Slant *        6        Forum
Home Home Home
The Place to Go for Slant Six Info!
Click here to help support the Slant Six Forum!
It is currently Thu Nov 20, 2025 2:55 am

All times are UTC-08:00




Post new topic  Reply to topic  [ 15 posts ] 
Author Message
PostPosted: Tue Feb 10, 2015 3:36 pm 
Offline
TBI Slant 6

Joined: Thu Nov 01, 2012 7:19 pm
Posts: 187
Location: Albuquerque, NM
Car Model:
Hello all, the W150 truck is progressing. Removed the manifolds today and spent about 2 hours searching for a triangular special washer that had fallen off during removal. Turns out it never was there - a regular thin washer had been substituted. :-( Anyway, the old manifold was a welded aluminum one. Super light! Passages were wet with fuel. Guess it was running a bit rich. The good news is all the exhaust ports are oil free. Haven't finished making a Dutra dual setup, so the regular stock exhaust manifold will go back on, along with a offy manifold and Holley 390 cfm 4bbl. Had been working on a dual 1 bbl offy manifold converted to use a pair of the Langdon Carter/Weber carbs - but trying to get the carbs to open in sync even with a beefed up Langdon linkage is difficult as the spring tension on the Carter/Weber carbs is pretty massive. Plus, I'm not sure how it will work here at 5500+ feet. The Holley has re-jetted with a new power valve (3.5) installed so the power valve isn't on during cruise. Oh, the old manifold junction leaked quite a bit:
Image

_________________
Tom
'86 Alfa Romeo Spider, red "Dinsdale"
'10 Corvette, red "" (no name yet)
'95 Ferrari 348, red "Zoom"
'04 Maserati, black "Evil"
'05 Aston Martin DB9, green "Bond, Treasury bond."
'82 Dodge W150 Power Ram, yellow "E. Valdez"


Last edited by spacecommander on Thu Feb 12, 2015 7:01 pm, edited 2 times in total.

Top
   
 Post subject:
PostPosted: Tue Feb 10, 2015 8:14 pm 
Offline
TBI Slant 6

Joined: Thu Nov 01, 2012 7:19 pm
Posts: 187
Location: Albuquerque, NM
Car Model:
Wow, this is a real headache. The last 2 I did were about 25+ years ago and I don't remember anything like this hassle-wise. The Offy manifold required a fair bit of work to get it to play with the 1982 exhaust manifold. The exhaust manifold has a stud for the middle manifold-manifold connection, and upon heating the manifold - the stud did not want to budge. So, the stud had to stay. The reason you want to remove the stud is so that it does not hit the carb adapter plate as it is quite tall. Things that needed to be done to get it to work - the three holes in the offy intake that connect to the exhaust manifold heat box needed to be enlarged considerably as the intake manifold mating surface to the head protruded quite a bit (.1!) past the plane where the exhaust manifold would mate to the head - the stud in the exhaust manifold barely slid in to the hole in the offy manifold and located the mating planes of the runners to the head incorrectly. Then the holes in the exhaust manifold had to be enlarged also as the long bolts that go through the intake outer edge of the heat box to the exhaust heat box were angled incorrectly - the bolts would not slip through even though the intake holes were oversized. Lastly the carb adapter plate had to be hacked a bit in the bottom as it hit the heat riser for the choke, and the stud hit it also. See pictures.
Image
Image

_________________
Tom
'86 Alfa Romeo Spider, red "Dinsdale"
'10 Corvette, red "" (no name yet)
'95 Ferrari 348, red "Zoom"
'04 Maserati, black "Evil"
'05 Aston Martin DB9, green "Bond, Treasury bond."
'82 Dodge W150 Power Ram, yellow "E. Valdez"


Top
   
 Post subject:
PostPosted: Tue Feb 10, 2015 10:11 pm 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
Ick!

Is the plate still going to seal on the manifold after that bit of hacking?


Top
   
 Post subject:
PostPosted: Tue Feb 10, 2015 10:27 pm 
Offline
TBI Slant 6

Joined: Thu Nov 01, 2012 7:19 pm
Posts: 187
Location: Albuquerque, NM
Car Model:
Quote:
Ick!

