Time for a carb and intake

[Vette66AirCoupe]

Hi guys,
I've been away for a while.

On my '60, 283CI with a solid lift cam of unknown origin (I'm guessing it's the cam that was in the 245 hp motor but have yet to try to adjust the valves so I don't have a clue really), I have a stock intake manifold and WCFB carb. The carb needs a rest on the shelf for maybe the rest of it's life. I'd like to change out the carb and manifold and replace the manifold with the Edelbrock Performer EPS #2703 which comes with an oil fill tube allowing me to keep my finned valve covers intact. I'm thinking about the Edelbrock #1403, 500 CFM Performer Carb with an electric choke. I'm embarassed to say I don't really know how many CFM's the WCFB is. I don't want to "overcarb". Is 500 CFM enough? My '66 big block has a 650 CFM Holley so 500 CFM's for a little 283 seems logical though that's not exactly a scientific analysis is it? :ugh Any guidance here would be appreciated.

 

[Tom Bryant]

The 245 horse engine used the same hyd cam as the base 4bbl engine. The 245 was the base engine with the dual carbs mounted to it. Without knowing it is hard to determine what cam you have but you could determint it's specs with a degree wheel mounted to the crank and a dial indicator reading the lobes. If you set the valves at .012 intake and.018 exhaust you will be in the ballpark and not be too tight and cause damage.

If I remember right a WCFB is around 350cfm. The 500cfm carb is right on the money for a 283 turning 5500 rpm or less. A 600 would work on a 6000 rpm engine. I used to run a 625cfm E series AFB on a ported and built street 283 back in the day that often saw 6500 rpm. Your intake choice is a good one for this engine. The runner size will give good velocity and off idle response in a small engine.

Tom

 

[Vette66AirCoupe]

Thanks Tom. You've given me the confidence to go ahead and pull the trigger on the manifold with the 500 CFM carb. If the cam is the one that was in the 270 HP 283 is that cams specs .012 and .018? I've heard that referred to as the "Duntov Cam". The car does have some giddy up but not much torque as you probably already surmised.

Terry

 

[Tom Bryant]

Yes those settings are for the Duntov cam as used in the 270 and solid lifter FI 283s. It was also used in the 340 and the 360 horse FI 327s in '62 and '63. The Duntov seems to like rear end gears in the 3.70 or lower (higher numerically) range. With a 3.70, 4.11, 4.56 you can just let out the clutch and go. With a 3.55 or 3.36 it takes a little more effort to move off idle from a stop especially with the close ratio 4 speed with the 2.20 1st gear.

I've run the Duntov in a 283 in a heavy car before (1962 Impala convert, 3 speed, 3.36 rear gear) and you could really feel the engine come up on the cam around 3000 rpm which is what they were designed for. They can be sluggish at lower rpms though. There are much better street cams available now for small engines if you decide it doesn't have the low and mid range torque you want.

Tom

 

[Vette66AirCoupe]

Hey Tom,

Is there anything pretty I can use to plug off the PCV fitting on the new Edelbrock carb? The car deserves better than gasoline hose with a bolt stuck in it.:cool

 

[Tom Bryant]

Most auto parts stores will have a drawer with plastic vacuum caps in various sizes and colors to cap off unused vacuum connections. I get them at NAPA.

Tom

 

[Vette66AirCoupe]

Color me naive but I was hoping to use the stock air cleaner but the new carb is much bigger. Does anybody know of an adapter that would work? It looks like I need to get from 5 1/8 top of carb to 4 1/4 opening in the air cleaner. There are adapters that go from a 4 1/4 in. carb to a 5 1/8 in. air cleaner but Summit doesn't think it will work in reverse order. ;help

 

[Tom Bryant]

I thought that the Edelbrock and AFB were the same size but I may be wrong. I see that the WCFB and AFB used the same carb to air cleaner gasket. The GTO and Firebird used what was basically the Corvette air cleaner and many have found their way onto Corvettes. I think that the GTO was Chrome steel instead of aluminum but other wise nearly identical. They were available from GM for years after the original Corvette part was discontinued.

I find that Year One lists the air cleaner base for AFB except Edelbrock. Then they list a seperate one for Q-Jet.

FP977 $75.95

The complete air cleaner is FP979.

I'd call Year One and ask what the opening diameter is and if it will fit the Edelbrock. Also ask for overall diameter as I'm fairly confident that your top will work on this base.

Tom

 

[Kid_Again]

any advice that includes the use of a SMALLER carb is good advice...i don't know how many engines i've ruined by just HAVING to have that 750 sitting on top

just had an engine spec'd for me by bill bradley, a 355ci with low compression (going to add back a vortech blower in the near future) and that summbitch just LOVED a 650..i now put on a 750dp with the secondary pump defeated as the first step to adding the vortech and well, it just doesn't like a 750 without forced induction

 

[Vette66AirCoupe]

I came up with a solution for the air cleaner thanks to a friend who works in a shop with some great equipment. I had him cut out a new flat base of the proper circumference and with the proper size carb hole in the middle along with some spacer rings out of 1/8" aluminum. Between the spacers and some gaskets I was able to mix and match to get a good height to clear all of my obstructions and still maintain clearance with the hood. I think I ended up using 3 gaskets and one ring in the end.

Here is the drivers side view showing the height of the choke linkage I needed to clear.

Here's the passenger side view showing the other height restriction on that side.

Sitting real pretty now!

