calling mopar small block gurus!!!!help needed

i just recently came into possession of a 318 small block
im pretty familiar with stock ones and thats what i have in my 52' right now but plan on putting this engine in soon

heres what i know about this engine
1965 318 block
bored 40 over
crank turned 10/10
flattop pistons with forged rods
new plugs,lifters,pushrods,cam,etc....

it also has a set of j-heads with it

now from what ive been reading i will need to get the block decked or the heads decked but im not sure..never done any maching work

my questions are:
is this a good set-up with minimal machine work to get around 400hp?
or what kind of hp should i be expecting?
should i try and find different heads?
or should i get the machine work done and go with what i have?

 

That's a 318 Poly, can be stroked & bored out to 400 CID. "Abomination" or "Panic" will check in eventuially, they top guns on the Polys. Aren't J heads for the LA?

 

Found an old thread here if you do have the 318 poly theres lots of good info here. http://www.jalopyjournal.com/forum/showthread.php?t=81380

 

wait what?
poly....i thought it was an la? didnt theystart la's in 63?
they are 340 heads

 

As far as I know, LA's started in '66? with the 273. LA 318 showed up the next year, I've got a '67 318 in my 34 pickup. Great engine, forged steel crank, wimpy stock heads that don't flow very well though.

 

The 318 LA motors didn't come around until late '66 or '67 I think. There was a 273 in '64 which was an LA motor.

 

but theres a great possibility it is an "A" engine and not a poly right?

 

Here's three ways for 400+ with an LA 318:

http://www.hotrod.com/howto/113_0304_318_small_block_build/index.html

http://www.popularhotrodding.com/tech/0810phr_chrysler_318_engine/index.html

http://www.popularhotrodding.com/tech/0901phr_mopar_318_magnum_engine/index.html




And if you realize that it's a Poly,...

 

ok so just thought about what i was told about the engine
he said it was blueprinted off a magazine article(i dont remember which one)
and that it was a high compression block...which didnt make sense to me since i didnt think they made a "high" compression 318 block

 

If it's got flat-top pistons it will be an LA as poly's have pistons which are fly-cut for the valves but as far as I know the 318 LA didn't come out until 66. The 273 was the first A engine at 273 cubes in 64 and 65 so it shouldn't be a 65 model

swifty

 

i know it says 65 on the block i do remember seeing that
the pistons he has for it are flattop(flat except a little cutaway on the top) eagle pistons.
like i said i dont know a ton about hot rodding engines besides bolt-ons

 

The LA engines started in 1964 with the 273 made from 64 thru 69 - The la 318 started in 67 thru 2002 - 340 from 68 thru 73 - J heads are LA style heads But will not work on 64 - 65 273 without modification to the head bolt angle ( Hot Rod Mag )
Poly 318 are great engines and there are lots of threads on the HAMB for Hotrodding that engine - The 318 LA is a great engine also with some tweeks like using a 273 forged crank - windage tray from 340s - ect ect ect Lots of threads for this engine too - If you have the poly 318 and are realy wanting the LA 318 I have a 76 318 Magnum pickup engine you might be able to with - Contact me if so - Jaxx in tn also

 

i know its a 318 and not a 273
im going to look at the engine again tomorrow and ill get all the numbers off of it
i have a 75LA block but it needs overhaulin if i want any real power out of it...i just put a new cam and intake on it for now..havent even started it since then

but if all else fails ill get my 75 block bored out and us the heads...who knows

 

go to my picks Mine has a LA class 318. if its a 65 block then its a 273 good motor hi reving. a Poly has two bolts holding the Valve cover down. to the block if the heads are decked more then 20 then you will need to have the intake milled to fit the new angle. the 318 in my dart would run 13,s all day long.

 

hi-revving? worth its spit?
ive never seen the original heads
apparently it was all set to be built and go in then the owner traded the car he was going to put it in so i traded for the engine...well can trade nothings in stone till i find out more about the block...i dont want a hastle...

 

Guys, the Poly head 318 is an "A" engine...

The 273/318/340/360 engines are "LA" engines.

A 1965-cast "LA" block would be a 273 c.i. engine...the earliest LA-block 318 casting date you will find is June 1966 for the '67 model year cars and trucks. The ONLY "LA" block earlier than that date is a 273. I've been around these since 1972, so I do have a little bit of knowledge there. You can look at the side of the block and it will tell you the cubic inches and the casting number.

How do you know this engine has 340 heads on it? First off, they will physically bolt on to the engine block, but the valves on the 340/360 heads will hit the cylinder walls, so the 340 heads will NOT work on the 273/318 without some machining at the top of the cylinder for clearance. I'm betting you have 273 or 318 heads.

Next is the heads and intake relationship. Keep in mind, ANY LA head will physically bolt on to ANY LA block...BUT...it does not mean it'll work! If, by chance, you have 1963/1964 - 273 cast heads, these will ONLY work with an intake from the same time. Later "LA" intakes and heads have the angle of the bolt holes drilled at a different angle than the early heads and intake. Availability of aftermarket intakes for the early "LA" heads is zero. Bonus for you is that any later 273 or 318 head will bolt right on. Plus, the 1985 and later 318 swirl-port heads will give you the best bang for the buck, and they are everywhere, cheap.

