I have two 68 318 engines,one in my car and one spare.I want to build a 318 over 300 HP and under 400 HP.
I don't want to use Magnum heads.I have 360 heads now with 1.88 intakes and 1.60 exhausts.I want a step by step guide to follow.
The engine in my car made 187 HP at the rear wheels.
Can somebody help me out?
Thanks!

get a 318-390 cu in stroker kit. performer rpm intake, some 1 5/8 tube headers and a mopar 284 .528 lift cam. should be there pretty easy. make sure you have a true 9-9.5:1 compression.

google lists multiple examples.

Either online builds or links to hard copy books on how to do it.

I don't want to stroke it.

Select pistons that will give you a true, calculated 9.5 compression ratio. Run the MP.528 solid cam. Performer RPM intake and a set of cheapo headers. You will exceed 300hp even with your stock stroke 318, however it will like a decent rear gear and torque converter, I would do something like a 3000rpm converter with a 4.10 rear gear.

why not stroke it if your going to change the pistons anyway? a stroker crank is only a few $100 more and then the investment is done.

next option would be to buy a cheap turbo off ebay and bug diszuster to see when his turbo kits will be ready.

spray what you have with some nitrous

if you're reluctant to change pistons because your not rebuilding then its going to be a lot harder to get to 300hp

duplicate

I am going to change piston.Want to be zero deck.

Don't want to seem like I'm pushing it on you but the price to do a full rebuild on stock stroke and building a stroker are basically the same.

The motor in my car now is a 360 based 408 stroker. After feeling the power on tap while still having a streetable motor I will never go back to a stock stroke motor.

EDIT: Besides, no one will know it's a stroker but you

Do you want 300 HP net or gross HP at the flywheel or the 300 net at the rear wheels?
What does the current motor have on it now, IE carb and intake, exhaust, compression ratio and cam?

Stock bottom end,J heads 1.88 int. 160 exh.Performer intake,600 cfm edelbrock,340 hi po manifolds and dual exhaust.3.55 sure grip 8 3/4.Cam is a purple shaft 260/268 duration 430/450 lift

If you run flat tops at zero deck with j heads your not going to have much compression, if your going to run zero deck get a set of closed chamber edelbrock heads.

What application, tire size, gearing, and such (stall speed) so we can estimate the power band required. What octane fuel and altitude to guide us towards a maximum compression ratio?
What sort of budget? any power adders?
How much work like porting, cutting valve spring seats, and such can you do or need to farm out to a shop?
The better flowing heads you start with will make the rest easier.

I have a valiant and used to run a 318 stock heads cut down to raise compression and added a camshaft similar to yours with headers and a good convertor with 391 gears while I don't know what hp it had but would run 14.50 ets quarter mile and would run 13.20 with a 125hp shot of nos.

3.91 gears are in the works.Best 1/4 mile with 3.55 gears is 15.86 at 89 mph

He can hit his power goal without the stroker. More is better but for 300hp this is not a deal breaker.

Either a set of KB 167 pistons or other flattops with 1.81 compression height. That gets the piston to 0.012" below deck. With the Mr. Gasket 0.028 head gasket you have 0.040 squish if you ever decide to go closed chamber. That's with a deck of 9.600.

To build a decent engine you have to take care and the first step is checking your main bearing alignment. Then have the block decks squared up to the crank and to each other. That way you have everything where it's supposed to be.

Piston swept volume is 661.6 cc and to get a true 9.5:1 compression you can have no more than 77.8 cc above the piston. Your 360 heads could be as much as 73cc. You need to cut the heads to 63cc if your pistons have 5cc in the valve notches.

For a camshaft I'd ask Hughes. I'm guessing that something with intake duration in the low 220s would be the ticket.

There are a myriad of 318 buildups online. The one most appropriate for you is this one, no stroker and no Mag heads:
http://www.hotrod.com/articles/mopp-0311-318-engine-buildup-and-dyno-test/

I'm sure that there have been other 400hp 318 articles using 360 heads.

One final observation: You are leaving power and driveability on the table by your choices. It'd be much easier to make 400hp with a 390 shortblock, and it will be much stronger on the street, because the torque curve starts earlier in the rpm range.

R.

I would look closely at your fuel system to make sure the in tank sock filter and lines up to the pump are good and not plugged up
The best way I know of testing the complete fuel system is to be able to fatten the jetting up on teh carb enough to make the 1/4 MPH slow down, if it will your good If it won't, fix it

You will need to run the piston about .040 to .055 out of the hole. Don't be afraid to do it. Use 10:1 compression. Order a cam from Jim at Racer Brown FOR YOUR APPLICATION. If you have manual steering you need Hooker 5204 headers. Power steering...IDK. With a 3.90 gear you can use a single plane intake. Cam accordingly.

