Holley 950 Ultra HP Carb

[USMC_Spike]

Here are some additional pics:

Assume the orange stripe spring for solid roller are used with
Hyd cam because of the larger valves, I can't recall either
2.3" or 2.3x", the valves were larger than the average bear.

engine was supposed to come with AED 950HO carb with
vacuum throttle plate for street use and also
for use with performance HEI. That didn't happen,
Terry Walters received payment for the AED carb,
acknowledged that he received it along with pre payment
and kept it! Didn't get the HEI either, said the MSD broke.

He made up excuses as to why I got stuck with Holley 950 Ultra XP
that had crap in it particles, flash, etc, didn't include the other parts
that were supposed to come with the carb.

I needed that vacuum throttle plate as I told him Chevelle is for street
strip use and DV says Vacuum advance, etc is good even on race engines.
TW didn't think so, and made excuses why he didn't include the items
I requested need to be in the engine.

-thx Spike

[stealth]

Spec sheet mentions a dominator carb at time of dyno test...?

[ClassAct]

What was the correction factor?
Is it a hydraulic roller or a solid.
1.4x TQ/CID is pretty F’ing high for that compression ratio AND an unported as cast intake manifold.

[USMC_Spike]

Yes, there was a lot of different things going on, etc.
Then they said, that engine was sold (thinking numerous time on ebay, [bait])
but they had something different I could buy (switch).
Yes, it is hydraulic roller cam.

@stealth, @ClassAct Yes, it is a port matched Holley Strip Dominator Oval to the AFR oval part heads.
You can see some of the matching work in the intake pics.
It's possible with these milled heads with 112cc chambers compression is higher.
TW says he doesn't do that because correction factor is always changing and he
doesn't like to fool with it.

These AFR heads, the intakes and chambers were supposed to be ported by DV himself.
I couldn't verify this as my insert-able video camera quit working on me.
AND AFR told me he developed this set of heads for their larger oval
port BBC heads.

So the cam is a single pattern cam with 1.8, and 1.7 rocker ratios as shown in
the prior pics.

I know what some of you are thinking and I was thinking also, you wouldn't expect
these part combinations in this engine. Imagine if something breaks, how will I
ever get it fixed?

Also, I don't even think TW tested the AED carb I payed for in advance, he just kept it for himself
or sold it to someone else.

-thx Spike

Post Script, I'm trying not to be bitter about this, as no one likes bait/switch. Sadly TW/DV lack of
support after you purchase their product, have issues, etc. I'm not in the best health any longer either
but I still try, that is why I post here y'all are smart and have experience--I don't have that experience.

Post Post Script, I've never been able to drive the Chevelle since after having the engine installed,
it was a disaster and had to be towed back to the house.

[HQM383]

What I see on the metering blocks is the lowered ifr appear to be almost flush with the surface. They will function better if recessed down to the level of the channel that crosses from the main well to the idle well.

I can understand someone wanting to hold onto proprietary information they have built up over the years but no one can copyright physics, its there for everyone to exploit. It's all been done before or being done somewhere else now. He could have let you post here as a primer for selling a book. "Want to know more, check out my latest book".

[USMC_Spike]

@HQM383, thanks. Got it, recess it to the point where its even with that other channel.

Thx

[1980RS]

I have one of the early 950hp Holley's with the non-replaceable air bleeds and it works great, as a matter of fact perfect. Everyone I have let try it wants to buy it but I am hanging on to that one. I had a chance to test a newer one this past year, ran like crap, was out of the box settings. Hesitated like a mo-fo. Put mine back on and the car ran great again.

[Monza355]

I have one of the early 950hp Holley's with the non-replaceable air bleeds and it works great, as a matter of fact perfect. Everyone I have let try it wants to buy it but I am hanging on to that one. I had a chance to test a newer one this past year, ran like crap, was out of the box settings. Hesitated like a mo-fo. Put mine back on and the car ran great again.

What’s the part number on that carburetor ? And do you have a picture of the main body ?

[rgalajda]

This is a Holley 950 Ultra HP not to be confused with the 950 Ultra XP ?

That cleaner you used is not for ultrasonic machines and surely not for carbs unless you want to destroy the finish.
I hope you didn’t just throw the metering blocks in without dismantling them.
You need to blow out all the circuits with compressed air.

The idle fuel restrictions seem small like HQM383 said . If the lower location doesn’t look drilled correct , you can move it back to the top. It’s not that big of a deal for now. Can you post more pics of the carb?
Preset all four idle mixture screws to 1 turn out.
Set the primary idle screw to .040 transfer slot exposure , approximately.
Set the secondary throttle screw to about the same.
This carb should have idle bypass air valve? If so I hope you know how to adjust it.
Read this https://static.speedwaymotors.com/pdf/42580801.pdf

( My car idles with 30 degrees timing )
Set the initial timing to a minimum of 32 degrees , restart engine with clean carb , and advance timing more if necessary to get a good idle . If the distributor has vacuum advance , it is not gonna work at idle hooked to manifold vacuum with that cam. So leave it unhooked for now.
We are looking to establish minimum initial timing required for this cam to produce a good idle with minimum throttle opening.
Is this an automatic ?
Do you have a vacuum gauge ?

Post back idle timing required . Idle rpm and idle vacuum.


As a note I believe the 950 Ultra HP when introduced had a 1.375 venturi

[rgalajda]

Also, fuel pressure should be 7.5 psi maximum and fuel levels set to near middle of sight glass.

[Tuner]

Also, fuel pressure should be 7.5 psi maximum and fuel levels set to near middle of sight glass.

