How far in the hole 318 pistons

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273 said:
everybody's level of compromise is different.
this. thank you for summing up everything i was going to say and spare everybody having to read it. and all in one sentence.
 
this. thank you for summing up everything i was going to say and spare everybody having to read it. and all in one sentence.
It's not only about compromise, it's about my idea being different from yours or anyone else's and yall's ideas being different than mine. Just because someone does something different, doesn't make it "wrong". How many times have we all seen a guy come on here saying I have "this" cam and I'm running "this" compression can you help me lake it work? The answer to that question is always a resounding YES. Yup, that cam they have might be way big for their compression, but it's what they HAVE. 10 times outta 10 if they listen and follow the advice of those here, it'll run and run better than they ever imagined. What some don't understand is, even when their advice is followed to the TEE matching this with that, there's always, always ALWAYS SOMETHING LEFT ON THE TABLE. Read that again. Something can ALWAYS be a "better" combination. Who was the guy on here recently who had a cam "too big" for the forum heros? @shittyslant6 wasn't it you? I think it was. He'll be a great example. That engine will run like gangbusters if he follows a few simple things...and I know he will because he's smart. The bottom line is, there's no ONE right way to do it. Your way, my way and someone else's way can all be the right way. Some people need to just shut up and get that through their thick skulls.
 
It's not only about compromise, it's about my idea being different from yours or anyone else's and yall's ideas being different than mine. Just because someone does something different, doesn't make it "wrong". How many times have we all seen a guy come on here saying I have "this" cam and I'm running "this" compression can you help me lake it work? The answer to that question is always a resounding YES. Yup, that cam they have might be way big for their compression, but it's what they HAVE. 10 times outta 10 if they listen and follow the advice of those here, it'll run and run better than they ever imagined. What some don't understand is, even when their advice is followed to the TEE matching this with that, there's always, always ALWAYS SOMETHING LEFT ON THE TABLE. Read that again. Something can ALWAYS be a "better" combination. Who was the guy on here recently who had a cam "too big" for the forum heros? @shittyslant6 wasn't it you? I think it was. He'll be a great example. That engine will run like gangbusters if he follows a few simple things...and I know he will because he's smart. The bottom line is, there's no ONE right way to do it. Your way, my way and someone else's way can all be the right way. Some people need to just shut up and get that through their thick skulls.
Mr. Rod, or do you prefer Mr. Rat? Thank you for your balanced and thoughtful reply, we will forward this to the colleagues for their perusals on the matter and expect a judgement on the matter sometime in the near future.

At this time, we request you keep doing things my way, the right way, and to my idea, because frankly that's the only way to do it; and no body can question that. i will, at request, lay forth the maths but frankly i think that there be no need for it at this time.

Much obliged,
-JYH LLC
 
It's not only about compromise, it's about my idea being different from yours or anyone else's and yall's ideas being different than mine. Just because someone does something different, doesn't make it "wrong". How many times have we all seen a guy come on here saying I have "this" cam and I'm running "this" compression can you help me lake it work? The answer to that question is always a resounding YES. Yup, that cam they have might be way big for their compression, but it's what they HAVE. 10 times outta 10 if they listen and follow the advice of those here, it'll run and run better than they ever imagined. What some don't understand is, even when their advice is followed to the TEE matching this with that, there's always, always ALWAYS SOMETHING LEFT ON THE TABLE. Read that again. Something can ALWAYS be a "better" combination. Who was the guy on here recently who had a cam "too big" for the forum heros? @shittyslant6 wasn't it you? I think it was. He'll be a great example. That engine will run like gangbusters if he follows a few simple things...and I know he will because he's smart. The bottom line is, there's no ONE right way to do it. Your way, my way and someone else's way can all be the right way. Some people need to just shut up and get that through their thick skulls.
yeah Its a big *** isky .505 505 .292/292. 108lsa. 10.85:1 comprerssion (theoretically) and speedmaster 170cc heads.
stock crank, 318, old used circle track 340 rods, $50 dollar torker 340, I already had the cam kit and heads, hell I even had some old mahle main bearings and ARP rod bolts I found at pomona.