For a 318 I'd go Performer RPM and leave it at that. No reason to gamble on a single plane.

Shoot, the mid '70s cast iron 360 EGR 4-barrel manifold was good for something like 390 hp in the Junkyard Jewel article. It's a real high rise design. It's super heavy but then again I got mine for $15.00. It's a spreadbore design so T-Quad or Q-Jet or Street Demon are your choices.

Well, for big bucks you can run the piston out of the block, it'll definitely not be a shelf stock piston, OR, you can mill the heads 0.040 to 0.055 to get the cc down to 63 as I suggested. Take your pick. IMHO milling is more simple and direct.

R.

You should deck the block. It's already in the mill. It don't hurt to run the piston out of the hole.

As for intakes, he's going to run a 3.9 gear and a 3k converter. Pissing away power with anything else, if he gets the correct cam.

The best non magnum stock head for a 318 would be a worked over 302 casting if you can find a set that isn't cracked.

Smallest fastest burn combustion chamber on a stock head. This gets your CR up and the fast burn chamber makes it pump gas friendly.

Dulcich got 400 HP out of a 318 with a heavily ported set of 302's but porting is $$$ unless you have the tools and talent and the castings are on the fragile side even unmodified.

It's one thing if this is a let's see what we can do with a 318 project but if budget is tight the cheapest/fastest path to your goal is to put those 360 heads on a 360 short block and add bolt on parts to taste.

Kevin

I know you said no Magnums. I think you need to look at the EQ magnum heads with the available 2.02 intake valves. They are already a 62cc chamber and take the LA intakes so you can keep your Performer. With the Magnum style rockers, you can also play with ratios. In bench tests, these flowed as well or better than the Edelbrock aluminum heads.
Here is Hughes version:
http://www.hughesengines.com/Index/produ...mp;partid=24235

I have been running a set for three years now. Only issue I had was clearance for the alternator but I solved that with spacers.
Craig

I think the iron ram head would be a better starting point and gives you room to grow. I wish they were available when I built my 360.
When I did that engine I started with a set AeroHead 2.02" valve 360 heads with hardened exhaust seats, These were unported and the valve spring seats were not cut for dual springs. They also were much larger chambers than advertised, and the quench areas were about 0.010" different between the heads. I had one head milled 0.040", and the other 0.050" (was using KB-232 quench dome pistons.) Then I spend at least an 12 hours porting the heads and cutting the valve spring seats, plus enlarge the long head bolt holes for oil flow when using head studs.
I also think the stud mount adjustable rocker gear for the iron ram/magnum heads is less expensive than the adjustable shaft mount rockers. On the stock heads, you might be able to use the stamped rocker arms, but at higher lifts and valve spring pressures I have seen the pushrods blow through the pushrod cup of the rocker arms.
When building any non-stock engine, I always measure for the correct pushrod length. Don't just buy an off-the-shelf set unless you have already measured and verified they are the correct length you need. Different heads and valve job (height of valve stem), cams, lifters, block and head milling, gasket thickness, and rocker arms, will make changes to the pushrod length needed.

For a cam, I would looks at something like Hughes SEH2428AL.
For a piston, the KB-167.
Cylinder head chamber volume of 62-64 (Compression below uses 64cc)
Mill block 0.010" so piston is 0.002" below deck
That should give about 9.5:1 compression depending on head gasket.
A bit pricy, but the Cometic C5917-036 is 0.036" compressed and 7.713cc volume which would result in a 0.038" quench distance, and 9.58:1 compression.
Using Hughes head flow numbers for the 1.920" intake Iron ram head (227 cfm @ 0.500 intake, 187.3 @ 0.500 exhaust), The Dynomation5 shows 350+ HP @ 5600-5700 RPM, and 375+ torque @ 4600 rpm (with a dual plane intake and small tube headers.) I had to guess at the port lengths, header lengths, and port cross section sizes, but I think it should be in the ball park. Low end torque is decent with 300+ ft/lbs @ 1600 rpm
The 600 cfm carb is OK, but looks to be giving up some power (maybe 10 HP? in the upper RPM range) compared to a 700 cfm carb.
Not sure how exhaust manifolds will affect this? I pluged in small short runners in the exhaust model and it looks like only about a 10 HP loss? (seems like a small loss to me?)

I forgot to add that a larger cam will add a little bit to the top end power (maybe 20 HP?), but torque below 5,000 starts dropping off quite a bit with the 9.5:1 compression. If this is more of a track car with gear and high stall converter, then a cam in the 230 duration range might work better? The smaller cam I listed would be better for a hot street car.

Junkyard jewel: http://www.hotrod.com/articles/318-small-block-build/