The Stovebolt Site Forums The Shop Area Engine Shop 235 (57-62) 4B Carb/Clifford Intk

Hello everyone,
I'm currently finishing a rebuild and we are adding an Edelbrock 4 barrel onto a Clifford intake manifold. I noticed the neck of the intake manifold has a higher end on the driverside, and a lower at the front end. I placed the carb and adapter plate on just to get a visual and seen the carb is at a tilt. Anyone seen this before? Any running issues I should be worried about?

Hello everyone,
I'm currently finishing a rebuild and we are adding an Edelbrock 4 barrel onto a Clifford intake manifold. I noticed the neck of the intake manifold has a higher end on the driverside, and a lower at the front end. I placed the carb and adapter plate on just to get a visual and seen the carb is at a tilt. Anyone seen this before? Any running issues I should be worried about?

The engine will sit down in the rear when mounted in the chassis so carb will be near level. Not to worry anyway as cars/trucks seemed to work okay in San Francisco where they were just about never on the level and run quite well in the movie "Bullet" chase scene. The smallest Edelbrock carb is a 500cfm which is way larger than a 235 needs and you have no heat to the carb which is a pain in cold weather and at the gas pump. Holley makes a 385cfm 4bbl and Ford has a hot water heated car base plate with that bolt pattern. My word is not from the alter and some have 4bbl 235's that run good so just try and learn along the way. Good luck.

Anticipates the engine in installed position, tilted down in back.
What carb?

My guess:

Engine sits in the vehicle front higher than rear. So the carb will be level once mounted.

What cfm carb is that?

Buy a good fire extinguisher. The lean backfires are going to be epic. Engine tilt will make the carb sit level, but you're going to have approximately three times the CFM capabilities the engine needs. You'll have lots of air, and virtually no gas due to low air velocity through the venturis.
Jerry

Jack Clifford developed that intake decades ago. The originals did not have provision for water heat to the bottom of the intake. The new versions have had that provision for quite a few years now.

https://cliffordperformance.net/store/ols/products/42-4500wh-chevy-235-intake-manifold

Yours looks to be one of Jack’s original design i takes with out the water heat.

You will have to do a little bit of tuning to get that carb dialed in, same for using the small 390 Holley, but once dialed in, that set up runs pretty good.

The bottom of the intake has a little open chamber. You can weld a plate with fittings to make a water chamber. Then run hot water from the thermostat housing, Stovebolt Engine Company sells a lower housing with a water outlet on the driver side, or dig up a 270 or 302 gmc lower housing. They will have either a boss that can be drilled, or the boss already drilled and tapped. The hot water helps keep heat on the bottom of the intake to assist in vaporizing the fuel.

Jack Clifford developed that intake decades ago. The originals did not have provision for water heat to the bottom of the intake. The new versions have had that provision for quite a few years now.

https://cliffordperformance.net/store/ols/products/42-4500wh-chevy-235-intake-manifold

Yours looks to be one of Jack’s original design i takes with out the water heat.

You will have to do a little bit of tuning to get that carb dialed in, same for using the small 390 Holley, but once dialed in, that set up runs pretty good.

The bottom of the intake has a little open chamber. You can weld a plate with fittings to make a water chamber. Then run hot water from the thermostat housing, Stovebolt Engine Company sells a lower housing with a water outlet on the driver side, or dig up a 270 or 302 gmc lower housing. They will have either a boss that can be drilled, or the boss already drilled and tapped. The hot water helps keep heat on the bottom of the intake to assist in vaporizing the fuel.

Thank you for the info and help, very much appreciated.

What I have now is a 1406 600 CFM. If I have to downgrade I definitely will. We will see how this plays out... [quote=JW51]My guess:

Engine sits in the vehicle front higher than rear. So the carb will be level once mounted.

What cfm

600 CFM is about right for a 350 V8 at 6K RPM. Your 235 should run OK with that carb at 10K or so - - - - -and the NASCAR engine builders will beat a path to your door to find out how you did that!
Jerry

Hahahahaha man... I may have over done it. But I have read numerous articles and folks are split with the set up being worked out and then some say it's too much.

Attached is a picture I robbed, to show the stock intake level, once the engine (a 261) is installed in the truck chassis.

Just friendly advice:

If your 235 is rebuilt to stock, not high performance, the best carburetor is a one barrel Carter YF 2100S on the stock intake and stock exhaust....my opinion.
If you haven't already, do the engine break-in run with known good stock parts.
Once you are satisfied, swap over to the performance setup.
If the performance setup works better, you have bragging rights.
Post your results so everyone here can read about it.

