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We have a partial restoration, and we wanted to manually turn over the motor once a month.
I assume we need to remove the spark plugs as it'll be too hard to overcome the compressive manually.
However, the inner two cylinders on each bank are instructed by the exhaust headers. The obvious solution is to remove the exhaust headers, but that seems like a very dumb design.
I have a Skip White 421 that I just put on my frame. I called and asked the same question because its going to be a while before it gets fired up. I was told its a good idea once every couple of months to rotate it so the valve springs that are under load will get some relief and the ones that aren't, will be. Besides that, I can't think of why its necessary.
Honestly; I don't know. The previous owner and his engine builder advised my partner on the build.
I can't find anything online which discusses it.
We'll have another chat to the engine builder.
Does anyone else know if and why this is beneficial?
I see no benefit. You aren't distributing any oil at that level of rotation and are merely causing parts to rub against each other without adequate lubrication.
However, the inner two cylinders on each bank are instructed by the exhaust headers. The obvious solution is to remove the exhaust headers, but that seems like a very dumb design.
That is a dumb design! Are those headers intended for angled-plug heads?
There are lots of great threads on this Forum to peruse if you want to change your headers before the car is completed.
I bet you are trying to remove the plugs with ratchet / socket. I too have headers and on some plugs, just use a short socket, then use a boxend wrench on the socket.
Sometimes plugs are easier accessed from underneath.
Back to your story. Every time you put a massive amount of torque on the crankshaft center bolt, the odds of it snapping off in the crank-snout increase.
You DO NOT want to go there.
Its one thing to manually turn a short block on a engine stand, but its another thing to do that with all the plugs in and all the belts on. A lot of stress on that damper bolt.
Looking at your photo in Post #1, there doesn't seem to be much clearance. If @HeadsU.P.'s suggestions don't work, perhaps you could use a pass-thru socket, like this, or a deep offset box end wrench, like this. I found it easier to work from under the car with stock manifolds, but much easier from above with long-tube headers.
This should probably be another question for your engine builder.
Last edited by Bikespace; Oct 30, 2020 at 08:14 AM.
As HeadsUP said, put a socket on the plug and use a box wrench to turn the socket, from under the car if necessary. You can also try a box wrench directly on the plug, without the socket.
I’m assuming this is a prior running engine. If so I would do the following.
I would spray some sorta aerosol oil in the combustion chambers IE WD40, PB Blaster, Deep Creep etc and put the plugs back in. Additionally I would pull the carb and do my best to get a good shot down each intake runner and get a good shot onto the exhaust valves through the exhaust ports. Depending on how long it will be sitting and how humid your area is I would back off your rocker arms and spray the entire valvetrain with the same stuff and seal up the whole motor (exhaust ports, intake ports etc)
As others have said I wouldn’t roll it over for the sake of rolling it over.
Also the deal about guys backing off valve springs. That’s a real thing but not so much for spring tension reasons. It’s more so to ensure the valve doesn’t stick in the open position from corrosion. This is most common with race engines that run methanol, but rust is a form of corrosion and that is the biggest worry.
Bringing it back is pretty straight forward. Reset the lash on the rockers and prime the oiling system with a primer tool. Don’t start it dry.
I see no benefit. You aren't distributing any oil at that level of rotation and are merely causing parts to rub against each other without adequate lubrication.
I am no engine build expert, but I thought about this a lot as my engine sat almost a year between rebuild and fire up. A journal bearing needs fluid and without oil pressure you are relying on assembly lube. I am not sure how many rotations you can have before the assembly lube is gone, so I just tried to keep the motor dry with desiccant plugs and desiccant bags in the intake.
I have developed a set of wrenches for doing the plugs on my engine. Most of them can be done with a socket and either a ratchet or with a wrench on the socket. A couple of them require a custom wrench I made by cutting, bending, and rewelding a 13/16” combination wrench.
Also I run Accel shorty plugs which helps with header clearance.
From: At my Bar drinking and wrenching in Lafayette Colorado
There is no need to "turn the engine" once a month - complete nonsense. Do you think new GM crate engines in the warehouse get "turned once a month" to keep them fresh..? They sit on the shelf for distribution and sale for a year or more. When we received new Chevys and Corvettes off the transport truck at the dealership in the mid 70's, those cars were parked in the storage lot. They would sit there without being started often for over a year. Charge the battery, prime the carb, and fire 'em up. No problem.
2020 Corvette of the Year Finalist (performance mods)
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Most collector cars sit all winter without starting them. I was starting mine to keep teh fuel in the carb from going bad and clogging it up. I use Stabil to prevent that. You just may be scoring your cylinders.
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Dumb question; turning over a motor
