L78 Holley Rebuild...

[WILMASBOYL78]

The black survivor is back from the Mini-Nats and I decided to send the 4557 to the doctor (Mr. Vintage) http://www.yenko.net/ubbthreads/images/graemlins/cool.gif for a rebuild. I have never touched the carb in 8 years...it is the original dated unit. Still has the original fuel block, lines and bracket. The original owner installed some kind of "old school" bracket to help kick in the secondaries (I guess)...you can see the bracket and pin in the photos. With a little help from Mr. Jackson, it will be good to go for spring driving.....check out the photos.

wilma

underhood before removal..


http://www.yenko.net/attachments/327995-tn_DSCN1048.JPG

[WILMASBOYL78]

...I finished the smog plumbing from the prior thread.


http://www.yenko.net/attachments/327998-tn_DSCN1049.JPG

[WILMASBOYL78]

..drivers side.

http://www.yenko.net/attachments/328000-tn_DSCN1050.JPG

[WILMASBOYL78]

..fancy "add on"

http://www.yenko.net/attachments/328001-tn_DSCN1051.JPG

[WILMASBOYL78]

..another shot



http://www.yenko.net/attachments/328002-tn_DSCN1052.JPG

[WILMASBOYL78]

..original choke setup...you can also see the fuel line bracket..it has a part number stamped on it...there is also a small design stamp in the brass fuel block..


http://www.yenko.net/attachments/328003-tn_DSCN1053.JPG

[WILMASBOYL78]

..carb off the engine.

http://www.yenko.net/attachments/328004-tn_DSCN1054.JPG

[WILMASBOYL78]

..another shot.

http://www.yenko.net/attachments/328005-tn_DSCN1055.JPG

[WILMASBOYL78]

..date stamp on air horn.

http://www.yenko.net/attachments/328006-tn_DSCN1060.JPG

[WILMASBOYL78]

So that's it...pack it up tomorrow and send to Ohio.

wilma http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif

[VintageMusclecar]

Tom;

First off, thanks...as always. http://www.yenko.net/ubbthreads/images/graemlins/beers.gif

Secondly...dunno if you'd noticed, but the carb has the wrong primary float bowl on it, and it's missing the bowl vent assembly. http://www.yenko.net/ubbthreads/images/graemlins/frown.gif

Eric

[WILMASBOYL78]

As requested...checked the metering blocks and they are the correct pieces.

rear-4519
front-6328

[Mr. Chevy]

Tom, car looks really good.. http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif How did you do at the Mini Nats?? What is the production date of this (the black) car??
Did you add the return spring coming off the front of the throttle assembly and attaching to the engine lift bracket?? This looks like it may be part of the added bracket you were talking about that the previous owner installed to enhance the secondaries...

Rich http://www.yenko.net/ubbthreads/images/graemlins/beers.gif

[WILMASBOYL78]

Thanks Rich!....not sure why they put that extra spring on....original setup uses small spring mounting to the rear. That spring is also there....I will see how things work once we get it back from Eric. Car was well received at the show...we got a Peoples Choice award. This show is kind of low key...folks just hanging out in the sunshine and having some fun. Cowl tag date on this vehicle is 12C...engine is 11/22. Spring arrived yesterday...time to get the children ready to play http://www.yenko.net/ubbthreads/images/graemlins/burnout.gif

[Salvatore]

Dual springs were common in the older days. Sometimes the idle did not come back to where it was set at. And also some of the guys liked a stiffer feeling on the accelerator. http://www.yenko.net/ubbthreads/images/graemlins/Can-I-Have-It.gif http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif

[WILMASBOYL78]

Sammy, how stiff is your spring..?? http://www.yenko.net/ubbthreads/images/graemlins/naughty.gif

wilma http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif

[Mr. Chevy]

Congrads on the Peoples Choice award Tom!!! http://www.yenko.net/ubbthreads/images/graemlins/worship.gif One of these years I would like to make it to either the Mini Nats or the Nationals with my Nova...

