Yes it will be when it is rebuilt. I am not going to try and repair it in the car, so once it comes out it will get a good cleaning and some machine work, then a good cleaning etc. I am going to invest money in heads and a cam and leave the stroker alone for now. Thanks all you have given really good advice and ideas. I will be building the next one myself.If you pull #3 main cap be sure to reset end play
I do not see how the flywheel bolts and flywheel were not too long on a previous crank and block? washers before and not this time. I think all factory bolts and crank flange thickness and flywheels are the same. I have manual 340s since 1978, never needed to drill from cam feed to thrusts. I do use a 3/4 groove #3 bearing
You made me look, MH ..... Why are there two wear patterns on the back of the #5 main cap in the 2nd pix in post #30? Aren't the flywheel bolts at the same radial distance around the crank axis? So is the edge of the flywheel's mounting recess contacting the back of the rear cap? If so, why?I do not see how the flywheel bolts and flywheel were not too long on a previous crank and block? washers before and not this time. I think all factory bolts and crank flange thickness and flywheels are the same.
There is only one groove. The other one that looks like a groove is not. It is the same height as the rest of the bearing cap.You made me look, MH ..... Why are there two wear patterns on the back of the #5 main cap in the 2nd pix in post #30? Aren't the flywheel bolts at the same radial distance around the crank axis? So is the edge of the flywheel's mounting recess contacting the back of the rear cap? If so, why?
I also just checked the rear surface of the #5 main cap on an early 360 and a'68 273 block, and neither has the inner step on the back of the cap behind the rear seal area, as seen in that same pix......???? It is almost like the rear flange of the crank has been shortened or the rear cap is not matched to the block.
There is only one groove. The other one that looks like a groove is not. It is the same height as the rest of the bearing cap.
Did you ever determine if the chamfer on the oil holes was what was scoring the bearings?
It appears that either they did not chamfer enough but if feels like there is barely any at all. Almost all the wear area is directly associated with the oil hole.Did you ever determine if the chamfer on the oil holes was what was scoring the bearings?
It could be the crap from the worn thrust bearing
I'm sure that's some of it, but the big scoring looked like not enough chamfer on the oil holes.
I always chamfer the main and rod feed holes before grinding. And add extra chamfer because some of it gets ground away.
I will chamfer them if the crank is ground already, but I don't like doing it any more if I can avoid it. My hand isn't as steady as it once was.
What’s your tool of choice for doing this
Not weird at all, #8 rod bearing is fed from the #5 main; #7 is fed from the #4 main.I also found #8 rod bearing totally wiped out, but #7 looks fine. Weird
Not weird at all, #8 rod bearing is fed from the #5 main; #7 is fed from the #4 main.
Possibly some crud/crap/debris left in the oiling path to #5, which, has been pointed out, is a partially separate oiling path vs. the path to 1-4. Would the 'scrapings' off of the #5 main bearing from a sharp edge on the oil hole wipe out the #8 rod bearing? IDK
Yes that is my worry. I do have solid cam so is there a way I can flush the engine. I know I am taking a risk for me a 66 year old man, tearing all this apart is a nightmare. I dont have my lift anymore.So back in the day I had a similar situation, fixed the crank replaced the bearings all was good until! One lifter collapsed, no biggie changed out the lifter and another one collapsed, pulled the lifters apart and they were full of metallic sparkles. That meant the rest of the engine was too.