Large Vortec bowtie, Engine?

General engine tech -- Drag Racing to Circle Track

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zums
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Re: Large Vortec bowtie, Engine?

Post by zums » Thu Sep 13, 2018 9:07 pm

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.
You really need to "know" what you have, the LPVB and SPVB are not raised runner heads, lets start with what EXACT intake do you have now, make and number
Tom

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Re: Large Vortec bowtie, Engine?

Post by 88bluestar » 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.

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Re: Large Vortec bowtie, Engine?

Post by zums » Thu Sep 13, 2018 10:36 pm

I can see why you think the head is raised runner because technically that intake is considered a raised runner, the ports on the head are just taller, not really raised much off the floor compared to older style 23* heads, is the intake stock because they are fairly small out of the box, and if it is stock put a pen light through the plenum and see where the large mismatch is with the head port
Tom

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Re: Large Vortec bowtie, Engine?

Post by 88bluestar » Thu Sep 13, 2018 11:51 pm

I gather its been ported, matched maybe.

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Re: Large Vortec bowtie, Engine?

Post by RTR-1 » Fri Sep 14, 2018 12:55 am

I think this intake manifold might be a better match for the Bowtie Vortecs? https://www.jegs.com/i/Edelbrock/350/2814/10002/-1

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Re: Large Vortec bowtie, Engine?

Post by 6.50camaro » Fri Sep 14, 2018 8:00 am

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.
Check the top of the 2-4 runner for a stamped p/n 10051102 if its there you have a non raised runner intake. GM used the sames core casting with the same p/n . They just machined them differently to be a raised or non raised intake and added the stamped p/n to the non raised intake .Dan

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Re: Large Vortec bowtie, Engine?

Post by Keith Morganstein » 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.
Automotive Machining, cylinder head rebuilding, engine building. Can't seem to quit #-o

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Re: Large Vortec bowtie, Engine?

Post by F-BIRD'88 » Fri Sep 14, 2018 2:05 pm

Glad to see others are mailing down the nitty gritty re the intake on vortec heads. I agree that a raised port intake is not the same or intent as a vortec head intake manifold.
No I don't have any pics or videos of Port insert tongues but we did just this on a set of brodix track 1 heads that some one way over ported including the port floor. We filled in the intake port floors about 1/4' with epoxy. The torque can way up. Port air speed cam way up. Peak flow went down a little. Dyno torque up, power about the same. . car et'd quicker as a result. That was the point.
355 cid SBC. It worked just like I said it would.
Yes you can make up removable inserts that will not fall apart. And or fill the port and intake floors with epoxy.
(Which you can remove later if needed for a different engine. Use a vortec intake to start with.
Super stock racers have been filling port floors and intake runner floors for decades.
Nothing new.

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Re: Large Vortec bowtie, Engine?

Post by Tuner » 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^^ :D 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.

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Re: Large Vortec bowtie, Engine?

Post by Tuner » Sat Sep 15, 2018 11:04 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^^ :D 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.

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Re: Large Vortec bowtie, Engine?

Post by rustbucket79 » Sat Sep 15, 2018 11:19 am

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.
I've never been involved with dirt oval engines, is there possibly some advantage to having somewhat of a "soft" powerband coming out of the corners?

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Re: Large Vortec bowtie, Engine?

Post by zums » 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^^ :D 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

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Re: Large Vortec bowtie, Engine?

Post by Tuner » 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
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^^ :D 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.

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Re: Large Vortec bowtie, Engine?

Post by zums » Sat Sep 15, 2018 8:20 pm

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^^ :D 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.
Well, a civil response, i can deal with that, yes, i also dont subscribe to the typical curve, it has to be specific for the engine combo and track, i was simply pointing out that from an efficiency stand point they need to be worked for each different combo, if you ever saw one, GM scallops out the side of the port for pushrod clearanse which makes the pinch limited to what you can do without welding, so basically out of the box you have a large gradient across the port, not the best scenario for v/e if rules allow working, also the large avr csa is not the best for his cube , compression, rpm and longer rod, so is it better to spend thousands to fit the engine to the head , or fit the head to the engine , comp, gear ect
Tom

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Re: Large Vortec bowtie, Engine?

Post by 88bluestar » Sun Sep 16, 2018 12:09 pm

Probably selling them. I literally have way to much gearing at a 7.00 final to even help it pull thru the bottom of the turns. Anyone want to trade for an equal set of small Vortec bow ties lol!?

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