I also noticed in the pictures that your green colored TCS plug wire that mounts to the switch on the passenger side head has a brown colored plug head on it. I was told that the brown colored plug heads started to surface on the mid to late seventy production cars and the earlier ones used a grey colored plug which is what the repro ones are colored. I had to get a repro one for my car because that portion of the wire was hacked off years ago by the previous owner. Luckily I still had the wiring and black colored plug head that plugs into the TCS solenoid on the intake. I found this coiled up in the wiring gutter...

Just another one of those "tid bits" of information that 90% of the rest of the population could care less about http://www.yenko.net/ubbthreads/images/graemlins/rolleyes.gif except for us crazy, maticulous car guys!!! http://www.yenko.net/ubbthreads/images/graemlins/grin.gif

Rich

[WILMASBOYL78]

Rich, you see "new" things on these "old" cars every time you work on them.....I've probably looked at that carb a hundred times and never noticed the incorrect float bowl http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif you just keep doin' and learnin'...I also noticed there's some orange paint overspray on the TCS plug.



wilma http://www.yenko.net/ubbthreads/images/graemlins/beers.gif

[Jeff H]

That was the first thing I noticed in your picture was te front bowl and vent missing. Maybe that is why they added that bracket thing when the bowl was swapped out.

[WILMASBOYL78]

Well the patient is out of the operating room and on to physical therapy http://www.yenko.net/ubbthreads/images/graemlins/grin.gif....the carb doctor did a good job of finding all of my Holley's ailments...and it had a few!! It's amazing how many things can be messed with in 39 years http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif so with a little more TLC and some corrective surgery we will be as good as new http://www.yenko.net/ubbthreads/images/graemlins/smile.gif..hope to have it back running by the weekend...pictures from the recovery room to follow http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif http://www.yenko.net/ubbthreads/images/graemlins/flag.gif

[kwhizz]

[ QUOTE ]
Well the patient is out of the operating room and on to physical therapy http://www.yenko.net/ubbthreads/images/graemlins/grin.gif....the carb doctor did a good job of finding all of my Holley's ailments...and it had a few!! It's amazing how many things can be messed with in 39 years http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif so with a little more TLC and some corrective surgery we will be as good as new http://www.yenko.net/ubbthreads/images/graemlins/smile.gif..hope to have it back running by the weekend...pictures from the recovery room to follow http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif http://www.yenko.net/ubbthreads/images/graemlins/flag.gif

[/ QUOTE ]


Now......"Maybe"......You'll have a car that "Run's" correctly and 'You" will maybe not be MIA........... http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif.......Eric "Rocks" http://www.yenko.net/ubbthreads/images/graemlins/worship.gif

Ken http://www.yenko.net/ubbthreads/images/graemlins/flag.gif

[Jeff H]

[ QUOTE ]
Well the patient is out of the operating room and on to physical therapy http://www.yenko.net/ubbthreads/images/graemlins/grin.gif....the carb doctor did a good job of finding all of my Holley's ailments...and it had a few!! It's amazing how many things can be messed with in 39 years http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif so with a little more TLC and some corrective surgery we will be as good as new http://www.yenko.net/ubbthreads/images/graemlins/smile.gif..hope to have it back running by the weekend...pictures from the recovery room to follow http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif http://www.yenko.net/ubbthreads/images/graemlins/flag.gif

[/ QUOTE ]

Sounds good, can't wait to hear how good it runs. I drove my L78 car with non functioning secondaries for over a year. I don't have the money to put a correct carb on it so I kept running the 3310 750 that came on it and it has no choke and has been monkeyed around with. It's still a blast to drive but I can't imagine how much better it would be set up correctly! Good luck with the fresh rebuild.

