What's the most power anyone has ever got out of a Tunnel Port ?

[e philpott]

How much power and at how many cubes is the most HP anyone has ever achieved out of the Tunnel Port ? 

[blykins]

Probably the best bang for the buck that I’ve done was a 696 hp 465ci Tunnel Port.

I’ve also done a 725 hp one, 511 cubes, with a solid flat tappet.

[e philpott]

is the 465 Gary's ? Both of those are stout for what they are and to me thats impressive for a cast iron factory head just as MBrunson TP on the dyno page

[TomP]

The heads that i raised the exhaust ports on made 660hp on a 454" with the factory single 4V and a sold flat tappet cam. That was with 5/16" stem 2.25 Hemi intake valves and 1.80" exhausts. The floors and top of the exhaust ports were welded up and the ports kind of looked like Blair's Super Stock heads. Sold those heads in 1990 and never seen them since or the 48 Ford truck the engine was in.

[1968galaxie]

Took a picture of an old Ford pickup several years ago at a car show.
Tunnel port 427 - interesting way up in Edmonton.

[TomP]

That could be it! I only ever saw the pictures of the truck the guy showed me, don't recall the flame but it was black and looked like something built in the 60's or 70's.

Though if it still has the heads (identifiable because the tops of the exhaust ports are welded up), those exhaust manifolds would cork up the raised ports. The port came to within 1/8" of the top bolt threads. I made header flanges that used a 5/16" bolt from the back like an MEL.

[django]

In 1969, a guy named Sam Auxier ran a 69 mustang in ultrastock (predecessor of pro stock). It had a tunnel port. It ran 10 teens.

[Qikbbstang]

I'd like to see some logically obtained flow-numbers of TP heads w/ some sort of runner to synthesize the pushrod tube in intake manifold.  vs "known" typical High-Perf FE heads....
Sammy Hagar "classic"  GT500 TP


https://www.youtube.com/shorts/LNEAiBSW6zA

[Qikbbstang]

It dawned on me that due to the FE's intake manifold/cyl head arrangement that comparison of a tunnel port intake runner/port must have a synthesized runner/with pushrod tube to test flow rates.. Almost comical to run cylindrical pushrod tubes through the port and not try out making sharpened leading and trailing edges. 

[mike7570]

How about the least power?  Or what a factory street TP would have been.
I had a factory supplied engine used by Mickey Thompson for endurance record attempts at Bonneville.
The only item I didn’t have was the correct carbs. The engine was stock 427 bore and stroke, 12.5-1 pistons, nascar rods, stock iron heads, 8v intake, stock adjustable rockers and solid lifters. Cam lift was about .577 (I didn’t know the duration) it even had a factory nylon coated timing chain gear.
I ran the ET & MPH numbers through Wallace Racing calculator and it showed the factory stock engine produced approximately 540hp.

[e philpott]

540HP is stout back then out of 427 cubes , was this engine a 1967 ?

[mike7570]

540HP is stout back then out of 427 cubes , was this engine a 1967 ?

It was built in 68/69 as far as I know. I was told Ford supplied all the engines for 3 different cars that Mickey Thompson took to Bonneville. I used 660 Holleys off my jet boat since it didn’t come with carbs. I also purchased Hooker adjustable race headers, not sure what Ford would have supplied for the exhaust.
(Paid $3,500 for the engine in 1983 😁)