Try calculating how much air you can pump through an engine. Since it takes two turns of the crankshaft to complete the 4 stroke cycle on all the cylinders, divide the cubic inch displacement in half, and multiply it by the RPM you intend to run. You will end up with "cubic inches per minute". Then divide that figure by 1728 (cubic inches in a cubic foot). You'll get CFM - - - -for an engine with 100% volumetric efficiency, which is an impossibility. The design of the glorified 1920's tractor engine cylinder head on a stovebolt would struggle to get 85%-90% VE under ideal conditions. I think you'll be surprised at how little CFM a stovebolt engine is actually capable of moving.

The laws of physics are not "suggestions" no matter how fervently a hotrodder wishes otherwise. Big carburetors and dual exhausts on a stovebolt are like putting lipstick on a pig- - - -the mouth breathers at a show and shine are impressed, but it's a lot simpler and probably less expensive to flush a few C-notes down the toilet, and stick with the system the GM engineers designed.
Jerry

I realize most everyone reading these threads KNOWS that Chevy sixes are superior to Fords but we used the better Offy intake and a 400 CFM on a 300 CID Ford six that was otherwise stock. That was all the 300 wanted. It wasn't too much, but it was certainly enough.

I would concur with Jerry. If you have a trailered drag-car, leave the line at 5000 RPM, and then accelerate; should run pretty well.

Hope your engine is a LOOOOOOOOOOOOOOOOONNNNNNNNNNNNNNNNGGGGGGGGGGGGGGG way from stock.

Good luck, and keep us posted.

Jon.

The "good news" about the internet, is that anyone can post.

The "bad news" about the internet, is that anyone can post!

Jon.

If you want to see a real example of backpedaling, ask Clifford for some documentation of the power gain claims they make for their products. Whomever writes their ad copy must be related to P.T. Barnum.

That intake was generally set up using the 390 Holley if you wanted to run a four bbl. It’s the one I used when I ran that intake. You have to tinker a bit to get it dialed in. The other option is the 450 Holley. I am not sure they still sell that one, they use to sell it as a ford replacement. The 600 is a possibility, but the others are right, you would want to use that carb on a very high performance motor, really race motor.

I run 2 350 Holley two bbl on my 261 which rated at the 1.5 4 bbl rating comes out at 245 cfm or so per carb, so about 490 cfm measured at 1.5 hg. It’s a pretty modified motor and runs pretty well on that set up, even from idle. So for a mild motor, 600 is likely too big.

Now, there is an alternative. Clifford sells a two bbl adapter and you could run a single 350 two bbl. Would be about 250 in a four bbl. A 500 Holley 2bbl would likely also work, as that carb works out to about 350 in a four bbl so would be in the range.

Buoymaker, that’s one beautiful 235 motor! Wish mine looked that pretty.

Thank you all for the help. In my initial post, I stated I was finishing a rebuild. The gentleman I got the engine from had it rebuilt years back and had the following done;
"As best as I remember, valve job, valve train, and lifters....bored 30 or 60 over with new pistons. Crank was turned +30 with new main and Rod bearings. I think I kept stock cam. And as I mentioned alum flywheel new clutch and pressure plate."
He also stated the engine was rebuilt at a stock car racing shop and he was running a Holley 500 prior to rebuild. We opened it up and he was spot on with the rebuild. So all I added was the headers and carb. I figured the edelbrock 600 would give it a kick. I will keep everyone posted. Oh and the gentleman who had this engine was a good man. Really honest and open. He opened his home and shop to me (a complete stranger) so we can inspect the engine before buying.

If I already had the 4 BBL intake, my first choice would be to run as far, and as fast as I could from any kind of 4 barrel carb, and use a Holley list number 7448 350 CFM 2 barrel. That will be only slightly over-carbureted, not the pie in the sky pipe dreams of grandeur that most stovebolt builders seem to prefer. The most common mistake virtually all hotrodders make, regardless of what kind of engine they're building, is "too much cam"- - -followed pretty closely by "too much carburetor". They end up with an engine that only runs well at astronomically high RPM ranges that the average street engine never sees.
Jerry

I am guessing you will not love that aluminum flywheel if you plan to drive the vehicle on the street.

Racing, yes, but street........hope your heel/toe driving technique is up to snuff.

I have owned two, and still have one of them; so very familiar with their advantages AND disadvantages. They significantly improve the way an engine will accelerate ABOVE a given threshold; and literally KILL ALL low-end torque!

The first was an off-topic 4 cylinder that made more than 2 HP/CID at the rear wheels! With a 5.13:1 rear end, it wouldn't pull a 1700 pound car in first gear below 2500 RPM. But when the tach hit 4000, you better be ready to shift, because 2 heart-beats later is was at 9000.

