The Stovebolt Site Forums The Shop Area Engine Shop 235 smoking, blow by, low oil pressure low power

Hi all,
Likely my first post here.

I have a 1962 c10 that was my granddads, I rebuilt the body (amateur backyard style) and got it on the road. Only took 4+ years of welding on the body etc.

So the truck was in another state at my dad’s house the entire time. He got the brakes working and got it running and driving, and stored it.

When I went to load it up to bring it home… apparently we both forgot that one of us had drained the oil at some point….

Basically idled it for roughly a mile without oil in it. I thought it was the noisy clutch, as it had been 6+ months since I had seen or driven it.

So when I got it home I drove it a bit (with oil in it of course), low power, cylinder 4,5,6 (or some combo) not making power, and burning oil. (Split exhaust so I know at least two of those cylinders were not firing. And a good bit of oil burning from 4,5,6.
After about a dozen test drives I pulled the original engine and popped in a used 235 I found for free. (This used one also burns oil and had low power, and cylinder 4,5,6 not firing (that turned out to be some combo of ignition: plugs, wires, distributor etc as I now have it firing on all cylinders, but still burning oil))

Anyhoo…. Ran without oil for a bit…That explains the worn bearings. And low oil pressure once hot at idle.

The low power was some combo of throttle/carb/etc as it now has decent power with a new universal carb from mikesCarbParts.

But…. Today I got the engine on a stand and pulled the pistons… to my surprise the rings look quite good, cylinders look pretty good (other than the hatch marks gone).
(Certainly will re-bearing and re-ring it).

Can just the lack of hatch marks on cylinder wall explain the burning oil?

(The valves guides are also quite sloppy) and most of the o-rings in valve stems were broken… )but this thing smoked all the time, especially under load.

Also, can I somehow measure the cam… maybe measure highest point? To see if cam is any good?

Also, is it likely the crank survived? With bearings showing copper (or whatever other metal) ?

The old Sun Electric Co. slogan that they put on all their diagnostic equipment definitely applies here- - - - - -"We test- - - -not guess!" Before you start throwing parts at the problem, some precision measurements need to be involved. The cylinders wear tapered, with the majority of the wear happening in the first 1 to 1 1/2 inches of the piston travel. If you can hang a fingernail on the ridge at the top of the cylinders where the rings don't travel, chances are a re-ring job won't last long. The ring ridge can be machined away with a tool made specifically for that job, but if the taper wear is much over .005", the rings will flex constantly trying to maintain contact with the cylinder walls and they will lose their tension quickly. You'll be back to burning oil when that happens. A ring running in a taper-worn cylinder is flexing 66 times a second at 2000 RPM. A quick and fairly accurate measurement of cylinder taper can be made with nothing but a used piston ring, a feeler gauge, and a calculator. Position the ring up against the top of the cylinder where the ridge begins, stack up feeler gauge blades to measure the ring gap, and write the measurement down. Use a piston to push the ring to near the bottom of the cylinder and measure the gap again. Subtract the bottom measurement from the top, and divide by 3. (Actually Pi- - - -3.14) The result will be the cylinder taper in thousandths of an inch.

Example:
Top measurement: .045"
Bottom measurement: .020"
Difference: .025"
Divide by 3.14 = .008"- - - - -time to rebore and install oversize pistons.

Also measure the crankshaft rod journals with a micrometer (not a dial caliper!) They should be round within about .001", and the taper wear from front to back should be .0005" or less. Egg shaped or taper worn crankshaft journals will wear out bearings in a hurry, and will also drop oil pressure.

Good luck with your rebuild!
Jerry

I did cylinder 1 ring gap check…

Top ridge: .103
Top: .129
Middle: .066
Bottom: .063

.129 - .063 =0.066

.067 divided by 3.14 = .021

So…. Guessing .030 over might be what I can expect (or more).

(I will be bringing it to a machine shop clearly).

(I wonder why the top ridge is bugger than bottom of cylinder… previous backyard re-ring?)

