[DeTomaso] Mismatched Intake and Head Ports

Mike Becker mikebecker679 at gmail.com
Sat Feb 13 01:39:59 EST 2016


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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