The one I currently have is in a 350P V-8 producing about 1.5 HP/CID. I started this build when I was younger, but it took 28 years to finish as I was always building carburetors for others. By the time I got it finished, my heel/toe coordination was not as good as it had been 28 years earlier.

Hot (after about 30 minutes) it idles grudgingly at about 1000 RPM. Until it warms to normal temperature, it won't idle below about 1800, and would die at every stop sign. Finally had to install a carb with a manual choke. Each time I approach a stop sign for the first 30 minutes, pull the choke (amount depends on how long the engine has been running). Yes, the car runs like a scalded dog about 3000 RPM, but if I knew it would take so long for me to finish, I would NEVER have considered the aluminum wheel. I rarely need 3000~6000 RPM these days.

Please understand BOTH of these engines were DESIGNED for high RPM (the four cylinder red-lined at 9500, the V-8 at 9000) so the aluminum wheel gave benefits.

Not saying you will have the same experience as I, but something to think about.

Jon.

Thank you all for the info and help. Very much appreciated.

You will definately have the experience that Jon is speaking of. That 235 needs inertia to get going. Aluminum flywheel is fine for a round track motor because once you are in the rpm range, you generally stay in that general range so you dont necesarily need the inertia. But a street driven car, you need some weight to get you parambulating. Clifford use to sell a really nice steel flywheel. McLeod made them for him. I have one on one of my motors. Purchased it probably in 85 or so. Clifford no longer sells them. A couple of years ago I spoke to McLeod they told me they still have the blueprints for making them but cost would be very high. If I remember correctly they speculated in the 700-800 range. So that is not really an option. So I think you are stuck figuring out what year motor you have, getting a stock cast iron flywheel, facing the pressure surface, flipping the ring grear around, balancing the flywheel with the pressure plate, and then the harder part, finding top dead center and confirming whether the bb on the flywheel and pointer on the bellhousing lines up, or whether you need to remark the flywheel for TDC.

Ditto on the aluminum flywheel comments. We ran one for several years on a 1/4 mile dirt tracker in California with 327 and 350 engines. RPM in the turns was 3K-3500, and at the end of the straightaway we were turning 7K or so. The flywheel allowed us to "stretch the straightaway"- - - -getting on the throttle sooner coming off the turns, and driving deeper into the turn before lifting off the gas. The lightweight wheel let the engine accelerate, and also slow down quicker. The "idle" speed on those engines was anywhere from 1500 to 2200, depending on which camshaft we ran. Low end torque was nonexistent. People have offered me big bucks to build a street engine like that, and I've always refused. Doing race engine stuff on a street machine is beyond stupid, and I didn't need the gripes, complaints, and bad reputation a disgruntled customer would spread over the grapevine, even though I would have done exactly what he asked for!
Jerry

Successful use of aluminum flywheel on the street:
1965 Valiant sedan, 3100 lbs., 340" LA engine, 350 hp?
Chrysler 833 4-speed, 3.09:1 1st gear
Chrysler 8-3/4" axle, 3.91:1 ratio.
Torque multiplication in 1st: 12.1:1
Blip the gas, slide the clutch out, done.

If your 1st gear X axle is less than 10, you want a steel flywheel or different gearing.

The sensitive part of the carburetor is the primaries. If they're small enough the car will have good manners.
2 bbls. only have primaries, and they're larger than the primaries of a 390.

Agree - my two examples:

4 cylinder - 15.2
V-8 - 9.36

Jon

Please listen to what Jerry and the other Jon have told you about that manifold and the 235. When I was in high school and college (very long time ago), this was supposed to be the ultimate "fix" for the 235...something you could bolt on and make it run just like a V8. And 4bbl manifolds were everywhere. J.C. Whitney sold them and they were also advertised in every hot rod magazine. What almost always happened was this: the person put on the manifold and whatever 4bbl they could find that would fit. The 235 now ran worse than ever and no amount of adjusting helped. But for some odd reason they would not abandon the scheme. Two...some mechanic boasting of "knowing a lot about racing engines" would tell the person he needed different spark plugs, a dual point distributor and special spark plug wires. So out the window went more money, unwisely wasted. Three...when none of that worked, that same mechanic would later tell the person what he really needed was a different cam to make it run right. And surprisingly many followed this advice and now had wasted a bunch more $$ on a 235 that might have to be pushed or parked on a hill to get it started, would not idle at all, would not run worth a flip and drank gas like crazy. Am I saying no inline 6 worked with a 4bbl? No. Pontiac Division had an Overhead Cam 6 that ran great with one...but it was a very special 4bbl engineered specifically for that engine. It was John DeLorean's project. Try to find one of those carburetors today. If you do, you'll need a whole bunch of money and even then the 235 will never run like that Pontiac did. Good luck!

