Author Topic: My New '68 Camaro Z/28 Butternut Yellow  (Read 44386 times)

bcmiller

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #240 on: August 03, 2014, 05:46:00 PM »
I am sure your friend knows what he is doing with carbs.

For the symptoms you liist, it sure seems like it is either the carb or something sticking in the distributor.

Personally, I think you can find a nice carb for less than that.
1968 Camaro SS 396 - now 468 BBC, M21, 12 bolt.
Looking for 68 Camaro with body number NOR 181016
Bryon

69Z28-RS

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #241 on: August 03, 2014, 05:54:27 PM »
I am sure your friend knows what he is doing with carbs.

For the symptoms you liist, it sure seems like it is either the carb or something sticking in the distributor.

Personally, I think you can find a nice carb for less than that.
I think Danny had the original carburetor for his car; just needs to be rebuilt to 'stock form'.. which would be cheaper than $640, OR he could buy a new 3310 for much less than that which would be fine on his engine *to drive*... 

and.. aren't there some folks who can rebuild his original carb for MUCH LESS  ($200?) and do it within a week or two?

Gary
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

dannystarr

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #242 on: August 03, 2014, 06:18:04 PM »
I was looking at that carb cause I thought I had to have THAT one. What's a 3310? Will everything line up and all the fuel connections, linkage and vacuum lines connect properly. I DO NOT want to do ANY mods. Just wanna throw it on and go... As far as sending out my original, I honestly don't wanna wait 15 or 20 days to get it back. Danny

janobyte

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #243 on: August 03, 2014, 07:10:42 PM »
Good advice from NOYENKO also....if the timing is wandering, or "sticking" at full advance, your engine will  run erratic. Like he posted, very easy to remove from the equation. BTY, CHP was very fair on the price when I had my distributor gone through last year. Plus certification ;D


Heed Gary's advice on carb replacement or rebuild. Food for thought, while your carbs getting refurbished, whatever, you do not need a high dollar carb to feed that 302. Sounds like you are just out to cruise. Don't think any no lift 7800 shifts in your car's future. Check Summit, they carry refurbished Holleys and Edelbrocks. (street avenger ?) You would be surprised the overall performance a 600 Edelbrock does atop that engine...just to tie you over.

Also check out Crane Corvette if you are pretty set on another 780 ,look to have a good rep and descent prices, see what they say.

I cannot see putting out $700 for another carb, when you own the born with...new base plate, metering blocks, neoprene gaskets, blow out protection, needles and seats etc,,would come in half that...








janobyte

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #244 on: August 03, 2014, 07:50:08 PM »
Oh-to answer your other question, The mentioned carbs come with necessary vacuum ports. But,,,isolate your problem 1st before throwing $$$ at it.

69Z28-RS

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #245 on: August 03, 2014, 08:01:28 PM »
I was looking at that carb cause I thought I had to have THAT one. What's a 3310? Will everything line up and all the fuel connections, linkage and vacuum lines connect properly. I DO NOT want to do ANY mods. Just wanna throw it on and go... As far as sending out my original, I honestly don't wanna wait 15 or 20 days to get it back. Danny

the Holley 3310 is Holley's generic OTC 4150 (780 cfm), and is the carb that is probably only half or more of the Z28 clones, and probably over the years has been on more than half of the real Z28's at one time or another.  I think everything will hook up correctly without any mods Danny..
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

bcmiller

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #246 on: August 03, 2014, 09:05:23 PM »
Gary is right.  A good original 3310 or 3310-1 will work fine and is 780 cfm (2 metering blocks).  I believe the later versiions (3310-2, 3310-3 etc) are rated at 750 cfm but they will work fine too.

For your needs you just need something 750 cfm or so that is a vacuum secondary carb.  

BUT, I would just try to get what you currently have working.  What did he do when he rebuilt your carb?  Standard rebuild?  Did it run OK on another engine?
1968 Camaro SS 396 - now 468 BBC, M21, 12 bolt.
Looking for 68 Camaro with body number NOR 181016
Bryon

maroman

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #247 on: August 03, 2014, 11:45:31 PM »
Not trying to make you run in circles, but take a good look at the distributor weights. With the carb modification he may have put light springs and heavy weights in there. It was a common thing to do.
Doug  '67 RS/SS 396 auto I know the car since new

MO

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #248 on: August 04, 2014, 03:17:24 AM »
As far as sending out my original, I honestly don't wanna wait 15 or 20 days to get it back. Danny

Don't be so anxious. Just wait a little and have your original rebuilt. I think you'll be happier in the end. Check with Jerry MacNeish.

dannystarr

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #249 on: August 04, 2014, 07:21:27 AM »
MO,
 I here ya, but I can't help it. I wanna drive it. I have spent SO much time with everything I need a payoff. And my health isn't the best. It's SO close now.

