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3/4 race cam

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#21 ·
Here are the cam spec's from my 1982 Isky cat. to give us an idea of what they are like.

1932 to 1953 Flathead V-8.

Street and strip 3/4 Race Cam!

Isky Max. #1 = 17/52 intake, 57/12 exhaust duration at .050", 249/249 advertised duration, .364"/.364" gross lift, lash .014"/.014".

And

Competition Full Race Cam!

Isky 400 Jr. = 18/60 intake, 60/18 exhaust duration at .050", 258/258 advertised duration, .400"/.400" gross lift, lash .018"/.018".

Remember that lift is right off the lobe here too..........

My copy of D2k isn't on this machine so would somebody please run the duration at .050" numbers backwards and tell us what the .050" cam timings actually are?

pdq67
 
#22 ·
Tokyo Torquer said:
Yes this term was used by the cam manufacturers back then. It means BS to me, but signified that the profile was intended for a car that saw the race track 75% of the time and the street ocassionally 25% of the time. That was the idea of that discriptor.

I do hate though when today when someone comes up to me and asks if I have a 3/4 cam in my car. I cannot think of an intelligent reply that means anything and telling them the actual cam specs flies over their heads.
Click to expand...
I'd Just say nope I wanted it to run on all 8 cylinders so I put the full cam in my car. :clonk:
 
#23 ·
My dad uses 3/4 race cam...full race cam etc,but he is definetly OLD school.His hotrod days were the late 40's and early 50's and he and his buddys are interesting to listen to.The flat head ford was king then and they did some amazing stuff.There was no performance parts house or even anything resembling an autozone then....most of the stuff they machined and made up as they went along.He still tells the story of dualing out a straight 8 buick he had by cutting in a second outlet and they bent all the pipe in a manual tube bender...they also converted alot of flathead fords to overhead valve by reworking 2 overhead valve 4 cyl heads,remachining them to fit a flathead....pretty amazing stuff when you think about it,so I let him get away with "3/4 race cam"
 
#24 ·
#25 ·
zdld17 said:
And I thought I was the only one stuck in the 50's. I even heard one guy say the cam was huge! Lobes that big ( illustrating size of small bass). My reply was " how did they get it into the motor?"
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My dad was a hot rodder that had many flatheads. That's where I heard it the first time. I was at a car show in July and a guy had a flat head Ford something with a "3/4 race cam" and special heads. It sounded very cool.
 
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#26 ·
PFFFFFFFFFFFFFFFF when u was like 14 i remeber my mab habd wiliams bitchen abour 3/4 race cams. it means **** all. is a generic tearm for a lumpyer thebn stock cam. i hate this tearm is should be abolosied from perfroamcne history
 
#27 ·
I guess the pup's don't understand OR have any respect for the old dogs!

You guys have to remember that life before the SB Chevy WAS the Flathead Ford!!!

And guy's, this is even before my time and I'm damned near as old as dirt!!!!

pdq67
 
#28 ·
pdq67 said:
I guess the pup's don't understand OR have any respect for the old dogs!

You guys have to remember that life before the SB Chevy WAS the Flathead Ford!!!

And guy's, this is even before my time and I'm damned near as old as dirt!!!!

pdq67
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Thanks. I wanted to say that, but had second thoughts. That is the heritage. Not only that, but all Chevy ever had to compete with Ford was an inline 6. LOL. :thumbsup:

There are still plenty of flathead engines and hot rods around. Still plenty of parts being made for them too.
 
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#29 ·
Lieutenant Longarm said:
PFFFFFFFFFFFFFFFF when u was like 14 i remeber my mab habd wiliams bitchen abour 3/4 race cams. it means **** all. is a generic tearm for a lumpyer thebn stock cam. i hate this tearm is should be abolosied from perfroamcne history
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HUH?????? Are you using an English keyboard?
 
