Don Terrill’s Speed-Talk

88bluestar wrote: ↑Thu Sep 13, 2018 8:00 pm It’s my hope that there is a market for these heads when the season concludes and sell them once I’ve had them cc”ed and gone over so I have proper flow numbers etc to show a potential buyer. The intake is a raised runner type to match the head so it’ll have to go as well.

88bluestar wrote: ↑Thu Sep 13, 2018 10:16 pm 10051103 - BOW TIE INTAKE MANIFOLD (RAISED RUNNER)
The intake runners in this aluminum intake manifold are raised .200" to match the ports in the raised runner Bow Tie cylinder head P/N 10051101. Its single-plane runner design maximizes horsepower at high rpm, and the gently curved runners enhance mid-range torque. The runner entries are radiused to minimize turbulence in the plenum and to promote uniform fuel distribution to all eight cylinders. An air gap beneath the runners isolates the intake charge from engine heat; there are no heat riser passages. The carburetor pad is drilled for a standard flange four-barrel.
The way it performs leads me to believe this is a 215cc head, and not the 225cc revised head.

Keith Morganstein wrote: ↑Fri Sep 14, 2018 12:19 pm There are some that get the large Bowtie vortec head to run very well, front of the pack on power, on a 355 SBC. Even in 2bbl classes. They have obviously spent the time to develop the combo, but it definitely is workable.

I didn't go that route, having built with the small port bowie or EQ vortecs, so I don't have the recipe. I'm quite sure Mike Jones would know what the cam should be.

Tuner wrote: ↑Sat Sep 15, 2018 11:02 am

Keith Morganstein wrote: ↑Fri Sep 14, 2018 12:19 pm There are some that get the large Bowtie vortec head to run very well, front of the pack on power, on a 355 SBC. Even in 2bbl classes. They have obviously spent the time to develop the combo, but it definitely is workable.

I didn't go that route, having built with the small port bowie or EQ vortecs, so I don't have the recipe. I'm quite sure Mike Jones would know what the cam should be.

^^THIS^^ You all who think this head is too big, too tapered, too big a bowl or too this-or-that, too whatever it is you are criticizing, most likely have not actually run them to know from experience what you are going on about. Do you really think GM engineers don't know how to make cylinder heads? OP, if you do change to a different head, don't be too quick to get rid of these because you could be throwing the baby out with the bathwater.

88bluestar wrote: ↑Wed Sep 12, 2018 11:06 pm 1/4-3/8 mile clay oval track, dryslicks often but still traction up high and on the bottom. I have a feeling that some fast cars are running either a small runner VB or EQ type small runner head, roughly around 185-190 cc runners.

Tuner wrote: ↑Sat Sep 15, 2018 11:02 am

Keith Morganstein wrote: ↑Fri Sep 14, 2018 12:19 pm There are some that get the large Bowtie vortec head to run very well, front of the pack on power, on a 355 SBC. Even in 2bbl classes. They have obviously spent the time to develop the combo, but it definitely is workable.

I didn't go that route, having built with the small port bowie or EQ vortecs, so I don't have the recipe. I'm quite sure Mike Jones would know what the cam should be.

^^THIS^^ You all who think this head is too big, too tapered, too big a bowl or too this-or-that, too whatever it is you are criticizing, most likely have not actually run them to know from experience what you are going on about. OP, if you do change to a different head, don't be too quick to get rid of these because you could be throwing the baby out with the bathwater.

zums wrote: ↑Sat Sep 15, 2018 11:42 am

Tuner wrote: ↑Sat Sep 15, 2018 11:02 am

Keith Morganstein wrote: ↑Fri Sep 14, 2018 12:19 pm There are some that get the large Bowtie vortec head to run very well, front of the pack on power, on a 355 SBC. Even in 2bbl classes. They have obviously spent the time to develop the combo, but it definitely is workable.

I didn't go that route, having built with the small port bowie or EQ vortecs, so I don't have the recipe. I'm quite sure Mike Jones would know what the cam should be.

^^THIS^^ You all who think this head is too big, too tapered, too big a bowl or too this-or-that, too whatever it is you are criticizing, most likely have not actually run them to know from experience what you are going on about. OP, if you do change to a different head, don't be too quick to get rid of these because you could be throwing the baby out with the bathwater.

Yea, sure, thats obvious by the op's first post, maybe the self proclaimed carb experts should stick to carbs
Tom

Tuner wrote: ↑Sat Sep 15, 2018 2:08 pm

zums wrote: ↑Sat Sep 15, 2018 11:42 am

Tuner wrote: ↑Sat Sep 15, 2018 11:02 am

^^THIS^^ You all who think this head is too big, too tapered, too big a bowl or too this-or-that, too whatever it is you are criticizing, most likely have not actually run them to know from experience what you are going on about. OP, if you do change to a different head, don't be too quick to get rid of these because you could be throwing the baby out with the bathwater.

Yea, sure, thats obvious by the op's first post, maybe the self proclaimed carb experts should stick to carbs
Tom

Have you actually run these heads? There could be several reasons the OP's engine is down on grunt coming off the corner. Perhaps you haven't noticed, there is more to tuning than just the carb. Ignition timing and the advance curve has more to do with tuning than the carb, because, basically, gasoline burns. In particular, these heads are unique because they need less spark advance than most people think and they are particularly allergic to too much timing at and below the torque peak. The timing that makes best power is too much to make best torque and low end grunt below the torque peak. A locked distributor or "all in at 2500" makes an exactly backwards advance curve because the electronic ignition's slew rate timing retard causes too much advance at low RPM when the timing is right for best power at high RPM.