318 Threw a Con Rod. Now What?

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Benfica73

Benfica73

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Sault Ste. Marie, Ontario
My 318 is dead. I have a later 904 with a lock up torque convertor in the dart and a 7.25 with 2.76 gears as I usually run the highway. There's a couple 318 and 360 engines for sale in my area. I have a nice set of rebuilt and ported 302 heads sitting on my shelf along with a 340 purple cam and lifters, performer intake and eddy 600 carb. I'd like to keep this trans and plan on swapping in my 8.75 rear with 2.76 gears.
My question is, if I went with a 360, would I need a 360 torque convertor to balance it, or should I just get a 318 and build it with the parts I got? I also have sealed power flat top pistons for a 318.
What would you do?
 
A 360LA either must have a 360 weighted converter or you can use a BM weighted flex plate
 
Yes. The 360s I'm finding seem to be mid to late 70s engines from rv's. Thanks for those links. Would you suggest installing my heads cam and carb in a 360 of this vintage?
 
I would build another engine.
 
The problem is, you have the 302 heads. They are pretty much 318 only. Though they will work on a 360, their ports and valves are small and not very supportive of a 360. I would sell them along with that performer intake. Buy a 360.....or better yet, a 5.9 Magnum and go with that.
 
Benfica73 said:
A BM weighted flex plate? Where can I find one of those?
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I had a 318 flexplate balanced at a machine shop. Cost 45 bucks. That was about 13 years ago. I'm still using it today behind a 360.

By the way, don't know what happened to the 318's rod, but that is most unusual. Seen stock bottom ends from the factory spin some high rpm's without issue... just saying
 
318willrun said:
I had a 318 flexplate balanced at a machine shop. Cost 45 bucks. That was about 13 years ago. I'm still using it today behind a 360.
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Bein's as how 360 weights are nowwhere near anyplace you can mount them on an OEM flexplate, I'd like to see how that was done
 
67Dart273 said:
Bein's as how 360 weights are nowwhere near anyplace you can mount them on an OEM flexplate, I'd like to see how that was done
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Same here. Anyway, find whatever you can afford and throw it in there. Only thing you will need is a torque converter for a 360 or like someone else said a weighted flexplate so the engine will stay balanced. Magnums balance differently than the LA. If it was just a daily driver car I would just leave the new engine just the way it is and drive it. Of course new gaskets first because it's easy to do with it out of the car. Slap on the four barrel and the 600 eddy if you want some more oomph. What intake and carb is on the thrown rod 318?
 
I had a 318 rod that did not play nice.

9L9YE4.jpg
 
Hey alpha, the intake and carb were on the 318. I was gonna install the heads and cam before she went boom...so the heads are off and #6 piston stays down in the cylinder while the rest move when I spin the crank. So the engine will come out completely over the next few days. I'll post pics when I strip it right down.
 
Maybe I jumped the gun by saying it was the connecting rod as I can't see exactly yet as the block is still in the car. But what else could it be, piston pin? I found quite a bit of material in the oil that I suspect was from a bearing.
 
Benfica73 said:
Maybe I jumped the gun by saying it was the connecting rod as I can't see exactly yet as the block is still in the car. But what else could it be, piston pin? I found quite a bit of material in the oil that I suspect was from a bearing.
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You never know for sure until you dig in and tear it down. Look at all pieces closely to see if you can spot anything that could have caused it...
 
67Dart273 said:
Bein's as how 360 weights are nowwhere near anyplace you can mount them on an OEM flexplate, I'd like to see how that was done
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lol.... I would take a pix, but it's on the car. I've had it done twice. 1st one went with a Dart I sold. The 2nd one is on the car now, and I had it also on the 360 that I put in a truck. They weld in a metal plate between one of the "arches" between the bolt holes. Then they drill to subtract the metal to get the perfect balance.
 
318willrun said:
lol.... I would take a pix, but it's on the car. I've had it done twice. 1st one went with a Dart I sold. The 2nd one is on the car now, and I had it also on the 360 that I put in a truck. They weld in a metal plate between one of the "arches" between the bolt holes. Then they drill to subtract the metal to get the perfect balance.
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IIRC, there are instructions on what angle to place such weights, how much, and how far out from center. But getting the B&M plate is easy.
 
Throwed rod means different things to different people. I know some people who would say they had a throwed rod if the engine started smokin. So, an inspection is best.
 
any thrown rods I ever seen were sb chives and the end result was a big hole in either the block or oil pan . lol
 
Well the performer has small runners for a 318, you can use one on a 360 and they work alright for a daily driver. I had a stock 360 with a performer and an eddy 600. It ran absolutely great It pulled down high teens for mileage in a 3/4 ton crew cab dodge. I was surprised. The engine wasn't beefy by any means but it would pull well all the way to 6000rpm. For a performance build however, I would use something larger like an Edelbrock RPM. Since I'm assuming your using it in a daily driver you don't really need a bigger manifold. I guess it all depends now on what you can pick up cheapest and in the best shape. If you find a 318 then toss in your cam and heads. If it's a 360 you can still use that cam but the heads I wouldn't put on the 360 unless of course the 360 heads were absolute crap and needed new guides and machinework. The 302 heads will bolt on the 360, but the runners and valves won't be big enough to support much high RPM. It will probably die out at 4500rpm but if that's what you've got then do whatever works. It will have a nice throttle response and some nice low torque for those 2.76 gears. I'm assuming the cam is small? What are the specs on it?
 
jimjimjimmy said:
any thrown rods I ever seen were sb chives and the end result was a big hole in either the block or oil pan . lol
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Post #13 a mopar I had, it happens to all makes.
It made a nice hole in the block and pan.
SOB would still start up and run the next day, after driving it 15 miles home the night before.
 
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