The only thing I will need to buy are lifters, headers, and some paint.

Is the cam too big for the street? probably. Is it cheaper than a new one? yes.
And it'll beat the **** out of my friends chevys.
 
Mr. Rod, or do you prefer Mr. Rat? Thank you for your balanced and thoughtful reply, we will forward this to the colleagues for their perusals on the matter and expect a judgement on the matter sometime in the near future.

At this time, we request you keep doing things my way, the right way, and to my idea, because frankly that's the only way to do it; and no body can question that. i will, at request, lay forth the maths but frankly i think that there be no need for it at this time.

Much obliged,
-JYH LLC
LOL
 
yeah Its a big *** isky .505 505 .292/292. 108lsa. 10.85:1 comprerssion (theoretically) and speedmaster 170cc heads.
stock crank, 318, old used circle track 340 rods, $50 dollar torker 340, I already had the cam kit and heads, hell I even had some old mahle main bearings and ARP rod bolts I found at pomona.

The only thing I will need to buy are lifters, headers, and some paint.

Is the cam too big for the street? probably. Is it cheaper than a new one? yes.
And it'll beat the **** out of my friends chevys.
It'll run good too. Don't let the fruitcakes convince you otherwise. Get the compression verified though, not theorized. That's important, but you already knew that.
 
It'll run good too. Don't let the fruitcakes convince you otherwise. Get the compression verified though, not theorized. That's important, but you already knew that.
the summit calculator said 10.85 and the crower calculator said 10.87. so It should be close to that especially with zero decking the block. I'll just retard the timing a touch on pump gas.
 
the summit calculator said 10.85 and the crower calculator said 10.87. so It should be close to that especially with zero decking the block. I'll just retard the timing a touch on pump gas.
You looky here hard head. Measure it! lol
 
this. thank you for summing up everything i was going to say and spare everybody having to read it. and all in one sentence.
The skew here is, Today's 3,500-stall juicewheel ain't the same as Yo' Daddy's, let alone Yo' Grandpappy's. 3.91's??......where we goin', & what tire are We runnin'??
 
The skew here is, Today's 3,500-stall juicewheel ain't the same as Yo' Daddy's, let alone Yo' Grandpappy's. 3.91's??......where we goin', & what tire are We runnin'??
we just runnin' some cheeze dick specials, let's say somewhere between 205/70-14 and 245/60-15 so something in the 26-ish range.

and we goin' to see your sister who lives on campus at college out of town. it's about an hour and a half drive in the middle of the night, mostly freeway. gas is $5 a gallon and i can't stand to lose much more of my hearing, let alone my mind. and my radio sucks, so it won't be loud enough to drown out the noise.
 
we just runnin' some cheeze dick specials, let's say somewhere between 205/70-14 and 245/60-15 so something in the 26-ish range.

and we goin' to see your sister who lives on campus at college out of town. it's about an hour and a half drive in the middle of the night, mostly freeway. gas is $5 a gallon and i can't stand to lose much more of my hearing, let alone my mind. and my radio sucks, so it won't be loud enough to drown out the noise.
Ahhh, You need a Corolla......
 
Ahhh, You need a Corolla......
my man!

look, i'm all for 3500 stall and some 3.91's if it's just me and big nose bobby pounding around town or grabbing short john so we can get over to the DQ and meet up with big wendy and her lil' sis.

but sometimes i actually like to get out of this **** hole town, see the sights for a bit, know that there's more to this world and one day think about leaving this dump behind in my rearview.

and frankly my motor, sanity or pocket book can't take 3.91's on the highway. so i'll just have to come to terms with being embarrassed by kids in their mustangs at all the stop lights because i put a 4bbl on my wheeze bag 318 2bbl.

but i've got flow masters that dump at the axle so it sounds boss and i jacked the line pressure in the trans and it'll bark 2nd, so i've got that going for me.
 
my man!

look, i'm all for 3500 stall and some 3.91's if it's just me and big nose bobby pounding around town or grabbing short john so we can get over to the DQ and meet up with big wendy and her lil' sis.

but sometimes i actually like to get out of this **** hole town, see the sights for a bit, know that there's more to this world and one day think about leaving this dump behind in my rearview.