[WILMASBOYL78]

Jeff, the matching numbers stuff is pricey...but you can make a good carb out of a regular street Holley. Why not have Eric rebuild your current unit or perhaps he has a better core to work with...you can't see those date codes from the driver's seat http://www.yenko.net/ubbthreads/images/graemlins/grin.gif http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif

[VintageMusclecar]

Greetings all;

Well, I had every intention of getting some pics posted up today, but I spent the better part of the day dealing with several uncooperative "patients", as Mr. Williams might say. Depending on how much I can get done tomorrow morning, I'll try to pop a couple of pics up sometime in the afternoon.

Ken;

Thank you. http://www.yenko.net/ubbthreads/images/graemlins/beers.gif

Jeff;

I'd be happy to help you with your 3310 if you'd like, just say the word.

Eric

[DarrenX33]

[ QUOTE ]
I'd be happy to help you with your 3310 if you'd like, just say the word.

[/ QUOTE ]

Why? http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif He has a perfectly good 4557 for that car. http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif Get that baby on there and I'll buy your 3310. http://www.yenko.net/ubbthreads/images/graemlins/grin.gif

[FRITO]

hey you guys can u help me i got a new project nova JUST GENRAL INFO LIKE WHAT IT WAS FACTORY I TRADED MY BOSS LADY CADDY FOR IT IT HAS A TAG ON FIRE WALL SAYS ST 69 WRN 11427 THERE IS A 53 53 BELOW THAT ON THE INSIDE IT HAS A PLATE WERE THE RADIO WAS ON MY OTHER NOVA HAS 12 BOLTS IN THE REAR COVER OF REAR END TRANNY WAS IN THE TRUNK HAS A TAG THAT IS STAMPED CY -69 ON THE DRIVERS SIDE OF TRANNY IT CAME WITH A BIG BLOCK ON A STAND SOPOSSED TO BE THE ORIGANAL MOTOR AND IT HAS GILLS ON THE SIDE LIKE A FISH tho motor has a casting number 3963512on the back driver side
head has acasting number of 3946074 alumunim has the factory intake its ulumunim and has funny lil snow flake casting on it does this help i hpoe its worth tho caddy i trade

[VintageMusclecar]

OK; the carb is wrapped up and will be on its back to Mr. Williams tomorrow.

To highlight a few things during the rebuild process;

First and foremost, the carb was suffering from a pretty bad case of fuel contamination. The filter on the left is the one out of the rear bowl on Toms carb, the one on the right is a new unit for comparisons sake.

http://www.yenko.net/attachments/329349-1_Filters.jpg

Yes, it is essentially plugged solid. The insides of the float bowl looked even worse.

[VintageMusclecar]

Next issue was the Borg/Warner needle & seats that had been previously installed. These units are responsible for more junked float bowls than I can count. http://www.yenko.net/ubbthreads/images/graemlins/no.gif

The problem lies with the extra threads below the groove for the O-ring--if this type of needle & seat is threaded too deeply into the float bowl, it will cut threads into the boss where a normal Holley needle & seat seals with its O-ring, thereby ruining the bowl.

http://www.yenko.net/attachments/329350-2_needle%26seats.jpg

[VintageMusclecar]

Next up was the accellerator pump cover. Whoever rebuilt the carb previously must've lost the correct clutch-head screws that secure this particular style of cover, and they replaced them with conventional Fillister head screws.

http://www.yenko.net/attachments/329351-3_Pump_Cover.jpg

Tom reported that the pump cover had been leaking...I wonder why? http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif

(please pardon the typo in the pic...I was in a hurry http://www.yenko.net/ubbthreads/images/graemlins/grin.gif )

[VintageMusclecar]

Toms carb was also equipped with an incorrect later-style primary float bowl, which also lacked the correct float bowl vent assembly this particular carb requires. To note; the later style bowls can not be converted to use a bowl vent lever as they lack the cast-in boss for the lever retainer.

