Odd gen 1 intake manifold measurement request

Chris_Murder

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I would like to know what are the diameters of tubes for the upper part of the gen 1 intake manifold as well as the lengths of the primary and secondary tubes.

If anyone could post up that information it would be greatly appreciated.

Thanks,
Chris_Murder
 
I've got one in the storage shed and could measure the tube diameters but without cutting the plenum open, I don't know how I would measure the lengths?

I am actually interested in doing this to compare the intake runners to other intakes, just not sure how to go about it.
 
I've got one in the storage shed and could measure the tube diameters but without cutting the plenum open, I don't know how I would measure the lengths?

I am actually interested in doing this to compare the intake runners to other intakes, just not sure how to go about it.

String and a tape measure would be enough for approximate runner length for what I need. However I will need the short and long runner lengths.
 
I'm not sure what Chris is cookin', but I am curious on the runner length and volume of the Cobra intake vs. the combined primary and secondary runners of the Gen1 intake.
 
OK, here are some pics and numbers...

Here is a shot of the intake runner openings where they would bolt up to the IMRCs...

IMG-20120401-00395.jpg


Side shot of intake...

IMG-20120401-00396.jpg


Measuring ID of runners...

IMG-20120401-00399.jpg

IMG-20120401-00400.jpg


I concluded after several measurements the ID of the runners to be 31mm.

They measure a bit funny the other direction because of the oblique angle to the face of the intake...

IMG-20120401-00401.jpg

IMG-20120401-00402.jpg


Note the different lengths of the primary and secondary runners...

IMG-20120401-00403.jpg

IMG-20120401-00405.jpg


Also note how the shorter runners tuck under the longer runners...

IMG-20120401-00404.jpg


To get access to measure the length of the runners, I removed one of the blowout plugs in the bottom of the plenum...

IMG-20120401-00406.jpg


Using a piece of small diameter poly rope with a couple o-rings slid onto it for movable markers, I was able to determine the length of the runners. The short runner inside length measured 6.75 inches (172mm) and the long runner inside length measured 9.125" (232mm). Note these lengths are along the inside edge of the runner(s).

The OD of the runner tubes pretty much measured 35mm...

IMG-20120401-00408.jpg


With an ID of 31mm and an OD of 35mm, the wall thickness is approximately 2mm which is pretty thin for anyone thinking about porting the intake...

IMG-20120401-00409.jpg


I may later cut the plenum apart and rig up a jig to measure the runner volumes but this should give enough info for what is needed for now.

I hope this helps. :)
 

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