conservative in their results. They SAID they were ususally on the low side.

The flow numbers from MY porter BEFORE he did his work were noticeably LOWER then the reported results from the SECOND porter. (second porter claimed peak 268, my guy flowed them at 251. The exhaust numbers WERE very close.)

Honestly speaking, this 'head flow numbers' is a giant headache. It seems you should get flow numbers independantly checked EVERY time. My porter flowed the heads 'independantly' and they were 17 cfm lower then the second porter reported.

Honestly I have just said "F**k it. Do 'um, flow 'um, install 'um and give me the bill" - he got the numbers up to 278 peak.