Tom provided a correct early style primary bowl, but it wasn't set up for the bowl vent lever either.

http://www.yenko.net/attachments/329352-4_BowlA.jpg

[VintageMusclecar]

Voila...one primary bowl now equipped for a vent assembly.

http://www.yenko.net/attachments/329354-5_BowlB.jpg

[VintageMusclecar]

Next thing was to correct the warp that was present on the metering block surfaces. If this step is skipped (and it often is), the carb can develop internal leaks that can cause all sorts of grief and aggrivation.

http://www.yenko.net/attachments/329355-6_machinedPMB.jpg

[VintageMusclecar]

The secondary side received the same treatment.

http://www.yenko.net/attachments/329357-7_machinedSMB.jpg

[VintageMusclecar]

The baseplate surface receives the same treatment as well

http://www.yenko.net/attachments/329358-8_baseplate_surface_machined.jpg

[VintageMusclecar]

The baseplate itself is also machined flat again on both sides instead of just the manifold side as many rebuilders do:

http://www.yenko.net/attachments/329359-9_Baseplate_top_machined.jpg

[VintageMusclecar]

The bottom:

http://www.yenko.net/attachments/329360-10_baseplate_bottom_machined.jpg

Finally, the baseplate was bushed for the primary throttle shaft, as despite the fact that this is a low-mileage carb, the funky secondary mechanical conversion that was noted earlier must've caused some extra wear as it definitely needed to be bushed.

[VintageMusclecar]

Finally, the carb was buttoned back up and all of the adjustments were baselined for re-installation.

http://www.yenko.net/attachments/329362-11_completeDS.jpg

Ain't much to look at when compared to the restored pics we're all so used to seeing, but this is what a 38-year-old carb looks like in its "natural state."

[VintageMusclecar]

The other side:

http://www.yenko.net/attachments/329363-12_completePS.jpg

[VintageMusclecar]

And lastly, the business side of the carb:

http://www.yenko.net/attachments/329364-13_completeBASE.jpg

And that wraps it up. The carb definitely had some issues from its previous rebuild, but it should be good to go for another 38 years now...as long as Tom gets that dirty fuel issue resolved, that is. http://www.yenko.net/ubbthreads/images/graemlins/grin.gif

Hope y'all enjoyed. http://www.yenko.net/ubbthreads/images/graemlins/beers.gif

Eric

[70 Forest Green Zee]

Just curious Eric... did Tom choose not to have the carb re-plated? I would have thought after all the machineing and new parts,it will run like brand new and it should look like brand new. http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif

Extreamly interesting thread by the way! http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif

[VintageMusclecar]

Randy;

Toms car is a low mileage "survivor" (am I even allowed to use that term???), and as such he elected to keep the carb in its current state of aging...or "patina", if you will, as a fully restored carb would certainly stick out like a sore thumb among its 38-year-old unrestored surroundings.

Eric

[WILMASBOYL78]

Looks like the doctor did another great job....it's great to have a guy like Eric to help keep the "fleet" in good running order. http://www.yenko.net/ubbthreads/images/graemlins/beers.gif Sending out the carb from our lawn mower tomorrow http://www.yenko.net/ubbthreads/images/graemlins/grin.gif

[SS427]

[ QUOTE ]
Next issue was the Borg/Warner needle & seats that had been previously installed. These units are responsible for more junked float bowls than I can count. http://www.yenko.net/ubbthreads/images/graemlins/no.gif


[/ QUOTE ]

That made this thread worth the read (in case some of you didn't think it was already http://www.yenko.net/ubbthreads/images/graemlins/wink.gif ). I KNOW that I have used the BW needle and seat on many rebuilds and have suffered many a floading condition and/or leaking afterwards. I never gave the needle and seat a second thought as being the culprit. Thank you very much for that information. Now if I can only retain that little tidbit of information in my pea sized brain. http://www.yenko.net/ubbthreads/images/graemlins/rolleyes.gif

[VintageMusclecar]

Perhaps I should clarify a little bit in regards to the B/W needle & seat issue;

It's not so much the fault of the component as it is the potential for damage by the installer. If you've ever taken notice, you can only thread a genuine Holley needle & seat down into the float bowl so far before the nut dis-engages the top of the needle & seat, preventing you from turning it down any farther where it could damage the boss where the O-ring seals.