No such animal as a "high-compression" LA 318. Only carbruation available was either a one or two-barrel carb, unless you had a late-'80s cop car or a pickup; then you could get a T-Quad or Rochester 4-bbl, depending on application and year.

The 273 was available as a solid-lifter cam engine throughout its existence, from 1963 through 1969.

 

If it is a dated 65 block, then it could go either way, the LA blocks probably began being cast in very late 65 because the finished LA 318 would have been on the showroom floors in fall of 66 with the introduction of the 67 model cars. One would be led to believe the poly 318 casting would have ended by mid 65, so a month casting date could solve the delema. Also, according to the older Mopar performance book, an LA used different head gaskets then a Poly, might be able to get a known LA head gasket and see if it matches up with your block. The head surface on the Poly should be a lot wider then the head surface on an LA block.

Elsewhere in the book, it states that block casting usually ran 3-6 months in advance of engine assembly. If that holds true, then no LA blocks should have been cast before spring of 1966, but a new design might have been different. Gene

 

i will look to see if the heads fit and so on tomorrow
the engine has no intake or exhaust
i have an offy intake i was gonna use

even if its a 273 but bored and such is it worth a trade for an 75 chevy i paid 500 for?with a now blown engine....stupid carb nut

 

give that damn motor back and get the truck back and leave the 360 in the car.

 

360?
i have a stock 318 in my car
the trucks 250 is blown and i dont wanna fool with it...i with he'd trade me for his scamp haha

 

ok but are the j-heads worth their spit when it comes to performance of should i just try and fix my beater truck?

 

Poly 318 engines were used in Canadian-built trucks and car through the 1967 model year. The last year of Poly 318 usage in US-built vehicles was the 1966 model year.

Makgreens, it is NOT an LA-318 if the cast date is 1965. Period, dot. It is a 273. The J-heads (340/360) will NOT work on that 273 because of valve clearance issues with the cylinder wall. You will need a set of '85-'92 swirl-chamber heads to run that engine to its best capacity and to avoid the valve issue, using stock iron heads. I've been around small-block Mopars since 1972. I know this to be true.

Last thing - Are you SURE you are reading the cast date as 1965, when it is actually 1985??? Gotta ask!

 

It is also entirely possible he has a 65 dated 318 poly block and a set of 340 J heads. He is looking at a project someone abondened, maybe because the guy couldn't get the heads to work on his block? How would you identify the difference between a poly 318 and an LA 318 with neither having a set of heads?

It was also my understanding that the 67 Canadian 318 you refer to were unused 66 polys installed in the trucks built in Canada until they were used up, not an uncomon move from Mopar at that time. Gene

 

well tomorrow will be the final call but its looking like im gonna keep my beater truck and he will keep that engine...i dont wanna downsize from a 318 to a 273 especially when i could just stroke the 318 down the road

 

A chevy motor (or any other common run of the mill motor) that has been blown up is probably not worth much. To put this into perspective, at the Jefferson Swap meet Sat there was a guy trying to sell a mid 70s 360 that had (supposidly) 7,000 miles on a rebuild he was asking $300 for. This was a running motor he could start up for you. Its going to cost you $500 to get this thing together and running, provided everything there is in good shape and fits together, it better look like new inside. IMHO. Gene

 

everything looks brand new except the heads...they needed to be dipped
on the chevy a nut from the carb fell in the intake and into a valve(i think).took the manifold off and there was no trace of the nut..so my best guess is that its stuck in a valve and thats why the engine is smoking and doesnt run for crap or its just my luck...i had to drive it 20 miles AFTER the nut fell in the engine...it was that or abandon it with my friends trailer attached

 

Depending on if the heads have 202 valves, non 202 heads will work on the 273.
Mak, I thought it was a 360 you put in the coupe. you can fix that chevy pretty cheap and pratice on it rather than the Mopar!! Mike

 

Edit, I just noticed they're J heads not Xs, significant value difference as those are also 360 heads and not unique to the 340. IMO if you can trade a wounded 75 chevy pickup for anything, you ought to take the trade

good luck

 

The J heads are worth more than spit - you can easily make 400 horse on a 360 with them, trust me I know.

I believe the bore notching on 273's and 318's is to open up airflow around the intake valve rather than for clearance.

Honestly though, 2.02 valves are too big for a mild 318. Velocity is king and those will kill some low end and unless you rev that sucker way up are no advantage on a mild motor.

I have built a few nice 318s and have either ported the stock heads (open up the pockets and smooth the ports) or used 360 heads with 1.88 intake valves.

If you are looking to build a bunch of streetable power, take those J heads, put hardened seats in them and have the guy open up the throats while he is in there, bolt them on a good 360 bottom end with a good cam, a set of real equal length headers, a good single plane intake and a 750 carb. This will show most other cars your tail lights. The biggest problem with the 360 is the compression ratio - it is really low in stock form. To bring it up requires pistons or, if you are a cheap bastard like me, whack .060" off the heads and .070 off the intake manifold faces.

 

In Australia they cut down 360 mains & stroke the 318 to 349. However the 340/360 were quite rare there. Considering the easy availability of 360s in vans & pick ups, stroking a 318 doesn't really add up here.