Retro-fitting roller lifters in 2 piece rear main seal blocks...

[chevybuilder18]

this is for those who didnt know about the bowtie vortecs, this article is an older one but now i have the latest revised ports to 225 cc's and D shaped exh port. this zz4355 was to small to get the heads to perform better.... but this is an example of how streetable the bowtie iron vortecs perform
http://www.superchevy.com/technical/...c/viewall.html if my 406 took complete advantage of the heads, we should see 450 hp and still a good amount of torque up to 480+ with the right roller cam.

"When it came to the best performance with the Vortec Bow-Tie heads, the results included 391 hp with the small-port heads and 386 hp for the large-port heads. The engine power curve peaked at 6,000 rpm with the Vortec Bow-Tie heads.The 391 hp average peak achieved with the small-port heads included the engine equipped with the single-plane Vortec intake, 1.6 rockers, the hot cam, and a 2-inch carb spacer. The same configuration was used with the large-port heads to achieve their 386 hp average.

So, why the 5hp difference with the smaller-port heads? Displacement, mostly. The large-port heads could use a larger-cube engine to make the most of their capability. Regardless, the new iron heads showed that they had the flow to keep up with--and surpass--aluminum heads.

The test session didn't compare aftermarket heads with the new Vortec Bow-Ties, nor were the iron heads ported or machined in any way. They were out-of-the box examples. We're interested to see how these low-cost alternative heads would fare against the competition, as well how airflow will improve with a little careful grinding.

The initial impression is not only encouraging, but downright impressive - especially for those of us on a tight engine-building budget. And for "spec-head" circle track engines, this latest version of the famed Bow-Tie iron head family seems just about perfect." These words came from the author and those are his words, not mine.



Read more: http://www.superchevy.com/technical/...#ixzz2BSfogKNU

[chevybuilder18]

Thinking hard about swapping 3 speed manual tranny in to my truck here soon, and fixing the doors, which i will post in a different thread.

[wraprail]

How old are you?
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[BigBlocksRule]

chevybuilder18, I love the big port heads but those tests were bogus.
I hope to take a couple of pics of production vortecs next to the bowties. The port on the bowties is almost 1/4" taller than production heads. If they used a standard vortec intake, there was a HUGE mismatch at the top of the port. This will create a huge amount of turbulence, particularly since there's a lot more airflow along the top of the port than the bottom.
I have the Chevy logo'd single plane intake, it's nuts how much material I'm going to have to remove just to get the ports to line up.
The big port vortecs are easily 550hp heads, better than any other iron offering I've compared 'em to.

[chevybuilder18]

Originally Posted by BigBlocksRule

chevybuilder18, I love the big port heads but those tests were bogus.
I hope to take a couple of pics of production vortecs next to the bowties. The port on the bowties is almost 1/4" taller than production heads. If they used a standard vortec intake, there was a HUGE mismatch at the top of the port. This will create a huge amount of turbulence, particularly since there's a lot more airflow along the top of the port than the bottom.
I have the Chevy logo'd single plane intake, it's nuts how much material I'm going to have to remove just to get the ports to line up.
The big port vortecs are easily 550hp heads, better than any other iron offering I've compared 'em to.

Yes there very big. I wish they made the right matching intake manifold to fit. I ask summit, and they told me the stage 4 summit vortec runners would match up i wasnt looking for single plane. if i have to port match vortec manifold to this setup i will do it.
Wraprail, im 19 going on 20. if this seriously doesnt add up to you im completely sorry. but keep an eye out and if i start looking wierd or something just let me know

[chevybuilder18]

Originally Posted by BigBlocksRule

chevybuilder18, I love the big port heads but those tests were bogus.
I hope to take a couple of pics of production vortecs next to the bowties. The port on the bowties is almost 1/4" taller than production heads. If they used a standard vortec intake, there was a HUGE mismatch at the top of the port. This will create a huge amount of turbulence, particularly since there's a lot more airflow along the top of the port than the bottom.
I have the Chevy logo'd single plane intake, it's nuts how much material I'm going to have to remove just to get the ports to line up.
The big port vortecs are easily 550hp heads, better than any other iron offering I've compared 'em to.

I forgot to add. All vortec runners are taller than the stock sbc. so any kind of manifold they had, did a run with, could of been port matched. with that being said, im going with a dual plane Wieands vortec manifold. i have seen this manifold, i am not impressed but it has the top of the runners on there where itll match with the line on the bolt holes. the bolt holes on my heads match dead even with the intake port, and this seems like the vantage point. i might have to seriously match these runners http://www.summitracing.com/parts/wn...make/chevrolet[

[BigBlocksRule]

The single plane lines up with production heads perfectly, only the Bowtie is a big mismatch. The raised roof of the port comes to us from LS engines, specifically the cathedral port heads. The higher the port roof, the straighter the shot from the carb venturi to the back of the valve. And that spells big airflow...
I'm considering using mine on a flat topped 406, around 12.5:1 compression on E-85.
As soon as the benefits to the corn lobby expire, we'll make ethanol out of something other than food. Sugar beets show the most promise with little waste, high sugar content, nearly weatherproof and don't really have a use other than sugar production. At any rate, I intend to show that when E-85 is run at a compression that makes it comparable to current pump gas compressions (I think 12.5:1 should be safe, like today's 87 pump gas with 9.5:1), the mileage will come up and the savings will be realized. 12.5 on the street should be pretty zippy and with the capabilities of the bowtie vortec head, it should make for a fun street/strip engine.