Is the plate still going to seal on the manifold after that bit of hacking?
Yup, there's plenty of metal surface left for the gasket to seat on.

Head mating surface has been scraped clean with razor blade, then cleaned with acetone. Runners to head gasket goes on dry - no hi-temp gasket cement. Ran a huge flat file over the exhaust runner mating surfaces - they're flat, amazingly. Doubt this can run worse than the old 1bbl that the previous owner "rebuilt" - every screw was rounded off, most were stripped. The 390cfm Holley is used - I rebuilt it with a real Holley rebuild kit. The throttle shafts aren't very worn at all. It will initially be a 2BBL as a quick change spring kit was installed and the super heavy black spring - the vacuum secondaries won't open. Once the primary side gets dialed in - then I'll play around with different springs and monkey with the pump shot so the secondaries open smoothly. It will be interesting to see how the vacuum secondaries work here at 5500+ feet. The little 390CFM 4(or 2)bbl should also work better in another way - the venturi ported vacuum line should provide a stronger signal to the distributor. Unfortunately I forgot to hook the vacuum gauge up to the distributor advance signal port of the old 1bbl before it was removed - my guess is it was providing not much vacuum at all - if any.

_________________
Tom
'86 Alfa Romeo Spider, red "Dinsdale"
'10 Corvette, red "" (no name yet)
'95 Ferrari 348, red "Zoom"
'04 Maserati, black "Evil"
'05 Aston Martin DB9, green "Bond, Treasury bond."
'82 Dodge W150 Power Ram, yellow "E. Valdez"


Top
   
PostPosted: Wed Feb 11, 2015 4:03 pm 
Offline
TBI Slant 6

Joined: Thu Nov 01, 2012 7:19 pm
Posts: 187
Location: Albuquerque, NM
Car Model:
Dagnabit! All done, carb return spring bracket and throttle cable support bracket fabricated, electric choke wired and hooked up, all fuel lines plumbed and vacuum lines hooked up. Cranked engine - cranked some more then it started and immediately the shout was woah! woah! as fuel shot out of the bowl-bowl transfer pipe in a jet about 2 feet long. Ok, that's not hard to fix - started taking carb off then noticed gas was EVERYWHERE inside carb - and as carb was removed I could see gas pouring out above the throttle plates???? Took carb outside and shook - gas poured out of idle bleed circuits - tilted the carb a bit and more gas poured out of idle bleed circuits on both primary and secondary side. What the heck? All I did was disassemble the two fuel bowls and the primary metering plate to replace the power valve and primary jets - put in new gaskets. Obviously I screwed up and pinched an o-ring somehow on the fuel transfer tube. Both floats are working properly. I'm completely and totally baffled. Should add that this carb was purchased used off ebay and I've never used it before.

_________________
Tom
'86 Alfa Romeo Spider, red "Dinsdale"
'10 Corvette, red "" (no name yet)
'95 Ferrari 348, red "Zoom"
'04 Maserati, black "Evil"
'05 Aston Martin DB9, green "Bond, Treasury bond."
'82 Dodge W150 Power Ram, yellow "E. Valdez"


Top
   
 Post subject:
PostPosted: Wed Feb 11, 2015 4:52 pm 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
Yikes! Scrutinize it for cracks and make sure the inlet valve assembly is clean and doing what it should. Perhaps it stuck open and drowned itself.


Top
   
 Post subject:
PostPosted: Wed Feb 11, 2015 5:03 pm 
Offline
TBI Slant 6

Joined: Thu Nov 01, 2012 7:19 pm
Posts: 187
Location: Albuquerque, NM
Car Model:
Quote:
Yikes! Scrutinize it for cracks and make sure the inlet valve assembly is clean and doing what it should. Perhaps it stuck open and drowned itself.
I'm going to get a fuel pressure tester - wondering if it was sky high as there's gas all over the floor of the manifold, etc.

