Engine Build and Plug Questions

I have The Mallory Comp SS / Aren't the UR6's a colder plug? If the UR5's are equal in heat range to the R43's is there really that much difference in what plug is used.
I think most of my problems are coming from this carb. I do agree a carb change is in order. Just need to verify a contact from here for a new or rebuilt one
You are correct on the Edlebrock internals.

 

Thanks for the reply, 850 cfm is not over kill for my cam? over carburating could cause problems also correct?

 

OK,I looked up the manual for those;



http://www.edelbrock.com/automotive_new/mc/carbs_acc/pdf/carb_owners_manual.pdf


You're right Larry those are for the primary circut,but I do recall that getting the primary circut to work right really helped the secondary transition much better. This is a VERY adjustable carb,many hate it because of that it is a pita carb for sure! An air fuel gauge would really help.GL



Derek

 

Listen to the Wizard Buicks love cmf's a lot of guys over the years would take off 800 Q-jet's and go to 1000 TQ'S and pick up 1.5-2 tenths in the 1/4

 

I thought I remember it correct,about page 7 in the manual;



The Step-Up function, which moves the Metering Rod to the Power Mode, is controlled by the Step-Up Spring. The base calibration has a spring which stages rich at 5" Hg.If your vehicle has a mid-throttle driveability problem that is encountered as the throttle is gradually opened, but then goes away upon further opening, it may be possible to eliminate thelean spot by using a stronger Step-Up Spring. The available Step-Up Springs are listed in the following chart along with their respective staging point. It is best to select a new spring onthe basis of vacuum readings, but in the absence of a gauge, try the strongest spring (highest vacuum rating) to see if the problem goes away. If the drive problem is cured by the strongspring, try the next weakest spring as well. If the strong one does not help, then the calibration problem is related to the A/F metering stage of either the Cruise or Power Modes. Use theCalibration Reference Chart to help select another combination.

Spring Color Blue Yellow Orange Pink PlainStaging Vacuum 3" 4" 5" 7" 8"("Hg) ​

A COMPLETE SET OF THESE SPRINGS IS AVAILABLE SEPARATELY AS EDELBROCK PART #1464.



I have also found that having the proper spring in there will help if the throttle is slammed to the floor.


Derek

 

I just looked at his site and the turnaround time for rebuilding / tuning is currently 12 months. Is he for real? I can't wait that long.

---------- Post added at 09:11 PM ---------- Previous post was at 08:50 PM ----------

Changing the step-up spring to 7hg and 8hg and moving pump rod up to top hole was the first thing I did.
I have completed many combinations of spring, rod and jet changes that my head is still spinning. even tried combinations for the 1407 (same carb but without electric choke and tuned for power not economy like the 1411)

---------- Post added at 09:17 PM ---------- Previous post was at 09:11 PM ----------

Already going to listen to everyone. Will post add in parts wanted soon.

 

Page 7 of the Eddy manual Derek posted:
Long Duration Camshaft
If the engine has a fairly radical camshaft it may require an excessive amount of throttle opening for idle and/or have low idle vacuum levels. Either condition can lead to poor levels of
adjustability and erratic idles.
Another fix for the above condition is to run as much spark advance as possible at idle. If the distributor is fitted with a vacuum advance unit, connect it directly to manifold
vacuum. If you are not able to employ vacuum advance for some reason, then the mechanical curve should have a low limit, which will allow you to use plenty of initial spark advance.
Measure the manifold vacuum at idle. If it is below 7" Hg, there is a good chance that the Metering Rods are in the up (rich) position. When combined with a high idle air rate this can
cause the Nozzles to discharge fuel at idle. Use a weaker Step-Up Spring (see section on Step-Up calibration) to keep the Rods down at idle. With some cams, a stiffer spring (pink or
silver) is necessary. Experimentation is the best way to determine which is best for your application.

This carb is at best is swap meet material period! It belongs on a mild SBC. Q-jet or a good Holley style carb and SP1. I am helping another board member with his old school Holley, same deal with his. Throttle plates were opened to far to run off the idle circuit, now that we got it working off the idle circuit its too lean and needs to be enlarged.

 

It looks to me that a Holley carb will work with the SP1 TA-1200
Do you think that the Holley #4781 with mechanical secondaries and manual choke is a good choice?

 

Talked with a local builder last week and he suggested a quick fuel Q- series 850 cfm carb would be a better choice than the Holley 850 DP. He said they are excellent and easily adjustable. He did not say anything bad about the Holley he just said that the Q is a little better quality and has better adjustments.
Has anybody had any good or bad experiences with this carb?
I still do not want to change my intake for the Q-jet and I do not have the clearence for the required spacer unless I change to a 2'' tall element and I do not think that there will be enough air flow. Please correct me if I'm misstaken

 

Didn't I direct you to Phil's thread where he was having problems with his 4781 in a PM? Sorry if I didn't, that is not a great choice. Q-series 850 cfm carb is a better carb. Some how I thought you wanted a spread bore set up, that is why I was saying Q-jet ou: some days I should just stay in bed........

 

Yes you did and after reading that thread it was determined that I was not going to go with the Holley. I am still not sure what I am going to get. Was just looking for some feedback on the Quick Fuel brand.
I have read on this site a few times that it has been said not to let someone tell you something unless they know about Buick engines (that's why I asked here).
I was just attempting to see if anyone has used that carb on a BBB with success.

 

Quick fuel has better quality control and far superior tech support IMO, if you do go holley be sure to take it apart and clean it 90% of the time they dont get all the shavings out, quantity vs quality pitfall

 

I am slowly getting this engine dialed in, just a lot slower then you pros. as soon as I fix my current situation with my rockers and pushrods. I would like address the plugs again, UR-4 and UR-5 both gapped at .040. Both sets of plugs were nice and light brown on #5,7,6 & 8 with little bit of black soot on top thread. On the other hand # 1,3,2 & 4 are bleach white with black soot on top thread, What would be the cause of this?

 

I guess no news is good news for me, I tend to worry to much about little things like that.

Tony

 

Here are the NGK UR-5 plugs gapped at .040 here is what they look like as of today
after about 2500 miles +/-

Can you tell me how do they look? Too Cold, Lean etc.
Adjustments needed?

any input would be appreciated,
Tony

 

1-2-3-4 look lean for some reason.....

 

That's what I was thinking until I read a few other posts that were talking about how it might be a little harder to read plugs with today's fuel mixtures. So I'm definitely not sure.

I read that you are supposed to run wot with new set of plugs then shut down and look at the plugs but, I was thinking that with all the knowledge and experience that is here on this site, there might be a suggestion or two that would help or some type of guesstimation on why the front of the motor has different color plugs then the back.

Tony