[DeTomaso] Mismatched Intake and Head Ports

Sat Feb 13 13:31:27 EST 2016

Thanks Dan,
Yes, the ports on the head are 2 1/2" by 1 3/4"
Yes, I have a Performer 351C-4V
Yes, I have the Edelbrock 7265 2V (wrong) gaskets  

I will try the Mr. Gasket 214, Summit has them.
mike

-----Original Message-----
From: DeTomaso [mailto:detomaso-bounces at poca.com] On Behalf Of Daniel C
Jones
Sent: Saturday, February 13, 2016 8:33 AM
Cc: POCA list <detomaso at poca.com>; David Briggs <d.briggs at cox.net>
Subject: Re: [DeTomaso] Mismatched Intake and Head Ports

Measure the cylinder head intake port height and width.  Unported 351C-4V
heads should measure 2 1/2" tall and 1 3/4" wide.  Also, check the part
number on the bottom of the intake manifold.  It appears you have an P/N
2665 Edelbrock Performer 351C-4V which intentionally has smaller ports than
the cylinder head, approximately 2 1/16" tall by 1 3/8" wide.  You don't
want to use those gaskets with the perimeter bead if they are not sealing
against both the head and intake. It appears you are using Edelbrock P/N
7265 which are 351C-2V gaskets.
If you haven't blocked off the exhaust cross-over, you may want to use a
turkey pan style gasket set as the pan keeps oil from splashing on the hot
cross-over passage.  There are other conventional gasket sets without the
bead around the perimeter that can be used with gasket sealer (e.g. Mr.
Gasket P/N 214).  You need to check the manifold alignment in case the
heads, intake or block have been milled.

Dan Jones

On Fri, Feb 12, 2016 at 11:27 PM, Mike Becker <mikebecker679 at gmail.com>
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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