On the B/W unit, due to the design, you can easily thread the needle & seat down far enough to do damage since the needle & seat itself contains the means of adjustment (screwdriver slot) as opposed to the 5/8" nut used on the genuine Holley part.

If someone was having issues with the carb that led them to believe the float levels might've been too high (such as a heavy or sinking float), one might try to lower the adjustment to the point where the extended threads on the B/W component start to thread themselves into the lower O-ring sealing boss, which in turn ruins the float bowl.

The other common result of the B/W needle & seat is stripping needle & seat threads right out the top of the float bowl. If you'll notice, this design has a reciever groove in the bottom of the lock nut. The nut is only designed to go on with this reciever groove facing the float bowl to compress the O-ring on the top of the needle & seat to seal it externally. I can't begin to count how many of those nuts I've seen installed upside-down...the result?...a leaky needle & seat that naturally prompts the mechanic to try to snug the nut down just a liiiiiiiiiiittle more to try to stop the leak. The result?...cranking the nut down only serves to draw the needle & seat straight up out of the float bowl, taking the bowl threads with it.

These are just a few of many reasons why I'm so adamant about using only OEM quality parts in my rebuilds & restorations.

Hopefully this will save someone a float bowl or two somewhere down the road.

Eric

[Jeff H]

Carb looks much better with the correct needle and seat and primary bowl. I sold my 4557 months ago for money to continue the restoration the JL8. It was dated wrong for my car anyway. I would like to get a more correct looking Holley 780 for my L78 and don't want to waste money on the 3310 since it's been messed with already. If I find a decent carb, I will be sending it your war Eric. Can't wait to hear how well this Nova runs with the rebuilt carb! http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif

[Rixls6]

Great read. http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif
Thanks Eric for the "insider" info about the needle & seat.
All my carbs would definitely be going to you when they need restoring. http://www.yenko.net/ubbthreads/images/graemlins/worship.gif

[Mr70]

"I also noticed in the pictures that your green colored TCS plug wire that mounts to the switch on the passenger side head has a brown colored plug head on it. I was told that the brown colored plug heads started to surface on the mid to late seventy production cars and the earlier ones used a grey colored plug which is what the repro ones are colored. I had to get a repro one for my car because that portion of the wire was hacked off years ago by the previous owner. Luckily I still had the wiring and black colored plug head that plugs into the TCS solenoid on the intake. I found this coiled up in the wiring gutter..."

I've only seen either the Black or the Brown TCS plug installed here originally on the 1970 Big Blocks so far...Cars like Bill B.,Dennis C.,Dave G.,Tony P.,& Dean R. survivor LS-6's to name a few.
I've only encountered the Grey on Small Blocks & have factory photos showing Grey on them too,but still not certian it was exclusive to just the SB. http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif

[Mr. Chevy]

Rick, the guy I spoke to about these plugs was out in California when I was calling around looking for the original style plug for my car. He was the one who gave me the info and he seemed to be very knowledgeable. I can't remember the name of the place but they dealt only with old car/musclecar electrical items.

He did state that the grey plugs were used on Big Block cars but like I said, earlier. I have never heard of a black colored plug going to this switch in the head but who knows there could have been a couple different manufacturers making these things back then for GM.. Plus it obviously had to be there if you observed it on some original, survivor cars... http://www.yenko.net/ubbthreads/images/graemlins/burnout.gif

Rich

[70LS6454]

Eric, great information as always,I learned something tonite.

Ray

[72-SS-L48]

I think Randy's comment (70 Forest Green) about the exterior condition of the carb was very interesting and Eric your response was great. I might be naive but I would imagine not too many people can take a carb all apart, rebuild it perfectly and put it back together maintaining the original "Survivor" look.

