Lookin @ your pics, did you notice the scuff marks on #5? Looks like you might have a cracked piston skirt.
I did notice but i didn't really think nothing of it. The block is at the machine shop now and my machinist inspected it before i left didn't tell me anything he said it was a good looking block. Its getting honed so i should be good i hope.
Those block are pretty hard. I had the same issue on my 6. I honed it out and replaced the pistons/rings after finding i had a broken piston on #4. Took it to the machine shop to get the new piston put on the con rod an the guy there told me it's a rather common problem on the 300's. I got a set of pistons from Auto Zone for 150 bucks. If you don't have it re-assembled i'd pop 'em out and give em a good lookin over. Especially if it's a higer mileage engine. I've only got 135k on mine and 4 out of 6 pistons had small hairline cracks in em.
Those block are pretty hard. I had the same issue on my 6. I honed it out and replaced the pistons/rings after finding i had a broken piston on #4. Took it to the machine shop to get the new piston put on the con rod an the guy there told me it's a rather common problem on the 300's. I got a set of pistons from Auto Zone for 150 bucks. If you don't have it re-assembled i'd pop 'em out and give em a good lookin over. Especially if it's a higer mileage engine. I've only got 135k on mine and 4 out of 6 pistons had small hairline cracks in em.
This is gonna be the second rebuild this engine gets nothing was wrong with it when i took it apart but i wanted to mildly do a performance build on a inline six since no one around here has one that i know of. Anyways the first time it got rebuilt was because number 6 just gave up on my dad coming back from Mexico we were in Little Rock and it decided to take a poop on us so my dad drove all the way home on 5 cylinders not the best idea but he had no other choice so when we got home the old 300 got its first stock rebuild!
I had the same thing happen to me. #4 broke the ringlands coming thru the mountains in West Virginia on my way to Ohio.Still finished the trip. Disassembled it when i got home and measured out the cylinders with a dial bore gauge and none of the cylinders were worn more than .0015" Those 300 blocks are super tough.The pistons don't wear the cylinders,the cylinders wear the pistons. Hope the rebuild is goin well. Keep us posted on the progress.
Well I visited the machine shop look like three of the cylinder walls are bad I have to bore the block .20 or .30 over. Is there really a diff? My dad said I should go with .20 over that way it won't drink so much gas is this true? Or it doesn't really matter?
Well I visited the machine shop look like three of the cylinder walls are bad I have to bore the block .20 or .30 over. Is there really a diff? My dad said I should go with .20 over that way it won't drink so much gas is this true? Or it doesn't really matter?
I think you might mean 0.020" or 0.030"! If you over bore it .20" or 0.30" you won't have much if any cylinder walls left!
The difference between .020" and 0.030" over bore will have very little effect on fuel mileage.
But if you can get by with a 0.020" over bore I'd go with that. The way I feel is only go enough to clean up the cylinders. Any more and you are just removing material and strength from the cylinders. Not to mention the more you remove now, the less you have to work with in the future if it ever needs to be rebuilt again.
I think you might mean 0.020" or 0.030"! If you over bore it .20" or 0.30" you won't have much if any cylinder walls left!
The difference between .020" and 0.030" over bore will have very little effect on fuel mileage.
But if you can get by with a 0.020" over bore I'd go with that. The way I feel is only go enough to clean up the cylinders. Any more and you are just removing material and strength from the cylinders. Not to mention the more you remove now, the less you have to work with in the future if it ever needs to be rebuilt again.
hahaha you know what i meant lol! hey i guess my dad was right 0.020 overbore it is!! thanks for clearing that up, i was kinda devastated when he told me because i was kinda on a budget but i guess I'm going all out on this build now!
if i do a 0.020 over bore what would the cubic inches be?
Sucks to hear bout the cylinders, but better to find out now rather than later. Figurging your C.I.D.(cubic inch dsplacement) is easy. Bore x Bore x Stroke x .7854 x # of cylinders = C.I.D.. So figuring yours would be: 4.020 x 4.020 x 3.98 x .7854 x 6 cyl. = 303.09399. I agree with Fordman, hone enough to clean it up. You can find .020" over pistons on summitracing.com for about 140 bucks,throw in another 20 bucks or so for shipping depending what part of the country you're in. I got mine from autozone cause they don't charge shipping. Hope ya don't have anymore surprises.
Well Idk my machinist has a bad habit of saying he'll give me a call but he won't. I kinda hate that and then he work weird hours but I'm gonna give him a call, I kinda fed up of waiting.
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If you over bore it .20" or 0.30" you won't have much if any cylinder walls left!
