[DeTomaso] Dyno Trip #1 and Roller Lifters.....

[Daniel C Jones]

> Test was done thru the Mangusta International ANSA copy mufflers.  Basically
> stock setup....

So was the 300 HP a number at the rear wheels or corrected to the crankshaft?
I'd be surprised if that engine made 300 at the rear wheels through the
Mangusta exhaust with a 570 CFM carb.  I have the flow numbers for the Y303
heads and ran the combo through Dynomation.  It predicts the engine should be
capable of around 340 HP at the crank and 275 at the rear wheels.  I also
ran one of the Ford crate SBF through Dynomation.  That engine is rated at
360 HP with the Z304 heads and Dynomation predicted 360 HP.

> Headers are Hall version #1 I believe....a tad bigger than stock. Good bends
> etc.

I assumed those have short primaries and a tiny collector like the Pantera
headers.

> Ford hotline dude said that they had experienced some gasket issues with
> X & Z303 heads...

Find out what the spring specs are for those heads.

> Springs should be sufficient to 6000-6500 I believe.  Again, out of the
> box.  I did vary and use the 1.73 rockers.

The FRPP/Crane rockers for SBF are 1.72:1.  351C/460 are 1.73.  I doubt the
tolerances are that tight so I assume the distinction is just to separate
Windsor and Cleveland dimension rockers.   Marc says he ran a Mellings high
volume pump and anywhere from 1/2 to 1 full turn on pre-load with the OEM
Ford roller lifters and had no problems.  His first thought was the same as
mine, perhaps the springs aren't up to task for a hydraulic roller cam with
a 1.72:1 rocker ratio.  He noted they swapped out the stock GT40 (iron head)
springs when they installed the first Anderson Ford Motorsport cam.  I also
have the results of a dyno test where they lost power when installed 1.72:1
ratio because the springs were insufficient.

> CR is around 9.8-10 if I did my math properly....

That's what I got when I did it.

Dan Jones