[TIN TIGR]

since i do not have a set of 670's to compare them with, i am curious about whether the port design on the 061's is the same..any real feedback on these heads?..i have read here that the chamber is "too open" and seems to detonate easily..i am just weird and like running unique stuff if it works..the motor will run on e-85, so it shouldnt detonate..

any experiences would be appreciated..thanks

[BILTIT]

I have some pics of the 670 ports and chambers after porting and chamber massaging (SD performance 260cfm), not sure if that will help?

[b-man]

For what it's worth, a fellow racer I knew who did quite a bit of head porting commented that the ports on his #061 heads were very similar to those on a #16 head.

[TIN TIGR]

what im looking for is if the 061s have that good early port, with a funny chamber, or some crappy ports with a funny chamber..the 061 is open as hell, and i can see where it should flow well at low lifts, especially if you can properly address the short side..no flow work yet, so im looking to save some time and effort by not re-inventing the wheel

[BVR421]

Isnt the 061 from 1967? Wasnt that the first open chamber Pontiac head? Used on lo-po 2b motors? Seems like it was a production test design when they had to move to better chambers for lower emissions. 1968 heads were then all open chamber.
Never seen one, I remember hearing its a great design.

[goquick]

The 061 heads have the first open chambers. They are even more open than the RA IV, RAII, and RAV engines. The port is about 1/16" lower at the short turn than a 670 head.

[GOAT490]

My 061's have fulfilled my needs for power, though they may not be as high as yours.

PHILLYGOAT

[Donovan]

I have a set of 16, 670 and 061 sitting here all clean as new and un-modified. want some comparative pics or info to make this topic more than speculative?

[TIN TIGR]

i was looking at your pictures donovan...very helpful..the chamber comparisons are startling..ya might want to snap gauge all 3 sets around the short side to see the differences


goat 490..what "mods" were done to the heads, and did you flow them before and after?

[68birdfreak]

It may be worth your time to send Gregg Merrick an email...pontiacengines.net
He is incredibly sharp Tin...can get you his phone number if ya like !
How are the CV1's coming along?

[tc]

Port shape is close to the same as the 670's, a little taller than other d-ports. They are 2.11 tall at the port opening. The difference I found while porting ( using a 1.72 template, Pete M style ) was the 670's needed alot of material removed below the seat to the guide and the 061's needed very little material removed.

[GOAT490]

My heads were originally done by Butler. I had them flowed on two benches. One was a 4.250" bore with no flow enhancer and max was 272cfm @ .550", the other was on a 4.31" bore with flow enhancer and the max was 294cfm @ .550". At least I think those are the correct #'s. Greg Merrick made molds of these ports and I believe he made some mods as Fasteddy's d-ports flowed 299cfm on the same flowbench that mine "only" flowed 294cfm. If you need the #'s from .100" - .550" I can probably dig them up and maybe fasteddy can post his #'s.

PHILLYGOAT

[Donovan]

average of all 4 ports on one head

Pushrod pinch -
061 - 0.952
670 - 0.936
16 - 0.922"

Short turn -
061 - 1.533
670 - 1.541
16 - 1.571"

Port entrance width -
061 - 1.120
670 - 1.125
16 - 1.100

Port entrance height -
061 - 2.075
670 - 2.092
16 - 2.093"

[GOAT490]

Found these on a previous post. This was on an "old" valve job.

4.250" no enhancer --- 4.350" w/flow enhancer
.100" 76.8/69.3 --- 74/60
.200" 143.9/116.2 --- 149/119
.300" 211.5/146.4 --- 217/157
.400" 262.6/168.8 --- 270/187
.500" 272.0/184.9 --- 294/206

PHILLYGOAT

[TIN TIGR]

thanks to all..