Is a 235 cc head too big for a small block 434?

[DRJDVM's '69]

I'm building a new small block 434 for the camaro and am still working on the heads.

We originally went with the Dart Platinum Pro 1's which is a 220 head. Well after waiting 6 months for the back order, they arrived... the first issue was there was a casting hole in one of the runners near the pushrod " galley". Darts response was "well you know you can just weld that up". That pissed me off to buy a brand new set of heads and have to fix them.

Then the second issue was the flow. They advertise 300 cfm.... the best we could flow them was 240 !!! Darts response was that they flowed them with their valves... fine.... we get one set of their valves and flow them again.... no change. I know the big thing is "wet flow" now, but come on..... 60 cfm difference ??

So the Darts are going back.... so now I need a new set of heads.
The car will be 99% street driven, manual 5 speed, 434 small block, Victor Jr intake, etc etc. We havent slected the cam yet because we wanted to get the heads figured out first.

My engine builder is looking at the Brodix heads. I just saw some stuff about World putting out a Motown 235 cc head with a 72 cc chamber.

So is a 235 head too big for a street driven 434 small block ?? I dont want to get lured in by "bigger is better"

[6'9"Witha69]

Cam specs and Compression will make for a better judgement.

[DRJDVM's '69]

The compression is going tobe around 10.5:1. Its going to be a street driven California car where the weather is pretty hot and the gas sucks.

I havent decied on the cam since I wanted to choose the heads first. It will probbaly be a hydraulic roller.

[6'9"Witha69]

If it is just street driven you may lose out on efficiency with heads that big, even with the added cubes. That and some Hyd Rollers will struggle to be big enough in the range of cubes / heads you are looking at. A solid may be better.

[malihoochie]

A 235cc head is not usually cosidered too large for that size motor.
The rpm range you actually operate in may dictate a smaller runner though.

[Lowend]

Believe it or not I have seen some absoultely insane 406 combos using the little tiny E-Tec 170 heads
Look here
http://www.nastyz28.com/forum/showthread.php?t=72681&highlight=E-tec
Marv D is a very well respected racer, and is not making this stuff up.
With a 434 I would be looking at the 200cc E-Tec's but I guess my point is that you just do not need that much runner volume

[6'9"Witha69]

Believe it or not I have seen some absoultely insane 406 combos using the little tiny E-Tec 170 heads
Look here
http://www.nastyz28.com/forum/showthread.php?t=72681&highlight=E-tec
Marv D is a very well respected racer, and is not making this stuff up.
With a 434 I would be looking at the 200cc E-Tec's but I guess my point is that you just do not need that much runner volumeThat is exactly my point, especially with a street car.

[69CamaroRacer]

I would look into AFR's 227 head..

[68sixspeed]

Lesson #1- most of the flow numbers these makers are throwing around are total b.s.- you just proved it on Dart, I have data to prove it on AFR; About the only one I've seen be honest is Edelbrock. (with the exception on M2 and some of the specialty CNC houses, they tend to know their stuff);

AFR 227's are a good head for the money, but they leave some HP on the table that can easily be had with additional hand porting and a better valve job. -Dan

[Lowend]

It should be noted that the 227's use some goofy valve train stuff. You are pretty much stuck with dedicated offset shaftrockers

I will tip you off to a little racer's secret head company
http://www.allproheads.com/
They are expensive and worth it

[Blown353]

It should be noted that the 227's use some goofy valve train stuff. You are pretty much stuck with dedicated offset roller rockers

I will tip you off to a little racer's secret head company
http://www.allproheads.com/
They are expensive and worth it

All Pro does indeed make great stuff. My friend uses their heads for almost all the deep pocketed roundy round & sprint guys around here, they never disappoint.

[MonzaRacer]

Ill stick with my AFR rep
As for too big ,,not if you have a proper cam ground give Cam Motion a call