Hello all, I am in the Kansas City area and my project truck (56 3100 with 261) is in central Arkansas. Not complaining, it's just the situation I am in. So wanting something to tinker with here, I gambled and bought a 235 engine for $200. I should take posession of it this weekend. I have wanted to try my hand a rebuilding an engine so I'm pretty stoked to do the tear down. Of course its a gamble so I'm not getting worked up to do the rebuild in the event its a bad block or head.
Currently its in a late 40s- early 50s truck and apears to have come from a 58-62 car (a guess based on breather and valve cover)
Acording to the seller it is "stuck". From the photos you can tell that at some point someone robbed the carburetor and the points/condenser.
Once I take possession I will post the casting #s At present the only number I have is for the head 3836848
As I progress I will post pics.
Rock49 aka C-Rodg work in progress 1956 Chevy 3100 261 engine
Hey Chris - Just from the pics you have, the center fill valve cover indicates it's likely '60-'62. The air cleaner is definitely a passenger car unit. But neither of those are definitive as they could have been swapped from another engine, just like this engine found it's way into the AD truck.
Looking forward to future pics and info to try and help with identification.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
With pistons for a Ford 223 cubic inch six, and a stroke increase to 4 1/8 inches, that 235 can become a 255 cubic inch engine. It requires a little creative machining, but the cost isn't a lot more than a full rebuild to stock dimensions. The 261 can approach 300 cubic inches with similar modifications. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Gdads51, At this time its all assumptions, speculation and wishfull thinking. Is it frozen or seized, untouched or bored over .060”, hydraulic or solid lifters? I will send pics of the block #s as soon as I get the engine.
Jon G, the 261 is good and runs fine. It and my 56 3100 are in Arkansas and I'm in Kansas city. I work on it when I go down for visits.
I have wanted to try my hand a rebuilding an engine for several years and the 235 was the right price. A learn as I go type of project, I can do here in KC. If all works out well and I rebuild the 235, then naturally I will have to find another project to put the 235 in.
Jerry, Thank you for the recomendations.
Last edited by Phak1; 09/25/202612:15 PM. Reason: Typo’s
Rock49 aka C-Rodg work in progress 1956 Chevy 3100 261 engine
In the meantime I have read through the 261build in the tech section, re read the attatche book, reviewed the engine section in my 55-59 chevy truck manual and the engine section in my 49-54 chevy pasenger car manual. And of course reading posts here on the Forum. Additionally I have been watching will it start and rebuild videos on the 235.
So, if you are going to rebuild an engine is there a benifit to getting it to run prior to tear down? I understand it has to rotate to make removal of the flywheel and bell housing easier but is there a benifit to hearing it run?
Also what is the difference between an overhaul and a rebuild? As I understand it. An overhaul is when you replace bearings, seals and rings but do not do any machine work. A rebuild involves machine work, and close to new everything. Or at this date have the terms become interchangeable?
Chris
Rock49 aka C-Rodg work in progress 1956 Chevy 3100 261 engine
Back in the dark ages (the 1950s) when I started tinkering with engines as a preteen kid hanging around Dad's auto shop, they did a lot of what was known as an "in the frame rebuild". The cylinder head and oil pan got removed, the wear ridge at the top of the cylinders got reamed away, and the cylinders got a quick hone job, the pistons got new rings, the valves were reground, and the Babbit-lined connecting rods got "adjusted" to the proper oil clearance by removing a shim or two, and everything got reassembled. That procedure could be done a time or two before the taper wear in the cylinders required a rebore job and oversize pistons. Sometimes, cylinders actually got bored with the engine still in the frame, and a portable crankshaft grinder could be set up to get the crankshaft round again for undersize rod bearings. More often, a rebore and crankshaft regrind was done after the engine was removed and torn down for a major overhaul. By the time an engine had 50K miles or so, it was not uncommon for it to have received one, or maybe two in frame repairs, and possibly a valve job in between ring and rod bearing jobs. Prior to the advent of "positive crankshaft ventilation" (PCV) systems, engines ate a lot of dirt, and rings and rod bearings wore out quickly from abrasive damage. Blowby combustion gas from worn piston rings also mixed with humidity and formed acids that ate away at bearings, etc. Metallurgy was also not the best, resulting in rapid engine wear. Some of the stovebolt engines we tinker with have probably been "rebuilt" multiple times.
