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Cam Experts.. please read

2104 Views 20 Replies 8 Participants Last post by  choaderboy2, 
K
Ok, so i ve been asked to look into some cams for sr20 motors..

i have access to a very very well known company and they will regrind

a few sets for me.. how would you go bout setting up what duration and

lift? The company suggested some numbers, but how exactly would you go

bout getting that done? Does JWT list their cam specs? or anyone else?


thanks
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S
stay away from any regrinds. Besides there are more things than lift and duration needed when designing a cam. Go buy some already made and be done.
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C
Regrinds are ghetto.
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Kteller8 said:
Ok, so i ve been asked to look into some cams for sr20 motors..

i have access to a very very well known company and they will regrind

a few sets for me.. how would you go bout setting up what duration and

lift? The company suggested some numbers, but how exactly would you go

bout getting that done? Does JWT list their cam specs? or anyone else?


thanks
Click to expand...
Cam desgin is a science, the days of ******* regrinds are long past. What you will get is a Chevy master that is close.

Regrinds screw up your rocker arm geometry. No regrinder is going to put any engineering effort into desgining a lobe profile considering valvetrain harmonics, etc.

Every company that had SR20 regrinds made cams with a very narrow powerband and sometimes less power than stock.

Mike
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S
I posted this in the double thread:

"Why waste your time creating your own? JWT spent years researching, testing and developing different grinds, just buy some from them. S3 or S4 is a good choice."

Then he Kteller replied with all this garbage saying why do anything unique and who cares if they're already made. So then I posted this congratulating him on his ignorance:


:D
See less See more
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Storm88000 said:
I posted this in the double thread:

"Why waste your time creating your own? JWT spent years researching, testing and developing different grinds, just buy some from them. S3 or S4 is a good choice."

Then he Kteller replied with all this garbage saying why do anything unique and who cares if they're already made. So then I posted this congratulating him on his ignorance:


:D
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Have the regrind company do something like a 270 degree duration and .500 lift on stock valve springs, its posible JWT does it.

Please report your dyno results.

Its all good, maybe we can learn a few things from desire to be unique. Learning is what its all about.

As a warning, it might get expensive to try to improve.

Mike
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JRios
That exactly what i wanted to do with my car. I have custom regrinds in my car right now. They're 270 x .403, the cam maker warned me about going any higher with the lift because there would be to much loss in base circle, so I settled with .403
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JRios said:
That exactly what i wanted to do with my car. I have custom regrinds in my car right now. They're 270 x .403, the cam maker warned me about going any higher with the lift because there would be to much loss in base circle, so I settled with .403
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Did you get to dyno your cams yet?

Mike
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JRios
Not yet, I plan to do it sometime in March or April.
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Kteller8 said:
Ok, so i ve been asked to look into some cams for sr20 motors..

i have access to a very very well known company and they will regrind

a few sets for me.. how would you go bout setting up what duration and

lift? The company suggested some numbers, but how exactly would you go

bout getting that done? Does JWT list their cam specs? or anyone else?


thanks
Click to expand...
http://web.utk.edu/~cjohns32/camlist.htm
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JRios said:
Not yet, I plan to do it sometime in March or April.
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Please post your results when yo uget around to it.

Mike
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T
Some regrinders maintain the base circle - how? - by metal spraying to build the cam up to the required amount of material. Why is it no-one mentions this when talking about regrinds?
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Storm88000 said:
I posted this in the double thread:

"Why waste your time creating your own? JWT spent years researching, testing and developing different grinds, just buy some from them. S3 or S4 is a good choice."

Then he Kteller replied with all this garbage saying why do anything unique and who cares if they're already made. So then I posted this congratulating him on his ignorance:


:D
Click to expand...


thanks everyone and its nice to see the other members of the forum, have at least some desire to learn and dont find humor in being such an a$$hole!
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choaderboy2 said:
Have the regrind company do something like a 270 degree duration and .500 lift on stock valve springs, its posible JWT does it.

Please report your dyno results.

Its all good, maybe we can learn a few things from desire to be unique. Learning is what its all about.

As a warning, it might get expensive to try to improve.

Mike
Click to expand...

Well I have access to a few sets of cams just sitting here, that have come through the yards..

because of who i know, i can get them regrinded by a good facility pretty cheap:

only problem is the availabity of a dyno :(
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T4 Primera said:
Some regrinders maintain the base circle - how? - by metal spraying to build the cam up to the required amount of material. Why is it no-one mentions this when talking about regrinds?
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metal spraying doesnt work too well, hard face welding is much better but its very expensive, like 60 bucks a lobe. Metal spray sometimes doenst attach well. Even hardface welding has porosity problems.

Mike
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Kteller8 said:
Well I have access to a few sets of cams just sitting here, that have come through the yards..

because of who i know, i can get them regrinded by a good facility pretty cheap:

only problem is the availabity of a dyno :(
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I hightly advise against attempting to regrind but keep us posted.

Mike
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choaderboy2 said:
metal spraying doesnt work too well, hard face welding is much better but its very expensive, like 60 bucks a lobe. Metal spray sometimes doenst attach well. Even hardface welding has porosity problems.

Mike
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I realise that generally the rebuilt lobes aren't in the same league as a new blank, although as with all things advances in the technology are made from time to time.

My point was to make people aware that a regrind doesn't always lead to reduced base circle diameters and changes in valve train geometry.
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K
exactly.. i know that they wont be the same as new blanks.. thats just common sense.. also why the new cams are priced a lot higher.. when talking with a company in asia bout setting up new blanks.. they run a crazy price..

but i dont see why regrinds wouldnt work just for a temp time frame or just to add a little extra to the setup? if i was going all out 900hp etc.. no regrind isnt what id do.
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Kteller8 said:
exactly.. i know that they wont be the same as new blanks.. thats just common sense.. also why the new cams are priced a lot higher.. when talking with a company in asia bout setting up new blanks.. they run a crazy price..

but i dont see why regrinds wouldnt work just for a temp time frame or just to add a little extra to the setup? if i was going all out 900hp etc.. no regrind isnt what id do.
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There is way,way more to designing a cam by just specing lift and duration.

Unless they are going to be very cheap, no one is going to buy them. Plus you are not going to get much power. As far as the significance of valvetrain geometry can camshaft desing, I suggest doing a lot of reading on the subject on a higher than internet forum level since you are planning to be in the business.

I am not discoraging you to try regrinds, please test them and share your results with us, I don't think that you are going to get good results like that but what the hell, give it a shot.

Mike
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choaderboy2 said:
There is way,way more to designing a cam by just specing lift and duration.
Mike
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I was just saying the same thing to someone in NZ who wanted to grind a cam to JWT specs - that the specs alone would not give him the profiles needed to prevent spring surge.

I told him to choose something with more duration for a given lift, or less lift for the same duration to keep things on the conservative side of what JWT does.

Personally, I would choose a JWT cam or possibly a Tomei. Both can be had with accompanying ECU upgrades. AFAIK, JWT has the edge on numbers and Tomei has the edge on price.

Regrinds just aren't that much cheaper than a billet if they are done properly.
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