 

[Silver Blue 58]

Your setup looks great I have a later model intake (hi-rise) on my 283 with the Edelbrock performer carb and I run the stock air cleaner with no clearance problems.
Performance is great with plenty of get up and go....even with the Powerglide!
I find the 283 to be an outstanding powerplant. Let us know how yours runs out



Fred

 

[Tom Bryant]

Nice fix. We'll be looking for a drive report.

Tom

 

[Vette66AirCoupe]

Tonight on the maiden voyage to to a local show the car ran beautifully. I had spruced things up with some stainless steel bolts and cleaned up the choke wiring encasing the two wires together with shrink tubing and tucking it into a couple of clips I bought at Carlisle. The clips that are used for the temp sending unit on the drivers side work well for the choke wiring on the other side so I bought a couple while I was at the mecca. Now the bad news. I took the air cleaner off when I got there to show a couple of guys how I solved the clearance problem and the air cleaner had quite a bit of oil in it. I'm guessing I have a crankcase ventilation problem but I'm looking for help here in dagnosing the problem. It's a paper air filter element, no oil. I wiped it out and drove it home and the oil was back. The inside of the fill tube is dry, no oil is backing up there. The crankcase is not overfilled with oil. The only way for oil to get inside the air cleaner is up through the carb. The outside of the air cleaner is compeltely clean. I did notice that the breather canister under the intake manifold was a bit funky when I had it exposed but I never had even a drop of oil in the air cleaner before and now I had enough that I could tilt the air cleaner base and watch the oil run. Here's what the breather canister looked like during the process.

I'm assuming that there is a ventilation problem and will check tomorrow for puffing from the draft tube but I'm at a loss for didagnosing this problem. Any advice would certainly be appreciated. The little 283 is running like a raped ape so I really don't think it's a mechanical issue. Oil pressure and engine temperature are normal. ;help

 

[Tom Bryant]

This is odd that you have the problem now but didn't before. What is different systenwise?

You still have a vented breather tube in front and a road draft tube in the rear. The valley and breather look normal to me. If the road draft tube and the breather cap are flowing freely I suspect the piston rings. That doesn't make any sense since it was ok before.

Have you done a leak down test? Did you find any puffing from the road draft tube once the engine was up to temp?

Tom

 

[Vette66AirCoupe]

Tom,

I have not been able to get any quality time with the car since Sunday. On Sunday I noticed that the draft tube was mounted with the flange sitting up on some excess silcone that had squished out the back of the intake manifold during installation. It was an "ah ha" moment that fizzled. I trimmed the silicone and got the tube mounted flush against the gasket thinking I had increased the tubes ability to draft but it made no difference, I'm still getting oil in there. I even took a look inside the fill tube hoping I had left some styrfoam in there but no such luck. I blew the draft tube out with some compressed air to make sure no killer spiders had sealed it up with some super web. I put it back to bed after that as I will need to be out of town starting Sunday and it's best for me to devote this weekend to the bride. I thought I might blow some compressed air into the fill tube just to make sure it actually comes out the draft tube when I get back. If nothing else works, I'm going to get the valves adjusted and then if I have no other brainstorms try to find the fitting that replaced the draft tube in later years that has the male fitting for a hose so that I can try a PCV valve on it. I'll keep you posted and let me know if you have any other thoughts.

 

[Kid_Again]

Tom,

I have not been able to get any quality time with the car since Sunday. On Sunday I noticed that the draft tube was mounted with the flange sitting up on some excess silcone that had squished out the back of the intake manifold during installation. It was an "ah ha" moment that fizzled. I trimmed the silicone and got the tube mounted flush against the gasket thinking I had increased the tubes ability to draft but it made no difference, I'm still getting oil in there. I even took a look inside the fill tube hoping I had left some styrfoam in there but no such luck. I blew the draft tube out with some compressed air to make sure no killer spiders had sealed it up with some super web. I put it back to bed after that as I will need to be out of town starting Sunday and it's best for me to devote this weekend to the bride. I thought I might blow some compressed air into the fill tube just to make sure it actually comes out the draft tube when I get back. If nothing else works, I'm going to get the valves adjusted and then if I have no other brainstorms try to find the fitting that replaced the draft tube in later years that has the male fitting for a hose so that I can try a PCV valve on it. I'll keep you posted and let me know if you have any other thoughts.

Boy, does this bring back memories. Note that I went to a Bill Bradley-spec'd 355. Among the many reasons that I did so was that no matter what I did, I had oil leaks all over the place with the rebuilt 327. The first hint of an oil leak was when the car started to run rough and when I pulled the plugs, each one was oil soaked. I had oil in the intake manifold and up through the carb. After much posting here and swearing at the original rebuilder, I fixed the problem by reinstalling the intake manifold gaskets, going with a new Edelbrock low rise manifold AND sealing the crap out of the manifold and head intake runner gaps with pounds of RTV.

In myh case, this worked as somehow there was enough of a mismatch between manifold-gasket-head that I was drawing oil in to all cylinders (and manifold) from the lifter valley.

I'm not convinced that's your problem but I mean to point out that you need to check any potential point of oil infiltration. The car actually ran pretty decently since the vacuum leak was low enough not to affect driveability. Go back to basics and check EVERYTHING without making assumptions.

Good luck

 

[Vette66AirCoupe]

Thanks Kid. Thinking logically about the problem you may have nailed it.

Terry

 

[Kid_Again]

Yup. no problem.

I just noticed that you'e in Delaware. We're going to look at real estate in Delaware with an eye to moving out of...well, I'll just be kind and call it New Jersey.

You're not too far from me anyways so let me know if you need some help with the car. I can always send my buddy VNV a post card from the well known resort town of Hockessin.