Don Terrill’s Speed-Talk

I would think it would as far as elevation goes. More over the DA plays a bigger factor seeing on the chart it veried from 3000 to 3500 over the two days . Less available oxyen less fuel needed . I'm no real tuning expert but if it were my car armed with the imforation at hand I'd pull at least 4 more jet sizes out and a little timing till I got the afr squared away . Then add timing back as needed to see what the car liked . It looks to go rich at the first hit too so a smaller discharge nozzle on the accel. pump might be in order there also. Again just my feelings and thoughts if it was my car. Dan

6.50camaro wrote: ↑Tue Aug 18, 2020 10:05 pm I would think it would as far as elevation goes. More over the DA plays a bigger factor seeing on the chart it veried from 3000 to 3500 over the two days . Less available oxyen less fuel needed . I'm no real tuning expert but if it were my car armed with the imforation at hand I'd pull at least 4 more jet sizes out and a little timing till I got the afr squared away . Then add timing back as needed to see what the car liked . It looks to go rich at the first hit too so a smaller discharge nozzle on the accel. pump might be in order there also. Again just my feelings and thoughts if it was my car. Dan

yes thats true about the rich spot right off the hop.

Here is one of the better times from last season with no exhaust.

Consider trying less timing. On the track my AFR 245 406 fell off at 37 degrees, and on the engine dyno made its best numbers at 34 and 35 degrees.
Keep pulling fuel out until the trap mph falls off. Lean won’t vary the time slips much, whereas rich will pick up when the air improves.
Your results may vary, but my junk picks up when I raise the 2 step RPM.
It would be interesting to try something like a super victor 2 to see if the intake is holding it back.
I bet the old cam with more rocker ratio would pick up, but that’s $$$ with shaft rockers.

allens wrote: ↑Tue Aug 18, 2020 10:17 pm Here is one of the better times from last season with no exhaust.

2019-09-08-run.png

Thanks Allen, looks like convertor flashed to about 5800 on that run with last years cam. Do you have the 60 foot number from that run ?

AFR was still really rich.

How did the weather conditions compare to the best run last year to the best run this year?

Am I reading the chart right that shows the two step on 4500 last year and 3500 this year?

Old School wrote: ↑Tue Aug 18, 2020 10:28 pm How did the weather conditions compare to the best run last year to the best run this year?

Am I reading the chart right that shows the two step on 4500 last year and 3500 this year?

Yes, two step was changed for the last few runs to 3500.

Old School wrote: ↑Tue Aug 18, 2020 10:28 pm How did the weather conditions compare to the best run last year to the best run this year?

Am I reading the chart right that shows the two step on 4500 last year and 3500 this year?

DA was slightly better, approximately 2700' on that one.

allens wrote: ↑Tue Aug 18, 2020 10:37 pm

Old School wrote: ↑Tue Aug 18, 2020 10:28 pm How did the weather conditions compare to the best run last year to the best run this year?

Am I reading the chart right that shows the two step on 4500 last year and 3500 this year?

DA was slightly better, approximately 2700' on that one.

Thanks

prairiehotrodder wrote: ↑Tue Aug 18, 2020 10:24 pm

allens wrote: ↑Tue Aug 18, 2020 10:17 pm Here is one of the better times from last season with no exhaust.

2019-09-08-run.png

Thanks Allen, looks like convertor flashed to about 5800 on that run with last years cam. Do you have the 60 foot number from that run ?

AFR was still really rich.

60' on that was 1.417, looks like the best 60' as well.

so correct me if i'm wrong but with all things being considered there may be no real change between this year and last year. The new cam and the old cam. Still need to tune the carb, drop the exhaust, and figure out why the overall combo isn't making the hp it should. Back to thinking about what was said about the heads or intake. And thinking the new cam has the "potential" to go faster. even if its not right now.

Has anyone seen dyno comparisons on this intake ? I thought it was about the best flowing one available out of the box. and 423 cubes isn't real big anymore for small blocks.

Is there really 100 hp to gained by porting the heads as one person stated ? That seems to go to be true. Can anyone back that up ?

Brian

i see AFR has a new intake #4811 thats not plastic. Not sure they make the plastic intake anymore. Looks pretty nice.

prairiehotrodder wrote: ↑Tue Aug 18, 2020 10:53 pm so correct me if i'm wrong but with all things being considered there may be no real change between this year and last year. The new cam and the old cam. Still need to tune the carb, drop the exhaust, and figure out why the overall combo isn't making the hp it should. Back to thinking about what was said about the heads or intake. And thinking the new cam has the "potential" to go faster. even if its not right now.

Has anyone seen dyno comparisons on this intake ? I thought it was about the best flowing one available out of the box. and 423 cubes isn't real big anymore for small blocks.

Is there really 100 hp to gained by porting the heads as one person stated ? That seems to go to be true. Can anyone back that up ?

Brian

I really can't see any difference between either cam by looking at the times. Largest difference was with/without exhaust.

PRH wrote: ↑Tue Aug 18, 2020 8:15 pm Here’s a question for Larry.......

If you put that motor as it sits on your dyno........ do you think it would only make around 500hp?
Or do you think there are issues with the car/combo that are contributing to the power numbers looking way lower than what you’d see on the dyno?

To me it seems unimaginable that motor would only make the kind of power that the ET/Speed calculators/programs are coming up with.

In other words, if you didn’t know what the car ran, and was just looking at the engine build itself, like if it were someone bringing in the untested engine for you to dyno test....... what kinds of numbers would you be expecting to see?

Note : in previous simulation Pics , i just used SuperFlow STP HP correction "without" the Friction correction ,
because i did not know what type of HP correction factor his Data logger might be using ???

if i use the complete SuperFlow STP with Friction HP correction Factor
it equals = 1.1083395440 ( his Data Logger HPC = 1.091 correction )
so if i moved my Shop + Dyno to his Dragstrip location for that 10.500 ET Run # 2 08/16/2020
i calculate it would make = 507.9 Peak on my Dyno @ 600 RPM/SEC test rate
.... and i think its way too Rich if his O2 Sensors are reading correctly ?? ... thats some more potential HP

i actually like his HP Curve .... its pretty flat down the DragStrip ... its just not showing a lot of HP

it sort of reminds of SuperStock SS/IA #041X Heads that had way too much speed everywhere
it ran 10.70's to 10.80's ... when a much better pair #041X with same Flow numbers , but way slower FPS velocity
set the NHRA Record at 10.132 ET ... both Cars were 1968 Camaros 3336 Lbs
... the way too fast FPS #041X Heads lost 105 HP at 7500 RPM upwards

i have 1 AFR 227CNC'd Head in my Shop ... might dust it off , re Flowtest it ,
but i've had 3 different pairs AFR 227 CNC'd Heads thru the years , and they had way too fast Floor Apex peak velocity
pegged by Pitot Probe 48+ inches H2O

KnightEngines wrote: ↑Mon Aug 17, 2020 1:46 am Those 227 heads are pretty shit out the box, years ago I ported a set for a guy with a 427 cube dirt late model, no word of a lie it picked up damn near 100rwhp without touching anything else.
They are small in the pinch & turbulent at high lift.
Open the pinch up to the limit of the casting & fix the turn to keep them stable.
Pull out 8 degrees of cam duration & get lift up to .700 or more & it'll be a different motor.

I couldn't agree more about the 227cnc intake ports, way too fast and choke really badly. I have reworked them and did a new cnc program and picked up a bunch off power. Yes cam is too big and needs way more lift.