302 casting on a set of 318 heads

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Here is another interesting thought to think about. The compressed exhaust gases really don't start expanding until they get a little ways out of the engine as they are heading down the exhaust system.

Just like this Rocket Engine pictured below in a free air environment.

20190411_185826.jpg
 
george et all
stick a head on a block with some dykem and scribe where the bores are
you can see if you can open the chambers any or if they overhang already and the block requires beveling on the intake (makes no difference on the ex if it is not physically hitting)
check the truck/ marine catalogs including Victor and McCord for gaskets also
 
George Jets said:
Like the size and specs on this one
Mr. Gasket Head Gaskets 1121G

Made for the LA 318s 4.140 in. Gasket Bore; 0.028 in. Compressed Thickness
Liking these specs a lot, wish they can keep them from leaking. Probably have to make sure surfaces are machined straight and clean.
Click to expand...
Couldent you spray both sides of the MRG gasket with spray hylomar sealant. Unless its already got a permatorque type sealant on it. I used to use hylomar on 2.2 turbo head gaskets. Worked well.
 
George Jets said:
Will elaborate more later in the day.

64 cc on stock 302 heads chamber volume.

69 318 9.2:1 stock pistons.
.050 down in hole
1.772 CH

The other 93 D100 318 flat tops are
1.755CH

302 valves are fine as is for great port flow, you want to keep the speed up not slow it down when it hits the larger valve opening.

The 302 heads have hardened seats, improved ports and port flow over the stock 318 heads of the 70s.

Here is the magic: LD4B Dual Plane aluminum intake, the port runners match factory 318 heads. So no turbulance there as long as you port match the gaskets and if any casting edges are sticking out debur them. Same with heads to the stock exhaust manifolds.

Then you want to open up your full exhaust system to 2.25 or 2.5".

The reasoning is you have hot compressed exhaust gasses leaving the stock manifolds at the exit looking for a place to expand out all the way out to the back. Literally drawing the hot gases out of the engine as they are expanding all the way out to the back of the car.

318 Magic: Smooth Port Flow and Port Speed in and out of the engine. Ma Mopar designed the manifolds with this in mind.

You can put headers on but then you are changing the engineer's dynamics, that can create lesser performance.

We have hit on a layout that works very very well, and other can choose to differ.

I always like hanging close to Ma Mopar. Those engineers ate Steak and Eggs for breakfast and could not wait to get into work for the day.

Good luck on your build. We are all learing along the way.

View attachment 1715387910
Click to expand...
I am curious what kind of HP this will make, and what cam to select with it.
 
moparmat2000 said:
I am curious what kind of HP this will make, and what cam to select with it.
Click to expand...

We got my friend Brian's Performance 318 built like this. he had the 69 Block with the good 230 factory HP engine and 9.2:1 compression to begin with. Overhauled it same stock valvel relief pistons, LD4B Intake, Edelbrock 1406, Mopar Performance 340 Cam, 340 Valve Springs, Stock Exhaust manifolds with 2.5" inche X Pipe exhaust all the way out the back. Easy 300 HP, we are thinking more like 325 and want to get it on the Dyno.

It's really something you would think the 318 would not do much. We just laugh when he takes it out and opens it up, so much power that you have got to watch it. My favorite saying when riding along with him is this thing has too much power. It's pretty unreal.

Want to help others here on FABO get their 318s cranking out that kind of power. Very Achievable . . .
 
OK picking this up from the other Wanted 302 for 318 head thread that was shut down for comments cause it was a for sale thread.

Thanks RRR for your input on the Felpro Head gaskets. Here is a little comparison so far as to what is available for the smaller bore diameter 318s.

Felpro 1008 bore diameter 4.180
Felpro 8553 PT bore diameter 4.170 (I measured this one)
Mr. Gasket 1121G bore diameter 4.140

Want to size this up to fit the 318 302 Closed Chamber Heads best we can.
Here is a picture of the Felpro 8553 PT on this 302 head pictured below. We found a new old stock OEM pair that fit the earlier 318 bores much better.
The Felpros just look too big, leaving compression, power and efficiency on the table.

8553 PT.jpg
 
63spf you were saying that you have a LD340 intake manifold. You will have to determine if that is the Large Port LD340 or the earlier one for the 318s with the same name LD340 with the small port runners that will work good with your 273.

You will have to figure out what you have there to make sure you get the good port match up to the 302 heads.
 
"We found a new old stock OEM pair that fit the earlier 318 bores much better."
do you have a pic and a part number?
hint
you want the gasket to fit where the cylinder "sleeve" is not inside it
 
Wyrmrider said:
"We found a new old stock OEM pair that fit the earlier 318 bores much better."
do you have a pic and a part number?
hint
you want the gasket to fit where the cylinder "sleeve" is not inside it
Click to expand...

While I technically agree, people have used the large bore FelPro blue gaskets on 273s for decades. It's really not critical. If it was a mass problem, there would be bore specific gaskets available. It's not.
 
depends on compression or blower rusty
4 bolts need all the help they can get- LA does have failures
heads dance around which is why 6 bolts on race motors
decks flex
IDK about LA but AMC produced extra thick decks for us on one months notice
they hand shaved the cores on the night shift, deeper bolt bosses also
we squared them up at whatever height we wanted
sent the blocks out with decks rough cut, they used the large bore "mexican" od on the cylinders for some extra cylinder thickness
The 252 Mexican motor had a larger bore than even the 4.0 which is 3 7/8
we ran 3 3/4 + .010 to keep cu inches under the Indy limit with the stock 199 3" stroke (Mexican production 252 used 3 1/2 stroke same as US 232)
on the Indy motors we used Bellevue washers for head o rings
head could dance around all it wanted- still held #4 1/2 in head bolts
 
And talking about 273 head gaskets, We have had many discussions here and no-one has come up with a steel shim 273 gasket to measure. I don't believe they were that small of a bore size. I had 2 off mine but pitched them. WTF was I thinking?
:wtf::BangHead::BangHead::BangHead:
 
in post #11 just the opposite on the mainland// those 360 block are gold.
 
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toolmanmike said:
And talking about 273 head gaskets, We have had many discussions here and no-one has come up with a steel shim 273 gasket to measure. I don't believe they were that small of a bore size. I had 2 off mine but pitched them. WTF was I thinking?
:wtf::BangHead::BangHead::BangHead:
Click to expand...
Mike...still have the ones that came out of my '67 273. What measurement would you like?
 
65Val said:
Mike...still have the ones that came out of my '67 273. What measurement would you like?
Click to expand...
Thanks for the offer but I got a pair of original steel shims from one of the gents here and measured them. I wonder where that thread went. I hope I bookmarked it. My bookmark file is getting pretty crowded. Yep, 19 pages of bookmarks. LOL

52 Year Old Head Gaskets
 
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