318 Stroker Build

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jakuzzie

jakuzzie

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Hi!

I want to build a 318 Stroker with at least 300hp at the wheels.
It should be idle smooth und depandable (dailydriver quality).

Things that are already in:

Edelbrock 600cfm Performer
Edelbrock 318/360 Intake
MSD Ignition E Curve
Light weight Connecting Rods
KB DomeTop Pistons +060
Hughes torque converter 2500 stall

The other stuff is stock like:
7 1/4 Rear end
A904
Heads
Cam
Valvetrain
Oilpump
...

What do I need? What do I have to change?

Thanks!
 
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what cylinder heads do you have?

dont think the 7 1/4 rear will last
 
yep- what heads- you can't pick pistons or cam till you sorta pick them all together - and exhaust
have you read the 318 porting thread at the top of the forum page?
late stock heads? magnum or magnum style heads? Enginquest Iron heads etc 318 heads ot 360 LA heads like late 318 4bbl?
start with a stock converter or the HP/340 converter and get a baseline -- internal or external balance
what do you mean lightweight connecting rods all the stock rods weigh about the same big question what rod bolts and are you going to have the rods professionally resized when you put the new bolts in? pressed pins or floating pins? if floating bronze bushings or steel on steel
headers or stock duals? (can't pick cam til you pick together)
 
probably using scat 4340 I beams with the 4 inch crank...

KB piston only come in two variety ....flat top or dished for the 390 stroker...
 
if using stock heads you had better cc them piece of plastic and a syringe get's close enough
In fact you need to cc any head- they can be way off of what is advertised
and you can open them up 5 cc if you have to
 
Would it be possible to run it with 4” crank, stock la heads and dometop pistons? Because i already run them in my 318 (stock crank).
 
Yes, if your pistons are set up for your stroke. Your stroker pistons will be shorter to handle the increased stroke of the 4.00 crank so pistons are going to be "stroker pistons". Your stock 318 cam will not get you 300 with only 80 more cubes. Look at the stock Mopar 400 for CID comparison, 190 HP! Then you can look at the 440 with a 3.75 stroke, 250 HP. But the bores were so much bigger. Change that cam! Id change that convertor too.
 
stroker pistons for a 4 inch crank will have a compression height around 1.466 inches ...that is the distance from the center of the wrist pin to the top of the piston...

if the pistons were purchased for a 318 with a standard 3.31 crank...they will not work.
 
jakuzzie said:
Hi!

I want to build a 318 Stroker with at least 300hp at the wheels.
It should be idle smooth und depandable (dailydriver quality).
Click to expand...
You don’t need a stroker kit to make 300hp. You have just about all you need right now.

Things that are already in:

Edelbrock 600cfm Performer
Edelbrock 318/360 Intake
MSD Ignition E Curve
Light weight Connecting Rods
KB DomeTop Pistons +060
Hughes torque converter 2500 stall
Click to expand...
The domed piston you have now will not work with a different crank

The other stuff is stock like:
7 1/4 Rear end, A904, Heads, Cam, Valvetrain, Oilpump. What do I need? What do I have to change?
Click to expand...
The rear, OE heads With the valve train need to be thrown out.
A new oil pump and cam only.
The 904 will need a total rebuild to handle the torque from a stroker.


I see you have no idea what this will take. I suggest a book first instead of a total tutoring here which will be long and lengthy and frustrating to the members.
Here you will learn but a school this is not.

Books to purchase are how to rebuild a small block Mopar and how to hot rod a small block Chrysler.
These are the best starting books bar none.
 
normal stroke is 3.31, your adding .69 inches so your piston is going to travel .345 inches higher in the bore. youll need pistons that are ~.345 shorter in compression height. Here are 2 pistons, one is stock, one is a stroker, see the difference? a stock piston on a stroked crank will hit the head. On a ultra low compression 318, its almost possible to run a .060 head gasket and make it work, but it would be close and of course you'd probably pop the top compression ring.
images?q=tbn:ANd9GcTgHf4VMJPSN1baTO0RpSjKnpL2Fv_GrGrK2OGUjimuDn5k_ok_Vg.jpg
 
1st off if you already have those pistons scrap the Stroker idea and run your stock 3.31 crank. If you dead set on running a 4 inch stroke you need some icons like these
ICON Premium Forged Pistons IC846-060
Like said before you do not need a stroker to make 300hp. A stock bottom end 318 with worked heads will make over 300 easy.
What heads do you have? Or plan to get?
What kb pistons do you have kb167 or 399?
 
Thanks for the answers!
If I don't go with the stroker and keep my crank, what cam suggest you? Don't want it to idle rough and shaking.
What heads do you prefer?

I got stock la318 open heads and 399 KB pistons.
 
Depends on what the OP really wants... Torque is what moves a car, so maybe he is after that wall of torque that only a stroker will get him.
Yes he can wind that little teener out and he will have his 300HP with a decent cam, but with a stroker he just stomps on it and has instant movement.
Of course a stroker with stock heads and small cam will fall on its face after 4500 rpm, and sure it will break that 7 1/4 rearend.

For illustration ONLY I have a attached dyno curves of a 318 (the junkyard jewel) and an average 408 with a bit of head and cam. The horsepower
level is higher (since I didn't have lesser engine curves :) ), but you see the difference?

Again, not advocating anybody... maybe it is torque the OP wants.

dynosheet.jpg
 
Lately i put a 8.75 rearend in so i think it will last ;)
The thing is, I just rebuilt that engine a year ago so I don't want to throw that new stuf away..
 
jakuzzie said:
Thanks for the answers!
If I don't go with the stroker and keep my crank, what cam suggest you? Don't want it to idle rough and shaking.
What heads do you prefer?

I got stock la318 open heads and 399 KB pistons.
Click to expand...
Lunati 10200702
 
Yes, then as many have said... keep your pistons and upgrade the rest (cam, heads).
When you search the forum I am sure you will find many builds that should suit you...
 
Thanks guys! You are the best. I let you know if there is a progress on the build.

Btw I already got 3.55 gears ;)
 
you will have to spin a 318 pretty high to get 300 hp at the rear wheels and in a small cube engine you'll need more cam...there goes your idle and lo speed power.
As suggested try to build for more lo rpm torque.Maybe a comp XE256 for the street in a 318.
if you build the stroker you get more torque quite easy but the bigger cubes will need more head and cam for hp. and may be expensive.
Best to get the mopar build books Rumble suggested!
 
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