The Stovebolt Site Forums The Shop Area Engine Shop 1957 235

I'd run 10w-30 oil with MMO or trans fluid in it for a little while, flush it out and refill it with 20w-50. Or use HRL's overfilled deisel/oil mix for 20 minutes, drain and fill with 20w-50.

Thank, I am thinking something like that. I first had 10w 30 in for the first start
in 20years. It has been operating with that since. Now with a tank of gas run thru,
I`d like to replace that oil that ran thru with something that I can leave in it awhile.

I have a clear oil line and can see air bubbles at the top of the line ,oil on the other side.
Is that a sign the oil pressure is insufficient?
The new gauge is low. Moves up slightly. Oil is pumped up and drains back down.
I guess my question is it OK to see air trapped in the line?

A few air bubbles in an oil pressure gauge line are not a problem. If you had a copper line, you just wouldn't see them, although they're always there. Getting OCD about a few bubbles is like lying awake at night worrying about why the faucet in the kitchen sink isn't dripping! Low oil pressure is virtually always caused by excessive clearance at one or more connecting rod or main bearings, or too-thin oil. An oil pump must supply more oil than the bearings need for pressure to rise at all. If it was possible to supply oil to the bearings at precisely the rate it leaks away, the engine could be adequately lubricated with ZERO oil pressure. That's not practical in real life, so oil pumps are engineered to provide an excess of oil volume. There is a spring loaded relief valve to prevent hydraulic lock and engine stalling. (Yes, I've seen that happen) Oil pressure is a "safety factor"- - - -whether it's 5 pounds or 50 pounds is immaterial. Excessively high oil pressure simply overstresses the distributor drive gear, which also runs the oil pump!
Jerry

I've been told two things: The higher your oil pressure is, the more work your engine is having to do to make that pressure. And I've been told 10 psi per 1000 rpm is a decent rule of thumb to follow...hence the reason most oil pumps for general use produce between 30 and 40 psi.

Great ! thanks fellas. I have used and still do on 1 truck copper lines.
They work the best ..unless you have to move it around any. I might say there is different quality lines offered.
I`ve had to pull the cluster on mine enough to weaken the copper. specially at the fitting.
So the clear tube works for now as long as I don`t think too much about it. LOL
I know visually this engine oil is being moved up and down. www.youtube.com/watch?v=5aBr-tiXN4w
at the end of this 23 second video you get an idea how much oil gets to the valves/rockers.

Your idle is too high in the video.

Thats right. I have since lowered the idle. Here is a video today.
Believing the gauge from right at zero..I`d say the pressure is 13-15 psi.
www.youtube.com/watch?v=SW52q1_0TYk

I rescued the water pump off the 1958`s original 235.
Would the water pump be the same as this 1957 235 uses?
Pics of water pump(s) and both engines.

Engines generate about as much water as fuel they consume, so just running up to operating temp. generates water but does not burn much off, best to leave it sit, just turning it over wipes oil off the lube. surfaces. Start it up in the spring and take it for a long drive!

Ed

to EdPruss ... ?

Sure did not think its that hard a question. Will a water pump from a 1958 235
fit a 1957 235. Mr pruss has answered this way before, kinda out there.

They should be the same. One of my Chevy Master Parts books says 1955 2nd series thru 1962 are the same for all 6 cylinders (235 & 261).

GM# 3774186

I am not sure. Thats not the #`s on this water pump . The housing for the 2 is different.
GM # 3736567 GM 16

www.ebay.com/itm/174756403116
this is most like this one...www.ebay.com/itm/186244136973

The numbers on the waterpumps are casting numbers, not part numbers.
After so many thousands of pump bodies cast, the mold is worn out so a new mold is made with its own casting number. There are at least four different casting numbers for the same application waterpump that I have seen. They all "fit" all 235/261 engines 55-62.
Now... a 3757232 pump is from 59-62. It will work just fine on a 57 or 58. But... if one is doing a picky restoration on a 59 with matching numbers then a 57 pump with casting number 3736567 will not do.
It will fit and run just fine, but the "Correct Police" will call you out.
In short... if it looks the same... it is the same.

The housing is different like I said. No 1959 , just 1958 and 57. So maybe not the same? IDK.
I can promise you the correct police have no bearing. I`ve never been to a car show in my life.
Thanks Jethro!! I`ll hang onto the 58 pump.

Aren`t the new casting numbers for worn out molds the GM numbers GM 16 GM 13 GM 14?
Bottle manufacturers would do same on their molds of mason jars that wore out

Difference in housing circled. Blue 1957 black 1958

As Jethro mentioned above, minor casting difference shown in your picture. Looks to be just a thicker bolt flange web and thicker wall of casting. Overall that is immaterial if it fits and does the task it's meant for. It will work in your application and that's all I think you are asking here.

Here are 2 waterpumps for a 235 from different manufacturers. Either will fit any 235 or 261 from 55 to 62.

He mentioned worn molds from repeated use , I don`t think a redesign of the housing? Just retooled back to spec.
As long as it works. I`d bet the one installed in the engine now has the open fined back version of the same pump.

