Is this possible, or is my dad having memory issues?

[BIRD67]

 My uncle owns a '68 Plymouth Barracuda, it has a 2.76 geared 8 1/4 differential.. My dad bought this car some time in the 1980s then sold it to him. My dad said the engine is a 318 with stock 360 non magnum heads, a single plane intake with an edelbrock 750 carb and an Erson cam, he also said that the car has long tube headers with 2 1/4 straight pipe and glasspacks.. The transmission, as of now is a blown up 904..

I asked my dad how he ucould use stock 360 heads on a 318 without losing all compression and he said that the cam had enough character that it made up in it.. I'm not sure how all of this works out power-wise but he said the car had a pretty much unlimited top end on the california freeways where he used to live..

Do any of you engine guru's think this engine combination is logical, does it make power or is my old man losing his memory?

I've attached some not so decent pictures of the car from 2 years ago..

[Cooter]

Well, My experience is the older one gets, the faster one was.....


However, It doesn't take alot of compression to run "Top end"...It's the Low end that usually suffers from low compression and the like....I too have heard from the older guys about the ever popular "Hemi Cop cars" that would always catch the fastest car in town when none of the 440 "pursuit" cars could even get close....My favorites are the "She'll jerk the front wheels off the ground in second gear son".....and the ever popular "I used to Jump pop bottles with it"....

[Challenger340]

The very early 318 Engines('68) had a higher Compression distance piston, if thats still whats in there ?
The 360 Heads would undoubtedly Lower the CR on any 318,
but,
if they are the "early" pistons, it may not be as long as you think ? or, as low as when 360 Heads are applied to the later 318's.

No matter,
it can be fairly "surprising", how well even the Low-pop 318's respond to the 360 Head Swap with the right Cam.

The stock 340 Cam used to work excellent, even on those low CR 318/360 head Conversions once the rpm came up !

I got NO PROBLEM believing yer Old Man !

[oldschool]

yeah,the older i get,the better i was....

[BIRD67]

The very early 318 Engines('68) had a higher Compression distance piston, if thats still whats in there ?
The 360 Heads would undoubtedly Lower the CR on any 318,
but,
if they are the "early" pistons, it may not be as long as you think ? or, as low as when 360 Heads are applied to the later 318's.

No matter,
it can be fairly "surprising", how well even the Low-pop 318's respond to the 360 Head Swap with the right Cam.

The stock 340 Cam used to work excellent, even on those low CR 318/360 head Conversions once the rpm came up !

I got NO PROBLEM believing yer Old Man !

Yes, from what he told me it is running the stock pistons and the engine is original to the car.. Oh btw, he's not running glasspacks he's running a set of thrush turbo mufflers on it.. I asked him what he thought the max rpm he could rev it to was and he said an absurd number like 7500 rpm.. is it even possible for a stock 318 block with the aftermentioned mods to sustain that? I would expect the bottom end and valvetrain to not be able to withstand such high engine speeds?

[mauve66]

Well, My experience is the older one gets, the faster one was.....


However, It doesn't take alot of compression to run "Top end"...It's the Low end that usually suffers from low compression and the like....I too have heard from the older guys about the ever popular "Hemi Cop cars" that would always catch the fastest car in town when none of the 440 "pursuit" cars could even get close....My favorites are the "She'll jerk the front wheels off the ground in second gear son".....and the ever popular "I used to Jump pop bottles with it"....

i've seen the photso of my dads 67 289 hipo 4 spd mustang doing it, they weren't standing up but laying down on their sides and the front wheel cleared it

[Challenger340]

Yes, from what he told me it is running the stock pistons and the engine is original to the car.. Oh btw, he's not running glasspacks he's running a set of thrush turbo mufflers on it.. I asked him what he thought the max rpm he could rev it to was and he said an absurd number like 7500 rpm.. is it even possible for a stock 318 block with the aftermentioned mods to sustain that? I would expect the bottom end and valvetrain to not be able to withstand such high engine speeds?
[/quote]

I'd pluck on the 7500rpm, it would need some stable Valvetrain Dynamics up there ?, not to mention stout Rod Bolts in the Bottom end ?
But,
we beat a few wee-18's "back in the day", right around 6K regularily, maybe a bit more ? with the 1968 340 "p" designation sticks.  

Dunno what, or even IF, we were still in the power range back then, most probably NOT, but they sure sounded good ?
Dyno's were a dream for us back then, however, 13.60's @ 98 mph with a "stock" '73 318 and 2.02 J Heads in an A-Body W/4.10's seemed GREAT back then !

[BIRD67]

Okay so I talked to my dad today, he said the cam is probably right around a 228/238 which is pretty choppy.. I asked him about the pistons and he said that they sit in the block and do not come in contact with the heads leaving a gap..

[elacruze]

The very early 318 Engines('68) had a higher Compression distance piston, if thats still whats in there ?

Interested...I didn't find any indication of this while researching my pending 318 build...a '68 210hp truck 318. Can you point out any resources, or do you know the compression/deck height? Knowing won't change what's inside the motor, but it's food for thought.

[Challenger340]

The very early 318 Engines('68) had a higher Compression distance piston, if thats still whats in there ?

Interested...I didn't find any indication of this while researching my pending 318 build...a '68 210hp truck 318. Can you point out any resources, or do you know the compression/deck height? Knowing won't change what's inside the motor, but it's food for thought.

Just from memory pulling them apart back in those days ?
We could measure back then, and they were within .020 of deck from what I remember ?, with a steel shim Head gasket.

I'm sure there's plenty enough online resources, to do a C.R. Check on 318's through the years ?
here's one dropping the CR from 9.2 in 1969 to 8.6 in 1971.
see here;
http://www.mymopar.com/enginespecs.htm

CR's started dropping round about 70-72 due the energy crisis, easiest way was to start dropping Compression heights on Pistons as Chrysler did.