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#31 ·
zdld17 said:
And I thought I was the only one stuck in the 50's. I even heard one guy say the cam was huge! Lobes that big ( illustrating size of small bass). My reply was " how did they get it into the motor?"
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LOL :D
When I was in high school, I had heard that very same thing from several "wannabe" hot rodders. You know, they used cams so big that they had to have the blocks cam bores bored oversized to make the cam fit :rolleyes:
 
#32 ·
I don't think anyone is dis-respecting the old school and older rodders. I just think cam technology along with all other automotive technology has come such a long way, that it makes no sense at all to refer to a cam as 3/4 race. "Back then" things were different , in todays world you get a cam card with all the specs, cams are degreed in, we don't have the good gas, etc.. so things are a little more detailed. there is nothing wrong with a flat head Ford, it was one of the first "true" hod rod engines.
 
#34 ·
Again, would somebody please run the duration at .050" numbers for those two Isky cams so that we can get a better idea just what the actual timing is like..

Thanks, I'd do it but I'm not on my machine! Suckers BROKE>>>>>>>>>>>............................Bad, Bad, Bad!!

pdq67
 
#36 ·
Wow lots of guys on here are pretty critical of the old boys at shows trying to make conversation about their cars!!! Damn, chill out fellas, not everyone is down with all the terminoligy and up to date tech. Heck if some old timer came over and asked me if i had a 3/4 cam in my car id probably say..."yeah somthing like that". I sure as hell wouldnt roll me eyes and tell him hes a dousche bag for not knowing anything about cars. Some people just enjoy the hobby as an onlooker and have no clue but they try to make conversation because theyre nice guys, obviously about somthing they heard about years ago.....Now on the flip side if youre talking about some clown being a blow hard about how he had a 66' camaro with a 15:1 427 hemi with a 6-77 supercharger and a 3/4 cam backed up by his M-23 and some track only gears. Then by all means clown on the man!!!
 
#37 · (Edited)
Right!!

What I am saying is that that is what they had to go by back then and it worked pretty darn good for them too!

Anybody backwards run the cams I asked to be ran yet??

Guys, I have to say that when I started driving, I wanted a '50 Ford 2-dr. b/c my Buddies drove them... But luckily I ended up with a '57 Chevy instead!!

Back then you could pick up a good '49 to '51 Ford for like $300 and stepping up to a '55 or '56 Ford was like $600 or so..

And to me to this day the '55 Ford with the non-Chrown Vic. chrome piece h/t on it is one damned good looking 2-dr h/t car!!

My Buddy had one and he had a hopped up Isky Z-30 cammed, Stromberg tripped, Heddman headered, .060" over Jahn's pistoned, high compressioned 292 Y-block in it and I/m here to say it ran darn good BUT not anywhere near as good as a hopped up 301 motor!!

pdq67
 
#38 ·
PDQ- you may appreciate this.
Back in the 50's, my brothers father-in-law used to run his car (50's something ford) at the drag strip that I run at now. At the time, the track was dirt and everyone ran snow tires. One guy came up with the bright idea of putting 1/4 20 stove bolts in his snow grips for better traction, Apparently, it worked because everyone accused him of cheating!
 
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#40 ·
pdq67 said:
Here are the cam spec's from my 1982 Isky cat. to give us an idea of what they are like.

1932 to 1953 Flathead V-8.

Street and strip 3/4 Race Cam!

Isky Max. #1 = 17/52 intake, 57/12 exhaust duration at .050", 249/249 advertised duration, .364"/.364" gross lift, lash .014"/.014".

And

Competition Full Race Cam!

Isky 400 Jr. = 18/60 intake, 60/18 exhaust duration at .050", 258/258 advertised duration, .400"/.400" gross lift, lash .018"/.018".

Remember that lift is right off the lobe here too..........

My copy of D2k isn't on this machine so would somebody please run the duration at .050" numbers backwards and tell us what the .050" cam timings actually are?

pdq67
Click to expand...
I have tried to get the numbers from running the DCR program backwards, but can not get close to the numbers.
 
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