Exactly what I am looking for - but I expect this has 2.9" or 3" runners? - I'll want 2 3/8" or 2 5/8" max runners.

BTW Hans4real sorry we have hi-jacked your thread!!!!!!!!

 

not trying to argue but wouldn't the fuel puddle up or be disturbed so much this wouldn't work?
I don't think I would even try to do it.....

We used a rectangle port rpm air gap on some big brodie BB2 plus heads and worked great...just had to fill the extra bolt hole with a plug. Without it plugged, it would have leaked.

 

I can't answer about fuel puddling or air flow disturbance, although I'm sure the disturbance is quite substantial. I do know if you install a rectangle port intake using a rectangle port gasket on oval port heads, it will work fine. I think the bottoms of the ports line up "fairly close". It's the top of the ports that are way off. My car has been this way,with several different intakes for 32 years. Currently it has a Holley Strip Dominator. It doesn't have the low end torque that it had with a GM 3885069 dual plane intake, so I may change it back someday.
This has been discussed here before and other forum members mentioned using rectangle port intakes with oval port heads with no problems. Also, rectangle port aluminum intakes seem to be easier to find.

 

No worries on the hi-jack, it's all relative in the topic.

Thanks for the input and all the ideas with the various replies. I appreciate the C3 gang. Looks like almost any BB intake will work with some ingenuity. Might just try the Torker and see if it works for my combo. If not, it's an easy swap back and a new search for the next option.

 

Asked and answered. Yes, you CAN use a rect port intake on oval heads. Yes, slapping them together without proper matching can present issues, and certainly isn't the best of practices. But, since proper matching CAN be readily accomplished (see post #14) the point is rather moot for anyone willing to follow thru with their work.


Glad you're OK with it, but my apologies anyway, as I didn't intend on my injector taking over here. Thought the topic had been sufficiently discussed.

Yep, it's a 2.9". Suggest you speak with Kinsler Fuel Injection (THE IR/FI gurus) about what is and isn't too much diameter for your specific needs/purposes. Bear in mind the overridding factors to optimum runner diameter and length are CID and at what RPMs you wish to maximize torque/power, with no required metering system signal for each cylinder.

 

Kinsler WOULD be the logical option for a oval or rect port unit - but soooooo expensive (especially so when adding shipping and UK taxes!!) - was considering using set from this guy - ebay item no. 251094717341

 

Understand....I was responding to the statement made about using rect port gaskets without mods to intake....

BTW, you changed your once rectangular port intake to oval port....different than using rectangular port intake on oval port head with just a gasket.....

 

I consider it a modified rectangle port intake that now fits oval port heads, but don't think we should get bogged down with semantics. Point is, there's a right way and wrong way of bolting these inherently dissimilar bits together, and we most apparently agree that simply slapping them together with a rect port gasket isn't the way either one of us would go about it.

FWIW, the epoxied intake I posted belongs to a fellow memeber local to me that followed my advice when he ran into this same issue. He used the race shop that I take most of my machine work to, tho I can't recall how much they charged, but I know it wasn't all that much.

 

If you do a bit of searching you can find quite a few references to people doing this.
Not only does it work, but quite often it works better than the "correct" intake does.

Here are a few excerpts from a thread over at Speed Talk-

I also have a customer that we built an engine for with oval port heads, and all he had was a rectangle port Team G intake.
After running it for about 3-4 months he changed to an oval port Team G, same intake just matched the heads better, and the car slowed down almost .2!
He called me wondering what the H@#& and all I could do is wonder the same thing. I can't explain it, but he went back to the Rect. port intake and the E.T. came back.
-----------------------
I saw a guy at the dragstrip wiith a retaangular tunnelram on ovel port heads. I worked at Edelbrock at the time, they said NOWAY. anyway, when he put on the correct manifold, his car SLOWED DOWN 10-11 MPH, and one full second, IT should not work, BUT it does.

JOE SHERMAN RACING ENGINES
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Back in the 70s & 80s Hardin Marine used rectangular int with oval ports.we wondered why so we did a back to back run with an equivalent oval port manifold.instant 28 H.P. with the rectangular manifold.any attempt to enlarge the oval port heads or roll the edges over to help the mismatch killed power.
------------------------

Also on the BBC Rectangular Manifold on an Oval Port Head ...

the first time i heard about anyone trying this was about 25 years ago
and that Racer claimed it was solid 2 Tenths ET gain !!!

about 6 or 7 years later a Customer came to the Dyno
and tried both an Oval Port -vs- Rectangular Port on
#781 Oval Port Heads in Back-to-Back tests.

then within a year of those Dyno tests,
i had another Customer try the same back-to-back tests.

in those Dyno tests from memory there was between 10 to 20 HP gains
with the rectangular port intake on oval port heads even with the
tremendous roof port mismatch !!!
10 to 20 HP should have only made about 1 Tenth ET gain,
yet most were claiming around 2 Tenths at the DragStrip.
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I cant explain it either, but I have heard it works well quite a few times.

 

Perhaps the mismatch aids port turbulence/velocity thus improving cylinder 'filling' ?

 

I'd caution extrapolating exceptions to the rule into any type of blanket statement that such mismatches are necessarily a good thing.

 

Well, back to the basics of the question, now that we have some great minds viewing the thread, if you were me and your options were to stay with the stock steel intake, go with the readily available Torker II or find a LS6 intake and modify for correct port matching, what would you do?

If I do go the route of least resistance and take with the Torker II, would that be better than the stock intake for a weekend driver?

 

In my opinion, If you have the stock intake and Q-Jet, You can't do much better, especially for a weekend driver.