DeTomaso Mailing List: June 98, Message #164

Negative, Tony,

It really isn't a better combustion chamber unless using the quench effect.

I have special pistons made by J&E that match the "quench" combustion
chamber upside down, and get all the advantages of the closed combustion
chamber at 9:1 (for my supercharged engine).  Besides, the closed combustion
chamber heads with flat top pistons at approximately 10 to 10.5:1 (don't
believe the advertising), work quite well with pump gas.  That is the big
advantage of the "quench" effect.  But to work, it must have a matching
piston part that comes no less than .040 from the head at top dead center.
An "open" chamber head would have to be down to 9 to 9.5:1 to resist
detonation with the same gas.

Ted (Vader) Mitchell
http://home1.gte.net/tmitch/pe.htm
http://home1.gte.net/tmitch/chpie.htm
http://home1.gte.net/tmitch/index.htm

-----Original Message-----
From: Tony Harvey <gt2hvit@hotmail.com>
To: Multiple recipients of list <detomaso@realbig.com>
Date: Wednesday, June 03, 1998 6:27 PM
Subject: Re: carbs


>HEY!!!  I have dished pistons with Aussie heads!  From what I have heard
>the dished piston gives you, yes a lower CP ratio, but they also produce
>a better combustion camber.  I therefore cc'd my heads and cylinders and
>with some carefull P & P ing and shaving produced the CP ratio I wanted.
>If I had the flat top pistons in this engine now I would have to content
>with using race gas in my driver.
>
>GT
>
>
>>Reply-To: "Ted M" <tmitch@gte.net>
>>From: "Ted M" <tmitch@gte.net>
>>To: Multiple recipients of list <detomaso@realbig.com>
>>Subject: Re: carbs
>>Date: Wed, 3 Jun 1998 13:12:37 +0000
>>
>>Why in the world would you run stock dished pistons with the Aussie 2V
>>heads.  The only advantage of the Aussie 2V heads over U.S. 2V heads is
>that
>>they (if you get the right ones) are closed combustion chamber.  This
>does
>>NO GOOD if you use the dished pistons (no quench!).
>>
>>Ted (Vader) Mitchell
>>http://home1.gte.net/tmitch/pe.htm
>>http://home1.gte.net/tmitch/chpie.htm
>>http://home1.gte.net/tmitch/index.htm
>>
>>-----Original Message-----
>>From: ROBERT J RUIZ <rjr46@choice.net>
>>To: Multiple recipients of list <detomaso@realbig.com>
>>Date: Tuesday, June 02, 1998 6:59 PM
>>Subject: carbs
>>
>>
>>>Okay, so here's the basic engine combo:
>>>
>>>  Aussie 2V heads
>>>  stock dished pistons
>>>  218/222 dur., 0.530" lift, 110 LSA cam
>>>  roller rockers
>>>  dual point distributor with Mallory Speed-o-Lite conversion
>>>  Weiand Xcelerator single plane intake
>>>  Hedmann headers - 1 3/4" primaries, 29" long, 2 1/4" collectors
>>>
>>>All that's left is the carb.  Though I'm a fan of the Thermoquad and
>>>Quadrajet spreadbore carbs, I need a squarebore carb to match the
>>>intake. Since the '69 Fairlane Cobra has been in storage for many
>years,
>>>Dad has graciously offered to let me "borrow" the 735 Holley that
>>>everyone seems to like so much.  I know I'll need to rebuild it, add
>an
>>>electric choke, and eventually go through the trial and error tuning
>>>process but, under my current schedule, I don't think I'll have time
>to
>>>tune it properly until I get back to St. Louis (sorry I'll miss you at
>>>Scott AFB, Mike).  From what I've heard about the 735's calibration,
>>>it's usually pretty good as is.  Problem is, Dad's engine is not stock
>>>(was a 428CJ, now a 454 cube stroked side-oiler) and I don't believe
>>>he's running the original jets, power valve, etc.  Anyone know what
>>>these should be (left my Holley book at home, dammit)?  Also, I have a
>>>750 Edelbrock Carter AFB clone on the other Cleveland and it might be
>>>interesting to do a back-to-back comparison.
>>>
>>>Thanks,
>>>Dan Jones
>>>
>>>P.S. Thanks to everyone who's answered all my questions thus far.
>With
>>>luck, I might just get the car done on time.
>>>
>>
>>
>>
>
>
>______________________________________________________
>Get Your Private, Free Email at http://www.hotmail.com
>