Factory Small Block Heads

[krazykuda]

Didn't Pontiac make a 4 cylinder by cutting a 389 in half? I watched a guy race one of the 4 cylinder Pontiacs. One head, One header, just a V8 missing a bank LOL. It had gone into the 11's too

I wonder if that's the same 4 cylinder Pontiac that Rick M. set the record with at Milan Dragway... He ran the flow bench at Jeep truck and he did all the development testing on the 5.7L hemi...

He put a 4 cylinder naturally aspirated with a carb in a rail and ran in the mid 8's... I asked him why he ran a 4 cylinder, and he said "It's half the parts and cheaper to build than a V-8"...

He was great at flowing heads, intakes, and carbs..

 

[krazykuda]

Bought a pair for my 318 last fall. Received 2 different casting numbers. Bonus, and maybe just luck, the little egr air ports were already tapped so I could simply locktite and screw in those little plugs to block them off.

Then grind off the bumps in the port floor so they don't impede flow...

 

[volaredon]

Bought a pair for my 318 last fall. Received 2 different casting numbers. Bonus, and maybe just luck, the little egr air ports were already tapped so I could simply locktite and screw in those little plugs to block them off.

There was also a #714 head, I have a set here, was told those are same as the #302 heads. Just like there are 2 different casting number magnum heads that are supposed to be identical.
The 714s I have came off a 91 318 out of a Dakota I parted out.
Last year for LA 318s and they have the sticky dots on them for temp like they've been redone.
If I use them they will come apart at least for inspection first.
I also have a set of #302s that I sent thru the machine shop a few years ago that I haven't used yet, standard local mom and pop valve job done there, but I do have a plan to use those ...
They will also come apart to check for casting boogers and those cleaned up at least.

 

[Hysteric]

When I see you in person, I will explain my findings if you are interested.

I would be interested in your thoughts. You can PM me with them if you feel like it.

 

[Hysteric]

Jamie from the Dead Dodge Garage channel recently pulled apart a 1968 318 that had one closed chamber head and one open chamber head. Apparently that engine didn't run very well, but probably for lots of other reasons.

At 34:29 of this video:

That engine was run excessively rich or too cold.

 

[stillrunners]

Are we mentioning those late 70's/80's 318 police heads ?

 

[rumblefish360]

So magnum heads, with Hughes shaft paired rockers, drilled for LA intakes. The perfect factory head.

MoPar Performance did offer such a head

 

[pauly]

Not head related but the steel crank 340 that came with my car (supposedly ran) has one cylinder .030” over with a different type of piston than the other 7 standard bore ones!

 

[273]

What I found surprising was the 273/318 heads out flows the Ford Winsor heads, Of course Ford has the Cleveland heads to make up for it.

 

[volaredon]

What I found surprising was the 273/318 heads out flows the Ford Winsor heads, Of course Ford has the Cleveland heads to make up for it.

Huh... Yet so many people say the 273/318 are "junk" and skip right over them to "gotta have a 360".... Weird to say the least.

 

[273]

Huh... Yet so many people say the 273/318 are "junk" and skip right over them to "gotta have a 360".... Weird to say the least.

There's definitely decent potential there.

 

[340sFastback]

What I found surprising was the 273/318 heads out flows the Ford Winsor heads, Of course Ford has the Cleveland heads to make up for it.

Which Ford Windsor heads? There have been a bunch of different ones over the decades. The '95 - '00 Ford Explorer GT40 production heads flowed 195 CFM intake. Do 318 heads flow those numbers?

 

[273]

Which Ford Windsor heads?

The ones Richard Holdener generally runs for stock.

There have been a bunch of different ones over the decades. The '95 - '00 Ford Explorer GT40 production heads flowed 195 CFM intake. Do 318 heads flow those numbers?

Sorry I generalized, the ones Richard generally uses for stock flow like 158 cfm.

 

[Hysteric]

Huh... Yet so many people say the 273/318 are "junk" and skip right over them to "gotta have a 360".... Weird to say the least.

Not to mentioned they all argued black and blue they can't flow but none of them bothered to port them to find out what they can do.

 

[Ottmundr]

Here is my list, in order, to the best performing factory small block heads as cast from the factory (273, 318, 340, 360).

