I am looking for some flow information on a set of NOS Phase I Bowtie heads that I recently scored. The casting numbers are #14011034 and I am trying to find out how well these things flow. They are NOS and have had some professional pocket porting done to them but nothing killer. I do know they are the earlier Phase I type and that the flow design matches the Phasee II heads that are still available with GMPP. I am building another small block 355 and I am looking for decent power and wondered if you might have any flow data on these heads. I was told that you might be in the know for these types of GM performance heads.

See this Team Camaro link for the engine combo I am building.

355ci Desktop Dyno Run (http://www.camaros.net/forum/ultimatebb.php?ubb=get_topic;f=4;t=008040)

Thanks....Graeme

I think you are looking for Gary not Dave --- and that would be my fault I think for accidentaly referring you to "Dave".

GMPP Gary, are you around and did you see this post? I would be interested in seeing if you have anything to share on the qualities of these early bowtie heads.

I have those heads, they were on 350 in a drag car I had. http://www.geocities.com/lonnie67_1966/vega.html They have a competition port including combustion chambers. With the port and mill, .030, I thought the chambers would be close to 64, they are at 70cc's. You should have yours checked, I had 1.0 less compression than I though I had.

I think they are great heads. Here's my flow numbers:

.2- 136.2/121.5 .3- 194.6/157.1 .4- 237.5/182.5 .5- 264/196.5 .6- 271/200

It was a superflow 600, don't know what bore size he used and exhaust was with no pipe. At .6 he put a 2" pipe over the exhaust about 6" long and got 222.

I ran these on my 400, I have several things wrong with my combo. Currently getting a facelift. I will still be using these heads. http://www.geocities.com/lonnie67_1966/blue.html

Lonnie

Thanks for the info Lonnie. I will plug this into the Desktop Dyno and see if it makes much difference. Take care and have fun with the facelift.

Graeme

I don't have flow numbers handy for those heads, but it doesn't matter since they've been modified. I would suggest that you have them flowed so that you know what they flow, but more importantly where they flow. That is to say at what valve lifts they flow so that you can select a correct camshaft. It will be important to know where they "stall" so that you don't over lift the valves and place undue stress on the valvetrain that doesn't bring any benefit. I would look for a flow bench with a swirl meter, swirl data can also be very helpful in camshaft selection relative to lobe profile.

Gary