About the only advantage I can see to doing an engine run before an overhaul is the ability to do a crankcase flush- - - - -fill the engine with inexpensive oil like Walmart "house brand" non detergent 30 weight, add 3 or 4 quarts of Diesel fuel so the crankshaft and rods dip down into the overfilled crankcase, and run the engine at a fast idle for 30 minutes or so. The crankshaft and rods will splash the diluted oil around like the agitator in a washing machine, and dislodge years' worth of sludge and dirt. That makes cleanup during a rebuild a lot easier. DO NOT DRIVE THE VEHICLE OR PUT ANY LOAD ON THE ENGINE! Drain the oil while it's still hot. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The absolute worst phrase I can think of is "There's an app for that!" Some things like the accumulated knowledge of several generations of master mechanics and hands-on experience just can't be condensed down into a few keystrokes on a computer! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I have never downloaded an application to my phone in my entire life.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
Back in the dark ages (the 1950s) when I started tinkering with engines as a preteen kid hanging around Dad's auto shop, they did a lot of what was known as an "in the frame rebuild". The cylinder head and oil pan got removed, the wear ridge at the top of the cylinders got reamed away, and the cylinders got a quick hone job, the pistons got new rings, the valves were reground, and the Babbit-lined connecting rods got "adjusted" to the proper oil clearance by removing a shim or two, and everything got reassembled. That procedure could be done a time or two before the taper wear in the cylinders required a rebore job and oversize pistons. Sometimes, cylinders actually got bored with the engine still in the frame, and a portable crankshaft grinder could be set up to get the crankshaft round again for undersize rod bearings. More often, a rebore and crankshaft regrind was done after the engine was removed and torn down for a major overhaul. By the time an engine had 50K miles or so, it was not uncommon for it to have received one, or maybe two in frame repairs, and possibly a valve job in between ring and rod bearing jobs. Prior to the advent of "positive crankshaft ventilation" (PCV) systems, engines ate a lot of dirt, and rings and rod bearings wore out quickly from abrasive damage. Blowby combustion gas from worn piston rings also mixed with humidity and formed acids that ate away at bearings, etc. Metallurgy was also not the best, resulting in rapid engine wear. Some of the stovebolt engines we tinker with have probably been "rebuilt" multiple times.
About the only advantage I can see to doing an engine run before an overhaul is the ability to do a crankcase flush- - - - -fill the engine with inexpensive oil like Walmart "house brand" non detergent 30 weight, add 3 or 4 quarts of Diesel fuel so the crankshaft and rods dip down into the overfilled crankcase, and run the engine at a fast idle for 30 minutes or so. The crankshaft and rods will splash the diluted oil around like the agitator in a washing machine, and dislodge years' worth of sludge and dirt. That makes cleanup during a rebuild a lot easier. DO NOT DRIVE THE VEHICLE OR PUT ANY LOAD ON THE ENGINE! Drain the oil while it's still hot. Jerry
How lucky a dad with an auto shop. I started in the late 50's with cox engines and then progressed to Tecumseh and BS engines, Mcculloch etc. Wasn't very old then, and that is also how I learned to read studying the manuals etc. could not care a bit about the books at school. Those old timer auto engineers back then did a fantastic job, the stuff now is not much better, just look at all the recalls and failures now with the new stuff.
Kicking self for selling off my Taskforce trucks. Still looking for an LCF or conventional big bolt in decent shape.
As of 10-26-2022, A 55.2 Taskforce long bed now the work begins
Part of the reason for all the recalls and failures in modern vehicles is the extreme complexity and various regulations that didn't exist back when.
Carburetors have their problems, and electronic fuel injection is great all day long, if all the related sensors are working as intended. Ignition systems with points had their issues as well and electronic ignitions systems with all their capabilities are also great as long as all the sensors, etc. are working as intended.
In the older vehicles, there were a few wires you needed to check if mice were a problem, today's vehicles have a million miles of wire that mice seem to love to chew on.
Small engines were the last ones to get significant emission regulations and those regulations are in part responsible for significant changes in the small engine manufacturer ability to produce products, of course the other is engines coming from China.
My brother converted his 1969 GTO to fuel injection, and ditched the awesome quadrajet carburetor against my protestations.
