[DeTomaso] detonation problems

Will Kooiman wkooiman at earthlink.net
Mon Oct 2 07:17:55 EDT 2006 

Cool!

Someone else may have a tip on how to install the intake properly.  I've
always done it by the numbers with no gasket sealant.  I follow the torque
sequence and torque in 3 steps.  After it heat cycles, I check the bolts.
You're probably supposed to retorque by loosening everything and doing it
all over again.  I don't do that.

Lately I've been gluing the gaskets to the heads, but that's because I have
aluminum A3 heads, and the gaskets must be trimmed to fit.  The "glue" makes
it easier to trim the gasket.

I used to always use the cork end rail gaskets, but lately I've been using a
bead of silicone.  Both methods have worked well for me.  The negative with
the silicone is you need to wait for it to dry.

And then there are the gaskets.  I always use Fel-Pro, but there may be
better gaskets.  I'm certainly not the expert.  The Fel-Pro gaskets I get
are one solid color, and they tear apart when you remove them - sorta like
wet cardboard.  I have a set of 4V gaskets that are much stiffer with
print-o-seal type stuff around the ports.  I would think the A3 gaskets
would seal better at the expense of more difficult cleanup on removal.

There was a guy in Hot Rod that had o-ring grooves cut in his intake.  I
don't remember how it all worked, but I believe he had some kind of nitrogen
filled o-rings in the grooves.  It was a mongo-turbo race engine.  The
o-rings made it easy for him to pull the engine apart since he didn't have
to fool with gaskets.  I'd love something like that, but you know it cost a
lot.  It's not like I change intakes every week, so I need to quit my
whining.

If you feel comfortable with the way you installed your intake, you may be
okay with simply retorquing it.  Maybe you have a bolt or two that isn't
tight anymore.

Will.

-----Original Message-----
From: detomaso-bounces at realbig.com
[mailto:detomaso-bounces at realbig.com]On Behalf Of redvobra at aol.com
Sent: Monday, October 02, 2006 12:07 AM
To: detomaso at realbig.com
Subject: Re: [DeTomaso] detonation problems


 I think you're on the money. I pulled the plugs today and the #1 plug was
covered in oil. I just replaced the intake, so I must have a bad seal there.
:(

 Time to order another set of gaskets and do it again.

 Thanks for the tip.

 -Chris

 -----Original Message-----
 From: wkooiman at earthlink.net
 To: detomaso at realbig.com
 Sent: Sun, 1 Oct 2006 5:51 PM
 Subject: RE: [DeTomaso] detonation problems

  There's a good chance you're sucking oil into one of the ports.

I once removed a bolt to attach a throttle return spring.  I didn't get the
bolt on tight enough.  It pinged some, but only when it was under load.  I
figured it was timing or bad gas.  When I later removed the intake, I could
see the trail of oil going into the port - right next to the replaced bolt.

It doesn't take much to allow oil to get sucked into a port.  It also
doesn't take much oil to cause detonation.

I'm not sure how you can resolve this without removing the intake.  If
you're good, you can probably see bits of aluminum on a plug.  I'm not that
good.  I'd think you'd have one plug that looks different from the rest, but
that's just a guess.  If it were me, I'd remove the intake and look for
trails of black going into a port.

I doubt that it's the carb.  Holley sets up their carbs a little rich to
prevent problems like this.

Will.

-----Original Message-----
From: detomaso-bounces at realbig.com
[mailto:detomaso-bounces at realbig.com]On Behalf Of redvobra at aol.com
Sent: Saturday, September 30, 2006 7:36 PM
To: jtaphorn at kingwoodcable.com; detomaso at realbig.com
Subject: Re: [DeTomaso] detonation problems


 Yeah, it's quite sluggish to get the rpm's up, even for a launch. Feels
like a really heavy flywheel or something. If I advance the timing a bit,
will it cause more detonation?

 Not sure about the total advance or the curve. Whatever is factory from the
Mallory Unilite distributor is what I have...

 Biggest change recently is that I swapped from a torker intake to a
performer intake so that I could put a stock engine cover on. Perhaps the
stock engine cover is not venting heat as well. Engine is warmer, plus it's
bringing in warmer air?

 -Chris
 -----Original Message-----
 From: jtaphorn at kingwoodcable.com
 To: redvobra at aol.com; detomaso at realbig.com
 Sent: Sat, 30 Sep 2006 3:49 PM
 Subject: Re: [DeTomaso] detonation problems

  Chris

Your initial timing is very low.  Does the car fell sluggish off throttle?

Perhaps more important than initial timing is the dimension of the curve and
total advance.

At what RPM are you getting total advance and what is it?

Also, the stock damper outer rings separate from the inner damper over time
and may shift causing the timing marks to be off.  It can be difficult to
detect this shift.  It is best to look at the status of the rubber insulator
between the two pieces.  Another approach is to find top dead center on #1
cylinder and see if the timing mark is at "0".  You need to determine if the
damper marks are accurate.

With this knowledge you can begin to set strategy.

JT
----- Original Message -----
From: <redvobra at aol.com>
To: <detomaso at realbig.com>
Sent: Saturday, September 30, 2006 3:33 PM
Subject: [DeTomaso] detonation problems


> My Pantera has always been a little on the verge of pre-ignition. If I put
> anything but premium Chevron into the car, it'll start pinging. But
> lately, it's been happening so often that it's becoming annoying. It's
> most noticeable when the car is fully warmed up, on throttle tip in.
> Initial timing is set at 8 degrees and it has a fresh Holly 650 on it.
> Dunno why it would be getting worse unless California gas is now sucking
> even more.
>
> Any thoughts/suggestions? Should I change the timing? Go to a colder plug?
>
> Thanks,
> -Chris
>
> ________________________________________________________________________
> Check out the new AOL.  Most comprehensive set of free safety and security
> tools, free access to millions of high-quality videos from across the web,
> free AOL Mail and more.
> _______________________________________________
>
> Detomaso Forum Managed by POCA
>
> Archive Search Engine Now Available at http://www.realbig.com/detomaso/
>
> DeTomaso mailing list
> DeTomaso at realbig.com
> http://ftl.realbig.com/mailman/listinfo/detomaso



________________________________________________________________________
Check out the new AOL.  Most comprehensive set of free safety and security
tools, free access to millions of high-quality videos from across the web,
free AOL Mail and more.
_______________________________________________

Detomaso Forum Managed by POCA

Archive Search Engine Now Available at http://www.realbig.com/detomaso/

DeTomaso mailing list
DeTomaso at realbig.com
http://ftl.realbig.com/mailman/listinfo/detomaso

_______________________________________________

Detomaso Forum Managed by POCA

Archive Search Engine Now Available at http://www.realbig.com/detomaso/

DeTomaso mailing list
DeTomaso at realbig.com
http://ftl.realbig.com/mailman/listinfo/detomaso

________________________________________________________________________
Check out the new AOL.  Most comprehensive set of free safety and security
tools, free access to millions of high-quality videos from across the web,
free AOL Mail and more.
_______________________________________________

Detomaso Forum Managed by POCA

Archive Search Engine Now Available at http://www.realbig.com/detomaso/

DeTomaso mailing list
DeTomaso at realbig.com
http://ftl.realbig.com/mailman/listinfo/detomaso

More information about the DeTomaso mailing list