318 build up suggestions

-
R

Relax360

Well-Known Member
Joined
Jan 6, 2010
Messages
553
Reaction score
61
Location
Oceanside CA
I will be building up a 67 318 block I have for my 67 Barracuda. The goal is to have a good street cruiser. I was thinking of a build like this.

67 Block and forged crank
K1 rods
RHS Heads with 1.92 stainless valves
Air Gap Manifold
Comp Cams 218/224 duration .462/.470 life with 1.5 rockers
KB Pistons or a forged pistons??

Thoughts on the setup? The goal is good street manners It will be attached to a 4 spd to a SG rear end with 3.55 gears

any feed back would be appreciated.

Brad
 
I've built a couple of 318 engines. IMO, the K1 rods are not needed. The OE rods are probably to expensive to rebuild and resize, so, a more inexpensive rod from, like, Eagle would do just great.

Also, a Hypuer-U piston is just fine for high performance useage. Pay attention to ring gap. I think the zero deck or close to it KB167 slugs would be a great fit.

You could also go one step up in cam no sweat. Being you have a 4spd. and 3.55's. I have used a Crane cam with very similar specs and it is a great driver cam that can deliver a respectable power level even from un ported dead smog heads and stock small valves.

Choose the cam on it's power band/operating RPM.
 
will eagle be a good brand to get rods from? I have heard of their quality issues with their crankshafts.

comp cams make a Magnum series Factory cam that specs 222/226 duration with a .496/.496 lift using 1.6 rockers this looks to be a good size cam power band is nice and big 1800-5800
 
Relax360 said:
will eagle be a good brand to get rods from? I have heard of their quality issues with their crankshafts.

comp cams make a Magnum series Factory cam that specs 222/226 duration with a .496/.496 lift using 1.6 rockers this looks to be a good size cam power band is nice and big 1800-5800
Click to expand...

Scat I beam rods are perfect and dont cost a lot at all.
 
I used the name in ref. only.

When it comes to a cam, I select the cam to be used first based on;

RPM band that I need/will be useing/driving in.

Lift. What the heads are capable of.
 
don't down play your stock 920 heads. I have a pair on a 318 that have produced 345 hp on a 318.
 
Another question i have is about Compression ratio. With RHS Iron heads and a zero deck what static CR number should I shoot for. I was thinking around 9.5

did you port your 920 heads?
 
9.5-1 is good for the small cammed engine. You'll need to know where the piston sits and it's valve relief cc's along with head cc, you'll also need to know what the head gasket diamentions are. How thick and it's bore size.
 
well I just ran over to storage to check what heads I have. the heads on the 318 right now end in 675 so I have 68 and later 318 heads on it at present.

the block date code is 8/17/66 so I am guessing it was one of the first batches of LA 318s made
 
Here's the combo from my '46 Dodge pu. Real strong and throaty sounding..

*Weiand single plane intake with a moroso 1 inch spacer, Holley 600 carb,
Mopar 450/455 ('68 340 4 speed cam), shaved 360 heads (go .040 a side and shave the intake face as well to spec), headers, cheap $30 double roller timing set from advance auto.
 
I'm using the eagle 340 4.00 stroke crank a set of I beam rods and a keith black forged piston with RHS heads and a comp solid flat tappet .535 int 228 .538 ext 226 on a 112 centerline with a 110 lobe seperation don't have it together yet But I'm thinking 475 at the tires with a 4 speed and 3.73 gears in a 1970 318 block
 
johnparts said:
I'm using the eagle 340 4.00 stroke crank a set of I beam rods and a keith black forged piston with RHS heads and a comp solid flat tappet .535 int 228 .538 ext 226 on a 112 centerline with a 110 lobe seperation don't have it together yet But I'm thinking 475 at the tires with a 4 speed and 3.73 gears in a 1970 318 block
Click to expand...

I'm just curious why not use a 340 block??..475 at the tires,i think your going to be very disappointed..
 