_________________
Tom
'86 Alfa Romeo Spider, red "Dinsdale"
'10 Corvette, red "" (no name yet)
'95 Ferrari 348, red "Zoom"
'04 Maserati, black "Evil"
'05 Aston Martin DB9, green "Bond, Treasury bond."
'82 Dodge W150 Power Ram, yellow "E. Valdez"


Top
   
 Post subject:
PostPosted: Wed Feb 11, 2015 5:26 pm 
Offline
Board Sponsor
User avatar

Joined: Sat Feb 08, 2003 2:37 pm
Posts: 4194
Location: CA
Car Model:
Unless it was high enough to bend or break things, I can't see that happening. We're dealing with a mechanical pump right? Even the big ones don't get past what, 8psi give or take? Fuel will come out anywhere it can if the valve doesn't do what it should.


Top
   
 Post subject:
PostPosted: Wed Feb 11, 2015 7:16 pm 
Offline
TBI Slant 6

Joined: Thu Nov 01, 2012 7:19 pm
Posts: 187
Location: Albuquerque, NM
Car Model:
?!!? pulses up to 4.5-5 PSI. Needle valves appear to be working via mouth blow test. Unless - the fuel is flowing in to the carb internals via other transfer areas before the float rises high enough to shut off the valve? Floats will get re-adjusted down as far as they go, carb will get rebuilt and fuel line hooked up and carb will sit in a bucket to see if there's internal problems.

_________________
Tom
'86 Alfa Romeo Spider, red "Dinsdale"
'10 Corvette, red "" (no name yet)
'95 Ferrari 348, red "Zoom"
'04 Maserati, black "Evil"
'05 Aston Martin DB9, green "Bond, Treasury bond."
'82 Dodge W150 Power Ram, yellow "E. Valdez"


Top
   
 Post subject:
PostPosted: Wed Feb 11, 2015 7:55 pm 
Offline
Supercharged
User avatar

Joined: Sat Feb 16, 2008 1:25 pm
Posts: 5613
Location: Downeast Maine
Car Model:
One Holley 390 user to another.

Vaseline on little tiny "O" ring between primary metering bock and carb body, this would be the path fuel takes to get to accelerator pump, and is exposed when changing a power valve. Vaseline on both "O" rings sealing metal fuel line between front bowl and secondary fuel bowl. If these O rings don't seat properly you will have fuel dribbling every were.

Vaseline on screws clamping quick change secondary spring hat to prevent ripping vacuum actuated membrane.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Image


Top
   
 Post subject:
PostPosted: Wed Feb 11, 2015 7:57 pm 
Offline
TBI Slant 6

Joined: Thu Nov 01, 2012 7:19 pm
Posts: 187
Location: Albuquerque, NM
Car Model:
Nope, the carb is shot - no idea how or what the previous owner did - but even with just a little bit of fuel in the bowls and sight screws removed - the gas just runs out the primary and secondary idle slots. Maybe the wrong metering block or gasket set was used?

Bah. Double bah with eggs on top and don't skimp on the pate.

_________________
Tom
'86 Alfa Romeo Spider, red "Dinsdale"
'10 Corvette, red "" (no name yet)
'95 Ferrari 348, red "Zoom"
'04 Maserati, black "Evil"
'05 Aston Martin DB9, green "Bond, Treasury bond."
'82 Dodge W150 Power Ram, yellow "E. Valdez"


Top
   
 Post subject:
PostPosted: Wed Feb 11, 2015 8:23 pm 
Offline
TBI Slant 6

Joined: Thu Nov 01, 2012 7:19 pm
Posts: 187
Location: Albuquerque, NM
Car Model:
Quote:
One Holley 390 user to another.

Vaseline on little tiny "O" ring between primary metering bock and carb body, this would be the path fuel takes to get to accelerator pump, and is exposed when changing a power valve. Vaseline on both "O" rings sealing metal fuel line between front bowl and secondary fuel bowl. If these O rings don't seat properly you will have fuel dribbling every were.

Vaseline on screws clamping quick change secondary spring hat to prevent ripping vacuum actuated membrane.
I use a tiny bit of mobil 1. ;-) Thanks - I'm wondering if the metering block to carb gasket is the correct one. Different holes? But - why is gas getting in to the top of the secondary throttle plates? That's just the one gasket between the fixed metering "thing" and the body - there isn't a secondary metering block. Bah. Something is seriously hosed on the holley. Maybe the previous owner decided to drill a few holes somewhere to let more gas in?

