[DeTomaso] Holley Ultra XP

[Will Kooiman]

Hi Everyone,

 

My newest discovery is the Holley Ultra XP carburetor.  You can get pics online.

 

Granted, I’m not an expert, but it’s the best 4150 I’ve seen to date.

 

No choke tower.  If you want a choke, this is a minus.  I prefer no-choke.

4-corner idle adjusted through the carburetor stud.  You only adjust the idle at the throttle blades if you can’t adjust it enough through the carburetor stud.  It’s pretty cool how it works, but it’s difficult to put into words.

The main body is aluminum and very light.  The whole carburetor feels ½ the weight of a normal Holley.  This is great, mostly because it’s a lot nicer dealing with it.

The base plate is drilled for 4150 or 4500 intakes.

The fuel bowls are larger than even the old dominator fuel bowls.

The fuel bowls have a drain plug.  I don’t see the point in this.  What’s wrong with the old way of removing one screw?  I’m not going to use it.  It wouldn’t be prudent.

The linkage can be progressive or 1:1 by moving one part of the linkage.

The metering blocks have something like 5 bleeds on each side.  I suspect Holley spent a lot of time making the fuel curve as perfect/progressive as possible.

Changeable air bleeds, but Holley makes a point to say don’t even think about changing these unless you are an expert.

The body is coated to prevent corrosion, even with E85.

Vent whistles (of course).

Black/grey just plain looks cool.

 

The only thing I don’t like is no ported vacuum and no vacuum for PCV.  This is a race carburetor, after all.  But… it isn’t hard to modify the base plate to add these ports.

 

I got turned on to the Ultra XP by watching Engine Masters (David Freiburger, Steve Dulcich, and Steve Brule).  I also got turned on to the B&B High Flow from their air filter test.

 

I don’t have a lot of miles on it yet, but this looks promising.

 

 

-------------- next part --------------
   Hi Everyone,


   My newest discovery is the Holley Ultra XP carburetor.  You can get
   pics online.


   Granted, I'm not an expert, but it's the best 4150 I've seen to date.


   No choke tower.  If you want a choke, this is a minus.  I prefer
   no-choke.

   4-corner idle adjusted through the carburetor stud.  You only adjust
   the idle at the throttle blades if you can't adjust it enough through
   the carburetor stud.  It's pretty cool how it works, but it's difficult
   to put into words.

   The main body is aluminum and very light.  The whole carburetor feels
   1/2 the weight of a normal Holley.  This is great, mostly because it's
   a lot nicer dealing with it.

   The base plate is drilled for 4150 or 4500 intakes.

   The fuel bowls are larger than even the old dominator fuel bowls.

   The fuel bowls have a drain plug.  I don't see the point in this.
   What's wrong with the old way of removing one screw?  I'm not going to
   use it.  It wouldn't be prudent.

   The linkage can be progressive or 1:1 by moving one part of the
   linkage.

   The metering blocks have something like 5 bleeds on each side.  I
   suspect Holley spent a lot of time making the fuel curve as
   perfect/progressive as possible.

   Changeable air bleeds, but Holley makes a point to say don't even think
   about changing these unless you are an expert.

   The body is coated to prevent corrosion, even with E85.

   Vent whistles (of course).

   Black/grey just plain looks cool.


   The only thing I don't like is no ported vacuum and no vacuum for PCV.
   This is a race carburetor, after all.  But... it isn't hard to modify
   the base plate to add these ports.


   I got turned on to the Ultra XP by watching Engine Masters (David
   Freiburger, Steve Dulcich, and Steve Brule).  I also got turned on to
   the B&B High Flow from their air filter test.


   I don't have a lot of miles on it yet, but this looks promising.