Cam in your original setup is too small IMO. I am going to build a similar setup using my XE284H. I say at least go with a XE274H w/ 1.6 rocker arms if your heads can handle it. Remeber you are going to need quite a bit of flow from the smaller displacement of the 318 to keep the velocity up in the big intake runners of that manifold.
I am going to go with forged pistons, IC844 which is the forged version of the KB167, maybe I will never need them but I would rather spend the extra money now. I am sure the KBs are very strong though.
As far as rods go I think a good OE replacement would be a good choice as mentioned, unless it is more cost effective to just reuse the orginals, I think they should be plenty strong, remember that the rod to stroke ratio of this engine is very high so the rods take alittle less abuse.
 
Relax360 said:
I will be building up a 67 318 block I have for my 67 Barracuda. The goal is to have a good street cruiser. I was thinking of a build like this.

67 Block and forged crank
Click to expand...

Good choice to keep. Later 318's had cast cranks.

K1 rods
Click to expand...
I'd go with Scat I beams like someone else mentioned. Almost cheap as Eagle rods and better reputation for quality.

RHS Heads with 1.92 stainless valves
Click to expand...
On a 318, larger port size may not be the best for low to mid RPM. If you want to spend money on heads look into a set of 302 castings and upgrade the valve to nice flat head 1.88 intake and 1.60 exhaust with a bowl blend

Air Gap Manifold
Click to expand...
The Edelbrock air gap manifold I used to own had a bad port mismatch on one intake pair - too big to just "port match" away. If you run the 302 heads look into a Weiand Action Plus unless you need a single plane intake for some reason.

Comp Cams 218/224 duration .462/.470 life with 1.5 rockers
Click to expand...
Should be fine for a street engine. Be sure to put a ZDDP additive in your oil.

KB Pistons or a forged pistons??
Click to expand...
As others have mentioned, the KB167's are good. KB sells both hypers and forged, if you call them they'll tell you the hypers are better unless you're racing hard or running heavy nitrous. With the 302 heads, the KB167's will give you around 10:1 compression.

Thoughts on the setup? The goal is good street manners It will be attached to a 4 spd to a SG rear end with 3.55 gears

any feed back would be appreciated.

Brad
Click to expand...
Have fun with it.

Cheers, Ken
 
What are you looking for HP-wise?

The RHS heads are great, but maybe not necessary depending on what you're looking for. If you're wanting 300-350 hp, you could probably just go 1.88/1.60" on the valves and have your stock heads cleaned up (casting marks removed etc, no heavy porting needed). Or go with a set of stock magnum heads, they flow well enough stock to put you into those numbers.

If you're looking for more, keep the RHS heads, but I'd definitely go with a bigger cam. I know a lot of folks that run Lunati 60403's on the street, they're advertised Duration 268/276 (226/234 @ 050"), Lift .494/.513. With the stock heads even a 60402, with advertised Duration 262/268 (220/226 @ 050), Lift .475/.494 would be a better choice, and that's still a very safe choice for a street engine. I wouldn't even run the 60402 with the RHS's, just seems like a waste of potential.

Hyper or forged is another one for the "what do you want to do with this engine" category. If you're looking for a street engine and 300-350 hp, the hyper's will be great. Just make sure your machinist knows about the ring gap being different than regular cast pistons. If you want 400+ hp or are looking to do some racing or later upgrades then I'd just go forged now. But if all you want is a fun engine with "good street manners" the hypers will be fine.

And if you do stay with small port heads (stockers, 302's) you'll probably want to find a small port intake manifold, which the RPM air gap is not.
 
Have any of you run RHS heads on a 318? Port size is only half of the equation if the port velocity is still good port size won't hurt that much. Not trying to disagree just looking for real world feed back on a setup.
 
And if you do stay with small port heads (stockers, 302's) you'll probably want to find a small port intake manifold, which the RPM air gap is not.
Click to expand...

The stockers, AKA 302 or others, will open up to a RPM window and could be a good head for the project after porting. Depending on if it can be done cheap enuff. It's kind of hard to beat the RHS price and performance combo.
 
stroked 340 said:
I'm just curious why not use a 340 block??..475 at the tires,i think your going to be very disappointed..
Click to expand...
Cause I can't afford a 340 Block and I'm building a cruiser not a race car. I've had plenty of 800 HP cars I want something that will have a bit of grunt when I want to play but will be a mild tempered ride otherwise.
 
You must log in or register to reply here.
-

Back
Top