Technical Tunnel Port 427...how streetable are they?

Odd...falcongeorge sent a great follow up answer, a copy of which is in my email, yet his post is missing. Did an admin remove it? :/

 

Lots of very good advice and info posted so far. I put a 352 in a 56 Ford (same chassis as 55 and,I believe, same external dimensions as the 427). As I remember, (swap done in 1960) one of the interference points was the flat and narrow block hugging stock exhaust manifold hitting the upper control arms. We solved the interference by raising the motor about 1/4 inch with shims under the motor mounts. If I remember correctly, the 1/4 shim did not raise the motor enough to fabricate a good set of headers at the flanges.

 

I removed it. the carb formula is a sacred cow on here, and I am not interested in endless meaningless debates about....trying to think of a polite word for it, but nothing is coming to me... As long as you got it that's the main thing.

 

I'm running 1500 cfm on my 427 Chevy.

 

geez, don't say that too loud on here Jim, they'll run you outta town on a rail...It'll be like Galileo's "Dialogue" all over again...

 

Well Hell, I'm running 2 ea 500cfm Edelbrocks on a 355 cid sbc, and they're hooked up straight, not progressive! And I have run up front on dirt with 800cfm on 302 sbc. I think that damn formula is a crock!!!!!!

 

....wasn't there a thread up recently about IR carb sizing?

 

I was told there would be no math on Fridays.
I actually am having a harder time understanding all the drama on this thread.

 

Google "Eagle crank failure", you'll get pages of issues. My friend lost a 331 SBF Ford with less than 2k easy miles on it due to a poorly cast and machined crank. Another friend built a 347 and had problems with it from the start, he put a handful of miles on it and the crank endplay was well out of tolerance in no time. Engine was built by someone who'd done dozens of high performance rebuilds and never had a problem with any of them until this Eagle crank. They finally swapped the crank out for something else and never had another issue.

 

Hmmm...doesn't feel like drama to me. Opinions differ, but so do the experiences of those who have them.

 

That Fairlane is too good to straight axle, looks just right IMHO!
A Google search on C7AE-A; 67 side-oiler or 68 marine FE block http://www.mustangtek.com/block/Block.html http://www.fordification.com/tech/castingnumbers-FEblock.htm
Screw in welch plugs and cross bolt mains. I only had a 390FE in my 66 GTA and Tri-Ys in RHD format (Australia) were a real PITA to install in a unibody with shock towers and that exhaust bolt pattern at 12 O'clock and 6 o'clock. I would think those huge tunnel ports whilst being impressive would love high RPM to get the best volumetric efficiency, similar to Boss 429 heads. What about some medium riser (MR) heads on the street as those tunnel port heads are rare these days. I would still love to side step the clutch with those TP heads

 

Great looking car! Loved the 56 CV I had way back when. I had 2 427's I ran back then but not in the 56. Had a 63 with a medium riser and like Beaner said it was way more engine than it needed (well maybe). The other was a 67 Mustang with a tunnel wedge. That was a fun car. Headers on both cars were a hassle even in the Galaxie. The Mustang's came in pieces and one tube on each side would crossover to the opposite side to the collector. I ran the same camshaft in both cars, a factory C8AX-D mechanical lifter. To this day it's one of the nastiest cams I have ever heard and boy did it run.

 

Dude, I hope you're gonna go forward with the TP heads. That would be a kick ass car with some serious wow factor built in. Exhaust is easy to figure out. Go for it!

 

It's happening, but may be longer than I thought. I won't run that block, or either crankshaft. After some research there's too many advantages to a beefed up block from Pond or Shelby to risk an old one damaging them. And to really make it streetable it wants to be stroked, so I'm building another 482 (just finished one a year ago). Probably run a TKO wide-ratio 5-speed manual with 600 hp...set up properly it could run the Power Tour. (Not sure I would, but it could.) I will go through the effort to get long tube headers possibly.

 

Oh, well. It was a neat idea, while it lasted.

 

Close inspection revealed that block had rotted from the inside out...it had been used in a boat and the corrosion in the water jackets must have been horrible...not much wall left, especially after being bored .040". If I run across a vintage block for cheap I'd be interested in building it, but great vintage blocks are still weak and not far off the price of aftermarket.

 

has it been sonic tested? if it has, pm the map to me, we'll talk. Its already .040 over eh? Well, that aint real good, but pm me anyway, we'll talk...

 

For the money that usually needs to be invested in an original block, not to mention the initial cost, and the added strength/improvements available with a new block, the cost of the Pond, BBM, and or Side Oiler Garage block looks more and more reasonable all the time.

 

Oddly enough, a gent who I called today on an original block told me the same thing.

 

....

 

OK two questions an they are just questions. One is why does a 427 need to be stroked to be streetable.

Then other is that tunnel port heads are designed to be run at a very high RPM and to take advantage of them they should be run at a very high RPM why would the transmission of choice for an engine that you want to keep wound up be a wide ratio transmission?

Again just questions.

 

its not about making the 427 more streetable, its about pulling harder on the tunnel ports earlier in the intake stroke. As the r/s goes down, peak piston acceleration goes up, and the peak moves earlier in the pistons motion. It will pull harder on the intake port earlier in the intake stroke. Overlarge CSA's tend to "like" low R/S and vise-versa.

 

I thought the whole point was to build a bad ass 427 for the street.

I was wrong.

 

These guys are friends of mine, the side exhaust I posted earlier was on one of their cars I just restored. My experience with the 482 in that car is what makes me happy to use the vintage upper end on a modern short block. I'd never do it on an original FE equipped car, but the Crown Victoria is a perfect candidate for this.

 

I understand the physics behind a longer plunger. It just seems counterproductive to me, if I were going to change the stroke at all (and this is just me) I would go to a 352 length stroke and make a very high winding 396 out of it.

You would be right if the thread were one of about 3 of us but yes you were wrong.

 

I'm with you Jim, just explaining the line of reasoning behind the stroker crank making a TP "more streetable". Rest assured that if (big if) I end up buying this block, it'll get a 3.78 crank...and a shitload of compression...

 

If this were a medium riser I'd find a better original block than the one I posted (it didn't pass our quality inspection) and use the original 427/$ crank I got and run with it. But regarding a tunnel port every higher end builder I've spoken with echo the same sentiments...
Modern blocks are vastly stronger
Minimum of 482 c.i. to run on street
Solid cam if ultimate h.p. is desired
Hydraulic cam if it will see road trips
Locate original carbs no matter what

Part of me still wants a nasty solid cam pulling 7800 rpm but the other knows I'm starting a business and spare time to babysit valve lash (aside from too many other vehicle projects) may not be readily available. Decisions, decisions.

 

And you do splain things better then I would Lucy.

 

PS...the original thread is a question...how streetable is a tunnel port? Turns out the answer is very, provided you have the displacement and dual plane intake, hydraulic cam makes it even more streetable. Less cool perhaps, but that wasn't the question

 

LOL I pitted on a car that we had to unload the valve train between rounds, I am running the valves on a car perhaps this afternoon between mowing on my acre of grass and working on my project and perhaps going to the dentist. Even for a novice you are talking half an hour once in a while to keep the valves in shape. Its not like every time to cruise to the store you got to adjust 'em and if it was that way it would not take you long to be in a position to unload the valve train between rounds.