[chevybuilder18]

Originally Posted by BigBlocksRule

The single plane lines up with production heads perfectly, only the Bowtie is a big mismatch. The raised roof of the port comes to us from LS engines, specifically the cathedral port heads. The higher the port roof, the straighter the shot from the carb venturi to the back of the valve. And that spells big airflow...
I'm considering using mine on a flat topped 406, around 12.5:1 compression on E-85.
As soon as the benefits to the corn lobby expire, we'll make ethanol out of something other than food. Sugar beets show the most promise with little waste, high sugar content, nearly weatherproof and don't really have a use other than sugar production. At any rate, I intend to show that when E-85 is run at a compression that makes it comparable to current pump gas compressions (I think 12.5:1 should be safe, like today's 87 pump gas with 9.5:1), the mileage will come up and the savings will be realized. 12.5 on the street should be pretty zippy and with the capabilities of the bowtie vortec head, it should make for a fun street/strip engine.

This is exactly what id like to do. but some guys shot me down on a different forum. going off topic here, id like to be able to call the people on here checkin this out by there first name if i could have the priveledge to.

[chevybuilder18]

BigBlocksrule, have you seen the intake example i put up? Vortec manifold, stealth intake its in the link above in my earlier posts. I know its a fubar if i buy this, but look at your heads, bolt hole location, and intake port location. the tops of the runners are dead even with eachother. even on these after market intakes the bolt holes and the roofs match up. the heads possibly could take these intakes.

[BigBlocksRule]

I'll put a dial caliper on my heads and intake when I get to the shop tonight. If those intakes were a fit for production vortecs, there's no way they'll fit these bowties without major port work.

[chevybuilder18]

Originally Posted by BigBlocksRule

I'll put a dial caliper on my heads and intake when I get to the shop tonight. If those intakes were a fit for production vortecs, there's no way they'll fit these bowties without major port work.

true but that doesnt shake me. if this doesnt pan out, ill kiss your but.

[INSIDIOUS '86]

What exactly are you trying to get this engine to do? For the money I've alway figures that there was a lot better heads out there than aftermarket vortecs. 225cc heads on a 350cube engine for the street is to much no matter how its shaped
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[BigBlocksRule]

The raised roof/runner makes it measure bigger than comparable heads since they're actually a bit longer. It would be more like 200 if trying to compare apples to apples. That's still a big honkin' head for a 350, but just right for a 400. The smaller bowties might be a better deal on a smaller engine.

[chevybuilder18]

These heads arent going on any 350.. lol that would be a flop on my part. just saving em for my tapped and drilled roller 406 just got done tapping the stud hole in the engine area. what do i wanna do with this. i have been trying for a cam from howards, 110 lsa, .495/.510 advertised 276/280 and at .050 231/? i cant remember the rest of the specs but the idea for the 400 is good valve lift, 9.5:1 SCR and a DCR that isnt gonna ruin my engine. predetonation isnt what i want. 2000 to 5500 rpms odda be good enough for rpm range, however, the heads might make it acceptable to make power at both low and top if port matched right, make the 406 produce power from 1800-6400 which the heads would support, and displacement, cam and intake make that possible. so yea i predict the engine will behave from 1800-6400 with these huge heads, not that ill ever go over 6400 rpms.

[chevybuilder18]

Look closely at these runners and bolt hole placements. they are nearly there, just few cc's off

[chevybuilder18]

waiting till next winter to get this 406 built. but spring time will be the machining part. Lets hope everything goes good. but for right now im gonna lower my truck and tidy it up, put some new rocker panels in, cab corners, and new doors in my truck so shes tucked up. also putting a new tranny in the truck, which ill keep posted about. whenever you guys feel like chiming in at anytime go ahead, the subject is still free game as the title states...

[INSIDIOUS '86]

Think that cam will be just a tad to radical for these lifters. Requiring heavy springs which may kill th rollers. I wouldn't go past 6krpm with factory stuff and not over .5 inch lift
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[chevybuilder18]

Originally Posted by INSIDIOUS '86

Think that cam will be just a tad to radical for these lifters. Requiring heavy springs which may kill th rollers. I wouldn't go past 6krpm with factory stuff and not over .5 inch lift
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not even wanting to go over 6000 then. i might do something else. im gonna make a few changes SCR so i can run mild

[BigBlocksRule]

I took a couple of pics of heads and intakes yesterday, will get them posted soon.
The big vortec bowtie ports are approx. 1.2" x 2.3". Production vortec ports are approx. 1.1" x 2.1". By comparison, the port opening for a big block rectangle port head is approx. 1.7" x 2.3" - these bowties aren't much smaller than those!!! I have the Edelbrock Victor Jr. intake for these heads, port openings on these are actually smaller than the production vortec, it'll take a good bit of porting. They align perfectly on the runner floors, but will require some carving to get the roof right. Kinda nuts, the GM version of the Performer RPM for vortec heads is almost a dead-on perfect match.
The more I handle these heads, the better I like 'em.

[chevybuilder18]

Originally Posted by BigBlocksRule

I took a couple of pics of heads and intakes yesterday, will get them posted soon.
The big vortec bowtie ports are approx. 1.2" x 2.3". Production vortec ports are approx. 1.1" x 2.1". By comparison, the port opening for a big block rectangle port head is approx. 1.7" x 2.3" - these bowties aren't much smaller than those!!! I have the Edelbrock Victor Jr. intake for these heads, port openings on these are actually smaller than the production vortec, it'll take a good bit of porting. They align perfectly on the runner floors, but will require some carving to get the roof right. Kinda nuts, the GM version of the Performer RPM for vortec heads is almost a dead-on perfect match.
The more I handle these heads, the better I like 'em.

see i told you these heads were budget AFR killers Oh just to let you know check this out http://www.summitracing.com/parts/dr...make/chevrolet dart has the intake we need. wide rpm range raised runners, may take less grinding then those stock vortecs because these are meant for 215 cc runners. the shapes of these runners are what get to me