and frankly my motor, sanity or pocket book can't take 3.91's on the highway. so i'll just have to come to terms with being embarrassed by kids in their mustangs at all the stop lights because i put a 4bbl on my wheeze bag 318 2bbl.

but i've got flow masters that dump at the axle so it sounds boss and i jacked the line pressure in the trans and it'll bark 2nd, so i've got that going for me.
Having ran 4.89's w/275/60-15's, 4spd., 383 w/1 7/8" headers, no radio, no HVAC, no floor padding,.....I feel Ya'...that was close to 35yrs ago, would I do it now? NFW,...but it was fun at the time, lol!!!!!
 
Wow! I sure did some responses that set off in all different directions! Maybe I will give more information and maybe someone that has pulled a 1972\1980 318 can give me an answer!
I have a 410 hot rod engine in my other car that runs low elevens and gets 23mpg on a run.
It is a 410 with 11/1 comp with forged pistons ,I beam rods, trick flow heads and a 340 victor port matched with 5 speed manual trans and 3.91 diff.
This is my other car that has 55000 miles on the clock and is a 1973 Australian Valiant charger 318 auto with air and steer and looks and drives like new with 95% factory original paint that is as good as the day it was built!
As a car like this is worth over $100 grand in aus I do not want to hot rod it but just keep it looking std but with a bit more poke. I have a spare set of heads that I have already worked on the ports and bowls and have ordered a set of 1.880 inlet valves and will be sending them to my head machinist that I have known for about forty years that will do a good 5 angle valve job and reduce the chambers to about 56CCs.
I am getting a roller camshaft and lifters for it but Mike at B3 needs to know a rough idea of compression to design a cam that idles like stock and has good low end response for me.
This car will have 360 exhaust manifolds and a 2.5 inch single system. The car at this time has a edelbrock performer manifold with an AVS2 500 on it but still sports the original 318 Fireball air cleaner that makes the engine bay look like stock.
I do not want to pull the heads off and let this car sit for months on end waiting for the parts to arrive from the USA.
All I am asking is has anyone measured how far in the whole was there 1971/1980 model 318 to find the average number that I can expect.
The small block mopar engines book that I have states the 1972 engines were .056 in the hole but I tend to think that they are generally further down and our Australian spec sheets on our 1973 318 says 8.2 to one compression. I will be machining down the heads to attempt to get about 56CCs and hopfully closer to near 9 to 1 comp.
Have a nice day!
 
Wow! I sure did some responses that set off in all different directions! Maybe I will give more information and maybe someone that has pulled a 1972\1980 318 can give me an answer!
I have a 410 hot rod engine in my other car that runs low elevens and gets 23mpg on a run.
It is a 410 with 11/1 comp with forged pistons ,I beam rods, trick flow heads and a 340 victor port matched with 5 speed manual trans and 3.91 diff.
This is my other car that has 55000 miles on the clock and is a 1973 Australian Valiant charger 318 auto with air and steer and looks and drives like new with 95% factory original paint that is as good as the day it was built!
As a car like this is worth over $100 grand in aus I do not want to hot rod it but just keep it looking std but with a bit more poke. I have a spare set of heads that I have already worked on the ports and bowls and have ordered a set of 1.880 inlet valves and will be sending them to my head machinist that I have known for about forty years that will do a good 5 angle valve job and reduce the chambers to about 56CCs.
I am getting a roller camshaft and lifters for it but Mike at B3 needs to know a rough idea of compression to design a cam that idles like stock and has good low end response for me.
This car will have 360 exhaust manifolds and a 2.5 inch single system. The car at this time has a edelbrock performer manifold with an AVS2 500 on it but still sports the original 318 Fireball air cleaner that makes the engine bay look like stock.
I do not want to pull the heads off and let this car sit for months on end waiting for the parts to arrive from the USA.
All I am asking is has anyone measured how far in the whole was there 1971/1980 model 318 to find the average number that I can expect.
The small block mopar engines book that I have states the 1972 engines were .056 in the hole but I tend to think that they are generally further down and our Australian spec sheets on our 1973 318 says 8.2 to one compression. I will be machining down the heads to attempt to get about 56CCs and hopfully closer to near 9 to 1 comp.
Have a nice day!
Tolerances vary, plus Australia might had different specs only way to know for sure is measure, but it's probably more than stock spec if it says .056" probably more like .080"-.100" is what I've always heard.
 