How far down the cylinder did you take your first measurement? If you measured up high (top 1/4 - 3/8" of the cylinder), it could be that a previous "rebuilder" may have gotten over zealous when removing a cylinder ridge to remove pistons. I would remeasure your cylinder bore at least 1/2" below the deck top, then re-compare your measurements.

Though I did not measure from deck to ring, I would estimate 7/16” down when I measured the ‘top’. I will get a few more measurements toward top of #1.

Am I wrong In Thinking that my ring gap should be .017 max, and have .063 at best… .129 worst … so might be a junk block? .112 is more than .060 over (which I assume is the max overBore). Or since I don’t know original ring gap… that ring might be the problem in my math…. ?
Edit: ^nevermind .129/3.14 is .040 over so I think I jumped the gun there.

I will probably do the other 5 pistons measurements tomorrow assuming I have some time after work.

I was not planning on needing all new bearings and pistons, but what’s another 7/800 dollars for an old truck…

I am guessing 1200 in parts and 1500 at machine shop. That’s likely a low Guess.
Now to find a machine shop.

Here's the most accurate way to measure cylinder taper, but unless you're building more than one engine, it might not be worth the cost. I've been using a shop full of precision tools for the past 50-something years, so sometimes I don't even think about the idea that not everybody is equipped that way!

www.ebay.com/itm/286564765887?

Jerry

So… I have been trying to remove the camshaft… and like a dummy I did not ask or buy a book etc.

So what book should I buy?

Turns out the valve lifters are all stuck in their hole.
I don’t want to use channel locks on them to get them out…. Surely that damages them?

Could I use feeler gauges (or some other quite smooth steel) to shove between lifter and cam, then rotate assembly to help push the lifter(s) out a bit more?

(I have them soaking in some combo of wd-40, roil, and pbBlaster for now).

Thanks.

PS: I am sure the machine shop would pull the lifters and cam… but I have never removed a camshaft… so I want to pull it,,, even if I just put it right back in.

Wally - On your question "what book should I buy?", for your 1962 C10 you will want to start with a 1960 Chevrolet Truck Shop Manual like this reprint form Classic Parts. Then you should get a 1961 Shop Manual Supplement, or you can get a CD with the full set of 1960-62 Shop Manuals.

These are available from a number of other sources too and you can also find used originals for sale if you do some web searching.

On trying to pry your existing lifters out by inserting something between the cam and lifter I would highly suggest NOT to do that unless you are planning to replace them or have them reconditioned. You are likely to damage the surfaces removing them in this way. And definitely do not use vise grips to try and grab/remove the lifters. Not only will this destroy the lifter surface, but it could also damage the lifter bore when trying to further remove the damaged/scored lifter.

Patience, Grasshopper- - - - -turn the cam until the base circle of the lobe is under the lifter, tap it down against the cam with a brass drift, and soak the whole works liberally with PB Blaster or KROIL. Repeat as required for all 12 lifters. That gets the lifters moving in their bores without having to pry or risk other damage. Once all the lifters are at their maximum upward travel the cam will slip out from under them. They don't necessarily have to be removed until later in the disassembly. Don't forget to remove the fuel pump and unbolt the thrust plate. it's accessible through the holes in the timing gear. The best "service manual" to have is a healthy dose of patience and common sense, no matter what engine you're working on. Stovebolt engines can handle an 80 overbore without any problem, but that would be the max most engine builders would attempt. Anything bigger requires "semi-finished" pistons that are ground to the diameter needed, and they are virtually impossible to find these days.
Jerry

It's possible to build a stovebolt engine with non-original parts- - - - -connecting rods and rod bearings for a big block Chevy V8, pistons for certain Ford, MOPAR, AMC/Jeep, or Japanese diesel engines- - - -roller valve lifters for a big block MOPAR, and non-standard main bearings. Unfortunately, that requires something that's even more scarce that OEM stovebilt parts- - - - -a competent machinist!
Jerry

Ordered those books. Thank you.

I got the lifters out today. Took about 15 minutes each of wiggling them up and down while rotating. Pretty sure the soaking in Kroil/seafoam mixture for about 24 hours assisted. A plastic stick assisted sometimes.

