Oval tunnelram core shift.

General engine tech -- Drag Racing to Circle Track

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pdq67
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Re: Oval tunnelram core shift.

Post by pdq67 » Mon Sep 11, 2017 1:07 pm

mag2555 wrote:Well in the first photo the pair of ports on the left are off set such that it would not hurt the flow, but with the pair of ports on the right that's a different story, as that off set is making for a tighter bend !

The Gaskets themselves look good to me and with the exit of the runners being so much under sized I do not see a issue once a normal port match is done but for what I posted about those right side pair of runners, as getting those right will take more work then just a port match!

Also a factor is these are cast to work with the peanut port heads too!

I hope your buddy understands that with amount of cid and today's other Manifolds for these oval port motors that there is no need for a 2-4bbl tunnel ram unles your into the eye candy of it ,or buzzing the motor up to the needed 8000+ rpm with that cid to use it!

Peanut port heads intake ports are wider than they are tall!

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F-BIRD'88
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Re: Oval tunnelram core shift.

Post by F-BIRD'88 » Mon Sep 11, 2017 1:12 pm

Don't equate the modern Perf RPM Dual Quad high rise with a old low rise dual quads/tripower.
it is a more powerful better beast. When you add carb spacers for height you get effectively net longer runner tuning too. Especially if you maintain the 180° plenum split in the spacers. (divided or hybrid type).
"dual plane"

GARY C
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Re: Oval tunnelram core shift.

Post by GARY C » Mon Sep 11, 2017 2:52 pm

Looks like it needs to come forward about 3/16" and gasket matched. How well does the distributor hole line up?

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Re: Oval tunnelram core shift.

Post by midnightbluS10 » Mon Sep 11, 2017 3:36 pm

mag2555 wrote:Well in the first photo the pair of ports on the left are off set such that it would not hurt the flow, but with the pair of ports on the right that's a different story, as that off set is making for a tighter bend !

The Gaskets themselves look good to me and with the exit of the runners being so much under sized I do not see a issue once a normal port match is done but for what I posted about those right side pair of runners, as getting those right will take more work then just a port match!

Also a factor is these are cast to work with the peanut port heads too!

I hope your buddy understands that with amount of cid and today's other Manifolds for these oval port motors that there is no need for a 2-4bbl tunnel ram unles your into the eye candy of it ,or buzzing the motor up to the needed 8000+ rpm with that cid to use it!
If it's core shift and not just exit hole shift, the entire port should have moved over, not just the exit which would have caused a lengthening or shortening of the port if the curve changed shape. Where'd the extra length come from or go? The plug that keeps that cavity open and not filled with metal is a specific shape. It can't just grown an 1/8", can it? If it moves, the entire piece moves, doesn't it? Or am I completely wrong here?

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Re: Oval tunnelram core shift.

Post by Tuner » Mon Sep 11, 2017 4:08 pm

Does anybody know which is out of place, the ports or the bolt holes ?? The ports could line up fine on the engine, but the bolt holes could be FUBAR.

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Re: Oval tunnelram core shift.

Post by GARY C » Mon Sep 11, 2017 11:57 pm

Tuner wrote:Does anybody know which is out of place, the ports or the bolt holes ?? The ports could line up fine on the engine, but the bolt holes could be FUBAR.
Thats why I asked about the dizzy hole, may just need to elongate the bolt holes.

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Re: Oval tunnelram core shift.

Post by mag2555 » Tue Sep 12, 2017 6:24 am

Looks to me like the gasket is made correct with the bolt hole centered on top of the port divider, no?

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Re: Oval tunnelram core shift.

Post by jeff swisher » Sun Sep 24, 2017 10:11 pm

The bolt holes all lined up as did the distributor hole..For those that were wondering.
He sent it back and scored a used one 150 miles away for less than 230 bucks and here is how it looks with the same gasket.
It is a Weiand also.
intake joe.jpg
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