318 Build - Expert Review Needed

[nm9stheham]

I think the stock 340 cam is max for a lo compression 318 on the street.The old generic 204 \ 214 would surely have good lo end torque for a street driven 318.

Fortunately, the OP has raised the chronically low 318 SCR a full by a point by the milled-to-58 cc 302 chambers (vs 68 cc chambers like the old standard 675 heads). So the DCR is still up there fine with the XE262 cam and is kept up with the faster ramps.

 

[318willrun]

Just more work. at the machine shop. A big horsepower build is not necessary here:

That was just my opinion, or 2 cents …. LOL

 

[PRH]

sell the 302's, and buy a set of magnum heads. More flow, bigger valves, still closed chamber for your compression.

Depending on how far along he is with the 302 heads, and just how interested he is in making more power....... a set of EQ 318B’s would be a good way to go.

 

[69cudaownr]

Thanks to everyone for their input. I'll get the 1.88's in there.

 

[PRH]

Only do it if blending afterward is part of the plan.

 

[69cudaownr]

Yes, thanks.

 

[toolmanmike]

302's aren't a bad head if you use them right.They aren't much different than the early LA heads like the 920's or the 178's or 234's. The closed chambers are efficient and the ports are small but matched to the needs of a 273 or mild 318. Like any engine, the hotter you build it the more port and valve you will need. I think gasket matching and bowl blending can improve any head.

 

[Jadaharabi]

I found this interesting article from a few years ago on the 318.

Build a Hot Mopar 318 for Street or Strip

 

[GAMoparMan]

Without all the build specs. Just plugging in conservative numbers....Estimating:
HP at the Fly - 288 at 4500
HP at the Wheel - 245 at 4500
Torque at the Fly - 386 at 3500
Torque at the Wheel - 328 at 3500

65MPH Cruising RPM around 2600ish | 155 HP/325 FT LB

*Added a Ignition Curve chart for you also. Would play around with 15* INT |12* MECH w/ 2 Heavy Springs. And then tinker with Vacuum advance to give you Total Timing around the 48-52* range at cruising. **Adjust for Octane/Pinging

 

[69cudaownr]

Without all the build specs. Just plugging in conservative numbers....Estimating:
HP at the Fly - 288 at 4500
HP at the Wheel - 245 at 4500
Torque at the Fly - 386 at 3500
Torque at the Wheel - 328 at 3500

65MPH Cruising RPM around 2600ish | 155 HP/325 FT LB

*Added a Ignition Curve chart for you also. Would play around with 15* INT |12* MECH w/ 2 Heavy Springs. And then tinker with Vacuum advance to give you Total Timing around the 48-52* range at cruising. **Adjust for Octane/Pinging

View attachment 1715271075 View attachment 1715271076 View attachment 1715271077 View attachment 1715271078

Super thanks!!! I am going to make one other small change from the Mr Gasket 1121 at .028 thickness to the Mopar Performance P4120094 at .024 thickness which gains between .5 - 1 cc. This is all good for a street car that I want to feel some pull on a green light.

 

[JBurch]

Actually you are loosing volume, as you are loosing .004 thickness in theory (.028 - .024 = .004).........AND as listed on Mancini's site the P4120094 gasket crushes at .040 to .042......the OLD P4120094 used to crush in the .024 to .028 range

64,000 thousand dollar question......are you looking to ADD volume, OR SUBTRACT volume to achieve your target compression ratio??

 

[toolmanmike]

Super thanks!!! I am going to make one other small change from the Mr Gasket 1121 at .028 thickness to the Mopar Performance P4120094 at .024 thickness which gains between .5 - 1 cc. This is all good for a street car that I want to feel some pull on a green light.

Let's see, going from the .028 Mr Gasket to the .024 MP is .004 of an inch. Four thousandths of an inch. About the thickness of a piece of paper. It won't make enough difference that you will ever feel or notice.

 

[forphorty]

Let's see, going from the .028 Mr Gasket to the MP .024 is .004 of an inch. Four thousandths of an inch. About the thickness of a piece of paper. It won't make enough difference that you will ever feel or notice.

Agreed. One also has to take into consideration the bore diameter of the gasket. Summits website has the compressed volume listed. At some point you are just splitting hairs. DODGE 5.2L/318 MOPAR SMALL BLOCK LA Head Gaskets

 

[toolmanmike]

Agreed. One also has to take into consideration the bore diameter of the gasket. Summits website has the compressed volume listed. At some point you are just splitting hairs. DODGE 5.2L/318 MOPAR SMALL BLOCK LA Head Gaskets

You know, now that you mention it, I can't remember that anyone ever measured a stock steel shim headgasket for bore size. I have no idea how big they were.