Cam slid out no problem.

That plastic cam gear is pretty wild stuff for the 50’s-60’s I would think.
I assume a new aluminum cam gear is recommended?

I remember rebuilding a mid 60’s mopar 383 that had a timing gear with nylon(if i remember correct) teeth.
I found the idea of plastic teeth nuts at the time which was back in 80. Funny thing is all the teeth were intact.

Pontiac used nylon (or some kind of plastic) chain teeth on late 60s-early 70s camshaft sprockets. Lots of them failed.

Stovebolts in cars ran a fiber gear (Bakelite) back as far as the early 1950s, at least. Trucks ran an aluminum gear. The plastic coated timing chain sprockets (not gears) were used in other engines during the 1960s. Those were notorious for the plastic getting brittle and breaking up- - - -and the debris would clog up oil pump pickup screens and cause low or no oil pressure.
Jerry

Egge or Northern auto parts kit or ??? Or Kanter ?

Got my block back from machine shop (cha-ching).

The crank is .010 under on main and journals now.
The cam is wiped.
The lifters are wiped.

So I need:
Pistons and rings .040
Main and journal bearings .010
Camshaft (think I will go stock for reliability/simplicity)
Lifters (or re-grind original?)
Oil pump or rebuild kit.

Egge prices are way higher than some other rebuild kits.

Standard (but over/under sized) rebuild kit ok? Like from northern auto parts. Kanter? Suggestions?

I would use as many of your original parts as you possibly can. For the last 20 years I've been hearing about absolute JUNK engine parts coming from China and failing in just a few hundred miles.

Today my brother called me about his newly rebuilt '69 GTO engine with complete top end failure of brand new parts. Lifters and rockers.

Last year a buddy had the same thing happen to his '72 Blazer. All the parts came from Summit. They gave him $2500 of valve train parts (different from the failed ones) for free.

Kanter's engine rebuild kits were junk 20 years ago. They're probably worse now. Have your rockers and lifters rebuilt. Same for pushrods.

Buy the parts individually, not in kits.

Send the cam to Schneider Racing Cams in California. Yea, I know, they are a racing cam place but they will do a stock grind and they have decades of experience with our inline motors.

https://www.schneidercams.com/

Send the lifters to Rocker Arms Unlimited, also in California. They can regrind the lifters for your nice reground cam. They can also rebuild your rocker arm assembly. One of the few, if not the only place, that can rebuild the rockers.

https://www.rockerarms.com/

When you have the head redone, consider having the stock guides drilled and lined with a bronze liner, and then have the tops of the guides cut for Teflon seals and forget the crappy rubber O ring seals. Those things fall apart about 10 minutes after you start using them. The stems need a little lubrication and so between the bronze liners and properly clearanced valve stems with the PC style Teflon seals you ought to be in pretty good shape with oil control through the valve guides and valve stems.

So now I am thinking bearings and rings from Egge.

On the camshaft regrind… the distributor gear has at least one messed up tooth… will they repair that also? Or need another cam?

Pistons from wherever (maybe summit).

Lifters I could have my machine shop regrind (he says he can) or send to California fine also.

Try to find NOS parts on ebay or someplace if you can.

I can find everything I need to build a stovebolt engine on Ebay- - - - -Egge is better than Jesse James- - - -he had to use a gun to rob people!
Jerry

@DragSix - Will Schneider regrind the lifters too?

@62 C10 Wally - I’m fairly certain that a 230/250 dizzy gear will swap right on. I have a part number stashed somewhere for a bronze version of it. If not that, there’s still about 9 bajillion junk Stovebolt dizzies around with gears you could use. I probably have one myself. There’s a cast vs steel compatibility issue you have to be careful about. Someone familiar can set you straight on that.

I can regrind lifters accurately in my shade tree back yard shop. So can any machinist who is willing to fabricate a very simple fixture to put the proper radius on the bottom where the lifter base contacts the cam lobe. Most of them just aren't willing to try.
Jerry

Schneider use to regrind lifters but I have been made to understand that they do not offer that service any longer and have since sold the lifter grinding equipment. They may be able to make a recommendation. Rocker Arms Unlimited is the only place that I personally know that can do it. On second thought, Powell cams may also regarding lifters so you may have an alternative source for the service.