_________________
Tom
'86 Alfa Romeo Spider, red "Dinsdale"
'10 Corvette, red "" (no name yet)
'95 Ferrari 348, red "Zoom"
'04 Maserati, black "Evil"
'05 Aston Martin DB9, green "Bond, Treasury bond."
'82 Dodge W150 Power Ram, yellow "E. Valdez"


Top
   
 Post subject:
PostPosted: Thu Feb 12, 2015 3:08 am 
Offline
Board Sponsor & Moderator
User avatar

Joined: Thu Oct 17, 2002 7:27 pm
Posts: 14747
Location: Park Forest, Illinoisy
Car Model: 68 Valiant
Check the gaskets for sure. There are some that look really close but will cause things like you are experiencing.

_________________
Official Cookie and Mater Tormentor.


Top
   
 Post subject:
PostPosted: Thu Feb 12, 2015 5:34 pm 
Offline
TBI Slant 6

Joined: Thu Nov 01, 2012 7:19 pm
Posts: 187
Location: Albuquerque, NM
Car Model:
Quote:
Check the gaskets for sure. There are some that look really close but will cause things like you are experiencing.
That was it. How's this for a gasket mismatch? The new one is in the lower left. The black one was what was there - notice the exposed corners of the secondary plate allowing the fuel to just drain out.

Image
So, the proper gaskets got installed as a full rebuild kit was installed. Fuel pressure was applied - no leaks, floats were checked, proper height, then the Carter AFB 400cfm was installed on the truck after a 10 min rebuild with consisted of replacing the accelerator pump. HUH????? Yep, tested the holly on the bench, and upon lifting the carb and in doing so tilted it about 15 degrees watched fuel run out the main jets. It was then I remembered how lousy the Holley carb was on my old Ramcharger that I owned back in the late 1980s. It had fuel problems at any kind of angle. Dug out the ancient Carter AFB, did the accelerator pump swap as the old one was totally dried out. No gaskets involved - the top gasket seemed OK. Bolted it to the mainfold, cranked it up and it started immediately once the fuel got in and idled just fine. Let it run for 5 min and turned it off - noticed a electrical burning smell and touched the choke housing - waaay hot. Removed line from choke housing to air cleaner and routed it to manifold vacuum. Fired car back up, fiddled with the idle mixture screws for a second, put the air cleaner on and took it for a drive. Has at least 10% more power than the old 1bbl, maybe 15% - smooth acceleration, no hesitation and I can go up hills in 4th that I used to have to shift down. No idea what sort of jets or springs are in there. ;-) Here's some pics - the aluminum cheezy bracketry is just temporary:
Image
Image
Image

_________________
Tom
'86 Alfa Romeo Spider, red "Dinsdale"
'10 Corvette, red "" (no name yet)
'95 Ferrari 348, red "Zoom"
'04 Maserati, black "Evil"
'05 Aston Martin DB9, green "Bond, Treasury bond."
'82 Dodge W150 Power Ram, yellow "E. Valdez"


Last edited by spacecommander on Thu Feb 12, 2015 5:39 pm, edited 2 times in total.

Top
   
PostPosted: Thu Feb 12, 2015 5:35 pm 
Offline
TBI Slant 6

Joined: Thu Nov 01, 2012 7:19 pm
Posts: 187
Location: Albuquerque, NM
Car Model:
Oh, quick question regarding the AFB electric choke - should some sort of thermal switch be placed inline with the power feed to stop applying power after the engine reaches a certain temp?

I'm beginning to remember how much I didn't like Holley carbs. The Holley on the Ramcharger got replaced with a Rochester Quadrajet and it worked infinitely better. Also remember monkeying endlessly with Weber carbs on VW bugs and Alfas. Finally somebody told me to toss them all out and get Dellortos. Best move - better power, better fuel economy - not that fuel economy was a worry back in the late 1980s. They look just like Webers but they actually work.

_________________
Tom
'86 Alfa Romeo Spider, red "Dinsdale"
'10 Corvette, red "" (no name yet)
'95 Ferrari 348, red "Zoom"
'04 Maserati, black "Evil"
'05 Aston Martin DB9, green "Bond, Treasury bond."
'82 Dodge W150 Power Ram, yellow "E. Valdez"


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 15 posts ] 

All times are UTC-08:00


Who is online

Users browsing this forum: Google [Bot] and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited