20v exhaust cam on a 16v small port head

xploding-twincam
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20v exhaust cam on a 16v small port head

Postby xploding-twincam » Sun Jan 13, 2013 7:54 am

Hey guys, this forum has been changing a lot,

Ok based on my topic, I have seen there has been post about this but I can't view it, can any one show me how to get to it???

If not, I have a few questions for yourl,
What are the cam specs(duration and lift) or a silver top and black top 20v motor?

Now can I fit just the exhaust cam on my 16v intake side?

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Re: 20v exhaust cam on a 16v small port head

Postby Crownvicman289 » Sun Jan 13, 2013 4:30 pm

Already tried it, the base circle is massively different thus making it a no go.

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Re: 20v exhaust cam on a 16v small port head

Postby xploding-twincam » Sun Jan 13, 2013 9:46 pm

Now what if i have the base circle skimmed down to the same as the 16v cam?
Is that all the problems?
reason is a few guys in SA have just re profiled the cams to different specs due to the cam being thicker then the stock 16v cam but i would like to know whats yourls input on it, also what are the specs on the 20v cams?

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Re: 20v exhaust cam on a 16v small port head

Postby 170bhp » Tue Jan 15, 2013 1:30 am

The guys from SA you are talking about are myself and a friend, many many years ago we used a 20v exhaust cam reground on the intake side of a 16v, the reason it was reground was two fold, first the base circle is too large and second BECAUSE the base circle is too large it means we can get it ground and get some extra duration out of it. The standard 20v ex cam duration is 250degree, we got 268degree and 8.2mm lift from getting it re ground, we did this to see what we could get 'on the cheap', it cost bugger all to do and worked reall good, infact said engine had this cam in it for many years with no problems at all, so does it work, absolutely BUT it must be re ground......which costs bugger all and you get more duration, win win!

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Re: 20v exhaust cam on a 16v small port head

Postby ga_goosh » Tue Jan 15, 2013 7:30 am

xploding-twincam wrote:what are the specs on the 20v cams?


here is a link with both the 20v cam specs along with the 16v cam specs small port and large port
http://www.billzilla.org/4agstock.htm
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xploding-twincam
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Re: 20v exhaust cam on a 16v small port head

Postby xploding-twincam » Wed Jan 16, 2013 10:08 pm

ah yes i have seen that, and that seems to be the only specs one can find, hence me asking if anyone else find they differe, some say the 20v cams are 254/256 but we will never truely know,

so what you guys think of the plan im trying to do?

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Re: 20v exhaust cam on a 16v small port head

Postby HASport AE86 » Fri Jan 18, 2013 9:25 am

....what is the purpose of doing this again? Why not just save up for 16v cams?
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Re: 20v exhaust cam on a 16v small port head

Postby xploding-twincam » Fri Jan 18, 2013 10:23 am

16v cams cost an arm and a leg and do not give you much gain,
So yes, working a budget we can afford to cut a cam to what spec we want,buy a set of cam gears for it, and still have money left over if we go this way over buying full after market cams
Cost vs kw we will win, 20v cams here are going so cheap cause guys can't sell the Stilver top cams when changing to black tops cams, making is easy for us to buy mod and fit and then it should be enough to give a 20v some good stick

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Re: 20v exhaust cam on a 16v small port head

Postby xploding-twincam » Fri Jan 18, 2013 10:28 am

@170bhp
Tell me, this spec of 268degree and 8.2mm
Was this done the only the intake cam? Did you run stock exhaust cam?
Also what power increase?
And did you do a re-shim?

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Re: 20v exhaust cam on a 16v small port head

Postby oldeskewltoy » Fri Jan 18, 2013 10:52 am

268 is a bit lopey for a stock engine.... it will likely lower dynamic compression as well... if you do nothing to bump static compression.

Orange Rocket is selling a brand new pair of Crower cams for $450... that is pretty cheap.... albeit they are more duration.
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Re: 20v exhaust cam on a 16v small port head

Postby xploding-twincam » Fri Jan 18, 2013 10:58 am

By the time we ship to SA it will be too much, if I convert that to our money, its alot