Why so much? 6 is more than plenty. 4 is enough as long is it is a steady 4 at WOT.

This is a Holley 950 Ultra HP not to be confused with the 950 Ultra XP ?

That cleaner you used is not for ultrasonic machines and surely not for carbs unless you want to destroy the finish.

https://www.amerevent.com/INFO/SAFETY/M ... LEANER.pdf
Butyl Carbitol 111-90-0 0.01 to 2.5%
Ecosurf EH-9 64366-70-7 0.5 to 4.0%
Sodium Metasilicate 6834-92-0 0.5 to 1.5%
Tetra Sodium EDTA 64-02-8 0.5 to 1.5%
Water 7732-18-5 QS

That is an excellent cleaner to use in an ultrasonic. Cleaners that are not acid are OK to use in ultrasonics. Sodium Metasilicate is not corrosive to aluminum and zinc, but a powerful machine with just water will eat anything if you run it long enough. You check the machine's health by seeing how long it takes to etch and erode the edges of aluminum foil with de-gassed water only (no cleaners).

Cleaners containing Sodium Hydroxide will eat aluminum and zinc but are good for iron and steel.

If parts are left in too long a powerful ultrasonic machine will etch surfaces with just plain water. "Too long" is relative to the power and frequency characteristics of the machine.

Here is pics of the metering blocks cleaning in ultrasonic cleaner, 1:1 LA Awesome cleaner and water.
It took the anodizing off parts of the block. Maybe 45 minutes was too long.

1:1 is stronger than necessary. A cup to 5 gallons might be enough. It is amazing how much the ultrasound seems to amplify the action of cleaners and rust removers.

I hope you didn’t just throw the metering blocks in without dismantling them.
You need to blow out all the circuits with compressed air.

The idle fuel restrictions seem small like HQM383 said . If the lower location doesn’t look drilled correct , you can move it back to the top. It’s not that big of a deal for now. Can you post more pics of the carb?

Have you never experienced the difference between high and low idle jet location on the same engine on the same day? High idle jet location always causes idle and transition A/F to be more irregular and idle to misfire. Some people like the high idle jet misfire because they think it makes their engine sound like it has "a big cam".

Preset all four idle mixture screws to 1 turn out.
Set the primary idle screw to .040 transfer slot exposure , approximately.
Set the secondary throttle screw to about the same.

With an engine which has low idle vacuum (such as this one is reported to have) having a lot of T-slot exposed on both primary and secondary will cause the A/F to swing rich when the vacuum increases from the low 5" value at curb idle to 15" or so at higher cruise RPM.

This is the most common reason a carb can have a good curb idle but turns slobbering "pig rich" at level road cruise.


You guys who are saying the .029" idle jet is too small are overlooking that a smaller idle air bleed might be a better way to get the desired fuel.

When vacuum increases from curb idle 5" to cruise 15" a larger IJ will have a larger flow increase than a smaller IJ.

Every engine and header/exhaust combination has its own idle circuit and T-slot calibration appetite, but many times a smaller IJ and corresponding IAB is a better plan than larger IJ and IAB because the A/F won't vary as drastically when manifold vacuum varies. Salt to taste.

This carb should have idle bypass air valve? If so I hope you know how to adjust it.
Read this https://static.speedwaymotors.com/pdf/42580801.pdf

( My car idles with 30 degrees timing )
Set the initial timing to a minimum of 32 degrees , restart engine with clean carb , and advance timing more if necessary to get a good idle . If the distributor has vacuum advance , it is not gonna work at idle hooked to manifold vacuum with that cam. So leave it unhooked for now.
We are looking to establish minimum initial timing required for this cam to produce a good idle with minimum throttle opening.
Is this an automatic ?
Do you have a vacuum gauge ?

Post back idle timing required . Idle rpm and idle vacuum.


As a note I believe the 950 Ultra HP when introduced had a 1.375 venturi

[USMC_Spike]

Thanks tuner, I always appreciate your advice.

Hope you've been well, long time since I"ve been here.
I learned a lot from you and keep what you've shared
and implement it.

[USMC_Spike]

Here are pics of the actual carb.

Note on the downleg boosters, the dark spots are not junk, but eroded away from
too much cleaner and too long a time ultrasonic cleaning 45 minutes. Sadly.

The unit is a lab grade Bronson, 4500. holds about 1.5 gallons.
I also have a larger Bronson that hold about 5 gallons.

- Thx Spike

[Tuner]

Here are pics of the actual carb.

Note on the downleg boosters, the dark spots are not junk, but eroded away from
too much cleaner and too long a time ultrasonic cleaning 45 minutes. Sadly.

The unit is a lab grade Bronson, 4500. holds about 1.5 gallons.
I also have a larger Bronson that hold about 5 gallons.

- Thx Spike

You lucky dog, the Branson units are the real deal.

The leak out the throttle shaft is because if the engine isn't running there is no vacuum to suck it in and keep it from running out when fuel gets on the butterfly from the pump squirt or dripping nozzles.

If the O-ring on the inlet needle and seat is old it won't hold fuel pressure and of course higher pressure is harder to hold back.

Can you measure the width and length of the T-slots in the base? With the butterflies all the way closed tight in the bore, where is the bottom of the slots located relative to the lower edge of the butterflies? How much slot, if any, is showing below the closed butterflies?

If you mentioned how it runs, I missed it. I think a #93 primary jet plus power valve is way rich. The 1.600" venturi has a funky booster signal but that is plenty too rich anyway I think.

[ClassAct]

IMO that thing needs annular boosters. Especially on pump gas. And no T-slot restricters is suspect. Most of the QF stuff has pretty big T slots.