Don Terrill’s Speed-Talk

Has anyone ported or dealt with any of the Trick flow sbc 175 heads?
While they aren't the most serious head, Trickflow is claiming plenty of material left for porting. According to their website it flows what the super 195 on intake does yet it outflows the 195 super on the exhaust by 17 cfm. I do like the stock appearance. Curious as to know their ported potential. Anyone?

Looks to me like they flow enough out of the box to make easy 480 hp at only .525" lift with a 10.5 comp.

On there other SBC heads I have ported the wall thickness was .250" in the areas you would need to rework heavily to port then up to 300 cfm, so I have no reason to think that these castings would be much different!

If you want to go by the numbers needed then this may help you out.

For a ported head with 2.02" valve the max diameter of the Intake bowl you would want to use would be 91% of the valve diameter or 1.85".
I am sure that Head is cast with atleast enough wall thickness to get to these dimensions, and with a 1.85" Throat in the bowl the rest of the port from the crown of the short turn on back to the Intake flange would need to be a circumference of 5.80"

I am going to guess that the out of the box Throat size on those heads is 1.750", or 86% for a 2.02" valve .
To get up to the max of 91% only .050" needs to be taken out of the valve bowl port wall thickness which like a posted is like .250".
The needed circumference of the rest of the port only needs to go up by .076" out of that .250" wall thickness to get to 5.80".

In short there is likely plenty of port wall meat there to even go up to a maxed out 2.05" valve size while using the out of the box valve seat as installed.

I however do not think they cast the head with the notion of going up to a 2.08" valve , but I could be wrong?

Thanks for your time in your reply. I really like the as cast stock appearing side of these heads. I'm also hearing of a fellow in California by the name of Billy Goyette who can remains an afr head to look "similar" to the old 461/462 iron heads. However, I am not sure how much he is charging for this service.

Interesting look to be a lot taller.

Another pic of the modified castings of the AFR heads. Not exact but definitely not bad.