351C Head Casting D3ZE-AA?

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MeZapU

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I made 278hp and 311ft/lb of torque at the wheels with my Aussie headed combo. I had some 2.19" intake valves in it. The valves helped on the low lift flow but didn't help much at all on the med to high lift flow. I did some pocket porting but there was not much metal to remove in the ports without them getting too thin. This is in a 4-speed car with the engine also having flat top pistons, H/R valvetrain, single plane Weiand intake, Holley 780 v/s, headers, the rest of the basic supporting hardware. I could have cammed it bigger and would have likely broke the 300hp mark. To be honest the combo left me feeling flat after about 4500rpms. It just didn't have the top end rush I would have liked. I had it tuned to within an inch of its life but it always left me wanting more.

Your goal of 375h/p at the flywheel with 2v heads may indeed be doable, but you're really going to need to spin it and spring for the supporting components to do so. If I were to duplicate my old Aussie heads today I probably had close to $2k into them. Cores, valves, machine work, hardened exhaust seats, springs, studs, guide plates, rocker arms. Heck, probably more than $2k. Looking back it's a lot of money to spend on a component that will always limit the power potential.

Last year I finished my 4V headed engine. I spent the same kind of money building the set of heads up from some GA cores. In the end I was very happy as the car made good power (362hp/350ft/lbs at the rear wheels with the same 356 cid.)and filled my nostalgia criteria for the build. It also had the performance feel that I was after all those years ago when I built the 2V Aussie headed engine. If I would have spent another $400 more and bought a set of aftermarket heads, it would have likely yielded an easy 40-50 more hp. This is with a streetable combination as well. Nothing too radical that you couldn't drive it in traffic. In all my searching I could only find one example where anyone said they made an honest 400hp with a 2V heads in a stock displacement combo. I'd still like to see the printout and torque numbers.

No specs to say how he did it. The tall intake and spacer show that the engine likely needed to really be spinning some high rpm's to pull that number if it was legit. The eddy current dyno's usually give high readings as well.
I wouldn't get too wrapped up in trying to get a specific horsepower number out of your engine. If the car is a cruiser or a daily driver, I would build the engine to best match your budget while keeping it reliable and the rest will fall into place. If the car is a weekend warrior then do as you wish, but again, I think the 2V heads will leave you flat like they did me.

 
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barnett468

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if you are asking about the specs on the video i posted i do have them somewhere and can post them tomorrow if i find them.

yes there are definitely a lot of fantasy numbers being claimed by people or very generous dynos or dyno operators.

 
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wrobinson

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My 13 year old wants to build a 1971-73 Mach 1 Mustang for his first car. We have found a Grabber Blue with white interior base model 1971 Mach 1 to start on.
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This is speculation on my part but, I believe that a small increase in valve size would still net a gain assuming the machine shop know how to properly fit and back cut the valves and cut the seats. Either way you go, your goals can be met. Keep us posted on the build. Chuck

 

wrobinson

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My 13 year old wants to build a 1971-73 Mach 1 Mustang for his first car. We have found a Grabber Blue with white interior base model 1971 Mach 1 to start on.
This is speculation on my part but, I believe that a small increase in valve size would still net a gain assuming the machine shop know how to properly fit and back cut the valves and cut the seats. Either way you go, your goals can be met. Keep us posted on the build. Chuck
You are correct about that. I still want to go with the BBF 2.09 intake valves. I am just so glad the heads are not just pure junk. Thank you for your input it has been very valuable.

 

djjsc

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Never understood why Ford used the open chamber 4V (large port) head in 1973-'74 but then installed 2V sized valves. No engineer on the planet would admit to a 2in valve in a 3in pipeline doing anything positive to flow. Ford's own data states the '72 351CJ @266HP; the '73 - 74 @248HP (some sources @246HP). The only difference is the valves; therefore the '73 up CJ heads are worth MINUS 20HP (+/-).

 
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