Distributor gear fine, but the dizzy gear on cam is mashed.

That makes the cam scrap iron. I don't know of any way to repair a gear on the cam. A good replacement cam would be the Melling CCS-1. It's close to a clone of the 261/Corvette solid lifter cam, with a bit more exhaust duration for better cylinder scavenging without creating a rough idle. Those cams can be found new on Ebay, or ordered through a local parts store like O'Reilly, Advance Auto Parts, Auto Zone, etc. New or reconditioned lifters always need to be used on a new cam.
Jerry

That's what I'm running in my 261

Ok I will order a ccs-1 I suppose.

Any idea if these pistons sound like they would work: “Pistons Sealed Power 1009P Chevrolet 235ci Blue Flame Corvette .040" Set/6”.
It’s on eBay. But I don’t know wrist pin or dimensional data’s.

Have you measured the cylinders to see what diameter they are now? You'll only need to bore them enough to eliminate any taper wear and get the cylinder walls straight again. That could be anywhere from .020" to .060" or more, depending on how many times it's been rebuilt already. Measure everything first- - - -then buy parts!

Bores are .040 over. (Per machine shop)

If they're for a 235, they should work. RockAuto has the same for $264 for a set of 6, but without rings included.
The stock piston pin diameter for a 235 is 0.866" per the 1962 Vehicle Info Kit.

Here are the spec's for Egge's offering for 235 pistons.
Bore Size (inches) 3.56250
Clearance 0.00200
Compression Height 2.06250
Distance Between Bosses 1.312
Head Type Flat
Overall Length (inches) 3.56
Wrist Pin size .8650O
Ring Set Up 2)3/32,1)3/16
Skirt Style Full Round

How much cylinder taper wear? If there's less than.005" taper, you don't need to buy new pistons- - - -just hone the cylinders and install new rings.
Jerry

I assume .00001 cylinder taper wear since I just got it back from machine shop, who bored and honed it to .040 over.

OK- - - -that information would have been helpful a little earlier on. The pistons you listed should be fine, with the exception of the fact that with every engine I've ever bored (several hundred of them) I had the pistons on hand before I ever made the first cut on the block. Each cylinder is bored to the exact diameter of the piston that goes into that hole, and the clearance is added with the hone. That accounts for any manufacturing tolerances between individual parts. It's the way racing engines are built, and it's also the way a well-qualified machinist does things.
Jerry

Slowly beginning assembly.

I did not take the old crank out, the machine shop did.

Is 1962 235 supposed to have a neoprene, or a rope rear main seal?


I have the crank in, but the rope seal makes it very difficult to spin the crank. Spins easy without the rope main seal.
(PlastiGauge indicates clearances are good)

Wally - Pretty sure the original style rear main seal was rope design. I recall reading many times that some of the currently available new rope seals seem to be too thick and cause the extra drag on the crankshaft.

Other should be along to provide more info, details and possible solutions soon.

Hint: when heating the cam gear to put it on the cam… first put the bracket around the spacer. Check 12 times.

Doh!

Heat it up again and it about falls out though, so Lucky.

Any suggestions for a fuel pump rebuild kit for 1962 235 ?

"Then and Now Rebuilders". Send them the old pump and it will come back better than new with an alcohol-resistant diaphragm and new one-way valves.
Jerry

Then and Now Automotive

Then and Now Automotive
Then & Now Automotive
447 Washington St
Weymouth, Ma 02188
Ph: 781.335.8860
Fax: 781.335.1925

They'll sell you a kit or rebuild it for you.

They rebuilt mine 10k miles ago. It works perfectly unlike two brand new ones that wouldn't pump a drop straight from the store.

Call them on the phone. They really do excellent work.

Then and Now Automotive

447 Washington St
Weymouth, Ma 02188
Ph: 781.335.8860
Fax: 781.335.1925

https://www.thenandnowautomotive.com/auto-parts-store