Well a year or so in to the conversion he's recently had some driveability issues especially on startup.
He asked me for suggestions on troubleshooting and I actually had none..
As it turned out, it was a bad throttle position sensor causing rough idle and stalling at low RPM.
In my opinion, one of the best things about driving antique vehicles is that they don't have any sensors or computers telling the engine what to do.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
It's also possible to retro-fit a computerized engine to use a carburetor and a distributor- - - - -create a "dumb" engine that doesn't need an engineer with a long pedigree to do basic maintenance. I'm in the process of doing that to a Ford 5.4L 3 valve overhead cam engine- - - - -as well as disabling the variable valve timing. I'll drive a GM HEI distributor with vacuum advance for a Chevy V8 from the front end of one of the overhead cams. I'll be running a Q jet and plugging off the injector holes in the intake manifold. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Fingers crossed, I "should" take posesion of the engine this week/ weekend. We will see.
In the meantime I have continued my research with a focus on the disassembly. Manual, tech articles and YouTube videos. None of which do a good job of imparting the knowledge that comes from experience.
Any particular part of the disassembly I should pay particular attention too?
So far I have Don't be in a hurry Take Pics along the way- More than I think I need. Everything Stay organized Bag everything Use a stamp to number- rods and caps Keep lifters with there push rods in order front to back Clean as I go Inspect as I go. Is it worn or damaged. Be safe. It's a heavy engine.
Thank you Chris
Rock49 aka C-Rodg work in progress 1956 Chevy 3100 261 engine
Those all sound like good advice. For me doing a disassembly, I find it helps to not only take lots of pictures, specifically trying to capture the initial state of each item/assembly being documented, but also to take the time while the memory is fresh to rename/title and save the pictures to indicate before or after, as well as what the point of the picture is taken to capture.
Examples include details like the presence of the internal oil line under the engine side cover that is part of the oiling pathway to the rocker system on the head, or closely checking each item as removed.
On the "Bag everything" note, be sure that includes a tag of some sort, preferably inside the bag or at least securely attached, that details the contents of the bag and where it came from on the engine. Adding a note about the condition would be helpful when it comes to rechecking your bags for what is still good and what may need repair or replacement. That can help you begin gathering information for identifying/locating/ordering needed parts.
Also highly recommended before you begin the tear down process, read through the Legacy Tech Tip 261 Rebuild which has some extensive knowledge sharing and helpful tips & suggestions.
Looking forward to seeing and hearing more on your 261 and progress on the project.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
Gdads 51 God point on the lables. I also like to take video.
side note: When I was working on a 49 fleetline I bagged and tagged everything. 10 years later when I finaly got back to the project I had a box of loose parts with bits of plastic everywhere. Not sure if mice got to it or the bags just deteriorated.
Chris
Rock49 aka C-Rodg work in progress 1956 Chevy 3100 261 engine
If you looking for videos jayhawker has a few were he takes one apart ,there are also a few others one is a machine shop that rebuilds one also when I remember it I will let you know .Found the two I was referring too
Last edited by KEVINSKI; 10/07/20267:04 PM. Reason: More imfo
If there's enough wear and/or carbon at the top of the cylinders to hang a fingernail, don't try to drive the pistons out past it. The rings will hang up, and probably break the ring lands of at least a few of the pistons. Instant paperweight if that happens. Reamer tools for cutting that ridge away are inexpensive, or some parts stores will rent you one with a deposit. Also, be very careful not to nick the crankshaft bearing journals with the threads on the rod bolts- - - - -stovebolt cranks are tough- - - - -but not hard, and it doesn't take much effort to put nicks in the bearing journals. Use some short pieces of 3/8 inch rubber fuel hose over the bolts to cushion the threads when removing or installing rods and pistons. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Kevinsky, Thank you, I regularly watch the Jayhawker and had watched the machine shop videos when they first came out. I will go back and watch them again.
Chris
Rock49 aka C-Rodg work in progress 1956 Chevy 3100 261 engine
Jerry, Thank you for the recomendation on posibly renting a ridge reamer, I will see if a local parts place has one for rent. If I have to buy one, are they a universal type tool, or should I look for a particular size?
Also I had seen where the fuel hose was used to protect the crankshaft during assembly. I would have never thought to do it during disassembly.
