Stroking a 318 engine

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OwdKasd

OwdKasd

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Can someone clarify what is involved with Stroking a 318. Sort of a summary of what's involved. Thanks!! Using a 396 as an example would be great.
 
I have an Eagle cast crank, stock floater rods, and ROSS pistons, I had KB pistons, but they don't like WOT throttle for a few minutes at a time, but for you, you would be fine. had to cut a little on the windage tray for the 4" crank, but that's it.
 
dodgetkboy78 said:
I have an Eagle cast crank, stock floater rods, and ROSS pistons, I had KB pistons, but they don't like WOT throttle for a few minutes at a time, but for you, you would be fine. had to cut a little on the windage tray for the 4" crank, but that's it.
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So is it Basically a full rebuild with Shorter Rods & Specially cut Crank?? I know I should know this stuff but I really only ever did stock rebuilds back in the Day.
 
OwdKasd said:
So is it Basically a full rebuild with Shorter Rods & Specially cut Crank?? I know I should know this stuff but I really only ever did stock rebuilds back in the Day.
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nope... either offset grind a stock crank or buy a new/used stroker crank...

then use longer rods to help rod angularity and short skirt pistons...
 
805moparkid said:
nope... either offset grind a stock crank or buy a new/used stroker crank...

then use longer rods to help rod angularity and short skirt pistons...
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Okay, I'm starting to understand. Would I need new Cam/Lifters, Springs, Push Rods. I want to do it right but try to keep the cost down. I am also considering resale value. Thanks fr the info!
 
OwdKasd said:
Okay, I'm starting to understand. Would I need new Cam/Lifters, Springs, Push Rods. I want to do it right but try to keep the cost down. I am also considering resale value. Thanks fr the info!
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to make the most of it... yes... needed... no... you wont be changing deck height on the block or heads but a couple thou for a clean up... so pushrods would be a no... if you want more cam you may need more spring and retainers to match...

a loose rule is adding 50 cubes negates 10* or duration in a cam... so an already stock cam will now be smaller... effectively...

as long as you dont have valve to piston issues (which the new pistons will already have reliefs) you'll be good as long as you keep static, SCR, and running compression, DCR, where they need to be...
 
805moparkid said:
to make the most of it... yes... needed... no... you wont be changing deck height on the block or heads but a couple thou for a clean up... so pushrods would be a no... if you want more cam you may need more spring and retainers to match...

a loose rule is adding 50 cubes negates 10* or duration in a cam... so an already stock cam will now be smaller... effectively...

as long as you dont have valve to piston issues (which the new pistons will already have reliefs) you'll be good as long as you keep static, SCR, and running compression, DCR, where they need to be...
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Got it, Thanks. My old Drummer actually owns a machine shop so I may get him to help me do it.
 
First thing have to do is decide which heads you want to run, basically open or closed chamber so you know what pistons get flat top or dish to get the right compression and port size and cfm for the HP and powerband you want. Some of the choices are open chamber LA 340-360 stock with some porting or eddy LA or closed chamber stock magnum's with some porting, EQ, RHS, Magnum Eddy's and W series heads etc...
 
Stroking a 318 is the same as stroking a 340 except the 318 has slightly smaller bore. Other than that they are the same.

If you are talking about a 4" crank then stock length rods are used with shorter pistons. If you use stock rods you will have to notch the block. If you go with Scat I-beam rods they are smaller and no block notching is needed. A 4" crank with Scat I-beams and the correct pistons will just drop right in with no block mods needed.
 
318s are great engines but if you are looking for a strong runner on a very tight budget locating a 360 and freshening that up with a good cam and good pistons would be your cheapest route.
 
I meant longer an d typed shorter....... i fogot about nothing my cylinder bores, it was no biggie. Shorter rods just takes away from the beauty of a MOPAR engine.....

Use stock length rods!
 
dodgetkboy78 said:
Wait, did someone say stroke it and use longer rods?

How in the hell is that going to compensate anything?
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pretty simple..compression height of the piston is changed to allow for the additional stroke with stock length rods...just math...
 
Biggest issues with adding stroke is the rest of the stuff that "should" go along with it. It doesnt have to, but to me, if you're spending the coin to get the higher output, then spend to get it. It's to the point now that the only real issue is the pistons. I won;t run hypers, and IIRC forged are considered semi-custom and more money than the typical 408/416 stuff. Otherwise it's all pretty much the same. But, a 360 built for performance with a mild cam and cheaper pistons will give you 80% of what a 4" stroked 396 will, for about 1/2 the money. So if resale and cheap are primary, build a carbureted Magnum 360for it.
 
Building a budget stroker is like building a budget early Hemi. It ain't gonna happen. If you wanna do an engine on a budget, I would stick with a stock bore and stroke one, OR plan on a longer build time.
 
Stroker is right, my pistons were 90 each.

I went with stock floater 318 rods, because they are the lightest/strongest Mopar made, IMO.

I think a 360 will make the power the 390 will, but it will not be *POWER* likethe 390. Hell, my 390 is a small port motor, I'll post a vid one day of a dry pavement take off with a dually pickup with a stock converter......... And all will be clear, LOL.

I agree, if you stroke, go all the way, no expense spared, if it's not in the budget, go 318 or 360.
 
StrokerScamp said:
Building a budget stroker is like building a budget early Hemi. It ain't gonna happen. If you wanna do an engine on a budget, I would stick with a stock bore and stroke one, OR plan on a longer build time.
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Point well taken! I've rebuilt many engines but never got too far away from stock so forgive my ignorance. It's not that I'm embarrassed by the 318 but I'd love to have something special under the hood. :glasses7:
 
Ignorance....hell, me too. LOL But I just know all too well from past experiences that it is REAL easy to get in so deep you lose motivation because it's taking such a toll on the budget. A lot of people think strokers are a bolt together deal, but they're not. There's lots of little things that can add up quick.
 
StrokerScamp said:
Ignorance....hell, me too. LOL But I just know all too well from past experiences that it is REAL easy to get in so deep you lose motivation because it's taking such a toll on the budget. A lot of people think strokers are a bolt together deal, but they're not. There's lots of little things that can add up quick.
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I can see exactly what you're saying.
 
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