Ford 427 "tunnel port" head curiousity?

[540Hotrod]

Hi Barry,

We spoke at the Red Lobster dinner at PRI. Darin Morgan flowed that set of Tunnel Ports I was telling you about for us. We just had it on the dyno..but it's all stock but with the old 427/425 flat tappet. Didn't make 600 HP!

Intake

.200- 176.8
.300- 240.0
.400- 279.2
.500- 306.3
.600- 326.1
.700- 342.3
.800- 304.0

Exhaust

.200- 115.1
.300- 152.7
.400- 179.5
.500- 190.0
.600- 196.6
.700- 201.4
.800- 201.2


JIM

These had 2.25 intakes and have a NASCAR provenance. The ports had been cleaned up somewhat...but nothing radical.


JIM

[SupStk]

Just curious if any of you has flowed the TP heads with an intake attached?

[blykins]

I've finished up two Tunnel Port builds lately. Heads were worked over, mainly closing up the CSA.

First build was a 465 inch motor, Pond cast iron block with a steel RPM crank, 3.980" stroke. Solid roller camshaft, 10.5:1. It made 696 hp @ 7000.

Second build was a 511 inch motor, Pond cast iron block, steel Scat 4.250" crank. Solid flat tappet, 12.5:1, GZ vac pump. It made 723 hp @ 7000.

Both engines used a dual carb intake, with twin 715 cfm Quick Fuel carbs and 1" Super Suckers.

Heads flowed around 370 cfm at lift on the intake side. 200 on the exhaust side with no tube.

[DaveMcLain]

Those are certainly two cool builds Brent. I'm surprised that there wasn't a greater difference in power between the two engines.

[blykins]

There was 67 lb-ft between them. 657 lb-ft vs 590 lb-ft.

I imagine I crippled the big build by going to a solid flat tappet. However, with the solid roller, I was getting some fretting of the rocker stands (T&D street rockers) with the spring pressure I was running...and it's a big undertaking to install race T&D's on Tunnel Ports. Decided to back it off for the sake of longevity. The solid flat tappet motor got PAC beehives, set up at 170/440 lbs.

[piston guy]

The second time Ford won LeMans it was with a Tunnel Port. It was also THE choice for Nascar use until the emergence of the Boss 429. Lesser funded teams ran them for many years as well. Holman Moody made special ''air foil" pushrod tubes in an effort to streamline the air flow. Not a big improvement for the effort. Ford engineers revised the head at least ten times and even made some of them in aluminum. As others have noted , they do work better when the engine size is increased by a stroker crank.

[427dart]

I've finished up two Tunnel Port builds lately. Heads were worked over, mainly closing up the CSA.

One of the three best looking engines ever built...427 SOHC..426 Hemi and pictured the FE 427's !!

[Krooser]

1969-1970 saw me as a smart ass 20-something crewing on a dirt stocker in SE Wisconsin. We had a hi-po 289 in the car and the owner/driver really didn't like small blocks so he took me to the back of the shop and we pulled a tarp off of a bank of engines sitting there gathering dust. To my surprise there was a 427 medium riser, a 427 high riser and a 427 tunnel port... we finished the season with the high rise engine.

[BILL-C]

20160317_162446_resized.jpg

Just finished a tunnel port 427 for a GT40 today!

[piston guy]

Nice one Bill,
I wonder if that is my old distributor?

[wwmtlineman]

Didn't the leMans engines have lowered compression around 9-1 so they would run on the available fuel they had to use ?

[piston guy]

10.5 according to the build sheets from back in the day.

[BILL-C]

We bumped the compression up to 12.0 on this one. It will be run in the US on good gas. Made 648 HP @ 6600 rpm and 561 TQ @ 5300. Had 500+ TQ from 4100 up, and hp only dropped 2 by 7000. Someone's gonna get killed!

[BILL-C]

I don't know if that was your old distributor Randy. Did yours have the 1/4 or 5/16 hex ? This one had the small hex, and was starting to crack, so we got a different drive with 5/16 hex on both ends and a truck distributor shaft. Also had to ream block.

[Truckedup]

Anyway I had the thing in a 68 Mercury Cyclone, it was a scary fast car, the car would loaf at about 155 to 160 all day long turning about 6000 to 6100 rpm. Anything past that and it got very light and twitchy, not at all fun to drive. About the most I ever saw on the tach was just shy of 7000 I guess that was about 180. If I had a clue about aero at the time or had listened to the guys that sold me the engine and bought the Talladega aero package they had for the 68 Cyclone I have no doubt it would have run 200+ easily. As it was I could make the run from Tampa to Gainesville on the then brand-new and nearly deserted on Sunday night I-75 in about 50 to 55 minutes, if I didn't run out of gas, which I did a time or two. In the low gears the car would turn well over 8000 very easily. So yeah the TP heads on a good block with a good cam, even way back when, was one very very serious piece.

180 mph on the street in a 68 Cyclone..? 160 MPH all day long ? Ok............