 

[MOPAROFFICIAL]

The only issue with the 1.6’s on the exhaust is you’ll cut through the induction hardening of the casting and need to install exhaust seat inserts for unleaded fuel........ for what would amount to what I consider a very minimal gain in that combo.

No need for 1.6 exh on this one.
The 1.5 with a little work will flow 150 CFM
It's easier, less work to get 200cfm with a 1.78

This is a very mild build.imo cam will be done @4800 to 5000rpm, maybe.
With as cast heads it 'might' make 260-270 hp. It's not just the cam, that cam is actually good for about 300'ish in a 318 with some bowl work... or basically if it had heads that went 210cfm around .500 with the expected.100-.400 cfm flow up to that peak.

Jmo

 

[PRH]

.....if it had heads that went 210cfm around .500 with the expected.100-.400 cfm.....

It’s going to take more than a little bowl work to get even close to 210(on my bench) from 302 heads.
That’s about what a medium to poorer flowing OE 2.02 J head flows.

I’ve had the current bench for 11 years....... and in that time I’ve never flow tested any “318” heads.

Going from memory, I seem to recall them flowing in the 175-180 range on my old bench.

I think the best of the 1.88 valve heads are the 308’s, which are a bit over [email protected] lift with a decent valve job on the current bench.

 

[Demuth]

I have a hot 318 410HP @ 5000 rpm street driven idles fine power anywhere the pedal is 3 speed on floor everything stock except the clutch and engine. When I find the time I'll try putting on here what I used.

 

[Demuth]

318 bore 30 over 3.950
Put in KB 167 pistons stock rods
73 360 heads all stainless steel valves both heads new rebuild. Intake 2.020 in. Exhaust 1.600 in Compression ratio 9.00 Combustion space 83.16
Also had heads machined for be hive springs to handle a .538 comp cam roller hydraulic howards roller rockers. Duel plain Edelbrock aluminum intake Edelbrock 650cfm electric choke stock crank MSD 6AL headers 410 HP @ 5000 RPM this is one stout 318 all I need now is a sure grip locker. This engine idles great runs great in any speed gear. The stock gears in the rear with the 3 speed will allow me to turn wheels at will and run 80 down the road no problem. Oh also have a 3 row aluminum radiator runs around 180 street driven car not set up for drag racing. Hope you enjoyed my post.

 

[Demuth]

Oh of course ballanced and blue printed

 

[stixx]

Sure is a very nice engine... but 410Hp @5000 is highly improbable for any 318. More like @6000rpm?
Not to be raining on your parade...

 

[Demuth]

Well, because you asked about "horsepower" guesses, then I'll just add if it's power you want, the heads would be the first that would get my attention. 302's in stock form aren't anything to get excited about.

I would have to agree need bigger valves to suck that air and fuel down for hp

 

[Demuth]

Sure is a very nice engine... but 410Hp @5000 is highly improbable for any 318. More like @6000rpm?
Not to be raining on your parade...

Your wrong dino sheet says 410 @ 5000 that roller cam makes the difference but you can believe what you want.

 

[Demuth]

2000rpm .......149hp.......Torque......392
2500..............190.............................399
3000...............234............................409
3500...............279..……....................419
4000..............323............................424
5000..............391...........................410
5500...............404..........................385
6000................402..........................352
6500...............390...........................315

 

[toolmanmike]

2000rpm .......149hp.......Torque......392
2500..............190.............................399
3000...............234............................409
3500...............279..……....................419
4000..............323............................424
5000..............391...........................410
5500...............404..........................385
6000................402..........................352
6500...............390...........................315

410 @5000 rpm is torque not horsepower. According to this chart it never made 410 horse. It maxed out at 404 @5500. Am I missing something in the conversation here?

 

[Demuth]

2000rpm .......149hp.......Torque......392
2500..............190.............................399
3000...............234............................409
3500...............279..……....................419
4000..............323............................424
5000..............391...........................410
5500...............404..........................385
6000................402..........................352
6500...............390...........................315

You are right my mistake 5500 RPM 404 HP 385 torque. I was looking at the 410 torque thanks for pointing this out again my mistake . 6000 RPM . 402 hp