I`m seeking correct timing for this engine. I`ve read 12 degrees.
I have it at 16 degrees and thats set by the highest steady VAC pressure and highest idle.
Idle is at 570rpm and no mechanical VAC advance. VAC pressure is 17 lbs at idle.
What should I have the timing set at?

It should be 12 degrees BTDC at around 400-500 rpm. 16 seems too high to me.

Old school way to set timing which also factors in the local gas's octane rating is to find a reasonable slight uphill grade...... accelerate uphill in high gear.....if you don't hear preignition or labor knock, add a bit more timing.....continue this routine until you do hear labor knock, then back timing off until it just stops. That's where the engine likes it's timing set. Then pull out the timing light, see where it is and use that for future reference. Of course if you ever haul or pull a real load with the truck you should be ready to adjust timing down a bit if necessary.

RonR
.

thanks! What I'm running into is poor power up hill. I got the truck up to 65mph on a flat road.
But even with a running start , a hill is a challenge to get to the top.
Seems if I have the timing set to 12 degrees ,it is hard to crank up. I`ll try again today at 12 degrees.
See how it does.
But setting the timing by the highest idle rpm and highest steady VAC pressure is not the way?

Setting the optimum idle mixture with vacuum works but not for engine timing.

This is a Rip Van Winkle engine, right? (been sleeping for 20 years or so).

Set it to factory specs and then test the compression. Look at the valve adjustment. You might have a bent pushrod or valve(s) sticking open.

You might even have a clutch slipping on hill climbs.

A 57 235 at 12 degrees initial? That is not really what you want. For 57 the factory setting was TDC, right at the bb. Some uses and applications specified 5 degrees before tdc. Let me get a copy of the Sun tune up chart for 57.

"But even with a running start , a hill is a challenge to get to the top."

Welcome to the world of yesterday engines. Your 235 had 140 crank HP (or SAE Horse Power) when it was new, engines today are rated at net HP, or actual HP to the rear wheels with all the accessory drag and power loss between the flywheel and rear tires factored in. So, lets say your 235 looses 20% of it's 140 HP getting to the rear wheels, now you got 112 HP, then since it's no longer a new engine and likely down on power from 1957 lets take a SWAG and reduce the 112 HP 10% for wear, now you have 100.8 HP, (likely less). Yep, it's probably doing just fine climbing hills, working it's little 100 HP butt off and getting no respect at all.

Now, someone is going to point out it's torque that does the work, and they are right. If we'd used torque, the numbers would be different but the results are the same. My wife's 10 year old Ram pickup has 410 rear wheel HP, running bobtail, it doesn't know what a hill is. My '51 3600 putting likely 70 HP to the rear tires starts sweating at the mere mention of a hill, heck I downshift in a 10 mph headwind.

RonR

Lots to think about. I drove to town this morning at 12 degrees. It seemed better.
I might be dealing with the best the ole girl can do. Engine has been sitting for 30+ years.
Maybe the sun chart drag six mentioned will give me more perspective. VAC test says the engine is healthy....enough.

I thought that seemed like a lot but that's what I get for trusting my phone instead of an actual shop manual.

They can take a few degrees advance in stock form, like 5-8. But 12 is probably too much. If you need 12 on a stock motor, there may be something else going on. The one issue is the mechanical advance. When I am rebuilding a distributor (a 2403 in the case of a 57), it is not at all unusual for me to find a missing spring, broken pivot or frozen weights. Sometimes, there is just so much gunk and dirt and grease that the weights just cant move like they should or sometimes at all. Also, if the end play between the housing and gear is excessive, and depending on how the distributor has been set in the motor, you end up with somewhat erratic timing settings or an unstable timing curve.

But there are a couple of issues to add to the problem. If the flywheel is not original to the motor. Different years have different timing requirements, and/or different flywheel's may have slightly different marks as to tdc engine to engine. One of the issues for us is there is no real easy way to determine tdc with the motor together.

So you are stuck with what you are stuck with. What I might do is first, set the timing at tdc at the flywheel bb. See how it runs. From there, see if you can get your hands on a dial back timing light. Advance it to 5 degree btdc and see how that runs. Then advance it 2 degrees at a time and see what it feels like.

Also, and I am sure you know this but to be complete, make sure the octane selector is centered on the hash mark on the distributor pad. One way to do this is to put the motor on tdc at the bb, trace the no. 1 wire to the body of the distributor and put a mark on the body of the distributor directly under the center of the no. 1 cap tower. Remove the cap, loosen the bolt on the octane selector hold down, center the hash mark, tighten the bolt, loosen the screw on the clamp and move the distributor until the rotor is at the mark you made on the body. Tighten the screw. Now you have your base line set.

Start the motor and use a timing light. Readjust the distributor to tdc if necessary, using the screw to loosen the clamp, not the bolt on the selector plate.

Now you can start advancing a few degrees at a time and see what the motor likes.

A lot of pages here, apologize if this has been addressed earlier. Are you assuming the fly wall BB as being TDC? On many flywheels, the BB represents 5 degrees BTDC.