I believe Australian engines did not get hit with with too many emissions requirements until later in the decade and in general were built off the original LA 318 specifications.
built in a new facility with an engaged workforce.
it will be closer to the book than not.
if the car is as original as you say all you can assume is that nobody has been in there before you

1972 block will have been cast before all the crap in the press about "bullets on wheels" being sold to 16 year old kids as well.

as stated elsewhere the gasket thickness and hole size or assumptions regarding chamber size and shape might alter CR by a few 0.1


you see it on the hemi 6s as well

mid to late 70s CR goes down, piston disappears down the bore, core shift problems some thick wall some thin wall some with the filled in webbing for 904/727/small block bell housing dowels, regardless of if necessary .

short of estimating by doing a compression check not sure you can be any more precise

id buy the cam based on what i have researched can be achieved in my budget with the standard head and block
then make it so, with head and block machine work and the chosen pistons.
KB or sealed power do slightly taller pistons go for the flat tops, rather the the Mount Kilimanjaro shaped ones. Everyone i know who used them in a performance build had to cam it top stop it pinging. (maybe they just build crap motors :)

id guess its going to be in the machine shop dismantled anyway

roller cam might involve sleeved bores or some kind of oil control in the lifter gallery
custom pushrods?? may be some clearancing for them
adjustable rockers
top of valve guide work for seals and space to get more spring in
appropriate length valves
special oil pump/dizzy drive. to cope with cam material
fuel pump hardened lever or electric?

it was all the extra work( $$$$) that put me off doing roller cam on hemi6 presume its similar on 318 although way more aftermarket support so maybe not. it will probably cost you less than it would have cost me

apologies if i had made too many assumptions about what you are trying to do


Dave
 
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How about searching out an '89 - '91 roller 318, or the earlier '86 - '88 roller 318?

The generation of 318 Roller Cam engines all came with the flat top pistons .040 ths down in the hole at 9.2:1 c.r. stock without even having to touch them.

With the factory 302 Closed Chamber heads with the large push rod holes, because the roller lifters sit higher and the pushrods need more room to swing in the heads.

Thin Mr. Gasket 1121 head gaskets at .028 ths compressed are available also.

Here is an '89 date coded 318 roller short block.

20200608_201627.jpg


302 closed chamber heads.

1020161100.jpg


Want a long snout roller cam (or the cam snout adapter). I currently have an '89 Truck with the roller 318 that came with the factory long snout roller cam, fuel pump eccentric and proper timing chain cover to mount the mechanical fuel pump to.

Got lucky on this one, as it had a fuel pump block off plate on the timing cover with all the good parts inside.

Surprisingly the factory roller cam performs quite well with the added 4 barrel carburetor, giving the engine the fuel it needs to perform. Factory valve train with the stock factory valve springs made for the roller cam allows higher rpm without the valve float.

If you go with a high lift roller cam, then you are going to have to re-engineer the valve train and springs.

Up to you... this has successfully worked for me. I am not a racer, but do enjoy a good running street driven vehicle with the added performance of the 4 barrel and the secondaries.

Good Luck with your projects.


☆☆☆☆☆
 
A 318 will swap in yes and I've ran one in my Dart long ago, but I've since unloaded all my teens. I used to get them cheap or free so hanging on to them was sort of foolish. Like collecting scrap. I deleted my post I figured I didnt want to upset the folks here and get banned its a mob mentality here with 318s LOL!:)
 
A 318 will swap in yes and I've ran one in my Dart long ago, but I've since unloaded all my teens. I used to get them cheap or free so hanging on to them was sort of foolish. Like collecting scrap. I deleted my post I figured I didnt want to upset the folks here and get banned its a mob mentality here with 318s LOL!:)
Mob mentality? And the 340/360/stroker guys aren't? :rofl:
 
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