FlamesAreWicked
Well-Known Member
Picked up a 71 340 long block (73 J 587 heads) recently that was supposedly a good running engine. After buying it and did some inspection, looks like there was some water in it. I talked to the guy I bought it from and he apologized and offered to help with some money back on making it right again. It was in a running driving car and after it was pulled, that’s when the moisture problem happened. The engine was in another state so pre inspection by me wasn’t an option. I have quite a few questions as this is my first rodeo in this
Currently it has what looks like .030 Silv o lite pistons that are 68-71 style and with 4 reliefs. I have some photos of the bores taken with a bore scope and one of the heads was taken off..
My questions are:
Would going another .010 remedy this?
This will be a cruiser 90% of the time with some spirited street driving here and there.. what would be a good affordable piston to replace them with?
I have reputable machine shop 30 mins from here that can do the work. How would I go about getting this done? If there’s anything I can do to save a few bucks and I’m able to do, I’ll do it. Disassemble everything and bring the parts and have them do the work/reassemble?
With new slugs I’m assuming a balancing job is required?
After taking some measurements it looks the J heads has 2.02 intake valves. Measured the cam lobes and it looks like it’s a .484 lift on the intake side. I noticed the valve springs have dampers and I’ve been told by a friend that was stock?
Anyhow, unfortunate but I’m still in good spirits to have this in my 68 Dart once it’s back to 100% I know enough to know that it’s beyond my current skill set. If it was something thrown together for a demo derby car.. sure I’ll throw it together to last a night or two lol. Some have said it might just need a hone.. that might be possible but I can’t make that call as I don’t have enough experience in such matters. There’s cross hatching in the bores still so it hasn’t had a ton of miles since the work was originally done..
This is the worst one so far.
Couple of shots of the head gasket on the head pulled.
At this point I just hope I can get back on track for install once this repair has been done.. I still have the other cylinder head to take off to inspect the cylinders on that side. To me it would more of a sure thing just go another .010 on it. I’m guessing that may something we won’t know for sure until it’s been opened up? Had it been a stock bore, I wouldn’t be as concerned since I’d have more left on the bone to cut but I digress.. hopefully this didn’t come off as scatterbrained. I’m sure I could do the reassembly myself with help from a friend. I just have zero hands on with this stuff (internal engine) and I’d rather not use this as the test run since it’s a sizable amount of money in all this.
Currently it has what looks like .030 Silv o lite pistons that are 68-71 style and with 4 reliefs. I have some photos of the bores taken with a bore scope and one of the heads was taken off..
My questions are:
Would going another .010 remedy this?
This will be a cruiser 90% of the time with some spirited street driving here and there.. what would be a good affordable piston to replace them with?
I have reputable machine shop 30 mins from here that can do the work. How would I go about getting this done? If there’s anything I can do to save a few bucks and I’m able to do, I’ll do it. Disassemble everything and bring the parts and have them do the work/reassemble?
With new slugs I’m assuming a balancing job is required?
After taking some measurements it looks the J heads has 2.02 intake valves. Measured the cam lobes and it looks like it’s a .484 lift on the intake side. I noticed the valve springs have dampers and I’ve been told by a friend that was stock?
Anyhow, unfortunate but I’m still in good spirits to have this in my 68 Dart once it’s back to 100% I know enough to know that it’s beyond my current skill set. If it was something thrown together for a demo derby car.. sure I’ll throw it together to last a night or two lol. Some have said it might just need a hone.. that might be possible but I can’t make that call as I don’t have enough experience in such matters. There’s cross hatching in the bores still so it hasn’t had a ton of miles since the work was originally done..
This is the worst one so far.
Couple of shots of the head gasket on the head pulled.
At this point I just hope I can get back on track for install once this repair has been done.. I still have the other cylinder head to take off to inspect the cylinders on that side. To me it would more of a sure thing just go another .010 on it. I’m guessing that may something we won’t know for sure until it’s been opened up? Had it been a stock bore, I wouldn’t be as concerned since I’d have more left on the bone to cut but I digress.. hopefully this didn’t come off as scatterbrained. I’m sure I could do the reassembly myself with help from a friend. I just have zero hands on with this stuff (internal engine) and I’d rather not use this as the test run since it’s a sizable amount of money in all this.