It's called M A R K E T I N G and American businesses are experts at it.

They put a Carter AFB on a 1917 Chevrolet 171 cubic inch four-cylinder engine.

Notice the 5 angels? They open up a vortex to make that car or truck really move.

You know it's fact because you can see it right there in print.

Angels not included.

Back in 1962 one of my high school friends got his first car- - - -a 1952 Chevy 2 door sedan with a 216 and a 3 speed that his father gave him after the local Ford dealer offered an outrageously low trade in number on the 62 Fairlane with the 221 V8 that he bought. He promptly bought a 3-carb aluminum intake manifold and some adapter plates and fitted the 216 with three (count 'em) Stromberg 97 two barrels and an electric fuel pump! His driveway had a slight uphill grade to the public road, and the car never made it up that incline. It did, however, end up with blistered paint on the hood from the carburetor fires caused by the lean backfires and flooding.
Jerry

In 1965 my dad decided to rebuild a 235 to go in a 1939 Chevrolet car that he had fixed-up. A racing friend talked him into pop-up pistons, cam, porting and polishing, dual exhaust and three BXOV-2. Back then those racing parts were a lot of money and I remember my mom giving him the "evil eye". Years later he told me it never ran to the performance level he was expecting, but don't tell your mother. When it was really cold outside, the engine would flood before he could get it started. It became a ritual with the battery charger, starting fluid and frozen fingers. Finally he got tired of messing with it and converted back to a standard intake with one carburetor so he would have less trouble.

Today there is a lot more Chevy I-6 information and insight available (basically facts), than what my father had in 65. He would have loved to have read about it, before he started on his venture.

Let me get this straight, and I don't mean to sound adversarial because I truelly enjoy reading and contributing here, but none of you have ever run a clifford manifold, let alone one with a 390, 450 or any other carb and you want to theoretically opine that no matter what, it will not work work or run well? I ran one with a 390 carb and it ran great. Could I have run a bigger carb, I guess but Jack Clifford (late 70s early 80s) told me that the 390 was the right carb for that manifold and that anything larger was too much. I used what he recommended and after a little bit of basic holley tuning, it was a very good set up.

How is it that those who have never actually run one of those intakes can be so insistant on poo pooing an induction system they have never ever used themselves?

I don’t see why the little Holley wouldn’t work fine on the primaries. And I appreciate that you can speak to it first hand.

Did it ever need the secondaries? And if so, how did you tune them?

Deagsix, we will give it our best shot and definitely keep everyone posted. Again, everyone has been super helpful and all this information is very much appreciated.

Were you running that Clifford manifold on a bone stock basic engine like the OP is? It seems like we're comparing apples to coconuts if other modifications are involved.
Jerry

Grandpas48 I made my own intake back in the sixties ran an AFB on it no heat ran good,be sure your accelerator pump is in good shape. My big objection to those Edelbrocks is not very good economy,I guess Vic Edelbrock figured you would always be on it anyway !!!

The small primaries (390) need only the right PV and MJ, the secondaries are as close as you will get to the right A/F curve.
As the CFM from bigger secondaries goes up (600), the mixture curve deviates more & more away from a small engine wants. You need an adjustable metering block or it will run lean at high rpm. No, a smaller HSAB or bigger MJ is not enough, but it's a start.

Haven't tried it, but a "universal" (JY V8) QuadraJet can be gotten pretty close by using all of the Sprint tuning parts. Great value for low $$. Bad: no manifolds for it, needs an adapter to Holley pattern.

The Q-Jet can be made to really run well on most applications, depending on the skill of the individual doing the tuning. MOST are 750 CFM, which is a fixed 150 on the primary side, and a "demand" 600 on the secondary side. So if the tuner understands what he/she is doing, the secondary will only supply what the engine asks for. Virtually impossible to overcarburate.

To anyone even considering using a Q-Jet, the paperback on tuning Q-Jets by Cliff Ruggles is absolutely required reading. One of the most user-friendly carburetor books I have ever read, and don't need a college degree in mathematics and physics to understand the book.

Jon

I think you're going to find you are over carbed for a 235. Did you consult edelbrock support on your application. I put that same carb on a 307 and it does well. But 70 less cubes its not going to meter fuel correctly.

How does the 230" Pontiac Sprint function with its original 750 QJ?
Very well.