The Stovebolt Site Forums The Shop Area Engine Shop 1961 261 engine

We bought a 1961 261 engine for the 46 1/2 ton. What modifications do I need to make to the engine mounts if any?? It had a '42 216 Installed. It looks like I need to change the motor mount location and assuming it is already set up for 12v? Thank you for all the responses.

You should install the water pump relocation plate made by Pre-68 Dave.

12v is non-standard - it would be hard to give wiring/electrical advice without knowing how your distributor is now wired?

You might want to try to describe how your ignition system is now wired.

Thank you tclederman for the reply. I will have to look and see about the ignition. I didn't know if Chevy went to 12v in all vehicles by then or not. The ignition system in the truck was still the original 6v. Haven't decided what to do a 6v or 12v yet. How will I be able to tell if the distributor is wired for 6 or 12 v? Thanks again for the help.

The 261 engine will run on either 6 or 12 volts equally well, so just go with whatever system you have at the present. If you choose to keep the original 6 volt system in place, simply use the flywheel, clutch, and starter from the 216 on the 261. There is a difference in the number of flywheel ring gear teeth and the tooth pitch of the starter pinion on a 12 volt setup, so the starter and flywheel must match. The 6 volt flywheel has 139 ring gear teeth, I believe, and a 12V flywheel has 168. Mixing and matching starters and flywheels results in noisy operation and rapid gear wear. The distributor doesn't care what voltage is used- - - -it's the coil that needs to match up, voltage-wise, and a 12 volt ignition system needs a resistor wired in series with the coil to prevent burning points. No resistor is needed for a 6V ignition system.
Jerry

Thank you Jerry

I have another question. Will the 61 261 mount directly in or will I have to change the engine mounts in the truck? It was to good of a deal to pass up for the price. The truck is not in front of me at the moment otherwise I could compare. I remember someone saying they changed the qay the engine mounts but can't remember the year.

The 261 should bolt in on the same mounts as the original engine. On later models, the plate between the timing cover and the block might have to be drilled for the "bird leg" front mounts, but the earlier engines with the flat rubber mount in the center of that plate are a direct bolt-in, I believe. You might have to drill a couple of holes to bolt the flat mount to the timing plate if the 59 engine has the side mounts instead of the one at the front.
Jerry

Thank you Jerry. The engine looks like it has holes drilled in the front for an engine mount but the bellhousing doesn't have the rear mounts like the 216. Can I swap the bellhousing to one that has the rear mounts and drill the holes like you suggested? Without making modifications to the frame. Trying to keep as much original as possible without welding.

The 216 bellhousing will be a direct bolt-on swap once the flywheel is removed. There are two bolts holding the bellhousing to the block that are hidden by the flywheel. Then you can use the original vertically-configured rear motor mounts instead of the angled ones on the later model bell housing. In 1954, the shape of the crossmember at the rear of the engine was changed, and the motor mounts between the bellhousing and that crossmember were angled at approximately 45 degrees. Your original 1946 bellhousing, flywheel, clutch pressure plate, and transmission will be a direct bolt-up to the 261 engine. That makes the only adaptation needed involving the front mount, on some engines. Drop me a PM and I'll share my phone number, if you like.
Jerry

Awesome thank you for the information and knowledge. I definetly will do the pm when I get everything in order.

Thank you Jerry. The engine looks like it has holes drilled in the front for an engine mount but the bellhousing doesn't have the rear mounts like the 216. Can I swap the bellhousing to one that has the rear mounts and drill the holes like you suggested? Without making modifications to the frame. Trying to keep as much original as possible without welding.

When swapping bell housings find someone with a dial indicator and check that the pilot bearing is concentric with the bearing retainer hole in the bell housing. If it's not concentric the transmission's clutch gear bearing and its pocket bearing won't last long. I have read that some of the bell housings were way off and that offset dowel pins were once available. Perhaps the Novak Jeep people in Logan Utah can help out here if needs be or the Pirate 4x4 people. Both have good web sites. I believe one of those is where I read about the concentricity issue. I checked mine last time the transmission was out and it was out of concentric to 0.010. I put it together anyway. I'll be dead before it wears out.

Mc Leod clutches used to make offset dowel pins, I seem to recall.

Ed

Thank you all very much I will check on it.

Any machinist with a lathe, a dial indicator, and a 4-jaw chuck can make offset dowel pins if it's necessary to have them.
Jerry