[DeTomaso] Mismatched Intake and Head Ports

Thomas Tornblom thomas at hax.se
Sat Feb 13 04:50:08 EST 2016


2V intake on 4V heads, no?

Thomas

Den 2016-02-13 07:39, Mike Becker skrev:
> I guess it's not quite clear from the picture and maybe I'm not describing
> it correctly.  In the picture of the head, it looks like the gaskets fit
> perfectly.  But in reality, the opening in the gasket is smaller than the
> opening in the head.  You can stick your finger in the port and feed the
> backside of the gasket.  It hangs over and overlaps the port by quarter inch
> on top and bottom and about an eighth of an inch on the sides.  Where I have
> highlighted the gasket, there's nothing behind it.  and that's the same on
> every port.
>
> Maybe I'm just overreacting.  I should put it together and see how it goes.
>
> mike
>
>
> -----Original Message-----
> From: DeTomaso [mailto:detomaso-bounces at poca.com] On Behalf Of Asa Jay
> Laughton
> Sent: Friday, February 12, 2016 10:16 PM
> To: detomaso at poca.com
> Subject: Re: [DeTomaso] Mismatched Intake and Head Ports
>
> I'm with Mike on this... you're doing something funny or something bigger is
> wrong.
>
> First, BOSS heads as Mike points out are identical to 4V heads, with the
> exception of the rocker pedestals being machined for screw-in studs.  In
> fact, I can take a stock set of 4V heads to a machinist, with the proper
> diagram, and he can make them BOSS heads just by doing the pedestals; there
> is NO difference in the ports.
>
> Second... you've done something to the gasket in the second photo matched up
> to the head.  It appears you've cutout the printo seal on that one port
> exactly where you have it highlighted.  All the other ports are pretty well
> matched, so I don't understand the game you're at here.
>
> I will admit I've never seen a set of used gaskets look as bad as those in
> your first photo, but I've used those exact same gaskets in the past on my
> Cleveland builds and have had ZERO problems with them.
>
> I recently switched to the stamped metal "turkey-tray" style however, to
> keep hot oil off the intake.
>
> It looks to me like you have a machining mis-match between the heads and the
> intake.  Either the angles are wrong on the intake or the block has been
> machined funky so the head's aren't actually on the proper plane.
> Instead of being flat-faced to each other, it appears you've got a gap at
> the top (maybe).  In other words, it looks to me like when your intake is
> torqued in place, the bottom face is probably flush to the head but the top
> of the face has a gap (imperceptible as it may be).
>
> Ports on the head look fine and proper size.
> Ports on the intake look fine and proper size.  What brand, part number is
> the intake?
> New gasket looks fine and proper size (except for that cutout I mentioned)
>
> I would dry-fit the intake to the heads and check for gaps.  Then fit the
> gaskets and dry-fit the intake again (no bolts and no torque) and check for
> gaps again.
>
> I can't tell you for certain what is wrong but you could spend a lot of
> money on new heads and a new intake and still have the same problem if it
> was the block that was machined wrong.
>
> Asa Jay
> (interested to see what Dan Jones comes up with)
>
>
> Asa Jay Laughton - W7TSC, MSgt, USAFR, Retired &  Shelley Marie Spokane, WA
> ******************************
> http://www.racingagainstautism.com
> http://www.teampanteraracing.com
> http://facebook.com/racingagainstautism
>
>
> On 2/12/2016 9:27 PM, Mike Becker wrote:
>> ok, maybe I am nuts.  But the ports  are way bigger in the heads.
>> Almost half an inch taller and quarter inch wider.
>>
>> I've attached 2 pictures.  When you look at the picture with the
>> gasket sitting on the intake manifold, it looks good, the size
>> matches.  Excuse my artwork, but on the picture of the gasket on the
>> head, I've highlighted with yellow the approximate area behind the
>> gasket where there is nothing, just the open port.  So fair enough,
>> along the sides, it's only about one eighth of an inch on each side,
>> no big deal.  But along the top and bottom, that means there will be
>> very little gasket material sandwiched between the head and the
>> intake.  My fear is that the thin strip of gasket material will blow out
> again, just like the last set of gaskets.
>> mike
>>
>>
>>
>> -----Original Message-----
>> From: Mike Drew [mailto:MikeLDrew at aol.com]
>> Sent: Friday, February 12, 2016 8:42 PM
>> To: Mike Becker<mikebecker679 at gmail.com> Cc:<detomaso at poca.com>
>> <detomaso at poca.com>
>> Subject: Re: [DeTomaso] Mismatched Intake and Head Ports
>>
>> Mike,
>>
>> You're a spaz. :)
>>
>> Boss 351 heads and standard 4V 351C heads are identical, except that
>> the Boss heads come from the factory with machining in the rocker arm
>> mount area so they can accommodate adjustable rockers, because the
>> Boss came with solid lifters. The rest of the head, including the
>> intake ports were absolutely identical.
>>
>> Now, it's possible that at some point somebody decked your block,
>> which lowers the heads and alters the relationship between the intake
>> and the heads. Normally the intake is machined accordingly if a bunch
>> of material is taken from the block. The heads are not only lower, but
>> also closer together since they move closer to the centerline of the
>> engine as they are moving down. So the bottom of the intake may need
>> to be machined to allow it to fit properly.
>>
>> Could that explain the mating problem you are seeing?
>>
>> Mike
>>
>> Sent from my iPhone
>>
>> On Feb 12, 2016, at 20:24, "Mike Becker"<mikebecker679 at gmail.com>  wrote:
>>
>>>     Hey Gang,
>>>
>>>     I've just torn down my top end on my Pantera because the intake
>>>     manifold gaskets were completely destroyed.  They were the so called
>>>     self-destructing Felpro Print-O-Seal / Print-O-Leak gaskets.  Only, I
>>>     see now what the real problem was.  I went to fit my brand new
>>>     Edelbrock gaskets and there's no way they'll work! It turns out I have
>>>     BOSS 351 heads and a Cleveland intake!  This undoubtedly contributed
> to
>>>     the early demise of the old intake gaskets.  because in the mismatch,
>>>     there are several places where there is minimal surface contact in
>>>     order to sandwich the gasket.  The result is that the gasket isn't
> held
>>>     in place for long.  While the engine was still assembled, there were
>>>     places where the entire blue stripe on the gasket material was
>>>     completely exposed, i.e. not sandwiched between the intake and the
>>>     head.  See attached photos for the results.
>>>
>>>     So, now what do I do?
>>>
>>>      - Switch to aluminum heads for a couple of grand (can't really afford
>>>     it)
>>>
>>>      - get a BOSS intake (can't seem to find one, they all look like
>>>     windsor intakes, except for one NOS unit for 3 grand!)
>>>
>>>      - fabricate home-made gaskets
>>>
>>>     I saw some nice original BOSS 351 iron heads on ebay for $2500.  Are
>>>     they really worth that much?  If so, mine are still very fresh, maybe
> I
>>>     could sell them to fund a set of Trickflow aluminum heads.
>>>
>>>     Somebody please help me before I blow a gasket!
>>>
>>>     thanks,
>>>
>>>     Mike Becker (San Diego)
>>>
>>>     1741
>>>
>>>     <<...>>  <<...>>
>>> <passengerside.jpg>
>>> <driverside.jpg>
>>
>
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-- 
Real life:   Thomas Törnblom             Email:	   thomas at hax.se
Snail mail:  Banvallsvägen 14            Phone:    +46 18 32 31 18
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