318/360 Crank/347 running on Dyno

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DusterKrazy said:
What pistons were used and about how much did it cost to have the crank cut? This sounds like something I'd like to try. I have a few 318's.
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He posted the piston part number somewhere in the thread-think it was silvolite 1266....and he milled them down .060"

But i don't think he charged himself the money for the machining on the crank ;)

I am curious how much that would amount to for someone who brought in a 360 crank and wanted it done.
 
Kirk, there's usually a set or two kicking around in the classifieds and much debate about whether or not the cracks will ever amount to much, other than an annoyance. That being said, you could buy a set of EQ magnums with the LA bolt pattern new for like $650 a set I think off eBay...or just buy the bare castings and have your machinist put them together

Honestly though, find a running engine out of the yard that has good compression and buy them
 
txstang84 said:
He posted the piston part number somewhere in the thread-think it was silvolite 1266....and he milled them down .060"

But i don't think he charged himself the money for the machining on the crank ;)

I am curious how much that would amount to for someone who brought in a 360 crank and wanted it done.
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Ok, thanks.

The machining cost maybe expensive but it does seem like a nice street engine.
 
txstang84 said:
Kirk, there's usually a set or two kicking around in the classifieds and much debate about whether or not the cracks will ever amount to much, other than an annoyance. That being said, you could buy a set of EQ magnums with the LA bolt pattern new for like $650 a set I think off eBay...or just buy the bare castings and have your machinist put them together

Honestly though, find a running engine out of the yard that has good compression and buy them
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Thanks....I'll pass this on. His 318 is running strong now but this build just makes sense. 400 HP out of a 'teen seems unreal. He's already got the headers and Eddy manifold, so if he dropped on the Magnum heads and a cam he would be in pretty good shape!
 
DusterKrazy said:
Late '91 to mid '02 5.2 and 5.9 (or whenever they dropped the 5.2/5.9 Magnum V8's. Dodge Dakota's, Ram's and full size vans.

You can usually find them for $100 or less here. Very hard to find a set not cracked between the valves in the combustion chamber.
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Thanks. I'll pass this on so he can be on the lookout for a set! I'll also tip him about the cracks.
 
DusterKrazy said:
Ok, thanks.

The machining cost maybe expensive but it does seem like a nice street engine.
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It wouldn't be that expensive to machine the pistons/crank. I would do this for about $700 and that would include balancing the crank. It would be up to the end user whether or not it made sense. I think a lot of people relegated to a 318 block could enjoy a medium displacement engine like this as long as they used it for what is intended---economical performance. Make no mistake this is not a race engine--This is a stand in substitute for a 360. J.Rob
 
txstang84 said:
He posted the piston part number somewhere in the thread-think it was silvolite 1266....and he milled them down .060"

But i don't think he charged himself the money for the machining on the crank ;)

I am curious how much that would amount to for someone who brought in a 360 crank and wanted it done.
Click to expand...

Federal Mogul also offers the right piston under part # 285np I believe. I would use 285cnp next time just for the coated skirts. J.Rob
 
I think that 360 Offy is a good manifold for torque on a 318.

Like you said, it's choking, though. I think you could even benefit from an LD4B or a Weiand Stealth without having to port match on the 302's. I'd be curious to see what that did. The 360 manifold is a good idea, but it's just a little on the low volume side, like the SP2P. Sort of like a step between the SP and LD series from Edelbrock.

The 302 heads, IMO, are better suited on a 318/ 340 crank 318. You are right on target with the Magnum heads and intake combo bumping it up.

One of the things that the 347/ 318:360 crank engine isn't, is a 318. It has closer needs to a 340 in head CFM, but it will not behave like a 340 in RPM.
 
RAMM said:
Federal Mogul also offers the right piston under part # 285np I believe. I would use 285cnp next time just for the coated skirts. J.Rob
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So, it's the 285np with sixty thousandths removed off the top? Where can you get them??

Do you just turn the 360 crank down to 318 main size??
 
First time I've seen this combo talked about. I know size matters but I like the idea of something outside the box. Not everybody needs 550 HP and 500 TQ.
 
