604 Crate Motor modded for road race

[JodyB]

How would the 2814 super victor meant for vortec bowties line up with the fastburn Hint, hint

[DaveMcLain]

I have one of those intakes here at the shop from a 604 crate engine. About a month ago I was running through four different intakes on a 383 Chevy engine intended for a jet boat. I tried the "Bowtie" single plane just for fun and I was amazed that while the power was about the same as the Performer RPM it dropped about 20lbs/ft of torque through the mid range. Granted this was not a high RPM engine build but neither is a 604 crate engine and after talking it over with a few other people I don't understand why GM would have used this intake on the 604 where I'd bet that a good dual plane would give it a spanking over a realistic RPM band.

[pamotorman]

maybe they had a lot in stock and this was a good way of getting rid of them.

[randy331]

I have one of those intakes here at the shop from a 604 crate engine. About a month ago I was running through four different intakes on a 383 Chevy engine intended for a jet boat. I tried the "Bowtie" single plane just for fun and I was amazed that while the power was about the same as the Performer RPM it dropped about 20lbs/ft of torque through the mid range. Granted this was not a high RPM engine build but neither is a 604 crate engine and after talking it over with a few other people I don't understand why GM would have used this intake on the 604 where I'd bet that a good dual plane would give it a spanking over a realistic RPM band.

What were the others you tested ?

Randy

[DaveMcLain]

I have one of those intakes here at the shop from a 604 crate engine. About a month ago I was running through four different intakes on a 383 Chevy engine intended for a jet boat. I tried the "Bowtie" single plane just for fun and I was amazed that while the power was about the same as the Performer RPM it dropped about 20lbs/ft of torque through the mid range. Granted this was not a high RPM engine build but neither is a 604 crate engine and after talking it over with a few other people I don't understand why GM would have used this intake on the 604 where I'd bet that a good dual plane would give it a spanking over a realistic RPM band.

What were the others you tested ?

Randy

I tried the Performer Air Gap, the Performer RPM and the Performer RPM Air Gap as well as this Bow Tie intake. There was a thread about it that I posted here on Speedtalk about a month or so ago. The application is a 5500RPM 383 for a jet boat and in my testing the Performer RPM was the best overall intake manifold. It made the most torque without sacrificing any significant HP to any of the other candidates. Best carburetor spacer on either RPM was a "hybrid" made from a four hole 1 inch with an oval over the top side and two holes over the deep side of the dual plane intake.

[In-Tech]

How would the 2814 super victor meant for vortec bowties line up with the fastburn Hint, hint

Thank you, I had a look at the specs compared to this gmpp that has port sizes for a std vortec head and it will be here tomorrow As a matter of fact, all the parts I ordered will be here tomorrow

[randy331]

I tried the Performer Air Gap, the Performer RPM and the Performer RPM Air Gap as well as this Bow Tie intake. There was a thread about it that I posted here on Speedtalk about a month or so ago. The application is a 5500RPM 383 for a jet boat and in my testing the Performer RPM was the best overall intake manifold. It made the most torque without sacrificing any significant HP to any of the other candidates. Best carburetor spacer on either RPM was a "hybrid" made from a four hole 1 inch with an oval over the top side and two holes over the deep side of the dual plane intake.

Ok, I remember that thread. Was just wonderin if the 2814 was included in the tested intakes.

The vortec bowtie you mentioned, in un-ported form, takes a lot of flow off a ported head. I've seen it take 50 off a ported large port Vortec head, and Ported GMPP fast burns, but was pretty good when relatively mildly ported. Was only takin 20 off after porting and made very good power on the engine.

On a set of un-ported Small port vortecs the un-ported bowtie only took about 20 off and that combo of un-ported small ports and GM intake made surprising power for what that engine was. Likely a dual plane would have made more TQ on that one.

The Motown has looked good in that mix too. Any chance you've tested it ?

Randy

[CGT]

How would the 2814 super victor meant for vortec bowties line up with the fastburn Hint, hint

It could be made to line up well, but it wouldn't be the best choice in my opinion. Nice manifold though.

