Best accelerating camshaft? (high rpm,high torque)

#1
Just wondering if their were any good opinions if one wanted to go fast and go fast quickly with out giving any further details.
EDIT: just to clarify..i am ONLY asking about the camshaft.

i was going to get the Black Mamba but everywhere is out of stock so i bought the .275 cam.
 
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CarPlayLB

Well-Known Member
#2
This question equates to "what spice to use"...garlic is great for steak, but no so much with vanilla ice cream.
Camshaft selection is a process that needs to take all the other components into account. Compression ratio? Carb? Header length? Governor?
 
#3
i was afraid i would need to explain further.
hmmm.. but i really need to know quick before the camshaft i just bought ships.

I'm just looking for a quick and responsive camshaft with stock 8.5 compression,something with almost too much torque that i will have to easily throttle into. other things i will worry about later if needed.

The normal Billet parts and governor removal are taken care of already,thanks.
 
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#5
No, there is NO "good" opinion possible, without those pesky details...

BM Jr is likely what that combo would like.
the .275 cam i ordered is like a middle between the jr and the sr besides the .275 having a 109LSA compared to Mamba jrs nice looking 104 LSA.


So you two don't know. i'm hoping someone that does will see this post and reply soon.
i may just need to adjust the torque converters stall speed.
Sorry i just REALLY want the best quality for the $100 i paid.
 
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#8
Like we both said, a cam is designed for a specific combination, so there is no "best", and any answer without all the variables is an uneducated guess.

But, if it's the .275 that has almost 240 degrees at .050 and on 109lc,, stock compression is going to make it fall on it's face until way up top. About where stock port/valve/carb begin to die.
Are you 100% sure? the isky cam is the same thing except less duration?
and what makes you think that?

i'm just testing you to see if you know what you're talking about. What would make it fall on its face?

stock besides : 18pound springs (UNTIL I GET A BETTER CAM RECOMMENDATION) performance exhaust and intake.
 
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trinik7597

Active Member
#9
What motor ? You say it's stock but then you say you have billet parts ? 18lb springs are stock gx140 springs ... Not really good .too many coils bind with any real lift . you need to build a motor so everything works together .
 
#10
Sounds like you already know if you're testing us? I wouldn't recommend a cam to anyone without engine details, weight, gearing etc. Sounds like you want a cam, not necessarily the right one for the job. BTW, 18# springs with the 275 won't cut it....


Sent from my Texas Instruments Speak and Spell...[emoji2]
 

CarPlayLB

Well-Known Member
#12
You will say we failed your "test" when your stock compression engine, 17 tooth clutch, 60 tooth rear gear, and 16" tall tire is such a dog!
 
#13
What motor ? You say it's stock but then you say you have billet parts ? 18lb springs are stock gx140 springs ... Not really good .too many coils bind with any real lift . you need to build a motor so everything works together .
sorry, i meant performance-wise it is basically stock besides the springs.
It's a predator 212cc .
 
#14
You will say we failed your "test" when your stock compression engine, 17 tooth clutch, 60 tooth rear gear, and 16" tall tire is such a dog!
i GUESS gear ratio is necessary to add so:
4:1 ratio. 48 tooth driven 12 tooth driver with 15 inch tires.

i apologize if i'm coming off on the wrong foot or anything bad it's just i'm trying to get the best cam for my setup in case i need to exchange my ordered 275cam monday morning .

let me think..
a gx390 carb i would like to work well with the cam (its on my list but dont want it if it won't benefit)
The block i don't mind clearancing for lift and i suppose i could work with a 36# spring kit only if it is well worth it Even though the cam i chose says for 18pound springs.

i wont hesitate to adjust the engagement speed of the torque converter with a yellow or maybe even a white driver spring.
This is the cam i purchased but am not sure about now: https://www.OldMiniBikes.com/275-Grind-Welded-Lobe-Clone-Core-Cam.html?category_id=1641 the .275,not the f-275. But like i said, my cam preference is quick with torque and fast rpms to match my gearing. Think of it like getting a car's 0-60 time as quick as possible :) and going as fast as you can 0-100mph. metaphorically speaking for a kart of course.
 
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#15
Ok, so it's on a kart? If you have a 4:1 static gear, the TAV multiplies that by 2.7:1 for low or first gear. Not sure how tall your tire is. Secondly, if it's a Comet TAV2 or knock off, they typically do not like high rpms. You can modify them as said, but even at 5500 the driven is fighting centrifugal force. Third, on a heavier kart, I think the 275 is gonna be a bit much.


Sent from my Texas Instruments Speak and Spell...[emoji2]
 
#16
i GUESS gear ratio is necessary to add so:
4:1 ratio. 48 tooth driven 12 tooth driver with 15 inch tires.

i apologize if i'm coming off on the wrong foot or anything bad it's just i'm trying to get the best cam for my setup in case i need to exchange my ordered 275cam monday morning .

let me think..
a gx390 carb i would like to work well with the cam (its on my list but dont want it if it won't benefit)
The block i don't mind clearancing for lift and i suppose i could work with a 36# spring kit only if it is well worth it Even though the cam i chose says for 18pound springs.

i wont hesitate to adjust the engagement speed of the torque converter with a yellow or maybe even a white driver spring.
This is the cam i purchased but am not sure about now: https://www.OldMiniBikes.com/275-Grind-Welded-Lobe-Clone-Core-Cam.html?category_id=1641 the .275,not the f-275. But like i said, my cam preference is quick with torque and fast rpms to match my gearing. Think of it like getting a car's 0-60 time as quick as possible :) and going as fast as you can 0-100mph. metaphorically speaking for a kart of course.
Well its only a hundred bucks.....try it and see!
 
#18
Ok, so it's on a kart? If you have a 4:1 static gear, the TAV multiplies that by 2.7:1 for low or first gear. Not sure how tall your tire is. Secondly, if it's a Comet TAV2 or knock off, they typically do not like high rpms. You can modify them as said, but even at 5500 the driven is fighting centrifugal force. Third, on a heavier kart, I think the 275 is gonna be a bit much.


Sent from my Texas Instruments Speak and Spell...[emoji2]
Yes it's on a kart. a really lightweight one. on the 4:1 ratio it loves to spin the tires with the stock cam but it gets up and going pretty quickly, i may even need to add a cement block or 2 in the back to help with the traction. 15inch rear and 13 inch front tires by the way.

i just like the feeling of acceleration in moderation just like driving a heavy tuned sports car. every millimeter of throttle will have a big impact on acceleration.
 

trinik7597

Active Member
#19
What predator old style or hemi ? If hemi 275 lift is maxed out with out head work . if old style what casting is the head ? Good for you on the apology
 
#20
What predator old style or hemi ? If hemi 275 lift is maxed out with out head work . if old style what casting is the head ? Good for you on the apology
It is a Hemi .i dont mind clearancing the block if needed. If i was to upgrade to higher compression would a 14cc be too much for this cam? it sounds like a really nice bump in torque and power.

I was in a rush to find out about the cam because i didn't know if OldMiniBikes shipped on weekends.
 
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