Two years post completion of my body off restoration, I developed a rod knock when the engine is started which completely disappears after oil pressure comes up to greater than 5psi, usually only a few revolutions of the crank. But, it is getting louder and I am not liking it. The current engine is a stock bore 235 from a 56 chev. passenger car. I should of looked in deeper during the restoration but it had great compression and only touched the upper end at the time which included a valve grind and new seals and a knurled guides, plus a change to a solid lifter cam.. I took the cheap way and should of pulled the pan and looked at bearing clearances but alas, I didn't and now faced with lifting an engine out and in again over my beautiful fenders.
Why I have the engine and transmission out, I will also go into the sm420 and replace third gear and the counter constant mesh gear too. Also a good time to check the clutch and flywheel.
I have finally found a 261 cu in engine, been looking for over 2 years. The block was bored .030 and I have since assembled it and it is awaiting the 848 head that I am currently running on my 235.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
Have you tried spinning the engine for a few seconds with the ignition off to build oil pressure? That won't make the bearing clearance any better, but it should minimize any further damage until you have the 261 ready to install. The old Caterpillar bulldozers with the gasoline pony engine used to get spun for a couple of minutes on a cold start with the compression relieved until the oil pressure came up before opening the Diesel throttle and starting the main engine. Spinning a stovebolt starter for 10-15 seconds before switching the ignition on won't hurt anything, as long as the starter and the battery are in good shape.
It only takes a few bolts and a little time and effort to lift the front end sheet metal off as an assembly- - - - -that makes the engine swap a lot simpler, and also eliminates any possibility of scarring up that nice body and paint work! 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!
That makes total sense Jerry on spinning the motor with the key off but alas I've started to remove the old sole so wont get chance to try that. Thanks for the info on the sheet metal removal. I am looking forward to some postmortem testing to find the noise, will start with all the rod bearings first, thinking that is where it lives. The 235 has never been rebuilt, stock bore, so I'm going through it and giving it to a friend to go in his AD Steve.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
So the 261 is going in yours? Man, you won’t know what to do with all those extra horses!ðŸ˜
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
Hopefully Marty I will be able to feel the difference, but really the 235 scooted around ok empty that is.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
Made some headway, out with the old. Tomorrow a cleanup day and put some tools away, looks like a war zone in the shop.
Last edited by sstock; 07/15/20195:55 PM.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
The only thing better than a 261 is a "300" that looks like a 261. I'm in the process of doing the machine work on one of them which will then get a workout on a bellhousing dyno. The numbers should be "INTERRRRRRESSSTING!" 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!
Jerry, can you accomplish a 300 cu inch with rod and crank work only or does it require a new piston too.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
Stock pistons! A.040" overbored 261 block and a 4 3/8" stroke comes out just a bit over 300 cubic inches. The crankpin size on the NASCAR rod is around 1 7/8", which allows a big offset from the original centerline. Total stroke change is 7/16". A standard bore 235 with original pistons, the same stroke increase and rods comes out at 266 cubic inches. The rod is a Carrillo tool steel item with a 6.450" center to center length. 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!
Had a pretty good couple of days in the shop. The 261 is ready to drop in, just finishing up on the generator R&R. A couple of pictures. Decided to do with some hardened exhaust seats because the exhaust valves were receded. New valves ,springs ,guides,seals too. Reground the cast cam at delta cams in Tacoma, they also resurfaced the solid lifters. Will run the bypass filter for awhile, this block is a 62 and never had its oil galley rod pushed in for a full pressure filter. Steve
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
Engine is all done, installed and break in oil dropped, cylinder head retorqued and solid lifters re-adjusted.
One thing worth mentioning for others is it is very important to retorque the Fel pro fiber faced head gasket. These gaskets do compress and the are designed to be retorqued, and you must do this. I checked my rocker arm lash after 150 miles or so and it had opened up considerably, even developed a lifter tap. Originally setup cold with intakes @.006 and [email protected]. I decided to set it up there because I knew they would open up on this new motor. Lash after 150 miles checked before I retorqued the head: #1 intake .007 #2 intake .008, exhaust .024 (That was the one tapping) #3 intake .007 exhaust .017 #4 exhaust .019 #5 ok #6 exhaust .015
Steve
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