If you are adding 12 degrees to the BB, I would agree with DragSix…that seems like an awful lot. If you are adding only 7 degrees to the BB, (5+7=12)….i don’t think that’s totally unreasonable.

On a well-worn engine, I’m not so convinced that timing numerically is the best way. Good to KNOW what it is numerically, but MoparGuy’s advice about seeing that the engine likes…is good advice.

I do know that my 235, of unknown mileage, runs LOUSY timed to the BB. It wants more timing than that..

"Also, if the end play between the housing and gear is excessive, and depending on how the distributor
has been set in the motor, you end up with somewhat erratic timing settings or an unstable timing curve"
Lets make sure I`m doing this right..timing light set to 12 degrees. Looking at the pointer
in the bell housing. I turn the DIST till the white bubble lines up with the pointer?


I believe some of this is going on. I don`t think it is excessive.
I`ll try and find what the engine likes by starting lower than I have before. At one point high and low, the engine will sputter if
I go too far either way.
Right now there is no labor knock. 65mph on flat ground is pretty good?

It sounds like you are still trying to set the timing essentially by vacuum, then adjusting without really having a baseline to start with, no? Yes, the engine will let you know if you went too far doing it that way, but when it does, you have indeed gone too far. Even a little retarded (as an example) will not sputter, but that couple of degrees retarded will cost you power without poor running. When it sputters, you are really killing the power.

Timing, turn the distributor to the bb in the flywheel. If this is a 57 motor and 57 flywheel, that is TDC. So you will get 24-28 degrees of mechanical advance at say 3500 rpm (12-14 degrees advance at the distributor at 1750 distributor rpm for a typical 2403 distributor, X2 at the motor). So that is your baseline at tdc. If you look at the sun charts you will see that the 55 motor (which was slightly different than the 57 motor) sets it at 5 btdc. 56, same, 59, same. So if you want to tinker, get a dial back and add 5 degrees tdc. You dial the 5 on the timing light and move the bb to the pointer, the dial back light compensates for the the 5 degrees. Its the easiest way I know to be accurate. So with say 24 - 28 degrees from the distributor and 5 degrees initial, you have 29 to 33 degrees advance total. The vacuum advance does not play a part in this calculation.

From here you can add 2 degrees, then 2 degrees using the dial back light. Otherwise you are just moving the advance forward until it pings and then backing off. A old method for sure, and one that often works, but sometimes, its too much advance even though its not pinging.

The other thing, its counter clockwise on the distributor to advance the timing, just to be complete.

Thanks Drag!! But no ,not setting the timing with the VAC anymore. I do want the needle on the VAC gauge
steady mostly at 17 lbs / idle. I`ll see if I can get my hands on a dial back.
Use that as a baseline of 12-14/rpm 1750. Yes 57 motor and Flywheel.

Excellent!

this what is happening. 1750rpm I set the timing to 14 degrees.
Back down to idle and check where the BB is now ,I cannot find it. Engine is at 14 lbs of VAC.
Really no change in performance, maybe less. I`m guessing there is no way to set the timing with the engine at idle?

I think you may be doing it wrong. I am presuming here, that you are using a 1 bbl. with the vacuum advance line below the throttle blade (stock Rochester for example, also Carter YF.) Set your idle to factory specifications. its pretty low like 400-450 maybe 500-550. Set the timing bb to the pointer. That is it. TDC.

The distributor is either going to have 12 degrees or 14 degrees of mechanical distributor advance. But the motor sees double that.

So 1750 distributor rpm is 3500 engine rpm, 12-14 distributor advance is 24-28 at the motor. The mechanical advance will come in gradually (as the rpm increases, the centrifugal force flings the advance weights- which are under the point plate- outward a measured amount until they are fully out no later than 3500 rpm, unless the mechanical advance mechanism is broken, rusted solid, or just so gummed up that the advance weights cant move.

So assuming the advance weights are moving, you have 24 to 28 degrees of mechanical advance.

Now, sometimes, the factory setting of tdc is conservative or you are in an area in which the motor can use a little more advance. This is where initial advance comes into play. Use the dial back light. Dial in 5 degrees advance. Point the light at the flywheel window, loosen the screw, move the distributor counter clockwise until the bb lines back up. Now, the motor starts at idle with 5 degrees of initial advance. The mechanical comes in gradually, and in this scenario, at 3500 rpm, you have 29 to 33 degrees of total advance (24 + 5 or 28+ 5 depending on the distributor.

Mike, very well described! Back in my misspent youth (early 70's) a good friend who was a fellow Mopar fanatic had a Sun Distributor machine along with a lot of other rather high end tools and instruments. We spent a few sessions tuning the dual point distributor in my 340 Duster when I was running NHRA E Stock. I think I've still got a box of springs and weights along with jets, needles and seats for AVS and Thermoquad carbs (back in the day the tech inspectors didn't know AVS's were stock in '70, Thermoquads were stock in '71 and 1,000 cfm Thermoquads were never stock. It was a simpler world back then.

RonR