BBC Heads

[anderson3754]

Well getting ready to pull the trigger on a new set of heads for the Better Half's
BBC 427 Chevelle.

The Motor specs:

427 BBC .030 over (433cid) approx 400-410 hp
current heads 049 castings ( new s/s valves etc)
comp ratio 10.2-1 KB pistons, cranking comp with throttle blades
open 185lbs
Lunati cam #60202 Flat tappet Lift .530/.542 Dur 219/227 LSA 112*
I cant remember when the intake closes after BDC at this moment.
RPM Performer intake
Older Holley 3310-1 780cfm
Long tube 1 7/8 headers
Roller Rockers
HEI Base timing 12*/ mech 21* total 33* at 2000rpm vac adv 10*
4spd 3:90 gears 27 Inch tires


I would like to purchase a set of aluminum heads however I have no problems with cast iron heads. I have 3 sets of SBC World Heads and just love them, 1 set of Trick flow SBC Alum heads G 1's, and there alright.

1st choice Brodix Race Rite Alum 270cc oval 2.25/1.88 valves 119cc
2nd World Merlin III Iron 269cc oval 2.300/1.88 valves 119cc

Now the Patriot Heads have sparked my curiosity being Alum and the price is attractive. However the 320cc runners (rec port), I'm thinking they are just gonna be to big, taking away low end torque. Also I have no knowledge as to their quality.

I may/might put a bigger cam in, but only slightly bigger, plus 5-6 degrees duration, lift in the .560 range. But I doubt it. This cam in the motor now really pulls the car nice, and it is the wife's daily driver in the summer.

I have read most of the links but it seems the more I read the more confusing it seems to become. Right now I'm relying on past experiences with my first two choices, feeling the Patriots are just gonna be to big for the smallish Rat Motors.

Just looking for some input :? Thanks

 

[grumpyvette]

a 427 bbc engines going to prefer the oval port heads with a cam duration anywhere close, to that duration range, and a dual plane intake like the air gap series will also be a better choice than a single plane intake running that cam duration.


you might want to also check out these trick-flow oval port heads, Ive had good results building 427-454 BBC engines for street use with those

http://www.summitracing.com/search/?key ... 0001&dds=1

http://www.trickflow.com/partdetail.asp ... toview=sku

http://garage.grumpysperformance.co...sue-based-on-mis-information.6414/#post-25995

http://garage.grumpysperformance.co...lock-chevy-heads-pictures-info.410/#post-1907
Weingartner Racing posted this info

BBC head flow including the new AFR 290cc
I just got my Brezinski set up in a decided to flow as many heads BBC heads as possible. I flowed all of these on a 4.310 bore and no exhaust pipe attached. I flowed the exhaust without an exhaust pipe attached and I only flowed the long port(the better flowing one). Here are the numbers enjoy.
AFR 290cc oval port cnc ported 2.25/1.88
INT EX
.2-167------141
.3-242------212
.4-298------242
.5-328------267
.6-356------274
.7-370------279
GM 820 2.19/1.88 this one has a weird chamber compared to the other 820s
INT EX
.2-145--------132
.3-207--------166
.4-256--------193
.5-295--------201
.6-308--------214
.7-301--------221
GM 702 BBC oval port closed chamber ported 2.19/1.88 33degree back cut on valves
INT EX
.2-180-------121
.3-247-------146
.4-283-------173
.5-307-------197
.6-314-------211
.7-314-------223
GM 990 BBC rectangle port valve job and bowl cutter used 2.19/1.88 33degree back cut on valves
INT EX
.2-183--------122
.3-245--------152
.4-290--------176
.5-317--------198
.6-329--------208
.7-338--------213
.8-341--------213
GM 291 BBC Rectangle port closed chamber stock 2.19/1.88
INT EX
.2-141---------112
.3-207---------139
.4-251---------163
.5-288---------180
.6-289---------194
.7-291---------197
GM 148 BBC ported 2.19/1.88 33degree back cut on valves
INT EX
.2-170-------139
.3-228-------156
.4-268-------177
.5-306-------196
.6-334-------212
.7-348-------223
.8-349-------230
BMF 310cc cnc ported 2.30/1.88
INT EX
.2-151------133
.3-219------171
.4-273------216
.5-317------258
.6-352------274
.7-372------289
.8-377------300
Dart 360cc 2.30/1.88
INT EX
.2-166--------107
.3-235--------147
.4-283--------183
.5-327--------210
.6-351--------230
.7-365--------244
.8-379--------257
RHS cast iron 320cc I ported the bowl only 2.25/1.88
INT EX
.2-163------136
.3-240------180
.4-281------212
.5-327------242
.6-361------261
.7-365------267
.8-373------271
GM Bowtie ported to the MAX 2.19/1.88
INT EX
.2-170------131
.3-241------163
.4-275------186
.5-307------208
.6-336------224
.7-358------235
.8-373------245
GM 820 oval port ported by me only on the bowl. This is one of my test heads 2.25/1.88
INT
.2-156
.3-220
.4-273
.5-295
.6-315
.7-337
.8-350
The only heads I ported on were the RHS 320cc and the GM 820. The others were ported by customers. They gave me permission to post. No port job besides the Bowtie head is anything more than the bowl. I was extremely happy with how the AFR head did and the 702 head. Both of those heads suprised me. The AFR looks tiny compared to the other heads I was flowing (you could probably put two of the AFRs ports in one of the Bowties) and moved a ton of air. The 702 has great low lift flow and I plan to do work on that head just to see what it will do. I plan on buying a 4.60 bore and slider just to see what will happen then. For the record I am not a dealer for any of the heads above. I am just giving you information.
Weingartner Racing

 

[anderson3754]

Thanks for the info. I'm gonna take a hard look at the Trickflows. Will be calling them on Monday wanting to know how high the exhaust ports are raised, its not listed on their online catalog.

Actually i was not even aware they made a BB head.

 

[grumpyvette]

Thanks for the info. I'm gonna take a hard look at the Trickflows. Will be calling them on Monday wanting to know how high the exhaust ports are raised, its not listed on their online catalog.

Actually i was not even aware they made a BB head.

your not alone!
lots of people don,t know they produce some really nice BBC heads, looking over the quality and price I think there a bargain
I plan on using a set on my NEXT BBC build