 So my girlfriend ordered the NEW Holley 0-4053 3923289 today. I will make payments to her when I get caught up. It will be here Wed. morning. I needed something anyway. Now I can send mine out at my leisure and have no down time. 3 days is better than 3 weeks.  ;D
Jerry should be heading back from Reno, as he is up there for the Barrett Jackson Hot August nights. Maybe I can connect with him soon.
 
 I disconnected the vacuum line from the smog pump and plugged it, no change. I did the same with the dist. line, no change. It still does the same thing. The rebuild guy is coming over tom at 10am to check it out. We will see what he can find. Plus I wanna learn after the diagnoses. I had 2 springs on the return and thought maybe that was causing it to pull to the side hard and bind. Like the old Auto Lite Carbs would do. So I pulled the extra one and left the original, no change. It's gotta be inside the carb. When you turn the idle adjust screw just a little to much, it climbs up to 2 or 3 thousand RPMs by itself. Something's gotta be wrong. Stay tuned ... Danny

dannystarr

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #250 on: August 04, 2014, 11:08:48 PM »
Well the carb rebuild guy just left. He checked it with a Vacuum gauge and sent me down to get 2.5 power valves instead of the 6.5 that are in there. So I don't know what that means, but hopefully it will work, I gotta pull the carb AGAIN, and get everything over to him. Then he said he would help me tune it and dial it in after reinstall. Stay tuned... No pun intended  ;D   ... Danny

little_hoss

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #251 on: August 05, 2014, 12:45:46 AM »
Did you happen to see what kind of vacuum your engine was pulling at idle? You typically size a power valve at 1/2 your engine vacuum at idle. With a 6.5 valve your pulling around 13" of vacuum at an idle. So with a 2.5 you would only be around 5" of vacuum at idle. At light cruising and idle, the power valve is closed because your vacuum is above the power valve rating. It doesn't open until WOT or when your vacuum drops below the valves rating and then allows fuel to flow through the power valve channel restrictor enriching your fuel mixture. They are basically a vacuum operated on and off switch for fuel. So with a 2.5" valve its not going to open until you drop below 2.5" of vacuum. Remember, an engine makes its most vacuum at idle and at WOT throttle its least amount of vacuum.
Eric

1967 Base
1969 Base 307 3spd matching #'s
1968 C-10 Short Fleet Custom

bcmiller

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #252 on: August 05, 2014, 02:26:31 AM »
Going by memory but I think the 6.5 power valve is correct for that carb.  Not sure why he would want to make the changes he told you.

It is not easy to diagnose a problem like this remotely, but I suspect a vacuum leak somewhere.  Possibly where the intake seals onto the heads or block. 

Did you check for a vacuum leak?
1968 Camaro SS 396 - now 468 BBC, M21, 12 bolt.
Looking for 68 Camaro with body number NOR 181016
Bryon

dannystarr

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #253 on: August 06, 2014, 07:07:23 AM »
Well I have to say I did look for a vacuum leak, but couldn't find any. Here is what the gasket looked like when I pulled the carb today. Is this ok? I don't remember any bleed thru like this before. I am not sure why he wanted to put the 2.5's in... I didn't see the vacuum gauge, I think he said 4.5. I just want it right or close to it for the money I spent on the rebuild. If it doesn't work when I get it back tom, going to cut my loses for now and just install the new carb. I wanna go to some car shows in the coming days and weeks. Danny

JoeC

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Re: My New '68 Camaro Z/28 Butternut Yellow
« Reply #254 on: August 06, 2014, 12:31:59 PM »
not related to the carb problem but another thing to check on unrestored cars........

the distributor mechanical advance has a rubber bump stop that can dry out and crumble off leaving
a smaller diameter steel pin. This can change your timing and advance by a large amount

many people installed aftermarket advance kits that came with weights, springs, and a bronze bushing, so if your car has that it should
be OK but if it still has the rubber bushing you may want to check it.