Don Woodruff

Don W.

When I spoke to John about his upcoming manifold some months ago he indicated some areas of the BT were too large. I really do not want to bother him as I want a set of heads.

And here’s what Jon Kaase has to say about flowbenches.

I haven’t personally dyno tested a Blue Thunder intake against the ‘B’ iron intake but that is planned in the near future.  To date for intake comparisons on the Y, I’ve only tested Blue Thunders against modified Blue Thunders and sheetmetal (fabricated) intakes.  But there’s way too much talk about air flow numbers and not enough about air quality.  Keeping the velocity of the mixture high while at the same time being able to support a larger volume of air throughout the rpm range is the key.  Runner shape and size is critical in getting this to happen.  But regardless, the intake runners must have more flow capability than the heads or the intake tracts themselves will be the choke point and those enhancements performed to the heads will not see their full potential.

For the stock Y heads, the factory ‘B’ intake manifold is suitably sized (slightly larger) but any modifications to the heads requires the ‘B’ intake to also be appropriately modified so it continues to out flow the heads.  This is where the Blue Thunder intake shines as it’s more suited for heads that have been modified and/or engines that have been increased in cubic inch.  As has already been said, the BT intake is obviously oversized for dead stock engine applications but start working on the camming and heads for improved flow, the stock ‘B’ intake is suddenly inadequate for the job.  The new intake manifold being worked on by John Mummert is expected to be an improvement in regards to the lowend torque curve for these engines while still maintaining the higher rpm characteristics that the BT intakes are noted for.

But with a fresh 312 dyno mule engine currently being put together, I’ll be performing some serious testing on intakes in the near future.  Header testing is also being planned.  When that time comes, I’ll put the call out for some of the other single four intakes and headers that I currently don’t have sitting here.

Gary Brunette comments about J Mummert's massaging the interior of the BT were very interesting.

On The FE site there is a fellow J.D. Crain that specializes in equalizing the flow of intake manifolds. Dyno testing by Jay has confirmed benifits of his work.

                                                   Michael

Thanks Don.  I do deal quite a bit with Ford FE engines where dismal flow numbers are observed in the heads but the end performance on the engine breaks all the rules with the right parts selection.  With an FE, the intake tracts are the key due to the shortened runner design within the FE heads themselves.  This is not saying that the heads in this instance are not important but instead emphasizes just how important the intake manifold itself is.  But on plenum volumes, my own experience points to the FE plenum sizes not being critical whereas the Y seems to be overly sensitive in this area.  I’ve got my own thoughts on runner design and will be curious to see if Johns’ new Y intake also mirrors my thoughts in this regard.

Although I haven't given much thought to testing the factory exhaust manifolds, what you bring up makes it a valid area to pursue.  When the time comes, I'll put the call out for borrowing a set of rams horn manifolds just to throw on the engine and get some numbers.  There are already the early and late cast iron passenger car exhaust manifolds sitting here so those can be subjectively tested also.  Part of the criteria here will be to determine the size and length of the lead pipes to use with these manifolds to get a real world comparison.  May consider two different diameter lead pipes also as gut feel says there's a difference to be found here also.