Oh that’ll getcha 350 ho right away.
400 hp is are ported iron or aluminum cylinder heads and a camshaft on top of it.
Big horsepower 318 builds
- Thread starter toolmanmike
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400 hp is are ported iron or aluminum cylinder heads and a camshaft on top of it.
He said 350-400. That's where he'd be. I'm splittin hairs here.
The videos I'm referring to are NA.
I think it's down to a number of things, not just one big thing.
My opinion, in descending order of importance:
1. Heads. The LS heads are just newer technology. Comparing cutting edge 2000s tech (ported AFR LS cathedral heads) to even the best available street heads for a sbm, unfortunately, there's really no contest.
2. Intake. That LS3 style intake is apparently VERY good, and seems to work VERY well over a broad rpm range.
3. Cams. The LS cams seem to be pretty aggressive, i.e. for a given duration they have quite a lot of lift.
4. Valvetrain geometry. LS platform addresses valvetrain geometry issues that older engines dealt with. (I'm assuming this ties in with point 3 above)
5. The little things. I'm making some assumptions here, but I'm thinking things like better reciprocating assembly geometry, optimized ring packages, better machining tolerances, more rigid blocks, etc. Maybe these things aren't big but they probably add another 10-20hp to the mix.
pink340swinger
Well-Known Member
I have an older comp eliminator engine I race. I would consider it a big horsepower 318 deal only a little smaller. It's 312 cubic inches, makes 725 hp @ 9200rpms. 4.0" bore 3.0" stroke Arrington heads, single 850 holley when I got it. Ran 8.50-8.60s @2250lbs. It has a tunnel ram with 2 fours now and I'm at 3000lbs trying to get it back in the 8s. It's pretty much a max effort engine, just a little outdated. It's all in the whole combination, not just one part that makes a car run.
In keeping with the NA….
Let’s compare flow numbers and port velocities.
This is a camshaft related issue, not cylinder head.
It is true. The better the cylinder head the better the power. A higher flowing cylinder head over stock allows more power and rpm.
While the OEM - LA head gets buried deep on this front, what do we have to replace it and compete? I can name 4 off the bat.
But yet! There a roller compared to a standard solid which is an edge. Mostly since MoPar guys cry at the thought of a roller cam.
The LS has a lifter bore size of?????
So in the past when our old time racers spun 8500/9500, it was black magic that we can’t reproduce suddenly?
Just wondering.
The modern blocks are better OOTB then ours from yesteryear.
And that’s where it stops.
There architecture is better and the advancements after 40/50/60 years is apparent. But let’s dumb down a modern engine and cripple it with a wet flow intake and 4150 carb, stick it with a SFT and see where and what we get.
No one owning these engines would ever do that and it’s a crying shame any old time engine guy has major fears and sudden cash flow problems in meeting what the others were born with. I get that. A roller cam, F.I. & OD transmissions are expensive and prohibitive to 99% here.
But if your going to compare engines, think before you speak on who has what in any real advantage and what can not be modified and equaled.
Hey! Didn’t Brett Miller make a 1,000hp NA SBM?
Currently being raced by the way.
YeAaaaaaaa, well, there’s that now huh?
I tell ya it’s a danm shame I don’t play lotto…..
Hell yeah! That sounds awesome. Can you post a picture?
Me acknowledging that the modern engines have advantages shouldn't be equated to me saying sbm is no good. Or that I disagree with you or anyone. I was just pointing out the ls5.3 I was referring to was NA.... after you suggested it was boosted. Not meant to be an affront to you - just a clarification.
I actually do try to think before I speak. I try to avoid knee jerk emotional reactions in all communication.
Again. A 5.3 L engine, low compression, with a sub 230 deg cam, making over 500 HP. That's damn impressive no matter the brand. If you or anyone wants to take offense to that....well I don't know what to say brother.
If anyone wants to be helpful here...can you or anyone suggest a sbm combo with a sub 230 cam (of any flavor), that will make 500+? I'd love to see the combo. Maybe I might even copy it. After all I am currently building a SBM. Would love to learn something that would help. Or maybe help someone else.
I was just thinking of a build like this when I wrote my reply above. (I had to stop for dinner) I hate to make it basic but it is simply put in simple terms of easy breathing in and out coupled with rpm.
The LA is born limited with there heads which are just a passenger head. They only go so far. There design goes back in time a very long time ago. Not yesterday. LOL!
Can you show me this 500hp - 5.3 build?
All you need to do is copy it as close as possible and exceed anywhere you can rather than fall just short.
Question for the head porting experts:
Would a well ported set of heads (like Edelbrock or SM) and a well matched intake get you there? 5 hundo HP with a 318 and say, a solid roller cam with sub 230 degrees or duration?
Would a well ported set of heads (like Edelbrock or SM) and a well matched intake get you there? 5 hundo HP with a 318 and say, a solid roller cam with sub 230 degrees or duration?
Newbomb Turk
Well-Known Member
If you are serious about making power like a late model engine you need to disabuse yourself of the notion that a Chrysler head with standard rockers is worth spending a nickel on.
If you want to build a 500 hp 318 with a small cam you use W2 heads or better.
Anything else is just expensive turd buffing.
Here's probably the tf used with the 217 cam to make 500 hp with 5.3l and mopar tf but there has been no signs that the mopars tf would do 500 hp with a 217 cam.
Here's the 799 heads the 5.3l started with and got 480 hp with a 221 cam
Here's the 799 heads the 5.3l started with and got 480 hp with a 221 cam
| 799 6.0L (and 5.3L) Castings | ||
| Valve Size: Intake - 2.00, Exhaust - 1.55 | ||
| Port Volume: Intake - 209 cc, Exhaust - 74 cc | ||
| Combustion Chamber: 64.0 cc | ||
| Target Bore Size: 4.000 (and 3.780) | ||
| Chamber Diameter (distance across): 3.876 | ||
| Flow data | ||
| Lift | In. | Ex. |
| 0.050 | 31.1 | 24.7 |
| 0.100 | 65.4 | 52.6 |
| 0.200 | 142.2 | 98.1 |
| 0.300 | 193.5 | 133.5 |
| 0.400 | 230.2 | 160.1 |
| 0.500 | 243.4 | 175.5 |
| 0.600 | 248.1 | 185.8 |
| 0.650 | 249.3 | 188.2 |
| 0.700 | 250.2 | 191.1 |
B3422w5
Well-Known Member
Could do it with Bloomer heads. They make great power
Not sure how much a 2.08 valve would be shrouded, but high lift 230@50 roller, 13 to 1 compression, good intake and carb, good ring pack, think it could be done pretty easily.
13:1?
I found out after I posted that he had Brian Tooley port those heads so they would even flow more.
B3422w5
Well-Known Member
True, was surprised the mopars flowed better on the exhaust side.
They flow a lot better than the stock LS 799 heads wonder how the mopar tf's would do compared to them?
Think the point is there a way to build a 318 to similar specs as the LS 5.3l and get similar hp and torque,
Mainly with similar 217 or 221 cams they used with the 5.3l to get 500 + hp.
B3422w5
Well-Known Member
Look at that, Rich answered your question!
It's not that I especially care about about gm products. I've never owned one. I'm just a little hung up on why a 5.2 sbm couldn't make similar power to a 5.3ls, with similar specs.
Seems the more sophisticated heads and intake are the biggest thing.
Could SM/Edelbrock/TF heads be ported to a level to close the gap highlighted above? The LS head is doing at .500, what it takes the sbm head .700 to achieve.
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