Don Terrill’s Speed-Talk

Well here's a update, heads flowed with stock chevy 1.94 valve on a 4.125 bore flowed 220cfm at .500. Needs unshrouded bad withn 1.94 valve. I beleive The Window gets smaller at higher lift without opening chambers up. But for a street car I choose Compression for gas mileage and torque down low. I know Flow will help torque too but beleive at a little higher RPM. Need to move out seat .020 so valve touching out farther and sandroll. Still ruff and probably get some better flowing valves on intakes and cut 30 degree backcut. Already got 1.6 stainless ones. He called me and said he had some time to flow them, so I havn't touched heads since last pic.

From much earlier in the thread. 1.85" / 1.6" combo with swirl figures. I posted this because it may be helpful to your combo. You will notice that the flows are similar to yours and will make a strong runner with proper components. The swirl profile is radically changed with backcuts and the flow profile also. For very high lift-rpm application I would go no back cut and for a street runner with about .5"-.55" cam I would go with the back cut valves. Will yours look exactly like these? No, but I bet they won't be far off either. Nice work and keep us posted.thanks, Charlie

NXBOY, you need to get rid of the flow regression you have between .550" and .600" lift even if the motor will be run using less lift!

More then likely the issue is starting at .500" lift from what I can see by your numbers.

I would bet that if the flow bench this head was tested on was not fully computerized, that on the test pressure Manometer you would be starting to see the test pressure reading bounce up and down in the .500" to .650" lift range which would indicate a tumble condition.
Pm me if you care to on dealing with this.

I Appreciate all The help guys. I was planning on back cutting valve, always do with mild cams. I did see the Chart Charly, Thanks, made clear for a .500 lift cam it would be the way to go. When I widen seat to raise it on valve about .020 I will be able to put the right amount of 60 back on seat from where the 75 took out alot of it, setting the bowl size. Seat can be .020 narrower also and plan on the 60 doing it. I feel both things will help a little bit. I really didnt want to ruin a head when it won't see a track most likely and as hard they are to find. I sure know getting older is not good for porting. Depth perception and clarity of port comparison made me feel like a beginner again Drug out a old 351w head I ported yrs ago in a hurry (maybe 45 min.) with the bigger bowl/chamber 351w head to show (sorry for the rust lol, when my friend first got his flow bench to test a port I've been using but never tested except at track. Darn things flowed better then these with stock valve job /1.82 valve , but more aggressive on SSR and corners. Plus the benefit of Bigger chambers. Plus the bigger ports near the bowl, past the pushrod pinch helps slow the air over the SSR. This 302 is going to be daily drove and maybe give my son some street time if he will Listen Next I going to throw some 1.94 valve in the 351 and do a race more a race type port job, got extras if I hit air lol. But I'm waiting tell spring lol.

another DIRTY Pic of 351w head 1.82 valve, Flowed upper 220s

Update: 65 289 heads are back from Terry's shop where they got milled and set up for screw in studs. DV has some testing to do on these and dyno is planned for after Christmas. Thanks, Charlie

Carnut1 wrote: ↑Fri Dec 01, 2017 12:32 pm DV has some testing to do on these and dyno is planned for after Christmas. Thanks, Charlie

Any update on dyno testing?

I will be attending DV's seminar next week so I will get the low down then. Thanks, Charlie

Carnut1 wrote: ↑Sat Jan 06, 2018 9:29 pm I will be attending DV's seminar next week so I will get the low down then. Thanks, Charlie

Charlie, do you think the GT40x heads will be tested at the same time? I thought that was the plan back in the late summer/fall.

Last conversation we talked about the dyno test it was scheduled after Christmas. It was to be 7 sets of heads on one short block and the gt 40x included. Thanks, Charlie

interested in those old boat heads.. hang in there Charlie..

Got it. Looking forward to updates.

Old as Dirt wrote: ↑Sat Jan 06, 2018 9:35 pm interested in those old boat heads.. hang in there Charlie..

I am really pulling for them as the underdog. With the rough surface treatment and smaller faster ports I think they will do well. Thanks, Charlie

At DV's shop getting ready for seminar and David has the 66 289's on the grinding bench doing some interesting chamber mods. He wants to test them on the dyno before sharing. Fyi, interesting.... Anyone else have some different chanber mods for these heads? Thanks, Charlie

What I would like to know is what head, cams , intake combos he is going to try