I pick up my 360 from the machine shop last week (My first motor build), started looking it over closely last night and I have a couple of questions.
The shop said the cylinders were only .004 out and recommended just honning them. They are honned, but I can still catch a fingernail on the ridge in 4 of the cylinders. Is this acceptable? (I know using a fingernail is not a great method of measurement, but I had ten of them with me)
The cam bearings were installed by the machine shop, but on inspection I noticed that the back two oil holes are not lined up with the holes in the block very well. One is blocked 50% and the other is probably 80% blocked. I am guessing this is incorrrect, but can anyone confirm that?
Also the cam freeze plug is not driven in square, it seems that could cause some wear issues.
Maybe I am too picky, but any info would be appreciated.
Did you use a ridge reamer before you knocked the pistons out? I always take the rodge off before I mic the bore. Cam bearings I would take it back and have them put them in right.
Doing the same ( rebuilding a 360 )
If you can just barely catch your fingernails on the ridge of the cylinder, It's really not that bad & acceptable.
As far as the cam bearings not being completely aligned dead center with the oiler holes, there is a reason for this.
The oil pump on a 360 is in the front of the engine thus providing more pressure to the front & not as much to the rear, by restricting those holes in the back by 50 to 80 % , it allows for more oil pressure to the back.
Think of it this way, you have a garden hose & water flowing, cover have of the hose outlet & you'll notice more pressure & stronger spray. Same principle. It's to compensate for the lower pressure at the rear of the engine.
That is exactly why I asked. Makes sense. Thanks Obnoxious 1.
I took the block to a very reputable but expensive shop yesterday afternoon. He is going to give me a second opinion on the whole thing. I'll keep my fingers crossed I guess.
IMO, and I may be wrong , but that dont make much sence to me, you would get better pressure but less oil flow. Your reference with the water hose, Forcing more pressure in a non pressurized system,would be the entire system) but by blocking off some of the oil hole on only 2 of the bearings, yes I guess in a sense this would create more pressure there but it would defiantly cut down on the volume of oil going there also. In a non pressurized system, be it gas, oil, water, the fluid is going to follow the path of less resistance. Your blocking off the garden hose somewhat would be the entire system, try putting a hole in the hose about a inch down the hose (now a open system) and see where the water will want to run. There is not much in the engine that will force oil to go any path and will always flow the path of less resistance.
Oil pressure is maintained by proper bearing clearance, not by restricting the flow of oil at its entry to the bearing. I would question this, maybe ask another shop familiar with this engine type. As far as the ring-ridge, there should be an acceptable limit measurable by a micrometer. What is the shops warranty on their work?
Good to hear. Sucks to buy new pistons but you will be happy in the long run.
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