[DeTomaso] Cleveland "Tunnel Port" Heads on ebay

[adin at frontier.net]

Bwahahaha - I remember watching the famouse rufus/capt. nice [1] trans  
am battles at Laguna Seca and Sears Point.  (Bud had two cars for  
Jones - one w/ grey interior and one w/ black interior.  One car just  
to cook while qualifying!)  Ol' rufus would twist that qualifying  
motor till the exhaust valves stuck out of the tail pipe - a sweeter  
sound you've never heard! (Well, the Canam McLarens w/ the Traco  
motors were sweet, too - if chebbies)

Ahhhhhhhh, those were the days . . . . .



[1] Rufus Parnelli Jones/ Mark Donohue


Quoting Daniel C Jones <daniel.c.jones2 at gmail.com>:

>> Ford tried tunnel port heads on 289 hi-po engines but found there was no
>> advantage over simply putting bigger valves in a std head.
>
> The 289/302 tunnel ports were the result of a rapid development program
> to increase the flow of the SBF head for Trans Am racing.  The tunnel
> port allowed a large area straight intake port that didn't have to bend
> around the pushrod. 2.12" diameter intake and 1.54" exhaust valves were
> used compared to 1.78" and 1.45" for the standard SBF head.  They made
> more power and were an advantage over standard SBF heads but the engines
> had reliability problems at the RPM they needed (tunnel port engines
> used an 8500 RPM rev limit).  One weak point was the the shaft mount
> rocker system borrowed from the Y-block.  Special connecting rods, a
> 4 bolt main, screw-in freeze plug, block and a forged steel crank were
> developed to help the tunnel port engines live and were carried over
> to the Boss 302 program which added the Cleveland canted valve heads.
> With the Boss 302's, reliability greatly improved and the rev limit
> raised to 9000 RPM.
>
>> These are likely salvaged experimental castings,
>
> The ones for sale were originally acquired from Junior Johnson who
> developed the tunnel port heads for Ford and are an early set that
> were used for valvetrain mock up on either a Fontana or Motorsport
> block (not the matching T-351 block).  Custom Jesel rocker arms were
> used.  Chad Decatur said the heads were ported by Diamond-Elkins and
> flowed 350 CFM on the intake side using 2.14" and 1.65" diameter
> valves. They were intended for Casey Luna's WOO sprint car but never
> raced.  A production batch was subsequently made and I've seen (in
> person) boxes and boxes of the heads and intakes, but not the matching
> blocks.  At one time, RDI was sitting on nearly the entire production
> run.  Dick Trickle won an Arca race at Daytona or Talledega with a
> pair, after which they were promptly banned.
>
> Dan Jones
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