DusterKrazy said:
So, it's the 285np with sixty thousandths removed off the top? Where can you get them??

Do you just turn the 360 crank down to 318 main size??
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Yes it is and any machine shop or Summit or Jegs can get them. You turn the crank down but keep in mind the rear seal also has to be turned down to 318 diameter. J.Rob
 
The 285NP is a stock replacement 318 piston with the stock 1.720 compression height.
 
Ramm...

Do you have the Compression distance of this piston on hand? I know you shaved .060" from it, but I'd like to compare it to a set that I have.

Also, did you do anything heavier to the ring gap, like the KB sets, from shaving?

I have a set of low comp .030 over flat tops that I'd be very tempted to do this on a #'s matching 318 '72 Dart.

I've got a 360 crank that may or may not be able to take another .010" cut, so if I already have the parts for this build, I'd be very tempted to do this.

I have a couple of 360 engines, but all I'm trying to do with the '72 Swinger is make it a good street car that gets some spine cracking on the pedal.

I could go with the 360, but something about the car's A/C system and all of the components left on it, intact, with the #'s 318 block, turned into a rubber killer for the street sounds extremely appealing.

the 318 that I have in the Scamp is great as is for a driver, but I want more out of the Dart without taking anything out of it's factory charm at a glance under the hood, so this may be what I'm looking for.
 
DaveBonds said:
Ramm...

Do you have the Compression distance of this piston on hand? I know you shaved .060" from it, but I'd like to compare it to a set that I have.

Also, did you do anything heavier to the ring gap, like the KB sets, from shaving?

I have a set of low comp .030 over flat tops that I'd be very tempted to do this on a #'s matching 318 '72 Dart.

I've got a 360 crank that may or may not be able to take another .010" cut, so if I already have the parts for this build, I'd be very tempted to do this.

I have a couple of 360 engines, but all I'm trying to do with the '72 Swinger is make it a good street car that gets some spine cracking on the pedal.

I could go with the 360, but something about the car's A/C system and all of the components left on it, intact, with the #'s 318 block, turned into a rubber killer for the street sounds extremely appealing.

the 318 that I have in the Scamp is great as is for a driver, but I want more out of the Dart without taking anything out of it's factory charm at a glance under the hood, so this may be what I'm looking for.
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The 285np comes as a 1.720 cht. I actually cut these to 1.658" cht. This engine has no problem on 87 octane. I did nothing different to the ring gaps-in fact I just put a non file fit standard set of moly faced rings from Hastings in. Top ring gap was .018" nothing fancy. I really like the simplicity of this engine. J.Rob
 
Ramm - I ran a 318/349 using cut down 1.72 CH slugs a few years ago....and ran into p-v issues, even with .100th off the top of the slugs.

Did you measure your p-v clearance?

Reason I ask is I suspect a lot of my issue was my shaved teen heads that I used......
 
Rat Patrol said:
Ramm - I ran a 318/349 using cut down 1.72 CH slugs a few years ago....and ran into p-v issues, even with .100th off the top of the slugs.

Did you measure your p-v clearance?

Reason I ask is I suspect a lot of my issue was my shaved teen heads that I used......
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I measured P-V clearance and it was large enough that I wasn't concerned seeing as how the valve was only lifting .432" with the stock rockers. Also keep in mind that I only removed .010" from the heads and this cam with a 112 LSA only has an overlap period of 37.5 degrees advertised. It is only 7.5 degrees at .050". Again I did not want to get into flycutting the pistons and this engine and cam were planned for before the chips started flying.

You're cut heads may have been the culprit, but who's to say without any data?J.Rob
 
I have one of these builds on the back burner myself. Its almost the same thing. Maybe some day I will get it done. I did cut valve pockets in the top for a bit more lift.

Nice street engine, loads of torque.
 
MRL Performance said:
I have one of these builds on the back burner myself. Its almost the same thing. Maybe some day I will get it done. I did cut valve pockets in the top for a bit more lift.

Nice street engine, loads of torque.
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Especially if you have the 360 heads and the crank and a 318 block fully cleaned and prepped.
 
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