opened up the engine last night...

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abodyjoe

abodyjoe

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well it spun #1 bearing.. #2 looks prety bad too. just have to figure out what i want to do now.... i should have a set of rods in the shed so i can replace these two and i may have a crank out there too. if not i have a couple 360 motors that i should be able to rob one from. not sure if this crank is able to be cut... still have to pull the rest apoart and see if there is any more damage.

would be a good time to make it a 408. lol...




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not really... i did lose the coil at top end of the track last time out... possible i guess that it hammered the rod bearing bad... but who knows.
 
How many run's do you have on that motor?
your oil pick up screen looks very clean and you had good oil pressure.
Lets take a look at your crank bearings.
It sure did eat the bearings up all the sudden, or did you have a clue?
Sorry to here the bad news Joe.
Rod caps held up and kept that rod in the motor.:cheers:
 
actually the damn thing ran smooth and normal... at 2500rpm you heard the knock but other then that smooth as can be.


i had it at the track months ago.. the car shut off and came back at top end of the track then i ran like one or two more runs came back and shut it off... then it wouldn't start... towed it home and found the coil took a crap.. put a stock one on it took it for a drive and it drove fine until i hit it a bit and it hit 2500 rpm i heard the noise.. haden't run since.. pulled it last week and pulled it apart last night. oil pressure the whole time.
 
memike said:
How many run's do you have on that motor?
your oil pick up screen looks very clean and you had good oil pressure.
Lets take a look at your crank bearings.
It sure did eat the bearings up all the sudden, or did you have a clue?
Sorry to here the bad news Joe.
Rod caps held up and kept that rod in the motor.:cheers:
Click to expand...



not sure how many runs.. not a ton because its not at the track alot... but on the street it really gets beat on... i had it on the highway alot last year and that means cruising at 3000-3800 rpm to keep up with everyone... i put alot of hard street miles on it the last couple years..
 
First think I'd check for is if all of the oil passage plugs are where they are supposed to be.
 
ramcharger said:
First think I'd check for is if all of the oil passage plugs are where they are supposed to be.
Click to expand...

Don't mean to take away anything from ramcharger ! But I thought the same
when I seen it was the front two that spun. Good call ramcharger.=D>

Keep us updated , I would like to see the crank bearings 8)
 
memike said:
Don't mean to take away anything from ramcharger ! But I thought the same
when I seen it was the front two that spun. Good call ramcharger.=D>

Keep us updated , I would like to see the crank bearings 8)
Click to expand...
Good call by both of you guys. 30 years ago, I had a friend of mine with a ton of bowtie experience build a 340 for me. He wasn't aware of all the oil passage plugs and left one out. Ended up spinning a rod bearing similar to this except when the bearing spun it also split and the two halve crossed into each other. Talk about UGLY! Needless to say, he didn't build the next motor. That was when I dug in and built my first motor with the help of another friend.
Sorry to hear of your misfortune but there's always something better that comes out of something like this.
 
memike said:
Don't mean to take away anything from ramcharger ! But I thought the same
when I seen it was the front two that spun. Good call ramcharger.=D>

Keep us updated , I would like to see the crank bearings 8)
Click to expand...



wouldn't an oil plug done this alot sooner?? i have been beating on the motor since 2004. and it was together before that.. not much runtime before that but run time..
 
Swedefish - I was pulling good oil pressure up until the time the bearing spun.
Abodyjoe - Probably. My spun bearing happened about a month after the motor had been built and installed. I remember it happened after a little 'street pass' at about 6K rpm when driving home one night.
 

gotch ya.. this thing regularly saw 5900 rpm. was at the track quite a few times and had quite a bit of hard street miles.. heck in 2007 i had it to the pocons 3 or 4 times (2 hours each way) carlisle (2 hours each way) poker run ( probably about 200 miles when all was said and done) and a few other long trips... they all were cruising at 3000 min.. most of the time at 3500 - 3800 rpm... so i'm thinking if that plug was out it would have happened well before this...
 
abodyjoe said:
so i'm thinking if that plug was out it would have happened well before this...
Click to expand...

I agree, but if the plug is missing that goes in between the pressure and return feeds, your oil pressure will show good but you will be feeding unfiltered oil through the crank. Never hurts to check.
 
Mine looked like that shortly after I got the car on the road. The guy I got it from rebuilt the engine but didn't have the rods resized. Had stock rod bolts in it too. I took it apart and it looked nearly identical to yours. Checked the rods and 5 out of 8 were out of round bad. I had them all resized and ARP bolts put in. Put it back together and haven't had any problems.

BTW: My crank was able to be turned and they did that. When I put it together the 2 cylinders on that journal checked .010 lower in the hole. I asked my machinist about it and he said that happens alot because they offset grind the crank usually with spun bearings because the bearings take more off of one side than the other. I can't say I was pleased to hear that. If it ever happens to me again I'll look for a different crank.
 
I had a 318 back in 82 and it the motor had over 175k on it and
was never took apart till I did!! and it was all factory.
It looked like yours but it was the crank bearings.
I was told it was because it was an a/c car.
A good line bore and over sized at the crank and new bearings
the rest of the way up. Can this be dun to the rods, or will it go out of ballance to bad?
 
have had the same problems with my moter. have found you need to modify the oil system alot for substaned high rpm. this was my first experience building a big small block an i lost the bottom end due to starvation 3 times before i did alot of reserch. mine would run all day at 4500-5500 but when you turned it up to 7000 she would starve the bearings
 
were you running a stock oilpan on that thing? If you are, running those kinda rpm's will do that. It'll suck the pan dry, then u get spun bearings
 
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