318 Engine Build help

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64physhy

64physhy

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I decided to start just one thread on my 318 build. I have one about cams, but I have questions about the whole thing. This is the first total rebuild I've done, so i need help. First off, here's what I have decided so far:
-Square deck to zero deck height, bored .040 over (unless already bored, then bigger)
-Stock crank (maybe forged crank from a 237 if I find one cheap)
-Stock '74 connecting rods
-KB-167 Flat top pistons
-Magnum heads (stock w/3 angle job and resurfaced .010)
-.043" Head gasket-should get 9.97:1 (.050 will get 9.79:1)
-MP# P5007477 pushrods (for LA blockswith magnum heads)
-Comp Cams XE274H (230/[email protected], and .521/.524 with 1.6 Magnum rockers
-Comp Cams 822 hydraulic lifters
-Intake ???
-Carb ???
-Ignition-MP electronic
-Headers (dougs or TTI)

I'll run a 2500 Torque Converter (Hughes). And want to put a shift kit in, but I saw somewhere that there's a better way by doing a simple mod yourself.
Questions:
What piston rings should I use? (prefer pre-fit over file-fit)
What intake? (I'm thinking air gap or m1)
Is there anything I'm missing? Does anything need to be done to the rods for the pistons?

I want it to be streetable, but be able to take it to the track from time to time. Trying for 400HP/380-390TQ

Thank you
 
You can use speed pro rings, Air-gap intake is more streetable and 650 CFM carb is enough. By dyno 2003 with this combo you can have 400 hp.

Br,
Minella
 
Thanks for the input. The aricles from Mopar Muscle and PHR both used similar combos and used Demon 750 carbs. If I can still get close to 400 HP with a 650, that's great (because I already have one). What does your desktop dyno say it would get with a Comp Cams 280H? (230*@.050 and .512 lift with the magnum 1.6 rockers)? I'm a little concerned about being too close to the limits of the springs and valve to piston clearance with the XE274H cam. Should I be?
 
Actually, PHR used an even bigger cam than the XE274H, but they did other mods to the heads for it. I don't want to start getting into a bunch of extra machining and parts.
 
A good 650 should be plenty of carb. They were enough for 347 Fords I've built with way more cylinder head and camshaft than you're using.

I have always had good luck with Quickfuel.

The Air Gap is a much better intake for your combo than the M1. You'll maybe give up a smidge of hp up top (maybe) for a ton of street-friendly torque down low.

It is highly likely that those pushrods won't work for you after you have the block decked. Especially with the nonadjustable valvetrain on the Magnum heads. I'd get it all put together, then measure and order custom length PR.

I'd clay it to be sure, but you should have a mile of p/v clearance.

Rings are worth a lot of hp. Choose wisely.

What year 318 are you starting with?

Steve
 
Starting with a '74 318. I've been leaning towards the Air Gap, low end torque is more important to me than high HP. Comp Cams 7.650" P/R are my second choice if the MP 7.625 isn't long enough. I think with the XE274H, the shorter ones will probably be enough, but with the 280H, I'll probably need the Comp Cams 7.650.
 
Is the base circle different on those two camshafts or something?

I know that's the length pushrod they used in one of those articles, but you really should measure before you buy anything. Mopar blocks seem pretty prone to variance.
 
I don't know how to measure for that. I guess I'll have to have the machine shop do it, unless it's something I can do. The base circles on both cams should be the same
 
You WILL have to file the top ring with the KB pistons. They specify a larger end gap due to the high ring placement. This is really no big deal, just make sure you set it up per KB's instructions.

As for brands, most any good moly ring set will be fine. I'm partial to Hastings, but have had good luck with numerous sets of Sealed Power/Speed Pro (both the same) rings.
 
Has anyone used the Professional Products Crosswind intake? It's supposed to be comparable to the AirGap for about $100 less.
 
The Crosswind is not an Air Gap... I don't see myself ever using another one. They work, but I found all kinds of issues.
 
I did the simulation using XE274H. But I concerned about to use stock magnum springs...I think is not a good idea. I would by a low buck spring set and keep the stock retainers and locks.

Br,

Minella
 
LXguy said:
Is the base circle different on those two camshafts or something?

I know that's the length pushrod they used in one of those articles, but you really should measure before you buy anything. Mopar blocks seem pretty prone to variance.
Click to expand...

Ok, probably a dumb question, but how do you measure that?
 
I'll look at getting better springs. I know the magnum springs are a different size (odd size). I've searched, but can't find what size (I've found it somewhere before, but can't seem to find it now). Anyone have a part number for them, or can lead me in the right direction?
As for the crosswinds intake, what kind of issues are there with it? Bad casting? Runners?
I think it already has a 650 on it (still haven't seen the car in person yet), so if that's enough, that'll save me enough to use on other things.
I picked up some Magnum valvecovers for a steal (shipping was more than they cost). Thanks for the help. I'm sure I'll have more questions, especially when I physically start the build.
Oh, any idea of what the machining will cost me?
 
I've been reconsidering my cam choice. I'm thinking maybe the Lunati 60402
that someone recommended in another thread. 262/ 268, Lift .475/ .494 (220 int./226 exh. at .50) with 1.5 rocker ratio, so .507/.527 with the 1.6 rockers in the magnum heads. Lunati says to use their 73949 springs with it (1.440 dia. seat load 120 lbs @ 1.650, open load 165 @ 1.250, bind .950, spring rate 363 lb/in). I checked the recommendation for their cams that have the same valve lift with 1.5 rockers as this one does with 1.6 rockers, and they recommended the same. Question is, will they work with Magnum heads?
To this point, I think I have most of the details ironed out other than the push rods and springs. It seems like I heard somewhere that LS1 springs are a direct fit for Magnum heads. Any one know?
 
Here's what I have so far:
Block was .030 over, bore looks good, so I'm going with that for now.
Magnum Heads 5 angle valve job
Dougs Headers
Went with a Comp Cams 284H Nostalgia Cam 239/246 @ .050, .516 lift with 1.6 arms (think it might be too much, but we'll see)
.028" Head Gaskets
Holley 650 DP
Hughes adjustable oil-through pushrods
3500 stall converter
Reverse Valve body racing trans

Still need:
Intake (Air Gap)
Chrome ignition module
8 3/4 rear 3.91 or 4.10 SG

What do you all think?
 
hey just to jump in but im by know means an expert but what is the most you can bore a 318 whithout problems?
 
Your build sounds good so far! I'm collecting parts for a 408 and and I was going to use the EQ Monster Magnums (2.02 intakes with .600 springs)from Clearwater Cylinder Heads. They were $975 shipped but the ones for the LA intake were out of stock and they really couldn't give a specific date when they'd have them ( about a month they said). Went with Edelbrock RPM's. Did you see the June 2009 Mopar Action Magnum Head shootout? Basically, stock Magnums flowed 199 intake/145 exhaust, the EQ's flowed over 240/176 with stock valves and 254/176 with 2.02's. I'd definately use the EQ's with all those other parts you have.
 
I just found them from Clearwater for $375 each with the 2.02's. With 3.91 gears and 3500 converter it sounds like you're gonna be turning some RPM's. These EQ's might be the best $$ you spend. Turn a strong car into a really strong car!
 
Your cam is not too far from the tried-and-true 284/.528 mech Mopar cam that has been popular for years (because it works). With about 10:1 comp, you should have a nice runner. Lightweight (Titanium) retainers will help with the high ratio rockers.

The 650 DP will do OK, but you will probably be more consistent (if not quicker) with a basic 3310 vac 750 Holley. Run what you've got, but try that next.
 
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