Eric the carb looks great, and you have such a talent for rebuilding / restoring these carbs. This thread is loaded with information. Thanks for the on-going education.

Tom - I can't wait to see your collection sometime soon.

-Dave

[Paul_S]

Nice job Eric,

It's nice to have it in it's original patina especially when compared to some over-restored carbs that are very dark or would be a major contrast to an original car. Did you treat the machined surfaces with anything for corrosion protection?

[VintageMusclecar]

Thanks, glad there was some useful info in there for some of you. http://www.yenko.net/ubbthreads/images/graemlins/smile.gif

Paul;

It isn't really necessary to to treat the machined surfaces since they're completely protected by the gaskets once the carb is assembled. Besides, there's really not much you can do for them (the machined surfaces) since you would have to run the whole casting through the entire chemical cleaning process(es) just to get the chromate to take on the machined surfaces, and doing so would seriously damage the rest of the original finish. It's pretty much an "all or nothing" sort of deal.

Eric

[WILMASBOYL78]

Well, we got the carb back on Friday...but there was no time on the Birthday for working in the shop. Finally got a chance to get her back together today....and as you would expect it worked great http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif Since Eric was worried about dirt/rust in the fuel system I decided to install an inline filter for a while to see if it picks up anything. I may eventually take it back off, but for now it seems like cheap insurance. Took the car out for a spin and it runs good...another quality job by the man from Ohio....Thanks, Eric.

wilma http://www.yenko.net/ubbthreads/images/graemlins/3gears.gif

carb back in place..

http://www.yenko.net/attachments/330259-tn_DSCN1101.JPG

[WILMASBOYL78]

another view...the day 2 secondary "gizmo" has been retired..

http://www.yenko.net/attachments/330260-tn_DSCN1103.JPG

[WILMASBOYL78]

in-line filter...

http://www.yenko.net/attachments/330262-tn_DSCN1104.JPG

[WILMASBOYL78]

..last one.

http://www.yenko.net/attachments/330263-tn_DSCN1102.JPG

[VintageMusclecar]

http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif

btw...belated happy birthday. http://www.yenko.net/ubbthreads/images/graemlins/beers.gif

[JRSully]

Now take it out and do some 5k powershifts, that is what I did today and it made the day a lot better. I would rather hear the engine scream rather than the kids

[Jeff H]

[ QUOTE ]
Now take it out and do some 5k powershifts, that is what I did today and it made the day a lot better. I would rather hear the engine scream rather than the kids

[/ QUOTE ]

I took the L78 for a spin today as well. Whatever I did to the generic 750 Holley to get the secondaries working has actually made the car easier to start as well! I still can't get used to having a full working 4 bbl carb. But I think my gas mileage is going down now! http://www.yenko.net/ubbthreads/images/graemlins/grin.gif

[ORIGLS6]

Hats off to Tom and Eric for keeping a 'correct' look on this car. http://www.yenko.net/ubbthreads/images/graemlins/flag.gif

Just another reason to hoist a toast to the talents and attention to detail Mr. Jackson puts into his work http://www.yenko.net/ubbthreads/images/graemlins/beers.gif

(And I have to agree with the opinions on the BW N&S items. I NEVER liked them, for performance OR appearance. http://www.yenko.net/ubbthreads/images/graemlins/thumbsdown.gif)

[Novadiecast]

OK, Now we need the burnout vidio!!!! http://www.yenko.net/ubbthreads/images/graemlins/burnout.gif

[1969l78]

[ QUOTE ]
Now take it out and do some 5k powershifts, that is what I did today and it made the day a lot better. I would rather hear the engine scream rather than the kids

[/ QUOTE ]


http://www.yenko.net/ubbthreads/images/graemlins/haha.gif http://www.yenko.net/ubbthreads/images/graemlins/haha.gif http://www.yenko.net/ubbthreads/images/graemlins/haha.gif http://www.yenko.net/ubbthreads/images/graemlins/haha.gif