Mustangaroo i need help

[Kstang]

Hey mustangaroo. I just got my oz head up and running and i am using a 4 barrel holley 8007 carb. I was wondering what your idle speed was on your 4 barrel. On the high speed cam the lowest we can get it is 2500RPM, then it goes to 2000RPM, and then after it has completly warmed up it will idle at 1000RPM. IF we adjust it any lower It will run really rough. The factory manual say that the idle should be set to around 650RPm. So is the increased RPM's at idle because of The larger carbs and more air flow. I also though that the reason we can't get it down any lower is that it needs a stronger ingition? Also this could be realated but our engine seems to be running hot. Unpressurized the idle(1000RPM) the tempature of the coolent was about 195 degrees F.

If you or any one else could offer any help it would be much appreciated!!

Thanks
Kevin

 

[Anonymous]

sounds like a timing problem to me...

 

[Kstang]

Yeah we checked the timing. It is set to 8 degrees

 

[Mustangaroo]

I just got my oz head up and running and i am using a 4 barrel holley 8007 carb. I was wondering what your idle speed was on your 4 barrel. On the high speed cam the lowest we can get it is 2500RPM, then it goes to 2000RPM, and then after it has completly warmed up it will idle at 1000RPM. IF we adjust it any lower It will run really rough. The factory manual say that the idle should be set to around 650RPm. So is the increased RPM's at idle because of The larger carbs and more air flow. I also though that the reason we can't get it down any lower is that it needs a stronger ingition? Also this could be realated but our engine seems to be running hot. Unpressurized the idle(1000RPM) the tempature of the coolent was about 195 degrees F.

Check the timing!
Vaccume leaks will cause it not to idle!
What cam do you have?
How many pounds vaccume are you pulling?

The Holley Power Valve will cause a engine with high vaccume to run very rich if at idel, you need to know your vaccume in order to get the correct Power Valve. They start at 55,65,75,85 etc... My Holley 500 2v engine won't run with a 55 installed and it run's better with a 65 and even still better with a 85, Jason had a 65 in his 650 4V and has now changed to a 85 and his improved upon going to a higher number power valve.
BTW my 2V pulls just over 20.5 on the gage and Jason's pulls 17 at idel about 700 rpm

 

[Mustangaroo]

KStang,
If this is your first Holley don't get discouraged, the Holley can be a real bitch to get matched, the Holley accellerator pump is adjustable
You have to have the right Power Valve
I even hate to bring up the fuel jets need to be matched to your setup
Just remember when you apply throtle, if it Bogg's it's too rich, if it falls on it's face it's too lean.

I'll email you my 866 toll free phone number and you can call me!

Ben

 

[Kstang]

Thanks.

We have the stock cam.
We have checked the timing
We never though about vacume!!!
We Don't know too much about the carb.

Yeah we just went out and bought a holley carb book. And we need to read up a little more on it.

kevin

 

[MustangSix]

If you can rule out a vacuum leak, you might look at the throttle stop screw on the secondaries. There is a small screw that holds the secondary throttle blades from sticking in the bore, but sometimes it's adjusted to the point it holds the blades open a little.

 

[LEROY POLL]

HELLO KSTANG

.....I REALLY LIKE YOUR BEFORE AND AFTERS.

LIVE IN GRACE

LEROY POLL

 

[Mustangaroo]

If it's a stock cam your vacum should be around 20, so you may find that it runs better with a 85 Power Valve, MustangSix is right, you need to check the carb out real good and make sure everything works and is adjusted correctly, or you'll be making many changes back and forth untill you get it dialed in. The good news is it will run really strong once you have done this!

 

[Kstang]

Ok we have checked the carb over many times for problems with sticking, and we plan on doing the vacume test tommrow. i think we need to switch to the 85 power valve like mustangaroo said. I am not sure what that is but i am sure i will find out in my book. Also we plan on taking it to the exhaust shop tommrow and there is a place that is a holley dealer that said to bring it by and he could help. This is my first time working with a holley carb this large and i have alot to learn

kevin

 

[Kstang]

o yeah

what about engine temp's

has any one noticed it running warmer with the change of the oz head

and does your engine compartment run warmer with the pacemaker headers?

 

[Mustangaroo]

I've not had any heating problems and it's been 100* here for the past few weeks and I've ran both a 160 and a 180 thermostat, both worked fine but I left the 160 in. I have Clifford Headers and since I had my head off and work done to it and raised my compression to 10.5.1 I have noticed much more heat from the headers, I even sealed up the air cleaner and ran a snorkle from it to the front grill to pull in a cooler air charge.

On another note, KStang if you havn't all ready installed 1.6 ratio rockers, now would be a very good time, stock the 200's valve lift is around .346 and just adding 1.6 rockers raises is to .371 better flow, more volume of air means more HP. Or pull the cam and install one of AZcoupe's new cams, with your 5 speed one of these would be very nice!

264: 264/264 - 214/214 - .450/.450 - 110* - 1600-5000
274: 274/274 - 224/224 - .450/.450 - 110* - 2000-5600

Cams are cheap, it's the labor to change them that's tough!

 

[Kstang]

Thanks,

I think we figured out the coolent problems.

We noticed some problems with our block when we changed the rings so we plan on building up a new block with a good cam forged pistons and rods apr bolts and get everything balanced so we can spin it up a little faster. I also plan on getting a 1.6 roller rocker when we build up the new block. So that will come just we want to get the carb figured out and we dont want to change to many variables at one time.


After reading our book that we bought "SpeedPro Series How to build and power tun holley carburetors" we found out that there is a Seconday Butterfly Idle Adjustment Screw It is on the bottem of the carb and we are going to adjust that they say that if it is not properly adjust then

"It's quite possible to have the rear butterflies open too much, letting too much air into the engine. In this case your won't be able to get the engine's idle speed down to a sensible level, even if the primary butterfly adjusting screw is completely wound off"

This is just what mustangSix was talking about, Thanks mustangsix!!!

After reading that we felt enlightinged. It described exactly what was happening.

We are also going to check the vacume and some other stuff you have suggested but i have a feeling that this is our problem.

Thanks
Kevin