Question for the Tunnel Wedge intake experts?

[427LX]

Would it help flow into runner if this radius area is larger than  the 1/4 inch radius as cast?  Will be running a 1 inch 4 hole merge type spacer also.

[pbf777]

     The "ultimate Flow" capacity, yes; power, driveability as a whole, maybe maybe not.  And the ideal execution, resulting in the best effect of that which one intends to address is going to differ, this due to the surrounding componentry and environmental conditions.   

     For example, I wouldn't say that the use of  "a 1 inch 4 hole merge type spacer" is always going to be "better" either!   

     Nope! Not the answer you were looking for, but the honest one.   

     Scott.

[427LX]

Have to have a starting place and figured some here have been around the block once or twice with this type manifold.

[Urgefor]

To elaborate a bit more on Scott's response, more information is needed to effectively answer your question.  Without more info, information provided could easily be incorrect once the build is finalized.

[Joe-JDC]

Before making changes to the intake, you need to know how much the heads flow, and how much the manifold runners flow.  If the manifold flows 110% or more of the head flow, then it is unnecessary to modify the intake for street usage.  Making the radius larger will only slow down the velocity in the runner because it shortens the runner's effective taper.  Joe-JDC

[MeanGene]

Joe, what is your opinion of the factory TW verses the Dove version? I have heard that the Dove is larger inside- better or worse? I have a Dove that came off a V-drive boat, and has two 660's with 2" spacers- spacers may have been for looks considering the boat history? Thanks!

[Joe-JDC]

The Ford TW as cast flows ~385-390cfm, and the Dove TW flows nearly 500 cfm as cast.  The Ford TW with a simple cartridge roll will flow 410cfm easily, and porting it to the 1247 gasket size will get 480cfm or more.  The TFS TW flows 500+cfm with the same port work.   A local Ford racer gasket matched his Ford TW and immediately lost 20lb/ft torque and the car slowed down.  He didn't believe me when I told him he slowed down the airflow, but the dyno test later proved it along with the slower et.  I ran two 2" open spacers on my 454 MR TW so that I could position the 660s in conventional direction instead of backwards.  Work well, but I had to go to a deeper gear to keep the et.  The Dove TWs that I have ported, flowed, etc., had a much larger plenum, and I don't personally know anyone who has successfully raced one.  I still have the Ford TW and a TFS TW, so I may be a bit biased.  Joe-JDC

[MeanGene]

Thanks Joe! Love to hear from someone who has had success with one. Thinking about selling it as I have an original PSE adapter plus two of Jay's new ones

[hwoods]

what about flow #'s on the BBM Tunnel Wedge?  TKS

[427LX]

Before making changes to the intake, you need to know how much the heads flow, and how much the manifold runners flow.  If the manifold flows 110% or more of the head flow, then it is unnecessary to modify the intake for street usage.  Making the radius larger will only slow down the velocity in the runner because it shortens the runner's effective taper.  Joe-JDC

Thanks for the info on the top radius Joe!  After I posted this question I found some info that making it larger will slow the air speed in runner a bit. This intake is cast for the 351W 9.5 deck engines and I will run it on my tried and true 427W which has about same bore/ stroke as a 428. Heads are TFS 225 HP and flow 330/258 at .600 lift. Cam is a 241/249 .600 HR and has been running great for 15 years now. Valve springs by Pac replaced 6 years ago.