1. Magnum heads. Speaking strictly of how they perform from the factory, I think these are my #1.
2. X head. Only put this ahead of the 308 because of the 2.02
3. 308 head. Gives up some valve size to the X head on intake side, but I like the exhaust port
4. J head. Really, this head works as well as a X head in my opinion, but most came with 1.88 intakes, thus it falls to #4
5. Smog 360 head, pick the casting. Yep, I put this ahead of the closed chamber 318 heads.
6. 318 heads (non magnum) - and pick your poison. I guess the 920 head may lead the way in performance. The 675 casting is not a bad choice either among the 318 heads. Many go bananas over the 302-swirl port closed chamber. I guess stacked up against the other 318 heads, ok. I think from the factory the 675 flows more.

40+ years of unleaded and my 675 heads have a few sunk valves lol.

 

[Ottmundr]

Didn't Pontiac make a 4 cylinder by cutting a 389 in half? I watched a guy race one of the 4 cylinder Pontiacs. One head, One header, just a V8 missing a bank LOL. It had gone into the 11's too

Isn't that what they did to the 318 for the Neon?

 

[RustyRatRod]

Which Ford Windsor heads? There have been a bunch of different ones over the decades. The '95 - '00 Ford Explorer GT40 production heads flowed 195 CFM intake. Do 318 heads flow those numbers?

The GT40P heads flow even more.

 

[273]

Not to mentioned they all argued black and blue they can't flow but none of them bothered to port them to find out what they can do.

Problem is most aren't willing to port.

 

[RustyRatRod]

Didn't Pontiac make a 4 cylinder by cutting a 389 in half? I watched a guy race one of the 4 cylinder Pontiacs. One head, One header, just a V8 missing a bank LOL. It had gone into the 11's too

Yeah, the Pontiac Trophy Four. Half a 389 is exactly what it was. 195 cubes and up to 155HP with a single four barrel carburetor.

 

[66fs]

Isn't that what they did to the 318 for the Neon?

No, completely different engine. Very strong and light.

 

[318willrun]

Isn't that what they did to the 318 for the Neon?

Never heard that. Neon 2.0 has a 3.27 x 3.35 bore/stroke. 318 has 3.91 x 3.31

 

[furrystump]

Everyone tells me that x heads are better than j's, and t/a heads are better than regular j's. While I've never tried X's, Rhett has them and he is really slow. KG engines uses the same CNC program for X's and J's. I took the T/A's off and put J's CNC'd by KG and finished by PRH and picked up a good amount. It's been 10.1@132 through exhaust manifolds on a 6.5" Street tire. If I stopped running within the constraints of F.A.S.T. and put a good carb, intake, headers and a cam and converter to match I imagine it would be in the 9.5 range if not a touch quicker with stock valve sized, stock pushrod location, no epoxy or weld J heads.

I agreed with the above…….even the really slow part. As to old work in a set of heads, I was told my X’s were head and shoulders above Brian’s T/A’s, but they were pretty long in the tooth at that point. His J’s are better than my X’s. Which are a pretty comparable deal. Both still have the pushrod pinch and the same guy had his hands on each before they were installed. Open chamber can be fixed with custom piston. I think with the LA’s at full tilt effort port work, core shift is more of a defining issue. Perfect castings, X’s are supposed to have more meat due to the big valve being originally planned for the head. I can’t run magnum stuff, so not on my radar. Our heads rocker systems are very different. My X’s are the original ones to the car and I’m a bit more conservative with them. Back to the garage to work on an AIR CLEANER! Oh, I have bigger valves than him. 2.055 intake 1.625 exhaust.

 

[65 Cuda 340]

I heard on good authority (a guy trying to sell me a slant six 62 Dodge) that the slant six was essentially half a Chrysler V-12.

 

[273]

I heard on good authority (a guy trying to sell me a slant six 62 Dodge) that the slant six was essentially half a Chrysler V-12.

A flat head 6 is a 5th of this engine

Chrysler A57 Multibank tank engine.

 

[65 Cuda 340]

A flat head 6 is a 5th of this engine

Chrysler A57 Multibank tank engine.

View attachment 1716370305

View attachment 1716370303

View attachment 1716370304

That's an impressive piece of engineering. How to turn a 100 hp flathead six into a 500 hp tank motor on the cheap.

BTW, Chrysler never made a V-12.