2.02 vs.1.94 intake valves on SBC

[Racerjk]

Hello,

I have a friend with a cylinder head shop who has hooked me up with a set of heads. I was running a set of Trick Flow Twisted Wedge heads,but I wanted to get rid of them. They made good power, but I've had trouble with breaking valvesprings and rocker arm studs.

Anyway,the new heads I'm getting are a copy of the Pro cylinder heads. I was really excited about getting these heads! However, when I went to get them my friend told me he put 1.94 intake valves in them. The Trick Flows had 2.02 valves.

Here's the deal: I'm getting these heads for next to nothing because he's trying to sell my Trick Flows. I can't get too upset with him because he's done me a favor and he's my best friend.

However, it seems like I've taken a step backward though. How much will this affect power and torque?? The engine is a 60 over 350 with a 280 Comp Magnum cam. I'll be going from a Perfomer RPM to an Air Gap with a Speed Demon 650 carb.

Like I said, I know this a good set of heads. I'm just not happy about the 1.94 valves.

 

[Ken E.]

Next to nothing is a very good price. A 280 Comp cam with 650 carb is a relatively mild setup and should be very compatible with the 1.94s. Go for it and don't look back.

 

[Racerjk]

I just don't want to lose any power.

 

[LargeCarMan]

You might gain some in reality.

 

[Racerjk]

quote:

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Originally posted by LargeCarMan:
You might gain some in reality.

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True, but stuff usually doesn't work that way for me!

 

[cousincletus]

You should actually gain low-end torque and the car will be more streetable with the smaller valves.

 

[DJ]

People get way too hungup on valve size. Most of the more mordern heads put the old bigvalve stuff to shame with "just" 1.94/1.50 valves.

Here are the numbers for the heads I am bolting on today
------I--E
.100 70/60
.200 146/115
.300 202/153
.400 244/172
.500 268/187
.600 275/193
That is with a 4.030 bore and 2.00/1.56 valves and just a 190cc port where stock on these was 170cc port and intake flow peak at 200-210. Oh and these are a GM casting but probably not one you can use. The companies putting bigger valves than this into this casting hurt low lift flow pretty badly. Not that bigger valves is always bad, you need an experianced shop that knows what works.