Need some 318 info, cross-generations

[///Matt]

Hi all.

I reently bought a 71 charger 318, on the info that it was "all original, a survivor"... Turns out I've been had. I pulled the motor with the intent to rebuild and retain, but found that the motor was cast 2-17-1977.... Happy birthday, motor.

So now I have these questions:

What exactly caused the 318 to have reduced compression ratings after 1974? Heads? Deck height? Simple gasket?

Are there anythings I need to watch out for while ordering parts, if I order on the basis that it is a 1971 Charger? Any part changes that will make me have to order for a 77-based vehicle?

Thanks,
Matt

 

[Lelo 500]

No I don't think so pretty much the same motor. Casting # might be different on the heads but still basically the same. As for compression, I think it had a lot to do with pistons further down in the hole.

 

[Bb70charger500]

Most everything will be the same but stuff like valves and other hard parts it would be best just to order parts for your year motor just order for a 77 dodge ram 150 that should get you proper parts as for power it's a 318 there isn't any but heads are a huge factor also they may have played with stroke and cam size Chrysler did a lot of different things also you'll have all sorts of smog stuff on it nothing a few minute s of unbolting won't hurt ,but overall I believe there the same but you never know cam bearings crank bearings might be diff too
Good luck

- - - Updated - - -

You could just find a poly motor they make good power and will drop right in or a newer 360 out of a van it truck there good and can easily make some power and would also drop in good luck

 

[DWilbur]

Hello Matt
Hughes Engines is a good resource for 318 LA engines. They are capable of making about 400 HP or build a nice stock one.

 

[///Matt]

Hi guys, thanks for the info.

fase alarm, as it turns out. All the grime on the motor made "71" look like "77". Although I'm certain the motor has been out of the car before, and I'm trying my damndest to verify if its original.... I can't find any portion of my vin stamped on it, so I'm leaning towards replaced, but not 100%. Any closer guidance for where it should be stamped? The left and right side of the block have the casting number and date, and the front has some numbers stamped which do not appear to have my vin in there.

 

[69Bee]

ID and VIN stamped on front driver side of the block, just under the head (behind the power steering). As far as working on the compression, use the following:

Pistons Sealed Power 526AP (flat top with 1.745" compression distance)
A nice RV cam or 4BBL cam for a 360
Whatever head gasket, as they don't have steel shim that I see anymore.

You could get a Cometic head gaskets, and get the thickness you desire, but is going to cost $$$ for them. All of the other parts are the same from 68 to 90 for the most part.

 

[Northern Runner]

Just looking through Hughes here I found these
http://www.hughesengines.com/Index/...cw==&level2=Q3lsaW5kZXIgSGVhZA==&partid=14093
Not sure if they're true steel shims, but they're .026in, and they're cheap!
If you want a nice cruiser the "302" heads in a lot of late 80's pickups are good. They give slight compression and give the motor some more torque. Though if you're gonna build the motor up, stay away from them, they'll just limit the motor.

As for the vin, If I remember correctly, it should be on the lower driver side on a flat spot toward the bottom of the motor. It'll probably be covered in grime so take a rag and some degreaser to it. Numbers/letters SHOULD be there, doesn't mean there will be any though.

 

[///Matt]

Thanks guys! I picked a set of cherry 302 heads today, out of a 86 van with only 40k miles on, there isnt even carbon build up on em hardly, the pistons were even smooth.

As far as them limiting me, i don't plan to go any higher than 380-ish hp, which Dulcich (spelling?) got with these heads and big valves. Gonna wait on the valves, since this head is so smooth already. Just gonna run em as is, and see how it goes. Picking up a hotter cam next week, probably something a step or two shy of the xe268 Comp. Got summit headers, performer intake, Eddy 1406 waiting to go on once I finish the bearing/ring job. I'll have to check out those pistons, 69bee. They are "taller" than the stockers? Summit doesnt show much for deck clearance, just diameter generally.

Once I get the motor in and purring, after I get bored of it I'm going to have the heads milled a little and bigger valves put in. I'm going to attempt my own port job here shortly. Got a set of junk stock heads to practice on, luckily.

right now I'm busy cleaning the block to prep for paint. All the local shops want an arm and a leg for thermal/jet, and I'm ballin' on a budget, so we'll just have to hooe for the best, lol.

 

[69Bee]

Thanks guys! I picked a set of cherry 302 heads today, out of a 86 van with only 40k miles on, there isnt even carbon build up on em hardly, the pistons were even smooth.

As far as them limiting me, i don't plan to go any higher than 380-ish hp, which Dulcich (spelling?) got with these heads and big valves. Gonna wait on the valves, since this head is so smooth already. Just gonna run em as is, and see how it goes. Picking up a hotter cam next week, probably something a step or two shy of the xe268 Comp. Got summit headers, performer intake, Eddy 1406 waiting to go on once I finish the bearing/ring job. I'll have to check out those pistons, 69bee. They are "taller" than the stockers? Summit doesnt show much for deck clearance, just diameter generally.

Once I get the motor in and purring, after I get bored of it I'm going to have the heads milled a little and bigger valves put in. I'm going to attempt my own port job here shortly. Got a set of junk stock heads to practice on, luckily.

right now I'm busy cleaning the block to prep for paint. All the local shops want an arm and a leg for thermal/jet, and I'm ballin' on a budget, so we'll just have to hooe for the best, lol.

They are taller by about 0.025". The deck height won't be shown, but it lists the compression distance.