Once again thank you. Chris
Rock49 aka C-Rodg work in progress 1956 Chevy 3100 261 engine
Chris - I've got a ridge reamer you could borrow and save your money. I'm gonna be out of town till mid next week, but if it can wait until I get back we can meet up to hand off for you to use.
Would be a great excuse to have lunch!
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
Most ridge reamers are adjustable over a wide range of cylinder diameters. There's at least a hundred of them listed on Ebay right now, new and used. Lisle and Snap-On sold the same basic design, a lathe-type cutter that climbed a very fine thread and cut the ridge out from the bottom up. I used the same one for over 25 years, on untold dozens if not hundreds of engines, and never managed to wear it out. I think it followed somebody home while I wasn't looking one day!
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Chris, I also have all the tools you need to rebuild an engine and the mics to measure the bores and bearing diameters.
Don
1967 GMC 9500 Fire Ladder Truck "The Flag Pole" In the Stovebolt Gallery 1946 2-Ton grain truck 1946 3/4-ton pickup, 1953 1-ton pickup 1957 1-ton flatbed dually, 1954 Pontiac Straight Eight Of all the things I've lost in my life, I miss my mind the most!
I will spend some time tomorrow formating photos to the scale acceptable for the forum.
After I verified it was stuck I removed the head. Cylinder 1 had water in it and 2-6 were dry. Each cylinder has different levels of surface rust. The ridge at the top of the cylinders was about the thickness of a credit card. I could not find any indicator such as a number stamped on a piston, so no idea if it has been rebuilt. The rocker arm assembly has a fair amount of crud build up as for the valves there is rust and carbon.
The pics will show greater detail.
For now these are the engine and head #s.
Head 8836848
Under valve cover con 9 L181 What I think= Conveyor 9. Dec 18 1961
Flat by distributor F0903A What I think= Flint Sep 3 car
Block by starter con3 129 What I think= Conveyor 3 Dec 2 1959
Block by side mount 3769716 The years it covers= 1958-63. 235 What I think= 1961-62 car 3 speed or powerglide.
Have a good one. Chris
Last edited by Gdads51; 10/26/20269:49 PM. Reason: Typo - Edited to add What I think
Rock49 aka C-Rodg work in progress 1956 Chevy 3100 261 engine
Chris - Here's some decoding based on your provided numbers/pictures:
Head - Should actually read "3836848" (casting numbers are notoriously difficult to read), 1956-62 235
Under valve cover - con 9 indicates the conveyor line assembling the engine / L 18 1 = Cast Dec 18th 1961 (not original to the block its attached to)
Flat by distributor - F = Flint plant / 0903 = Sept 3rd of the model year / A = Passenger car regular production 235 engine with standard 3 speed or overdrive transmission
Block by starter - con3 = conveyor line 3 on the engine build line / I 29 = Cast September 2nd 1959
Block by side mount - 3769716 is the block casting code for a 1958-62 235
So it reads as a 1959 passenger car 235 block with a 1961 235 head.
Hope this is helpful.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
When I pulled the head, cylinder 1 had about an inch of water in it. The remaining 5 were dry. I have cleaned the cylinders and piston heads a good as I can with a wire brush. I have orderd a variety of cone brass brushes for my drill, when they come in I will do a better clean. In the meantime I plan on sealing around the pistons and filling the cylinders with evapo rust to get rid of the rust.
Last edited by Rock49; 10/26/20266:00 PM.
Rock49 aka C-Rodg work in progress 1956 Chevy 3100 261 engine
Those cylinders are going to need to be rebored to eliminate the rust pits, so the pistons are junk. You can shorten the disassembly process by using a big hole saw in a low speed variable drill motor or a drill press, and cutting away the piston crowns just inside the piston ring diameter. 235's have a bore size of 3 9/16", so use a carbide-tipped hole saw about 3 3/8" in diameter and cut down just past the piston ring area, maybe 3/4" or so. Once that is done, hammer on the middle of the piston to break it away from the stuck rings.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
As for the head. the intakes will take some doing to get them to move. The exhaust all move with some light taping. And of course rust. From what I can tell the deck may have ben milled or maybe not. Along with pics of the valves I have attached a photo of the casting number which looks to me to have had some milling.
Let me know your thoughts.
Rock49 aka C-Rodg work in progress 1956 Chevy 3100 261 engine