[DaveMcLain]

I tried the Performer Air Gap, the Performer RPM and the Performer RPM Air Gap as well as this Bow Tie intake. There was a thread about it that I posted here on Speedtalk about a month or so ago. The application is a 5500RPM 383 for a jet boat and in my testing the Performer RPM was the best overall intake manifold. It made the most torque without sacrificing any significant HP to any of the other candidates. Best carburetor spacer on either RPM was a "hybrid" made from a four hole 1 inch with an oval over the top side and two holes over the deep side of the dual plane intake.

Ok, I remember that thread. Was just wonderin if the 2814 was included in the tested intakes.

The vortec bowtie you mentioned, in un-ported form, takes a lot of flow off a ported head. I've seen it take 50 off a ported large port Vortec head, and Ported GMPP fast burns, but was pretty good when relatively mildly ported. Was only takin 20 off after porting and made very good power on the engine.

On a set of un-ported Small port vortecs the un-ported bowtie only took about 20 off and that combo of un-ported small ports and GM intake made surprising power for what that engine was. Likely a dual plane would have made more TQ on that one.

The Motown has looked good in that mix too. Any chance you've tested it ?

Randy

I've never tested a Motown intake and to be fair I would bet that the GM single plane would have fared better if I had been turning it another 1000 or so more RPM. Some time I'd like to try a set of the GM fast burn heads on a build. I think they would work great but the last time I checked they were kind of expensive when compared to other things.

[randy331]

I think they would work great but the last time I checked they were kind of expensive when compared to other things.

They are. I think they are over $1100 bare now, and over $1500 assy. Not many want to pay that when you can buy an entry level AFR head for just a bit more.

CGT on here can tell you current price.

If you bought them bare and put even a reasonable set of valves/springs/locators/retainers/locks/ etc and went to 7/16 rocker studs you'd be over $1500 and have a head that flows 260 cfm.

The set on my engine have good 5/16 stem valves, nextec springs, tool steel retainers, I probably got $3000 in them now with machining too.

But those Fast Burns ported make surprising power and produce some of the best BSFC #s for a 23* head.

Randy

[JodyB]

I agree with randy331. For the price point, the fastburns are a questionable option. Out of the box, mine look like crap compared to the large port iron vortec bowties i've seen. Though gm is pricing them out of the market as well. Given the mowtown vortec intake is out of production, i'm gonna stick with a 2814 as the best grind-to-work.Maybe a 2971 if you're ready for a real headache

[dfarr67]

When I was shopping vortec heads it came down to Edelbrock etec200, GM fastburn 200, AFR vortec (base cnc). There was no info on the GM head, the etec was supposed to be good in a ported version- but when all the costs are considered I bought the assembled AFR name....also I was concerned about the GM exhaust port fitting existing headers.

[randy331]

Given the mowtown vortec intake is out of production,

The 061040 Motown and the 061041 Motown are the same casting just machined different.

I have both those part Numbers in the shop and both have 061040/061041/061050 cast into the lifter valley side but the part number it is, is machined into the top.

I think the intake flange is only difference. The 041040 is .470" ish thick while the 061041 is .630" ish, but if I remember right the 061041 has had a little machined off the intake flange so it was even a little thicker, but the 061040 is new so it's like it came.

You could make the 061040 work on vortec heads with a thicker gasket. It's been better than the 2814 in the tests I've seen.

Randy

[Keith Morganstein]

The Motown vortec intake was the best I tested on Bowtie vortec heads.
I mocked one up on both stock and EQ vortec heads. The Motown runners were much larger than the head ports on the stock style heads. It didn't line up very well either so I never tested it on those stock style heads. Maybe I should have?

[zums]

Hold on,, before you throw dirt on the 2814, its csa is bigger than all listed so if you are going to use it, it needs more rpm before its size is a benefit, on a 355 its going to need to be higher than 8000, to beat a motown, whoever posted that the GM eliminator was not a good intake obviously didnt put some time into examining the plenum, with a little work they are a decent manifold- the 2814 also lines up better than most with vortec bowtie heads
Tom